0001437749-24-003599 | 10-K | XBRL Viewer

Treasury Stock [Text Block]

18. Share Repurchase Programs

Effective April 1, 2022, our Board of Directors authorized the repurchase of up to 100 million shares of our common stock by March 31, 2025. As of December 31, 2023, we repurchased a total of 19.6 million shares of our common stock under the 2022 authorization. These repurchases may be made on the open market or through other transactions. Our management has sole discretion with respect to determining the timing and amount of these transactions.

Our previous authorization, which was effective April 1, 2019, through March 31, 2022, was approved by our Board of Directors for up to 150 million shares of common stock. As of March 31, 2022, we repurchased a total of 83.3 million shares of our common stock under the 2019 authorization.

The table below represents shares repurchased under repurchase programs during 2023 and 2022:

	Number of Shares Purchased				Average Price Paid [a]
	*2023*		2022		*2023*		2022
First quarter [b]		2,908,703		11,014,201	$	203.19	$	249.95
Second quarter [c]		606,581		3,100,683		199.81		232.87
Third quarter		-		9,490,339		-		221.52
Fourth quarter		-		3,501,667		-		201.33
Total		3,515,284		27,106,890	$	202.61	$	231.76
Remaining number of shares that may be repurchased under current authority								80,392,027

[a]	In the period of the final settlement, the average price paid under the accelerated share repurchase programs is calculated based on the total program value less the value assigned to the initial delivery of shares. The average price of the completed 2022 accelerated share repurchase programs was $248.32.
[b]	Includes 7,012,232 shares repurchased in 2022* under accelerated share repurchase programs.*
[c]	Includes an incremental 1,847,185 shares received upon final settlement in 2022* under accelerated share repurchase programs.*

Management's assessments of market conditions and other pertinent factors guide the timing, manner, and volume of all repurchases. We expect to fund any share repurchases under this program through cash generated from operations, the sale or lease of various operating and non-operating properties, debt issuances, and cash on hand. Open market repurchases are recorded in treasury stock at cost, which includes any applicable commissions, fees, and excise taxes.

Accelerated Share Repurchase Programs – The Company has established accelerated share repurchase programs (ASRs) with financial institutions to repurchase shares of our common stock. These ASRs have been structured so that at the time of commencement, we pay a specified amount to the financial institutions and receive an initial delivery of shares. Additional shares may be received at the time of settlement. The final number of shares to be received is based on the volume weighted average price of the Company’s common stock during the ASR term, less a discount and subject to potential adjustments pursuant to the terms of such ASR.

On February 18, 2022, the Company received 7,012,232 shares of its common stock repurchased under ASRs for an aggregate of $2.2 billion. Upon settlement of these ASRs in the second quarter of 2022, we received 1,847,185 additional shares.

ASRs are accounted for as equity transactions, and at the time of receipt, shares are included in treasury stock at fair market value as of the corresponding initiation or settlement date. The Company reflects shares received as a repurchase of common stock in the weighted average common shares outstanding calculation for basic and diluted earnings per share.

Note 1 - Nature of Operations

12 Months Ended

Dec. 31, 2023

Nature of Operations [Text Block]

1. Nature of Operations

Operations and Segmentation – We are a Class I railroad operating in the U.S. Our network includes 32,693 route miles, connecting Pacific Coast and Gulf Coast ports with the Midwest and Eastern U.S. gateways and providing several corridors to key Mexican and Canadian gateways. We own 26,110 miles and operate on the remainder pursuant to trackage rights or leases. We serve the western two-thirds of the country and maintain coordinated schedules with other rail carriers for the handling of freight to and from the Atlantic Coast, the Pacific Coast, the Southeast, the Southwest, Canada, and Mexico. Export and import traffic is moved through Gulf Coast, Pacific Coast, and East Coast ports and across the Mexican and Canadian borders.

The Railroad, along with its subsidiaries and rail affiliates, is our one reportable operating segment. Although we provide and analyze revenues by commodity group, we treat the financial results of the Railroad as one segment due to the integrated nature of our rail network. Our operating revenues are primarily derived from contracts with customers for the transportation of freight from origin to destination. The following table represents a disaggregation of our freight and other revenues:

Millions	*2023*		2022		2021
Bulk	$	7,358	$	7,537	$	6,656
Industrial		8,238		8,205		7,323
Premium		6,975		7,417		6,265
Total freight revenues	$	22,571	$	23,159	$	20,244
Other subsidiary revenues		872		884		741
Accessorial revenues		584		779		752
Other		92		53		67
Total operating revenues	$	24,119	$	24,875	$	21,804

Although our revenues are principally derived from customers domiciled in the U.S., the ultimate points of origination or destination for some products we transport are outside the U.S. Each of our commodity groups includes revenues from shipments to and from Mexico. Included in the above table are freight revenues from our Mexico business which amounted to $2.8 billion in 2023, $2.7 billion in 2022, and $2.4 billion in 2021.

Basis of Presentation – The Consolidated Financial Statements are presented in accordance with accounting principles generally accepted in the U.S. (GAAP) as codified in the Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC). Certain prior period amounts have been reclassified to conform to the current period financial statement presentation.

Note 5 - Retirement Plans - Amounts Recognized in the Statement of Financial Position (Details) - Pension Plan [Member] - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Noncurrent assets	$ 924	$ 1,033
Current liabilities	(31)	(31)
Noncurrent liabilities	(373)	(364)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	$ 520	$ 638

Amount of asset, recognized in statement of financial position, for overfunded defined benefit pension and other postretirement plans.

+ References + Details

Document And Entity Information - USD ($)	12 Months Ended
Document And Entity Information - USD ($)	Dec. 31, 2023	Feb. 02, 2024	Jun. 30, 2023
Document Information [Line Items]
Entity Central Index Key	0000100885
Entity Registrant Name	UNION PACIFIC CORP
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2023
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Document Transition Report	false
Entity File Number	1-6075
Entity Incorporation, State or Country Code	UT
Entity Tax Identification Number	13-2626465
Entity Address, Postal Zip Code	68179
Entity Address, Address Line One	1400 Douglas Street
Entity Address, City or Town	Omaha
Entity Address, State or Province	NE
City Area Code	402
Local Phone Number	544-5000
Title of 12(b) Security	Common Stock (Par Value $2.50 per share)
Trading Symbol	UNP
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 123,000,000,000
Entity Common Stock, Shares Outstanding		609,777,914
Auditor Firm ID	34
Auditor Name	Deloitte & Touche LLP
Auditor Location	Omaha, Nebraska

Note 14 - Debt - Schedule of Unsecured Debt (Details) (Parentheticals) - Unsecured Debt [Member]	12 Months Ended
	Dec. 31, 2023
The 4.750% Notes, Due February 21, 2026 [Member]
Debt Instrument, Interest Rate	4.75%
Debt Instrument, Maturity Date	Feb. 21, 2026
The 4.950% Notes, Due May 15, 2053 [Member]
Debt Instrument, Interest Rate	4.95%
Debt Instrument, Maturity Date	May 15, 2053

Note 14 - Debt (Tables)

12 Months Ended

Dec. 31, 2023

Schedule of Debt [Table Text Block]

Millions	*2023*			2022
Notes and debentures, 2.2% to 7.1% due through February 14, 2072	$	33,383		$	33,658
Equipment obligations, 2.6% to 6.2% due through January 2, 2031 [a]		770			809
Finance leases, 3.1% to 6.8% due through December 10, 2028		158			234
Commercial paper		-			200
Receivables Facility (Note 10)		-			100
Term loans		-			100
Unamortized discount and deferred issuance costs		(1,732	)		(1,775	)
Total debt		32,579			33,326
Less: current portion		(1,423	)		(1,678	)
Total long-term debt	$	31,156		$	31,648

Schedule of Maturities of Long-Term Debt [Table Text Block]

Millions
2024	$	1,427
2025		1,426
2026		1,515
2027		1,285
2028		1,235
Thereafter		27,423
Total principal		34,311
Unamortized discount and deferred issuance costs		(1,732	)
Total debt	$	32,579

Unsecured Fixed Rate Debt Securities Issued Under Current Shelf Registration [Table Text Block]

Date	Description of Securities
February 21, 2023	$0.50 billion of 4.750% Notes due February 21, 2026
	$0.50 billion of 4.950% Notes due May 15, 2053

Note 5 - Pension and Other Postretirement Benefits - Changes in PBO and Plan Assets (Details) - Pension Plan [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Projected benefit obligation at beginning of year	$ 3,725	$ 5,296
Service cost	52	93	$ 110
Interest cost	187	123	104
Actuarial loss/(gain)	146	(1,557)
Gross benefits paid	(230)	(230)
Projected benefit obligation at end of year	3,880	3,725	5,296
Fair value of plan assets at beginning of year	4,363	5,554
Actual return/(loss) on plan assets	235	(992)
Non-qualified plan benefit contributions	32	31
Fair value of plan assets at end of year	4,400	4,363	$ 5,554
Funded status at end of year	$ 520	$ 638

Note 14 - Debt (Details Textual) - USD ($)
$ in Thousands

9 Months Ended

12 Months Ended

Apr. 15, 2022

Sep. 30, 2023

Dec. 31, 2023

Dec. 31, 2022

Feb. 03, 2022

Proceeds from Issuance of Commercial Paper

$ 1,400,000

Repayments of Commercial Paper

$ 1,600,000

Commercial Paper, Maturity Duration, Minimum (Day)

11 days

Commercial Paper Maturity Duration, Maximum (Day)

64 days

Commercial Paper

$ 0

$ 200,000

Board of Directors Authorized Debt Issuance

$ 12,000,000

Board of Directors Remaining Debt Issuance

5,600,000

Long-Term Debt, Gross

34,311,000

Revolving Credit Facility [Member]

Line of Credit Facility, Remaining Borrowing Capacity

$ 2,000,000

Long-Term Line of Credit, Total

$ 0

Line of Credit Facility, Expiration Date

May 20, 2027

Allowable Debt Per Debt to Net Worth Coverage Ratio as Defined Facility

44,400

Outstanding Debt as Defined by Facility

34,300

Cross Default Provision as Defined By Facility

150,000

4.163% Notes, Due July 15, 2022 [Member]

Debt Instrument, Repurchase Date

Apr. 15, 2022

Debt Instrument, Repurchase Amount

$ 750,000

Debt Instrument, Interest Rate, Stated Percentage

4.163%

Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed

100.00%

Equipment Trust Certificate [Member]

Long-Term Debt, Gross

^[1]

770,000

809,000

Equipment Trust Certificate [Member] | Railroad Assets, Equipment [Member]

Debt Instrument, Collateral Amount

900,000

Secured Debt [Member]

Long-Term Debt, Gross

$ 0

$ 100,000

[1]	Equipment obligations are secured by an interest in certain railroad equipment with a carrying value of approximately $0.9 billion at both December 31, 2023 and 2022.

Note 5 - Retirement Plans - Benefit Payments (Details) $ in Millions	Dec. 31, 2023 USD ($)
2024	$ 230
2025	229
2026	229
2027	230
2028	231
Years 2029 - 2033	$ 1,188

Note 12 - Accounts Payable and Other Current Liabilities (Tables)

12 Months Ended

Dec. 31, 2023

Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]

	*Dec. 31,*			Dec. 31,
Millions		*2023*			2022
Accounts payable		$	856		$	784
Income and other taxes payable			685			628
Compensation-related accruals			533			938
Interest payable			389			379
Current operating lease liabilities (Note 16)			355			331
Accrued casualty costs			307			242
Equipment rents payable			98			109
Other			460			431
Total accounts payable and other current liabilities		$	3,683		$	3,842

Note 5 - Retirement Plans - Plan Assets Measured At Fair Value (Details) - Pension Plan [Member] - USD ($)
$ in Millions

Dec. 31, 2023

Dec. 31, 2022

Dec. 31, 2021

Fair Value, Recurring [Member]

$ 4,400

$ 4,363

$ 5,554

Fair Value, Recurring [Member] | Defined Benefit Plan, Debt Security [Member]

4,400

4,363

Fair Value, Recurring [Member] | Venture Capital And Buyout Partnerships [Member]

^[1]

Fair Value, Recurring [Member] | Defined Benefit Plan, Real Estate [Member]

554

611

Fair Value, Recurring [Member] | Common Trust And Other Funds [Member]

Fair Value, Recurring [Member] | Other Assets Pension Plan [Member]

382

622

Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]

^[2]

Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Defined Benefit Plan, Cash [Member]

176

1,111

Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Defined Benefit Plan, Equity Securities [Member]

Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | US Treasury and Government [Member]

^[3]

Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Corporate Debt Securities [Member]

Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Defined Benefit Plan, Equity Securities, Common Stock [Member]

Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]

176

1,104

Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Defined Benefit Plan, Cash [Member]

3,209

1,879

Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Defined Benefit Plan, Equity Securities [Member]

Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | US Treasury and Government [Member]

^[3]

Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Corporate Debt Securities [Member]

1,508

803

Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Defined Benefit Plan, Equity Securities, Common Stock [Member]

1,696

1,069

Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]

Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Defined Benefit Plan, Cash [Member]

Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Defined Benefit Plan, Equity Securities [Member]

Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | US Treasury and Government [Member]

^[3]

Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Corporate Debt Securities [Member]

Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Defined Benefit Plan, Equity Securities, Common Stock [Member]

Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] | Fair Value, Recurring [Member]

Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] | Fair Value, Recurring [Member] | Defined Benefit Plan, Cash [Member]

3,385

2,990

Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] | Fair Value, Recurring [Member] | Defined Benefit Plan, Equity Securities [Member]

Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] | Fair Value, Recurring [Member] | US Treasury and Government [Member]

^[3]

Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] | Fair Value, Recurring [Member] | Corporate Debt Securities [Member]

1,508

803

Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] | Fair Value, Recurring [Member] | Defined Benefit Plan, Equity Securities, Common Stock [Member]

1,696

1,069

Fair Value Measured at Net Asset Value Per Share [Member] | Fair Value, Recurring [Member]

181

1,111

$ 966

$ 1,338

[1]	Registered investment companies measured at NAV include bond investments.
[2]	Includes accrued receivables, net payables, and pending broker settlements.
[3]	Registered investment companies measured at fair value are stock investments.

Note 3 - Accounting Pronouncements

12 Months Ended

Dec. 31, 2023

Accounting Standards Update and Change in Accounting Principle [Text Block]

3. Accounting Pronouncements

In December 2023, the FASB issued Accounting Standards Update No. (ASU) 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which requires business entities to expand their annual disclosures of the effective rate reconciliation and income taxes paid. The ASU is effective for fiscal years beginning after December 15, 2024, may be adopted on a prospective or retrospective basis, and early adoption is permitted. The Company is currently evaluating the effect that the new guidance will have on our related disclosures.

In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures, which requires business entities to enhance disclosures about significant segment expenses. The ASU is effective for fiscal years beginning after December 15, 2023, on a retrospective basis, and early adoption is permitted. The Company is currently evaluating the effect that the new guidance will have on our related disclosures.

The entire disclosure for change in accounting principle. Includes, but is not limited to, nature, reason, and method of adopting amendment to accounting standards or other change in accounting principle.

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-Paragraph 1
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Reference 30: http://www.xbrl.org/2003/role/disclosureRef
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Reference 31: http://www.xbrl.org/2003/role/disclosureRef
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Reference 32: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 1
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Reference 34: http://www.xbrl.org/2003/role/disclosureRef
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Note 7 - Income Taxes - Schedule of Deferred Income Tax Assets (Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Deferred income tax liabilities:
Property	$ (12,987)	$ (12,910)
Operating lease assets	(404)	(411)
Other	(556)	(591)
Total deferred income tax liabilities	(13,947)	(13,912)
Deferred income tax assets:
Operating lease liabilities	394	401
Accrued casualty costs	168	164
Accrued wages	50	50
Stock compensation	26	26
Other	186	238
Total deferred income tax assets	824	879
Net deferred income tax liability	$ (13,123)	$ (13,033)

Note 6 - Other Income

12 Months Ended

Dec. 31, 2023

Other Income and Other Expense Disclosure [Text Block]

6. Other Income

Other income included the following for the years ended December 31:

Millions	*2023*			2022			2021
Real estate income [a] [b]	$	414		$	381		$	263
Net periodic pension benefit/(costs)		52			84			25
Interest income [a]		52			23			4
Environmental remediation and restoration		(37	)		(47	)		(17	)
Gain from sale of investment		-			-			36
Other [a]		10			(15	)		(14	)
Total	$	491		$	426		$	297

[a]	Prior periods have been reclassified to conform to the current period disclosure.
[b]	2023 includes a one-time $107 million transaction. 2022 includes a $79 million gain from a land sale to the Illinois State Toll Highway Authority and a $35 million gain from a sale to the Colorado Department of Transportation. 2021 includes a $50 million gain from a sale to the Colorado Department of Transportation.

Cybersecurity Disclosure Information

12 Months Ended

Dec. 31, 2023

Cybersecurity Disclosure Information [Text Block]

Item 1C. Cybersecurity

Risk Management and Strategy

The Company is subject to cybersecurity threats that could have a material adverse impact on our results of operations, financial condition, and liquidity. See also our discussion in the Risk Factors in Item 1A of this report. As a component of our Company-wide enterprise risk management framework, we implemented a cybersecurity program whose objective is to assess, identify, and manage risks from cybersecurity threats that may result in adverse effects on the confidentiality, integrity, and availability of the electronic information systems that we own. We regularly perform internal security assessments, engage third-party consultants to conduct external security assessments, and participate in, conduct, and/or administer exercises, drills, and recovery tests as part of this program. We also maintain training programs and policies and procedures designed to safeguard employee handling and use of data, internet usage, controlled access measures, and physical protections. We consult with industry groups, monitor threat intelligence reports, and communicate with various government agencies in an effort to stay up-to-date on changes in the cybersecurity threat landscape. This program, in addition to addressing our own information systems, is also designed to oversee, identify, and reduce the potential impact of a security incident at a third-party service provider or that otherwise impacts third-party technology and systems we use.

Internal Cybersecurity Team

The Company’s internal information security organization (Internal Cybersecurity Team), led by our Executive Vice President and Chief Information Officer (CIO) as well as the Assistant Vice President and Chief Information Security Officer (CISO), is responsible for coordinating all aspects of the Company’s electronic information security systems, including prevention, detection, mitigation, and remediation of cybersecurity incidents, as well as implementing, monitoring, and maintaining our enterprise-wide security strategy, standards, architecture, policies, and processes. Our CIO reports directly to our Chief Executive Officer, our CISO reports to our CIO, and reporting to our CISO are our Deputy Chief Information Security Officer (Deputy CISO) and other experienced information security personnel responsible for various parts of our business. In addition to our internal cybersecurity capabilities, we also periodically engage assessors, consultants, auditors, and other third parties to assist with assessing, identifying, and managing cybersecurity risks. When the Company learns of a cybersecurity incident at a third-party service provider, the Company’s respective department contacts maintain communication with the third-party service provider and communicate any cybersecurity incidents to the CISO.

Security Policy and Requirements

As part of the Company’s Crisis Management Plan, the Company's cybersecurity Incident Response Plan (the IRP) provides a framework for responding to cybersecurity incidents. The IRP sets out a coordinated approach to discovering, investigating, containing, tracking, mitigating, and remediating cybersecurity incidents, including a framework for elevating and reporting findings and keeping senior management and other key stakeholders informed and involved, based on assessments regarding the scope or significance of incidents. The IRP applies to the Company’s extended computing environment, including electronic information resources that are owned or used by the Company and are routinely relied on to support our operations.

The Internal Cybersecurity Team has robust processes and redundancies in place designed with the objective of deterring, detecting, mitigating, and responding to potential cybersecurity threats, which includes a vulnerability assessment, prioritization, and remediation program. The Internal Cybersecurity Team also performs regular system penetration testing to validate our security controls and assess our infrastructure and applications. All management employees take mandatory periodic security awareness training on the Company’s data security policies and procedures, which is supplemented by Company-wide testing initiatives, including periodic phishing tests. Additionally, in 2023, our Board of Directors and certain management employees participated in a tabletop exercise to simulate a response to a cybersecurity incident, and our Internal Cybersecurity Team incorporated the findings from this exercise into our processes.

Our information security program is designed to align our defenses and resources to identify, assess, and address more likely and more damaging cyber events, to provide support for our organizational mission and operational objectives, and to position us to deter, detect, mitigate, and respond to a wide variety of potential attacks in a timely fashion. Our information security program employs quantitative and qualitative approaches to evaluate the effectiveness of controls and assess the resiliency of critical computing resources. This data is combined with knowledge of common attack techniques to assess the likelihood of components being compromised and assess potential financial implications under different scenarios. The results are used to help identify potentially material risks and provide insights which are taken into account when prioritizing our security initiatives.

Material Cybersecurity Risks, Threats, and Incidents

Due to the evolving nature of cybersecurity threats, it has and will continue to be difficult to prevent, detect, mitigate, and remediate cybersecurity incidents. While we are not aware of having experienced any material effects or reasonably likely material effects on our Company, its business strategy, results of operations, or financial condition resulting from cybersecurity threats or incidents to date, as a critical infrastructure provider, we may be a target of well-funded and sophisticated adverse actors. There can be no guarantee that we will not be the subject of future risks or incidents that have such an effect, or that we are not currently the subject of an undetected risk or incident that may have such an effect.

We also rely on information technology and third-party vendors to support our operations, including our secure processing of personal, confidential, sensitive, proprietary, and other types of information. Despite ongoing efforts to continue improvement of our and our vendors’ ability to protect against cyber incidents, we may not be able to protect all of the information systems we use. Incidents may lead to reputational harm, revenue and client loss, legal actions, or statutory penalties, among other consequences. For a more detailed discussion of these risks, see our discussion in the Risk Factors in Item 1A of this report.

Governance

The Board of Directors has delegated primary oversight of the Company’s cybersecurity risk to the Audit Committee, which receives updates on cybersecurity risks and incidents at each regularly scheduled Audit Committee meeting from the CIO, CISO, and other members of management, as needed. When making decisions regarding director appointments and committee assignments, the Board of Directors takes into consideration the cybersecurity experience of directors and director candidates and strives to maintain cybersecurity expertise on the Board of Directors and Audit Committee. We have protocols by which certain cybersecurity incidents are reported to the Audit Committee and Board of Directors.

At the management level, our CIO, CISO, and Deputy CISO, each of whom has extensive cybersecurity knowledge and skills gained from over 27 years, 28 years, and 19 years of relevant work experience, respectively, head the Internal Cybersecurity Team that is responsible for implementing and maintaining cybersecurity and data protection practices across our business, with our CIO reporting directly to our Chief Executive Officer. In 2023, our CIO was appointed to serve as a member of the U.S. Cybersecurity Advisory Committee (CSAC) of the Cybersecurity and Infrastructure Security Agency (CISA), which provides recommendations to CISA on a range of cybersecurity issues, including corporate cyber responsibility, technology product safety, and efforts to raise the baseline of cybersecurity practices for a variety of entities to enhance the United States’ cyber defense. Our CISO and Deputy CISO receive reports on cybersecurity threats from a number of experienced information security professionals for various parts of our business on an ongoing basis and, in conjunction with other management personnel, regularly consult on risk management measures implemented by the Company to identify and mitigate data protection and cybersecurity risks.

In addition, our Risk and Compliance Committee (RCC) is responsible for oversight and support of the Company’s Enterprise Risk Management and Compliance and Ethics programs and is comprised of the Executive Leadership Team and the Senior Vice President and Chief Accounting, Risk, and Compliance Officer (Compliance Officer). The RCC also created a subcommittee, the Enterprise Risk Management Committee (ERMC), who is charged with continually monitoring, evaluating, and managing enterprise risks. The ERMC includes the Compliance Officer, General Auditor, Vice President Law - Finance and Compliance, Vice President and Chief Safety Officer, CISO, and Assistant Vice President - Corporate Strategy. The RCC and ERMC both meet throughout the year and receive periodic updates on cybersecurity from the CISO and Deputy CISO.

Note 13 - Financial Instruments

12 Months Ended

Dec. 31, 2023

Financial Instruments Disclosure [Text Block]

13. Financial Instruments

Short-Term Investments – All of the Company’s short-term investments consist of time deposits and government agency securities. These investments are considered Level 2 investments and are valued at amortized cost, which approximates fair value. As of December 31, 2023 and 2022, the Company had $16 million and $46 million of short-term investments, respectively. All short-term investments have a maturity of less than one year and are classified as held-to-maturity.

Fair Value of Financial Instruments – The fair value of our short- and long-term debt was estimated using a market value price model, which utilizes applicable U.S. Treasury rates along with current market quotes on comparable debt securities. All of the inputs used to determine the fair market value of the Corporation’s long-term debt are Level 2 inputs and obtained from an independent source. At December 31, 2023, the fair value of total debt was $28.5 billion, approximately $4.1 billion less than the carrying value. At December 31, 2022, the fair value of total debt was $28.1 billion, approximately $5.2 billion less than the carrying value. The fair value of the Corporation’s debt is a measure of its current value under present market conditions. The fair value of our cash equivalents approximates their carrying value due to the short-term maturities of these instruments.

Note 14 - Debt - Schedule of Debt (Details) (Parentheticals)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Notes Payable to Banks [Member]
Debt Instrument, Maturity Date	Feb. 14, 2072	Feb. 14, 2072
Notes Payable to Banks [Member] \| Minimum [Member]
Debt Instrument, Interest Rate	2.20%	2.20%
Notes Payable to Banks [Member] \| Maximum [Member]
Debt Instrument, Interest Rate	7.10%	7.10%
Equipment Trust Certificate [Member]
Debt Instrument, Maturity Date	Jan. 02, 2031	Jan. 02, 2031
Equipment Trust Certificate [Member] \| Minimum [Member]
Debt Instrument, Interest Rate	2.60%	2.60%
Equipment Trust Certificate [Member] \| Maximum [Member]
Debt Instrument, Interest Rate	6.20%	6.20%
Finance Lease [Member]
Debt Instrument, Maturity Date	Dec. 10, 2028	Dec. 10, 2028
Finance Lease [Member] \| Minimum [Member]
Debt Instrument, Interest Rate	3.10%	3.10%
Finance Lease [Member] \| Maximum [Member]
Debt Instrument, Interest Rate	6.80%	6.80%

Note 4 - Stock Options and Other Stock Plans - Additional Information Regarding Stock Option Exercises (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Intrinsic value of stock options exercised	$ 23	$ 53	$ 84
Cash received from option exercises	27	27	58
Treasury shares repurchased for employee payroll taxes	(5)	(8)	(15)
Income tax benefit realized from option exercises	5	8	16
Aggregate grant-date fair value of stock options vested	$ 14	$ 13	$ 14

Note 9 - Accumulated Other Comprehensive Income/Loss (Tables)

12 Months Ended

Dec. 31, 2023

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

Millions	Defined benefit plans			Foreign currency translation		Unrealized gain on derivative instruments [a]			Total
Balance at January 1, 2023	$	(378	)	$	(204	)	$	-	$	(582	)
Other comprehensive income/(loss) before reclassifications		5			58			16		79
Amounts reclassified from accumulated other comprehensive income/(loss) [b]		(111	)		-			-		(111	)
Net year-to-date other comprehensive income/(loss), net of taxes of $31 million		(106	)		58			16		(32	)
Balance at December 31, 2023	$	(484	)	$	(146	)	$	16	$	(614	)

Balance at January 1, 2022	$	(658	)	$	(256	)	$	-	$	(914	)
Other comprehensive income/(loss) before reclassifications		-			52			-		52
Amounts reclassified from accumulated other comprehensive income/(loss) [b]		280			-			-		280
Net year-to-date other comprehensive income/(loss), net of taxes of ($92) million		280			52			-		332
Balance at December 31, 2022	$	(378	)	$	(204	)	$	-	$	(582	)

Note 5 - Retirement Plans - Components of Net Periodic Pension and OPEB Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Net periodic pension cost	$ 0	$ 9	$ 85
Pension Plan [Member]
Service cost	52	93	110
Interest cost	187	123	104
Expected return on plan assets	(248)	(293)	(270)
Actuarial loss	$ 9	$ 86	$ 141

Consolidated Statements of Financial Position - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 1,055	$ 973
Short-term investments (Note 13)	16	46
Accounts receivable, net (Note 10)	2,073	1,891
Materials and supplies	743	741
Other current assets	261	301
Total current assets	4,148	3,952
Investments	2,605	2,375
Properties, net (Note 11)	57,398	56,038
Operating lease assets (Note 16)	1,643	1,672
Other assets	1,338	1,412
Total assets	67,132	65,449
Current liabilities:
Accounts payable and other current liabilities (Note 12)	3,683	3,842
Debt due within one year (Note 14)	1,423	1,678
Total current liabilities	5,106	5,520
Debt due after one year (Note 14)	31,156	31,648
Operating lease liabilities (Note 16)	1,245	1,300
Deferred income taxes (Note 7)	13,123	13,033
Other long-term liabilities	1,714	1,785
Commitments and contingencies (Note 17)
Total liabilities	52,344	53,286
Common shareholders' equity:
Common shares, $2.50 par value, 1,400,000,000 authorized; 1,112,854,806 and 1,112,623,886 issued; 609,703,814 and 612,393,321 outstanding, respectively	2,782	2,782
Paid-in-surplus	5,193	5,080
Retained earnings	62,093	58,887
Treasury stock	(54,666)	(54,004)
Accumulated other comprehensive loss (Note 9)	(614)	(582)
Total common shareholders' equity	14,788	12,163
Total liabilities and common shareholders' equity	$ 67,132	$ 65,449

Note 16 - Leases - Schedule of Lease Maturities (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
2024, Operating Lease	$ 361
2024, Finance Lease	55
2024, Leases	416
2025, Operating Lease	375
2025, Finance Lease	42
2025, Leases	417
2026, Operating Lease	296
2026, Finance Lease	35
2026, Leases	331
2027, Operating Lease	237
2027, Finance Lease	30
2027, Leases	267
2028, Operating Lease	199
2028, Finance Lease	11
2028, Leases	210
After 2027, Operating Lease	300
After 2027, Finance Lease	0
After 2027, Leases	300
Total Operating lease payments	1,768
Total Finance lease payments	173
Total lease payments	1,941
Less: Interest, Operating Lease	168
Less: Interest, Finance Lease	15
Less: Interest	183
Present value of Operating lease liabilities	1,600
Present value of lease liabilities	1,758	$ 1,865
Long-Term Debt [Member]
Present value of Finance lease liabilities	$ 158

Note 1 - Nature of Operations (Tables)

12 Months Ended

Dec. 31, 2023

Disaggregation of Revenue [Table Text Block]

Millions	*2023*		2022		2021
Bulk	$	7,358	$	7,537	$	6,656
Industrial		8,238		8,205		7,323
Premium		6,975		7,417		6,265
Total freight revenues	$	22,571	$	23,159	$	20,244
Other subsidiary revenues		872		884		741
Accessorial revenues		584		779		752
Other		92		53		67
Total operating revenues	$	24,119	$	24,875	$	21,804

Note 17 - Commitments and Contingencies - Personal Injury Liability Activity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Balance, Current	$ 307	$ 242
Personal Injury [Member]
Balance	361	325	$ 270
Current year accruals	112	107	93
Changes in estimates for prior years	89	55	48
Payments	(179)	(126)	(86)
Balance	383	361	325
Balance, Current	$ 113	$ 84	$ 64

Note 11 - Properties (Tables)

12 Months Ended

Dec. 31, 2023

Property, Plant and Equipment [Table Text Block]

Millions, Except Estimated Useful Life			Accumulated		Net Book		Estimated
As of December 31, 2023	Cost		Depreciation		Value		Useful Life
Land	$	5,426	$	N/A	$	5,426		N/A
Road:
Rail and other track material		18,837		7,344		11,493		42
Ties		11,985		3,895		8,090		34
Ballast		6,345		2,061		4,284		34
Other roadway [a]		23,175		5,368		17,807		47
Total road		60,342		18,668		41,674		N/A
Equipment:
Locomotives		9,295		3,591		5,704		18
Freight cars		2,765		956		1,809		23
Work equipment and other		1,344		546		798		17
Total equipment		13,404		5,093		8,311		N/A
Technology and other		1,388		574		814		12
Construction in progress		1,173		-		1,173		N/A
Total	$	81,733	$	24,335	$	57,398		N/A

Millions, Except Estimated Useful Life			Accumulated		Net Book		Estimated
As of December 31, 2022	Cost		Depreciation		Value		Useful Life
Land	$	5,344	$	N/A	$	5,344		N/A
Road:
Rail and other track material		18,419		7,096		11,323		43
Ties		11,676		3,699		7,977		34
Ballast		6,222		1,950		4,272		34
Other roadway [a]		22,411		4,970		17,441		47
Total road		58,728		17,715		41,013		N/A
Equipment:
Locomotives		9,166		3,606		5,560		18
Freight cars		2,562		898		1,664		23
Work equipment and other		1,253		473		780		17
Total equipment		12,981		4,977		8,004		N/A
Technology and other		1,254		525		729		12
Construction in progress		948		-		948		N/A
Total	$	79,255	$	23,217	$	56,038		N/A

Note 16 - Leases (Details Textual) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Finance Lease, Right-of-Use Asset, Accumulated Amortization	$ 497	$ 658

Note 9 - Accumulated Other Comprehensive Income/Loss - Schedule of Reclassification (Details) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2023

Dec. 31, 2022

Dec. 31, 2021

$ 12,163

$ 14,161

$ 16,958

^[1]

(32)

332

679

Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]

14,788

12,163

14,161

Other comprehensive income/(loss) before reclassifications

(378)

(658)

Amounts reclassified from accumulated other comprehensive income/(loss) [b]

^[2]

(111)

280

(106)

280

Accumulated Foreign Currency Adjustment Attributable to Parent [Member]

(484)

(378)

(658)

Other comprehensive income/(loss) before reclassifications

(204)

(256)

Amounts reclassified from accumulated other comprehensive income/(loss) [b]

^[2]

Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]

(146)

(204)

(256)

Other comprehensive income/(loss) before reclassifications

^[3]

^[3]

Amounts reclassified from accumulated other comprehensive income/(loss) [b]

^[2]

^[3]

AOCI Attributable to Parent [Member]

^[3]

Other comprehensive income/(loss) before reclassifications

^[4]

(582)

(914)

(1,593)

Amounts reclassified from accumulated other comprehensive income/(loss) [b]

^[2]

(111)

280

^[4]

(32)

332

679

^[4]

$ (614)

$ (582)

$ (914)

[1]	Net of deferred taxes of $31 million, ($92) million, and ($237) million during 2023, 2022, and 2021, respectively.
[2]	The accumulated other comprehensive income/loss reclassification components are 1) prior service cost/credit and 2) net actuarial loss, which are both included in the computation of net periodic pension benefit/cost. See Note 5 Retirement Plans for additional details.
[3]	Related to interest rate swaps from equity method investments.
[4]	AOCI = Accumulated Other Comprehensive Income/Loss (Note 9)

Amount of equity (deficit) attributable to parent. Excludes temporary equity and equity attributable to noncontrolling interest.

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-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30))
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-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

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-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 4.E)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480418/310-10-S99-2

Note 1 - Nature of Operations - Summary of Freight and Other Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenue from Contract with Customer, Excluding Assessed Tax	$ 24,119	$ 24,875	$ 21,804
Bulk [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	7,358	7,537	6,656
Industrial [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	8,238	8,205	7,323
Premium [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	6,975	7,417	6,265
Cargo and Freight [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	22,571	23,159	20,244
Other Subsidiary Revenues [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	872	884	741
Accessorial Revenues [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	584	779	752
Other Miscellaneous Product and Service Revenues [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 92	$ 53	$ 67

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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Balance (in shares) at Dec. 31, 2020

Note 7 - Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Federal statutory tax rate	21.00%	21.00%	21.00%
State statutory rates, net of federal benefits	3.40%	3.60%	3.70%
Deferred tax adjustments	(1.20%)	(1.00%)	(0.60%)
Dividends received deduction	(0.60%)	(0.50%)	(0.50%)
Excess tax benefits from equity compensation plans	(0.10%)	(0.20%)	(0.30%)
Other tax adjustments	0.00%	0.00%	(0.20%)
Effective tax rate	22.50%	22.90%	23.10%

Consolidated Statements of Changes in Common Shareholders' Equity - USD ($)
$ in Millions

Common Stock [Member]

Treasury Stock, Common [Member]

Additional Paid-in Capital [Member]

Retained Earnings [Member]

AOCI Attributable to Parent [Member]

^[1]

Total

1,112,200,000

(440,900,000)

Balance at Dec. 31, 2020

$ 2,781

$ (40,420)

$ 4,864

$ 51,326

$ (1,593)

$ 16,958

6,523

Conversion, stock option exercises, forfeitures, ESPP, and other (in shares)

$ 0

679

^[2]

200,000

600,000

Conversion, stock option exercises, forfeitures, ESPP, and other

$ 0

$ 1

Share repurchase programs (Note 18) (in shares)

(33,300,000)

Share repurchase programs (Note 18)

$ 0

$ (7,315)

(7,291)

Cash dividends declared

$ 0

(2,800)

Balance (in shares) at Dec. 31, 2021

1,112,400,000

(473,600,000)

Balance at Dec. 31, 2021

$ 2,781

$ (47,734)

4,979

55,049

(914)

14,161

6,998

Conversion, stock option exercises, forfeitures, ESPP, and other (in shares)

$ 0

332

^[2]

200,000

500,000

Conversion, stock option exercises, forfeitures, ESPP, and other

$ 1

$ 0

113

$ 114

Share repurchase programs (Note 18) (in shares)

(27,100,000)

(27,106,890)

Share repurchase programs (Note 18)

$ 0

$ (6,270)

(12)

$ (6,282)

Cash dividends declared

$ 0

(3,160)

Balance (in shares) at Dec. 31, 2022

1,112,600,000

(500,200,000)

Balance at Dec. 31, 2022

$ 2,782

$ (54,004)

5,080

58,887

(582)

12,163

6,379

Conversion, stock option exercises, forfeitures, ESPP, and other (in shares)

$ 0

(32)

^[2]

300,000

500,000

Conversion, stock option exercises, forfeitures, ESPP, and other

$ 0

$ 50

113

$ 163

Share repurchase programs (Note 18) (in shares)

(3,500,000)

(3,515,284)

Share repurchase programs (Note 18)

$ 0

$ (712)

Cash dividends declared

$ 0

(3,173)

Balance (in shares) at Dec. 31, 2023

1,112,900,000

(503,200,000)

Balance at Dec. 31, 2023

$ 2,782

$ (54,666)

$ 5,193

$ 62,093

$ (614)

$ 14,788

[1]	AOCI = Accumulated Other Comprehensive Income/Loss (Note 9)
[2]	Net of deferred taxes of $31 million, ($92) million, and ($237) million during 2023, 2022, and 2021, respectively.

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount of equity (deficit) attributable to parent. Excludes temporary equity and equity attributable to noncontrolling interest.

Note 4 - Stock Options and Other Stock Plans - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Outstanding, Options (in shares)	1,974
Outstanding, weighted average exercise price (in dollars per share)	$ 169.64
Outstanding, Weighted-Average Remaining Contractual Term (Year)	5 years 10 months 24 days	6 years
Outstanding, Aggregate Intrinsic Value	$ 135	$ 86
Granted, Options (in shares)	351
Granted, weighted average exercise price (in dollars per share)	$ 202.81
Exercised, Options (in shares)	(233)
Exercised, weighted average exercise price (in dollars per share)	$ 118.29
Forfeited or expired, Options (in shares)	(20)
Forfeited or expired, weighted average exercise price (in dollars per share)	$ 218.46
Outstanding, Options (in shares)	2,072	1,974
Outstanding, weighted average exercise price (in dollars per share)	$ 180.56	$ 169.64
Vested or expected to vest, Options (in shares)	2,053
Vested or expected to vest, weighted average exercise price (in dollars per share)	$ 180.23
Vested or expected to vest, Weighted-Average Remaining Contractual Term (Year)	5 years 10 months 24 days
Vested or expected to vest, Aggregate Intrinsic Value	$ 134
Exercisable, Options (in shares)	1,423
Options, exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 164.48
Options, Exercisable, Weighted-Average Remaining Contractual Term (Year)	4 years 9 months 18 days
Options, Exercisable, Aggregate Intrinsic Value	$ 115

Note 8 - Earnings Per Share

12 Months Ended

Dec. 31, 2023

Earnings Per Share [Text Block]

8. Earnings Per Share

The following table provides a reconciliation between basic and diluted earnings per share for the years ended December 31:

Millions, Except Per Share Amounts	*2023*		2022		2021
Net income	$	6,379	$	6,998	$	6,523
Weighted-average number of shares outstanding:
Basic		609.2		622.7		653.8
Dilutive effect of stock options		0.4		0.6		0.8
Dilutive effect of retention shares and units		0.6		0.7		0.8
Diluted		610.2		624.0		655.4
Earnings per share - basic	$	10.47	$	11.24	$	9.98
Earnings per share - diluted	$	10.45	$	11.21	$	9.95

Common stock options totaling 0.9 million, 0.3 million, and 0.2 million for 2023, 2022, and 2021, respectively, were excluded from the computation of diluted earnings per share because the exercise prices of these stock options exceeded the average market price of our common stock for the respective periods, and the effect of their inclusion would be anti-dilutive.

Consolidated Statements of Comprehensive Income (Parentheticals) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Total other comprehensive income/(loss), tax	$ 31	$ (92)	$ (237)

Note 5 - Retirement Plans (Tables)

12 Months Ended

Dec. 31, 2023

Schedule of Net Funded Status [Table Text Block]

*Funded Status*
Millions	*2023*			2022
Projected Benefit Obligation
Projected benefit obligation at beginning of year	$	3,725		$	5,296
Service cost		52			93
Interest cost		187			123
Actuarial loss/(gain)		146			(1,557	)
Gross benefits paid		(230	)		(230	)
Projected benefit obligation at end of year	$	3,880		$	3,725
Plan Assets
Fair value of plan assets at beginning of year	$	4,363		$	5,554
Actual return/(loss) on plan assets		235			(992	)
Non-qualified plan benefit contributions		32			31
Gross benefits paid		(230	)		(230	)
Fair value of plan assets at end of year	$	4,400		$	4,363
Funded status at end of year	$	520		$	638

Schedule of Amounts Recognized in Balance Sheet [Table Text Block]

Millions	*2023*			2022
Noncurrent assets	$	924		$	1,033
Current liabilities		(31	)		(31	)
Noncurrent liabilities		(373	)		(364	)
Net amounts recognized at end of year	$	520		$	638

Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block]

Millions	*2023*			2022		2021
Net actuarial (loss)/gain	$	(159	)	$	272	$	813
Amortization of:
Actuarial loss		9			86		141
Total	$	(150	)	$	358	$	954

Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Table Text Block]

*Underfunded Accumulated Benefit Obligation*
Millions	*2023*			2022
Projected benefit obligation	$	404		$	394
Accumulated benefit obligation	$	399		$	382
Fair value of plan assets		-			-
Underfunded accumulated benefit obligation	$	(399	)	$	(382	)

Defined Benefit Plan, Assumptions [Table Text Block]

Percentages	*2023*			2022
Discount rate		5.00	%		5.21	%
Compensation increase		4.00	%		4.10	%

Percentages	*2023*			2022			2021
Discount rate for benefit obligations		5.21	%		2.80	%		2.42	%
Discount rate for interest on benefit obligations		5.14	%		2.40	%		1.90	%
Discount rate for service cost		5.19	%		2.91	%		2.61	%
Discount rate for interest on service cost		5.21	%		2.86	%		2.53	%
Expected return on plan assets		5.25	%		6.25	%		6.25	%
Compensation increase		4.10	%		4.10	%		4.40	%

Schedule of Net Benefit Costs [Table Text Block]

Millions	*2023*			2022			2021
Net Periodic Pension Cost:
Service cost	$	52		$	93		$	110
Interest cost		187			123			104
Expected return on plan assets		(248	)		(293	)		(270	)
Amortization of:
Actuarial loss		9			86			141
Net periodic pension cost	$	-		$	9		$	85

Cash Contributions for Qualified Pension Plan, Benefit Payments for Non Qualified OPEB Plans [Table Text Block]

Millions	Qualified		Non-qualified
2023	$	-	$	32
2022	$	-	$	31

Schedule of Expected Benefit Payments [Table Text Block]

Millions
2024	$	230
2025		229
2026		229
2027		230
2028		231
Years 2029 - 2033	$	1,188

Schedule of Allocation of Plan Assets [Table Text Block]

		Percentage of Plan Assets
	Target		December 31,
	Allocation 2024		*2023*			2022
Equity securities		20% to 30%		24	%		48	%
Debt securities		70% to 80%		75			51
Real estate		0% to 2%		1			1
Total				100	%		100	%

Defined Benefit Plan, Plan Assets, Category [Table Text Block]

	Quoted Prices			Significant
	in Active			Other			Significant
	Markets for			Observable			Unobservable
	Identical Inputs			Inputs			Inputs
Millions	(Level 1)			(Level 2)			(Level 3)			Total
Plan assets at fair value:
Temporary cash investments		$	-		$	-		$	-		$	-
Registered investment companies [a]			-			-			-			-
Federal government securities			-			1,508			-			1,508
Bonds and debentures			-			1,696			-			1,696
Corporate stock			176			5			-			181
Total plan assets at fair value		$	176		$	3,209		$	-		$	3,385
Plan assets at NAV:
Registered investment companies [b]												-
Venture capital and buyout partnerships												554
Real estate funds												30
Collective trust and other funds												382
Total plan assets at NAV											$	966
Other assets/(liabilities) [c]												49
Total plan assets											$	4,400

	Quoted Prices			Significant
	in Active			Other			Significant
	Markets for			Observable			Unobservable
	Identical Inputs			Inputs			Inputs
Millions	(Level 1)			(Level 2)			(Level 3)			Total
Plan assets at fair value:
Temporary cash investments		$	1		$	-		$	-		$	1
Registered investment companies [a]			6			-			-			6
Federal government securities			-			803			-			803
Bonds and debentures			-			1,069			-			1,069
Corporate stock			1,104			7			-			1,111
Total plan assets at fair value		$	1,111		$	1,879		$	-		$	2,990
Plan assets at NAV:
Registered investment companies [b]												68
Venture capital and buyout partnerships												611
Real estate funds												37
Collective trust and other funds												622
Total plan assets at NAV											$	1,338
Other assets/(liabilities) [c]												35
Total plan assets											$	4,363

Note 4 - Stock Options and Other Stock Plans

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Text Block]

4. Stock Options and Other Stock Plans

In April 2000, the shareholders approved the Union Pacific Corporation 2000 Directors Plan (Directors Plan) whereby 2,200,000 shares of our common stock were reserved for issuance to our non-employee directors. Under the Directors Plan, each non-employee director, upon his or her initial election to the Board of Directors, received a grant of 4,000 retention shares or retention stock units. In July 2018, the Board of Directors eliminated the retention grant for directors newly elected in 2018 and all future years. As of December 31, 2023, 16,000 restricted shares were outstanding under the Directors Plan.

The Union Pacific Corporation 2013 Stock Incentive Plan (2013 Plan) was approved by shareholders in May 2013. The 2013 Plan reserved 78,000,000 shares of our common stock for issuance, plus any shares subject to awards made under previous plans as of February 28, 2013, that are subsequently cancelled, expired, forfeited, or otherwise not issued under previous plans. Under the 2013 Plan, non-qualified stock options, incentive stock options, retention shares, stock units, and incentive bonus awards may be granted to eligible employees of the Corporation and its subsidiaries. Non-employee directors are not eligible for awards under the 2013 Plan. As of December 31, 2023, 1,090,770 stock options and 245,107 retention shares and stock units were outstanding under the 2013 Plan. We no longer grant any stock options or other stock or unit awards under this plan.

The Union Pacific Corporation 2021 Stock Incentive Plan (2021 Plan) was approved by shareholders in May 2021. The 2021 Plan reserved 23,000,000 shares of our common stock for issuance, plus any shares subject to awards made under previous plans as of December 31, 2020, that are subsequently cancelled, expired, forfeited, or otherwise not issued under previous plans. Under the 2021 Plan, non-qualified stock options, incentive stock options, retention shares, stock units, and incentive bonus awards may be granted to eligible employees of the Corporation and its subsidiaries. Non-employee directors are not eligible for awards under the 2021 Plan. As of December 31, 2023, 981,484 stock options and 1,059,344 retention shares were outstanding under the 2021 Plan.

The Union Pacific Corporation 2021 Employee Stock Purchase Plan (2021 ESPP) was approved by shareholders in May 2021. The 2021 ESPP reserved 10,000,000 shares of our common stock for issuance. Under the 2021 ESPP, eligible employees of the Corporation and its subsidiaries may elect to purchase shares with a Company match award. Non-employee directors are not eligible for awards under the 2021 ESPP. As of December 31, 2023, 754,708 shares were issued under the 2021 ESPP.

Pursuant to the above plans 31,979,909; 33,185,971; and 34,011,624 shares of our common stock were authorized and available for grant at December 31, 2023, 2022, and 2021, respectively.

Stock-Based Compensation – We have several stock-based compensation plans where employees receive nonvested stock options, nonvested retention shares, and nonvested stock units. We refer to the nonvested shares and stock units collectively as “retention awards”. Employees also are able to participate in our ESPP.

Information regarding stock-based compensation expense appears in the table below:

Millions	*2023*		2022		2021
Stock-based compensation expense, before tax:
Stock options	$	16	$	14	$	15
Retention awards		71		68		66
ESPP		20		17		7
Total stock-based compensation expense, before tax	$	107	$	99	$	88
Excess income tax benefits from equity compensation plans	$	11	$	21	$	26

Stock Options – Stock options are granted at the closing price on the date of grant, have 10-year contractual terms, and vest no later than 3 years from the date of grant. None of the stock options outstanding at December 31, 2023, are subject to performance or market-based vesting conditions.

The table below shows the annual weighted-average assumptions used for Black-Scholes valuation purposes:

Weighted-Average Assumptions	*2023*			2022			2021
Risk-free interest rate		3.9	%		1.6	%		0.4	%
Dividend yield		2.6	%		1.9	%		1.9	%
Expected life (years)		4.5			4.4			4.6
Volatility		29.3	%		28.7	%		28.3	%
Weighted-average grant-date fair value of options granted	$	48.31		$	51.92		$	39.97

The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant; the expected dividend yield is calculated as the ratio of dividends paid per share of common stock to the stock price on the date of grant; the expected life is based on historical and expected exercise behavior; and expected volatility is based on the historical volatility of our stock price over the expected life of the stock option.

A summary of stock option activity during 2023 is presented below:

	Options (thous.)		Weighted-Average Exercise Price			Weighted-Average Remaining Contractual Term (yrs.)		Aggregate Intrinsic Value (millions)
Outstanding at January 1, 2023		1,974		$	169.64		6.0		$	86
Granted		351			202.81		N/A			N/A
Exercised		(233	)		118.29		N/A			N/A
Forfeited or expired		(20	)		218.46		N/A			N/A
Outstanding at December 31, 2023		2,072		$	180.56		5.9		$	135
Vested or expected to vest at December 31, 2023		2,053		$	180.23		5.9		$	134
Options exercisable at December 31, 2023		1,423		$	164.48		4.8		$	115

At December 31, 2023, there was $16 million of unrecognized compensation expense related to nonvested stock options, which is expected to be recognized over a weighted-average period of 1.0 year. Additional information regarding stock option exercises appears in the following table:

Millions	*2023*			2022			2021
Intrinsic value of stock options exercised	$	23		$	53		$	84
Cash received from option exercises		27			27			58
Treasury shares repurchased for employee payroll taxes		(5	)		(8	)		(15	)
Income tax benefit realized from option exercises		5			8			16
Aggregate grant-date fair value of stock options vested	$	14		$	13		$	14

Retention Awards – Retention awards are granted at no cost to the employee, vest over periods lasting up to 4 years, and dividends and dividend equivalents are paid to participants during the vesting periods.

Changes in our retention awards during 2023 were as follows:

	Shares (thous.)		Weighted-Average Grant-Date Fair Value
Nonvested at January 1, 2023		1,069		$	196.47
Granted		297			202.88
Vested		(317	)		165.34
Forfeited		(53	)		206.43
Nonvested at December 31, 2023		996		$	207.76

At December 31, 2023, there was $82 million of total unrecognized compensation expense related to nonvested retention awards, which is expected to be recognized over a weighted-average period of 1.4 years.

Performance Stock Unit Awards – In February 2023, our Board of Directors approved performance stock unit grants. The basic terms of these performance stock units are identical to those granted in February 2022, including the annual return on invested capital (ROIC) and operating income growth (OIG) performance targets. The OIG performance targets compare to companies in the S&P 100 Industrials Index plus the Class I railroads. We define ROIC as net operating profit adjusted for interest expense (including interest on average operating lease liabilities) and taxes on interest divided by average invested capital adjusted for average operating lease liabilities.

The February 2023 stock units awarded to executives are subject to continued employment for 37 months, the attainment of certain levels of ROIC, and the relative three-year OIG. We expense two-thirds of the fair value of the units that are probable of being earned based on our forecasted ROIC over the three-year performance period, and with respect to the third year of the plan, we expense the remaining one-third of the fair value subject to the relative three-year OIG. We measure the fair value of performance stock units based upon the closing price of the underlying common stock as of the date of grant. Dividend equivalents are accumulated during the service period and paid to participants only after the units are earned.

Changes in our performance stock unit awards during 2023 were as follows:

	Shares (thous.)		Weighted-Average Grant-Date Fair Value
Nonvested at January 1, 2023		594		$	199.82
Granted		251			202.81
Vested		(78	)		189.29
Unearned		(127	)		186.11
Forfeited		(23	)		218.31
Nonvested at December 31, 2023		617		$	204.50

At December 31, 2023, there was $13 million of total unrecognized compensation expense related to nonvested performance stock unit awards, which is expected to be recognized over a weighted-average period of 0.8 years. This expense is subject to achievement of the performance measures established for the performance stock unit grants.

Employee Stock Purchase Plan - Our ESPP started in July 2021. Employee and Company contributions are used to issue treasury shares the month after employee contributions are withheld based on the settlement date closing price. The Company matches 40% contributed by the employee up to a maximum employee contribution of 5% of monthly salary (limited to $15,000 annually). We expense the Company contributions in the month the employee services were rendered (i.e., the month the employee contributions were withheld).

Note 7 - Income Taxes

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Text Block]

7. Income Taxes

Components of income tax expense were as follows for the years ended December 31:

Millions	*2023*			2022			2021
Current tax expense:
Federal	$	1,417		$	1,465		$	1,446
State		314			340			347
Foreign		6			7			8
Total current tax expense		1,737			1,812			1,801
Deferred and other tax expense/(benefit):
Federal		219			320			199
State [a]		(104	)		(59	)		(44	)
Foreign		2			1			(1	)
Total deferred and other tax expense		117			262			154
Total income tax expense	$	1,854		$	2,074		$	1,955

[a]

In 2023, Nebraska, Iowa, Kansas, and Arkansas enacted corporate income tax legislation that resulted in a $114 million reduction of our deferred tax expense. In 2022, Nebraska, Iowa, Arkansas, and Idaho enacted corporate income tax legislation that resulted in a $95 million reduction of our deferred tax expense. In 2021, Nebraska, Oklahoma, Idaho, Louisiana, and Arkansas enacted corporate income tax legislation that resulted in a $32 million reduction of our deferred tax expense.

For the years ended December 31, reconciliations between statutory and effective tax rates are as follows:

Tax Rate Percentages	*2023*			2022			2021
Federal statutory tax rate		21.0	%		21.0	%		21.0	%
State statutory rates, net of federal benefits		3.4			3.6			3.7
Deferred tax adjustments		(1.2	)		(1.0	)		(0.6	)
Dividends received deduction		(0.6	)		(0.5	)		(0.5	)
Excess tax benefits from equity compensation plans		(0.1	)		(0.2	)		(0.3	)
Other		-			-			(0.2	)
Effective tax rate		22.5	%		22.9	%		23.1	%

Deferred income tax assets/(liabilities) were comprised of the following at December 31:

Millions	*2023*			2022
Deferred income tax liabilities:
Property	$	(12,987	)	$	(12,910	)
Operating lease assets		(404	)		(411	)
Other		(556	)		(591	)
Total deferred income tax liabilities		(13,947	)		(13,912	)
Deferred income tax assets:
Operating lease liabilities		394			401
Accrued casualty costs		168			164
Accrued wages		50			50
Stock compensation		26			26
Other		186			238
Total deferred income tax assets		824			879
Net deferred income tax liability	$	(13,123	)	$	(13,033	)

In 2023 and 2022, there were no valuation allowances against deferred tax assets.

A reconciliation of changes in unrecognized tax benefits liabilities/(assets) from the beginning to the end of the reporting period is as follows:

Millions	*2023*			2022			2021
Unrecognized tax benefits at January 1	$	34		$	38		$	74
Lapse of statutes of limitations		(4	)		(3	)		(1	)
Decreases for positions taken in prior years		(1	)		(4	)		(24	)
Increases for positions taken in current year		1			3			3
Refunds from/(payments to) and settlements with taxing authorities		-			-			(12	)
Increases/(decreases) for interest and penalties		-			-			(3	)
Increases for positions taken in prior years		-			-			1
Unrecognized tax benefits at December 31	$	30		$	34		$	38

We recognize interest and penalties as part of income tax expense. Total accrued liabilities/(receivables) for interest and penalties were ($4) million and ($3) million at December 31, 2023 and 2022, respectively. Total interest and penalties recognized as part of income tax expense/(benefit) were ($1) million for 2023, ($2) million for 2022, and ($5) million for 2021.

Several state tax authorities are examining our state income tax returns for years 2018 through 2022.

We do not expect our unrecognized tax benefits to change significantly in the next 12 months. The portion of our unrecognized tax benefits that relates to permanent changes in tax and interest would reduce our effective tax rate, if recognized. The remaining unrecognized tax benefits relate to tax positions for which only the timing of the benefit is uncertain. The unrecognized tax benefits that would reduce our effective tax rate are $30 million for 2023, $31 million for 2022, and $31 million for 2021.

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

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Insider Trading Arrangements	12 Months Ended
Insider Trading Arrangements	Dec. 31, 2023 shares
ecd_TradingArrByIndTable
Material Terms of Trading Arrangement [Text Block]	Item 9B. Other Information On October 24, 2023, Elizabeth F. Whited, President, adopted a trading plan intended to satisfy Rule 10b5-1(c) to sell up to 7,500 shares of Union Pacific Corporation common stock, of which 7,500 are to be acquired upon the exercise of vested stock options, between February 14, 2024, and April 18, 2024, subject to certain conditions. On December 15, 2023, Todd M. Rynaski, Senior Vice President and Chief Accounting, Risk, and Compliance Officer, adopted a trading plan intended to satisfy Rule 10b5-1(c) to sell up to 5,271 shares of Union Pacific Corporation common stock, of which 5,271 are to be acquired upon the exercise of vested stock options, between March 15, 2024, and September 16, 2024, subject to certain conditions.
Elizabeth F. Whited [Member]
ecd_TradingArrByIndTable
Non-Rule 10b5-1 Arrangement Terminated [Flag]	false
Rule 10b5-1 Arrangement Terminated [Flag]	false
Trading Arrangement, Securities Aggregate Available Amount	7,500
Non-Rule 10b5-1 Arrangement Adopted [Flag]	false
Trading Arrangement Adoption Date	October 24, 2023
Trading Arrangement, Individual Name	Elizabeth F. Whited
Trading Arrangement, Individual Title	President
Rule 10b5-1 Arrangement Adopted [Flag]	true
Todd M. Rynaski [Member]
ecd_TradingArrByIndTable
Non-Rule 10b5-1 Arrangement Terminated [Flag]	false
Rule 10b5-1 Arrangement Terminated [Flag]	false
Trading Arrangement, Securities Aggregate Available Amount	5,271
Non-Rule 10b5-1 Arrangement Adopted [Flag]	false
Trading Arrangement Adoption Date	December 15, 2023
Trading Arrangement, Individual Name	Todd M. Rynaski
Trading Arrangement, Individual Title	Senior Vice President and Chief Accounting, Risk, and Compliance Officer
Rule 10b5-1 Arrangement Adopted [Flag]	true

Note 10 - Accounts Receivable (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounts Receivable, Allowance for Credit Loss, Current	$ 9,000	$ 10,000
Total Transfer Capacity, Undivided Interests to Investors under Receivables Securitization Facility	$ 800,000
Receivables Securitization Facility, Duration (Year)	3 years
Value Outstanding, Undivided Interest Held by Investors Under Receivables Securitization Facility	$ 0	100,000
Accounts Receivable, Supporting Undivided Investor Held Interest	1,700,000	1,600,000
Interest Expense	$ 1,340,000	1,271,000	$ 1,157,000
Receivables Securitization Facility, Maturity Date	Jul. 31, 2025
Asset-Backed Securities, Securitized Loans and Receivables [Member]
Accounts Receivable, from Securitization, Default or Dilution Ratio	1.00%
Interest Expense	$ 9,000	10,000	$ 4,000
Maximum [Member]
Total Transfer Capacity, Undivided Interests to Investors under Receivables Securitization Facility	800,000
Other Assets [Member]
Accounts Receivable, Allowance for Credit Loss, Noncurrent	$ 71,000	$ 58,000

Note 15 - Variable Interest Entities

12 Months Ended

Dec. 31, 2023

Variable Interest Entity Disclosure [Text Block]

15. Variable Interest Entities

We have entered into various lease transactions in which the structure of the leases contain variable interest entities (VIEs). These VIEs were created solely for the purpose of doing lease transactions (principally involving railroad equipment and facilities) and have no other activities, assets, or liabilities outside of the lease transactions. Within these lease arrangements, we have the right to purchase some or all of the assets at fixed prices. Depending on market conditions, fixed-price purchase options available in the leases could potentially provide benefits to us; however, these benefits are not expected to be significant.

We maintain and operate the assets based on contractual obligations within the lease arrangements, which set specific guidelines consistent within the railroad industry. As such, we have no control over activities that could materially impact the fair value of the leased assets. We do not hold the power to direct the activities of the VIEs and, therefore, do not control the ongoing activities that have a significant impact on the economic performance of the VIEs. Additionally, we do not have the obligation to absorb losses of the VIEs or the right to receive benefits of the VIEs that could potentially be significant to the VIEs.

We are not considered to be the primary beneficiary and do not consolidate these VIEs because our actions and decisions do not have the most significant effect on the VIE’s performance and our fixed-price purchase options are not considered to be potentially significant to the VIEs. The future minimum lease payments associated with the VIE leases totaled $831 million as of December 31, 2023, and are recorded as operating lease liabilities at present value in our Consolidated Statements of Financial Position.

Note 14 - Debt - Schedule of Debt Maturities (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
2024	$ 1,427
2025	1,426
2026	1,515
2027	1,285
2028	1,235
Thereafter	27,423
Long-Term Debt, Gross	34,311
Unamortized discount and deferred issuance costs	(1,732)	$ (1,775)
Total debt	$ 32,579	$ 33,326

Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

+ References + Details

Note 4 - Stock Options and Other Stock Plans - Stock-based Compensation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Stock options	$ 16	$ 14	$ 15
Retention awards	71	68	66
Total stock-based compensation expense, before tax	107	99	88
Excess income tax benefits from equity compensation plans	11	21	26
Employee Stock [Member]
ESPP	$ 20	$ 17	$ 7

Note 16 - Leases (Tables)

12 Months Ended

Dec. 31, 2023

Lessee, Lease [Table Text Block]

		*Dec. 31,*			Dec. 31,
Millions	Classification		*2023*			2022
Assets
Operating leases	Operating lease assets		$	1,643		$	1,672
Finance leases	Properties, net [a]			244			310
Total leased assets			$	1,887		$	1,982
Liabilities
Current
Operating	Accounts payable and other current liabilities		$	355		$	331
Finance	Debt due within one year			49			67
Noncurrent
Operating	Operating lease liabilities			1,245			1,300
Finance	Debt due after one year			109			167
Total lease liabilities			$	1,758		$	1,865

Lease, Cost [Table Text Block]

Millions	*Dec 31, 2023*			Dec 31, 2022
Operating lease cost [a]		$	369		$	338
Short-term lease cost			24			18
Variable lease cost			41			13
Finance lease cost
Amortization of leased assets [b]			38			52
Interest on lease liabilities [c]			8			12
Net lease cost		$	480		$	433

Contractual Obligation, Fiscal Year Maturity [Table Text Block]

Millions	Operating Leases			Finance Leases			Total
2024		$	361		$	55		$	416
2025			375			42			417
2026			296			35			331
2027			237			30			267
2028			199			11			210
After 2028			300			-			300
Total lease payments		$	1,768		$	173		$	1,941
Less: Interest			168			15			183
Present value of lease liabilities		$	1,600		$	158		$	1,758

Weighted Average Remaining Lease Term and Discount Rate [Table Text Block]

	Dec. 31,
		2023
Weighted-average remaining lease term (years)
Operating leases			5.8
Finance leases			3.5
Weighted-average discount rate (%)
Operating leases			3.6
Finance leases			4.5

Lessee, Lease, Other Information [Table Text Block]

Millions	*2023*		2022
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$	323	$	319
Investing cash flows from operating leases		33		31
Operating cash flows from finance leases		9		15
Financing cash flows from finance leases		65		91
Leased assets obtained in exchange for finance lease liabilities		-		-
Leased assets obtained in exchange for operating lease liabilities	$	241	$	173

Note 7 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2023

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

Millions	*2023*			2022			2021
Current tax expense:
Federal	$	1,417		$	1,465		$	1,446
State		314			340			347
Foreign		6			7			8
Total current tax expense		1,737			1,812			1,801
Deferred and other tax expense/(benefit):
Federal		219			320			199
State [a]		(104	)		(59	)		(44	)
Foreign		2			1			(1	)
Total deferred and other tax expense		117			262			154
Total income tax expense	$	1,854		$	2,074		$	1,955

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

Tax Rate Percentages	*2023*			2022			2021
Federal statutory tax rate		21.0	%		21.0	%		21.0	%
State statutory rates, net of federal benefits		3.4			3.6			3.7
Deferred tax adjustments		(1.2	)		(1.0	)		(0.6	)
Dividends received deduction		(0.6	)		(0.5	)		(0.5	)
Excess tax benefits from equity compensation plans		(0.1	)		(0.2	)		(0.3	)
Other		-			-			(0.2	)
Effective tax rate		22.5	%		22.9	%		23.1	%

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

Millions	*2023*			2022
Deferred income tax liabilities:
Property	$	(12,987	)	$	(12,910	)
Operating lease assets		(404	)		(411	)
Other		(556	)		(591	)
Total deferred income tax liabilities		(13,947	)		(13,912	)
Deferred income tax assets:
Operating lease liabilities		394			401
Accrued casualty costs		168			164
Accrued wages		50			50
Stock compensation		26			26
Other		186			238
Total deferred income tax assets		824			879
Net deferred income tax liability	$	(13,123	)	$	(13,033	)

Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]

Millions	*2023*			2022			2021
Unrecognized tax benefits at January 1	$	34		$	38		$	74
Lapse of statutes of limitations		(4	)		(3	)		(1	)
Decreases for positions taken in prior years		(1	)		(4	)		(24	)
Increases for positions taken in current year		1			3			3
Refunds from/(payments to) and settlements with taxing authorities		-			-			(12	)
Increases/(decreases) for interest and penalties		-			-			(3	)
Increases for positions taken in prior years		-			-			1
Unrecognized tax benefits at December 31	$	30		$	34		$	38

Note 16 - Leases - Schedule of Leases Term and Discount Rate (Details)	Dec. 31, 2023
Operating leases (Year)	5 years 9 months 18 days
Finance leases (Year)	3 years 6 months
Operating leases	3.60%
Finance leases	4.50%

Note 4 - Stock Options and Other Stock Plans (Details Textual) - USD ($)	7 Months Ended	12 Months Ended
	Jul. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jun. 30, 2018
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number (in shares)		2,072,000	1,974,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)		31,979,909	33,185,971	34,011,624
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date	40.00%
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate	5.00%
ESPP Employee Contribution Annual Limit	$ 15,000
Share-Based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)		10 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)		3 years
Share-based Compensation Arrangement by Share-based Payment Award, Conditions (in shares)		0
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total		$ 16,000,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)		1 year
Retention Awards [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number (in shares)		996,000	1,069,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)		4 years
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total		$ 82,000,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)		1 year 4 months 24 days
Performance Retention Awards [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number (in shares)		617,000	594,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total		$ 13,000,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)		9 months 18 days
Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period (Month)		37 months
Share-based Compensation Arrangement by Share-based Payment Award, Performance Period (Year)		3 years
Union Pacific Corporation 2000 Directors Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)		2,200,000
Share-based Compensation, Retention Shares Granted to Each Non-employee Director upon Initial Election to Board (in shares)					4,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding, Number (in shares)		16,000
Union Pacific Corporation 2013 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)		78,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number (in shares)		1,090,770
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number (in shares)		245,107
Union Pacific Corporation 2021 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)		23,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number (in shares)		981,484
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number (in shares)		1,059,344
Union Pacific Corporation 2021 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)		10,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period (in shares)		754,708

Note 16 - Leases

12 Months Ended

Dec. 31, 2023

Lessee, Operating and Finance Leases [Text Block]

16. Leases

We lease certain locomotives, freight cars, and other property for use in our rail operations.

The following are additional details related to our lease portfolio:

		*Dec. 31,*			Dec. 31,
Millions	Classification		*2023*			2022
Assets
Operating leases	Operating lease assets		$	1,643		$	1,672
Finance leases	Properties, net [a]			244			310
Total leased assets			$	1,887		$	1,982
Liabilities
Current
Operating	Accounts payable and other current liabilities		$	355		$	331
Finance	Debt due within one year			49			67
Noncurrent
Operating	Operating lease liabilities			1,245			1,300
Finance	Debt due after one year			109			167
Total lease liabilities			$	1,758		$	1,865

[a]

Finance lease assets are recorded net of accumulated amortization of $497 million and $658 million as of December 31, 2023 and 2022, respectively.

The lease cost components are classified as follows:

Millions	*Dec 31, 2023*			Dec 31, 2022
Operating lease cost [a]		$	369		$	338
Short-term lease cost			24			18
Variable lease cost			41			13
Finance lease cost
Amortization of leased assets [b]			38			52
Interest on lease liabilities [c]			8			12
Net lease cost		$	480		$	433

[a]	Operating lease cost is primarily reported in equipment and other rents in our Consolidated Statements of Income.
[b]	Amortization of leased assets is reported in depreciation in our Consolidated Statements of Income.
[c]	Interest on lease liabilities is reported in interest expense in our Consolidated Statements of Income.

The following table presents aggregate lease maturities as of December 31, 2023:

Millions	Operating Leases			Finance Leases			Total
2024		$	361		$	55		$	416
2025			375			42			417
2026			296			35			331
2027			237			30			267
2028			199			11			210
After 2028			300			-			300
Total lease payments		$	1,768		$	173		$	1,941
Less: Interest			168			15			183
Present value of lease liabilities		$	1,600		$	158		$	1,758

The following table presents the weighted average remaining lease term and discount rate:

	Dec. 31,
		2023
Weighted-average remaining lease term (years)
Operating leases			5.8
Finance leases			3.5
Weighted-average discount rate (%)
Operating leases			3.6
Finance leases			4.5

The following table presents other information related to our operating and finance leases for the years ended December 31:

Millions	*2023*		2022
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$	323	$	319
Investing cash flows from operating leases		33		31
Operating cash flows from finance leases		9		15
Financing cash flows from finance leases		65		91
Leased assets obtained in exchange for finance lease liabilities		-		-
Leased assets obtained in exchange for operating lease liabilities	$	241	$	173

Note 11 - Properties (Details Textual) $ in Billions	12 Months Ended
Note 11 - Properties (Details Textual) $ in Billions	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Number of Depreciable Asset Classes	60
Cost of Property Repairs and Maintenance	$ 2.5	$ 2.4	$ 2.1
Railroad Transportation Equipment [Member]
Term of Depreciation Studies (Year)	3 years
Railroad Transportation Track Assets [Member]
Term of Depreciation Studies (Year)	6 years

Note 2 - Significant Accounting Policies (Details Textual) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Revenue, Remaining Performance Obligation, Amount	$ 149	$ 194

Note 9 - Accumulated Other Comprehensive Income/Loss - Schedule of Reclassification (Details) (Parentheticals) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Total other comprehensive income/(loss), tax	$ 31	$ (92)	$ (237)

Note 18 - Share Repurchase Programs (Details Textual) - USD ($)
$ / shares in Units, $ in Millions

3 Months Ended

12 Months Ended

21 Months Ended

36 Months Ended

Feb. 18, 2022

Dec. 31, 2023

Sep. 30, 2023

Jun. 30, 2023

Mar. 31, 2023

Dec. 31, 2022

Sep. 30, 2022

Jun. 30, 2022

Mar. 31, 2022

Dec. 31, 2023

Dec. 31, 2022

Dec. 31, 2021

Dec. 31, 2023

Mar. 31, 2022

Apr. 01, 2022

Stock Repurchase Program, Number of Shares Authorized to be Repurchased (in shares)

150,000,000

100,000,000

Treasury Stock, Shares, Acquired (in shares)

606,581

2,908,703

3,501,667

9,490,339

3,100,683

^[1]

11,014,201

^[2]

3,515,284

27,106,890

19,600,000

83,300,000

Treasury Stock Acquired, Average Cost Per Share (in dollars per share)

$ 0

$ 199.81

$ 203.19

$ 201.33

$ 221.52

$ 232.87

^[1],[3]

$ 249.95

^[2],[3]

$ 202.61

$ 231.76

Treasury Stock, Value, Acquired, Cost Method, Including Amount Paid in Excess

$ 712

$ 6,282

$ 7,291

Accelerated Share Repurchase Programs (ASRs) [Member]

Treasury Stock, Shares, Acquired (in shares)

7,012,232

1,847,185

7,012,232

Treasury Stock Acquired, Average Cost Per Share (in dollars per share)

$ 248.32

Treasury Stock, Value, Acquired, Cost Method, Including Amount Paid in Excess

$ 2,200

[1]	Includes 1,847,185 shares repurchased in 2022 under accelerated share repurchase programs.
[2]	Includes 7,012,232 shares repurchased in 2022 under accelerated share repurchase programs.
[3]	In the period of the final settlement, the average price paid under the accelerated share repurchase programs is calculated based on the total program value less the value assigned to the initial delivery of shares. The average price of the completed 2022 accelerated share repurchase programs was $248.32.

Note 19 - Related Parties

12 Months Ended

Dec. 31, 2023

19. Related Parties

UPRR and other North American railroad companies jointly own TTX Company (TTX). UPRR has a 37.03% economic and voting interest in TTX while the other North American railroads own the remaining interest. In accordance with ASC 323 Investments - Equity Method and Joint Venture, UPRR applies the equity method of accounting to our investment in TTX.

TTX is a rail car pooling company that owns rail cars and intermodal wells to serve North America’s railroads. TTX assists railroads in meeting the needs of their customers by providing rail cars in an efficient, pooled environment. All railroads have the ability to utilize TTX rail cars through car hire by renting rail cars at stated rates.

UPRR had $1.8 billion and $1.7 billion recognized as investments related to TTX in our Consolidated Statements of Financial Position as of December 31, 2023 and 2022, respectively. TTX car hire expenses of $399 million in 2023, $402 million in 2022, and $375 million in 2021 are included in equipment and other rents in our Consolidated Statements of Income. In addition, UPRR had accounts payable to TTX of $60 million and $68 million at December 31, 2023 and 2022, respectively.

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 1
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section S99
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
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-URI https://asc.fasb.org//850/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Note 5 - Retirement Plans - Weighted Average Actuarial Assumptions (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Discount rate	5.00%	5.21%	2.80%
Compensation increase	4.00%	4.10%
Discount rate for benefit obligations	5.21%	2.80%	2.42%
Discount rate for interest on benefit obligations	5.14%	2.40%	1.90%
Discount rate for service cost	5.19%	2.91%	2.61%
Discount rate for interest on service cost	5.21%	2.86%	2.53%
Expected return on plan assets	5.25%	6.25%	6.25%
Compensation increase	4.10%	4.10%	4.40%

Note 14 - Debt - Schedule of Debt (Details) - USD ($)
$ in Thousands

Dec. 31, 2023

Dec. 31, 2022

Unamortized discount and deferred issuance costs

$ 34,311,000

(1,732,000)

$ (1,775,000)

Total debt

32,579,000

33,326,000

Less: current portion

(1,423,000)

(1,678,000)

Total long-term debt

31,156,000

31,648,000

Notes Payable to Banks [Member]

Equipment Trust Certificate [Member]

33,383,000

33,658,000

^[1]

770,000

809,000

Finance Lease [Member]

Commercial Paper [Member]

158,000

234,000

200,000

Secured Debt [Member]

100,000

Term Loan [Member]

$ 0

$ 100,000

[1]	Equipment obligations are secured by an interest in certain railroad equipment with a carrying value of approximately $0.9 billion at both December 31, 2023 and 2022.

Note 13 - Financial Instruments (Details Textual) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss, Current	$ 16	$ 46
Debt Instrument, Fair Value Disclosure	28,500	28,100
Fair Value of Total Debt Less of Carrying Value	4,100	5,200
Fair Value, Inputs, Level 2 [Member]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss, Current	$ 16	$ 46

Note 14 - Debt - Schedule of Unsecured Debt (Details) - Unsecured Debt [Member] $ in Billions	Dec. 31, 2023 USD ($)
The 4.750% Notes, Due February 21, 2026 [Member]
Debt Instrument	$ 0.5
The 4.950% Notes, Due May 15, 2053 [Member]
Debt Instrument	$ 0.5

Note 2 - Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2023

Restrictions on Cash and Cash Equivalents [Table Text Block]

Millions	*2023*		2022		2021
Cash and cash equivalents	$	1,055	$	973	$	960
Restricted cash equivalents in other current assets		10		10		19
Restricted cash equivalents in other assets		9		4		4
Total cash, cash equivalents, and restricted cash equivalents	$	1,074	$	987	$	983

Note 17 - Commitments and Contingencies

12 Months Ended

Dec. 31, 2023

Commitments Contingencies and Guarantees [Text Block]

17. Commitments and Contingencies

Asserted and Unasserted Claims – Various claims and lawsuits are pending against us and certain of our subsidiaries. We cannot fully determine the effect of all asserted and unasserted claims on our consolidated results of operations, financial condition, or liquidity. We have recorded a liability where asserted and unasserted claims are considered probable and where such claims can be reasonably estimated. We currently do not expect that any known lawsuits, claims, environmental costs, commitments, contingent liabilities, or guarantees will have a material adverse effect on our consolidated results of operations, financial condition, or liquidity after taking into account liabilities and insurance recoveries previously recorded for these matters.

In December 2019, we received a putative class action complaint under the Illinois Biometric Information Privacy Act, alleging violation due to the use of a finger scan system developed and managed by third parties. Union Pacific and the plaintiff are currently in the discovery phase. While we believe that we have strong defenses to the claims made in the complaint and will vigorously defend ourselves, there is no assurance regarding the ultimate outcome. Therefore, the outcome of this litigation is inherently uncertain, and we cannot reasonably estimate any loss or range of loss that may arise from this matter.

Personal Injury – The Federal Employers’ Liability Act (FELA) governs compensation for work-related accidents. Under FELA, damages are assessed based on a finding of fault through litigation or out-of-court settlements. We offer a comprehensive variety of services and rehabilitation programs for employees who are injured at work.

Approximately 95% of the recorded liability is related to asserted claims and approximately 5% is related to unasserted claims at December 31, 2023. Because of the uncertainty surrounding the ultimate outcome of personal injury claims, it is reasonably possible that future costs to settle these claims may range from approximately $383 million to $494 million. We record an accrual at the low end of the range as no amount of loss within the range is more probable than any other. Estimates can vary over time due to evolving trends in litigation.

Our personal injury liability activity was as follows:

Millions	*2023*			2022			2021
Beginning balance	$	361		$	325		$	270
Current year accruals		112			107			93
Changes in estimates for prior years		89			55			48
Payments		(179	)		(126	)		(86	)
Ending balance at December 31	$	383		$	361		$	325
Current portion, ending balance at December 31	$	113		$	84		$	64

Environmental Costs – We are subject to federal, state, and local environmental laws and regulations. We have identified 333 sites where we are or may be liable for remediation costs associated with alleged contamination or for violations of environmental requirements. This includes 32 sites that are the subject of actions taken by the U.S. government, including 20 that are currently on the Superfund National Priorities List. Certain federal legislation imposes joint and several liability for the remediation of identified sites; consequently, our ultimate environmental liability may include costs relating to activities of other parties, in addition to costs relating to our own activities at each site.

Our environmental liability activity was as follows:

Millions	*2023*			2022			2021
Beginning balance	$	253		$	243		$	233
Accruals		99			84			69
Payments		(107	)		(74	)		(59	)
Ending balance at December 31	$	245		$	253		$	243
Current portion, ending balance at December 31	$	91		$	67		$	60

The environmental liability includes future costs for remediation and restoration of sites, as well as ongoing monitoring costs, but excludes any anticipated recoveries from third-parties. Cost estimates are based on information available for each site, financial viability of other potentially responsible parties, and existing technology, laws, and regulations. The ultimate liability for remediation is difficult to determine because of the number of potentially responsible parties, site-specific cost sharing arrangements with other potentially responsible parties, the degree of contamination by various wastes, the scarcity and quality of volumetric data related to many of the sites, and the speculative nature of remediation costs. Estimates of liability may vary over time due to changes in federal, state, and local laws governing environmental remediation. Current obligations are not expected to have a material adverse effect on our consolidated results of operations, financial condition, or liquidity.

Insurance – The Company has a consolidated, wholly-owned captive insurance subsidiary (the Captive), that provides insurance coverage for certain risks including general liability, property, cyber, and FELA claims that are subject to reinsurance. The Captive entered into annual reinsurance treaty agreements that insure workers compensation, general liability, auto liability, and FELA risk. The Captive cedes a portion of its FELA exposure through the treaty and assumes a proportionate share of the entire risk. The Captive receives direct premiums, which are netted against the Company’s premium costs in other expenses in the Consolidated Statements of Income. The treaty agreements provide for certain protections against the risk of treaty participants’ non-performance, and we do not believe our exposure to treaty participants’ non-performance is material at this time. We record both liabilities and reinsurance receivables using an actuarial analysis based on historical experience in our Consolidated Statements of Financial Position. Effective January 2019, the Captive insurance subsidiary no longer participates in the reinsurance treaty agreement. The Company established a trust in the fourth quarter of 2018 for the purpose of providing collateral as required under the reinsurance treaty agreement for prior years’ participation.

Indemnities – Our maximum potential exposure under indemnification arrangements, including certain tax indemnifications, can range from a specified dollar amount to an unlimited amount, depending on the nature of the transactions and the agreements. Due to uncertainty as to whether claims will be made or how they will be resolved, we cannot reasonably determine the probability of an adverse claim or reasonably estimate any adverse liability or the total maximum exposure under these indemnification arrangements. We do not have any reason to believe that we will be required to make any material payments under these indemnity provisions.

Note 12 - Accounts Payable and Other Current Liabilities

12 Months Ended

Dec. 31, 2023

Accounts Payable and Accrued Liabilities Disclosure [Text Block]

12. Accounts Payable and Other Current Liabilities

	*Dec. 31,*			Dec. 31,
Millions		*2023*			2022
Accounts payable		$	856		$	784
Income and other taxes payable			685			628
Compensation-related accruals			533			938
Interest payable			389			379
Current operating lease liabilities (Note 16)			355			331
Accrued casualty costs			307			242
Equipment rents payable			98			109
Other			460			431
Total accounts payable and other current liabilities		$	3,683		$	3,842

Note 17 - Commitments and Contingencies (Details Textual) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Sites Identified	333
Sites Subject of Actions Taken by US Government	32
Sites on Superfund National Priorities List	20
Personal Injury [Member]
Recorded Liability Related to Asserted Claims	95.00%
Recorded Liability Related to Unasserted Claims	5.00%
Personal Injury [Member] \| Minimum [Member]
Loss Contingency, Estimate of Possible Loss	$ 383
Personal Injury [Member] \| Maximum [Member]
Loss Contingency, Estimate of Possible Loss	$ 494

Note 11 - Properties - Schedule of Property and Equipment Major Categories (Details) - USD ($)
$ in Millions

Dec. 31, 2023

Dec. 31, 2022

$ 81,733

$ 79,255

Property, Plant and Equipment, Accumulated Depreciation

57,398

56,038

24,335

23,217

Land [Member]

5,426

5,344

Roadrail and Other Track Material [Member]

5,426

5,344

18,837

18,419

Property, Plant and Equipment, Accumulated Depreciation

11,493

11,323

$ 7,344

$ 7,096

42 years

43 years

Road Ties [Member]

$ 11,985

$ 11,676

Property, Plant and Equipment, Accumulated Depreciation

8,090

7,977

$ 3,895

$ 3,699

34 years

Road Ballast [Member]

$ 6,345

$ 6,222

Property, Plant and Equipment, Accumulated Depreciation

4,284

4,272

$ 2,061

$ 1,950

34 years

Road, Other [Member]

^[1]

$ 23,175

$ 22,411

Property, Plant and Equipment, Accumulated Depreciation

17,807

^[1]

17,441

$ 5,368

^[1]

$ 4,970

47 years

^[1]

47 years

Road [Member]

$ 60,342

$ 58,728

Property, Plant and Equipment, Accumulated Depreciation

41,674

41,013

18,668

17,715

Equipment, Locomotives [Member]

9,295

9,166

Property, Plant and Equipment, Accumulated Depreciation

5,704

5,560

$ 3,591

$ 3,606

Equipment, Freight Cars [Member]

18 years

$ 2,765

$ 2,562

Property, Plant and Equipment, Accumulated Depreciation

1,809

1,664

$ 956

$ 898

Equipment, Work Equipment and Other [Member]

23 years

$ 1,344

$ 1,253

Property, Plant and Equipment, Accumulated Depreciation

798

780

$ 546

$ 473

17 years

Equipment [Member]

$ 13,404

$ 12,981

Property, Plant and Equipment, Accumulated Depreciation

8,311

8,004

5,093

4,977

Technology Equipment [Member]

1,388

1,254

Property, Plant and Equipment, Accumulated Depreciation

814

729

$ 574

$ 525

Construction in Progress [Member]

12 years

$ 1,173

$ 948

Property, Plant and Equipment, Accumulated Depreciation

1,173

948

$ 0

[1]	Other roadway includes grading, bridges and tunnels, signals, buildings, and other road assets.

Note 16 - Leases - Schedule of Lessee's Assets and Liabilities (Details) - USD ($)
$ in Millions

Dec. 31, 2023

Dec. 31, 2022

Operating leases

$ 1,643

$ 1,672

Total leased assets

1,887

1,982

Operating, liabilities

1,245

1,300

Total lease liabilities

1,758

1,865

Properties, Net [Member]

Finance leases

^[1]

244

310

Accounts payable and Other Current Liabilities [Member]

Operating, liabilities

355

331

Debt Due Within One Year [Member]

Finance, liabilities

Debt Due After One Year [Member]

Finance, liabilities

$ 109

$ 167

[1]	Finance lease assets are recorded net of accumulated amortization of $497 million and $658 million as of December 31, 2023 and 2022, respectively.

Note 12 - Accounts Payable and Other Current Liabilities - Schedule of Accounts Payable and Other Current Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Accounts payable	$ 856	$ 784
Income and other taxes payable	685	628
Compensation-related accruals	533	938
Interest payable	389	379
Accrued casualty costs	307	242
Other	460	431
Total accounts payable and other current liabilities	3,683	3,842
Equipment [Member]
Equipment rents payable	98	109
Accounts payable and Other Current Liabilities [Member]
Current operating lease liabilities (Note 16)	$ 355	$ 331

Note 14 - Debt

12 Months Ended

Dec. 31, 2023

Debt Disclosure [Text Block]

14. Debt

Total debt as of December 31, 2023 and 2022, is summarized below:

Millions	*2023*			2022
Notes and debentures, 2.2% to 7.1% due through February 14, 2072	$	33,383		$	33,658
Equipment obligations, 2.6% to 6.2% due through January 2, 2031 [a]		770			809
Finance leases, 3.1% to 6.8% due through December 10, 2028		158			234
Commercial paper		-			200
Receivables Facility (Note 10)		-			100
Term loans		-			100
Unamortized discount and deferred issuance costs		(1,732	)		(1,775	)
Total debt		32,579			33,326
Less: current portion		(1,423	)		(1,678	)
Total long-term debt	$	31,156		$	31,648

[a]

Equipment obligations are secured by an interest in certain railroad equipment with a carrying value of approximately $0.9 billion at both December 31, 2023 and 2022.

Debt Maturities – The following table presents aggregate debt maturities as of December 31, 2023, excluding market value adjustments:

Millions
2024	$	1,427
2025		1,426
2026		1,515
2027		1,285
2028		1,235
Thereafter		27,423
Total principal		34,311
Unamortized discount and deferred issuance costs		(1,732	)
Total debt	$	32,579

Debt Redemption – On April 15, 2022, we redeemed all $750 million of outstanding 4.163% notes due July 15, 2022, at a redemption price equal to 100% of the principal amount of the notes plus accrued and unpaid interest.

Credit Facilities – At December 31, 2023, we had $2.0 billion of credit available under our revolving credit facility, which is designated for general corporate purposes and supports the issuance of commercial paper. Credit facility withdrawals totaled $0 during 2023. Commitment fees and interest rates payable under the Facility are similar to fees and rates available to comparably rated, investment-grade borrowers. The Facility allows for borrowings at floating rates based on Term Secured Overnight Financing Rate (SOFR), plus a spread, depending upon credit ratings for our senior unsecured debt. The Facility, set to expire May 20, 2027, requires UPC to maintain an adjusted debt-to-EBITDA (earnings before interest, taxes, depreciation, and amortization) coverage ratio.

The definition of debt used for purposes of calculating the adjusted debt-to-EBITDA coverage ratio includes, among other things, certain credit arrangements, finance leases, guarantees, unfunded and vested pension benefits under Title IV of ERISA, and unamortized debt discount and deferred debt issuance costs. At December 31, 2023, the Company was in compliance with the adjusted debt-to-EBITDA coverage ratio, which allows us to carry up to $44.4 billion of debt (as defined in the Facility), and we had $34.3 billion of debt (as defined in the Facility) outstanding at that date. The Facility does not include any other financial restrictions, credit rating triggers (other than rating-dependent pricing), or any other provision that could require us to post collateral. The Facility also includes a $150 million cross-default provision and a change-of-control provision.

During 2023, we issued $1.4 billion and repaid $1.6 billion of commercial paper with maturities ranging from 11 to 64 days. As of December 31, 2023 and 2022, we had $0 and $200 million of commercial paper outstanding, respectively. Our revolving credit facility supports our outstanding commercial paper balances, and, unless we change the terms of our commercial paper program, our aggregate issuance of commercial paper will not exceed the amount of borrowings available under the Facility.

Shelf Registration Statement and Significant New Borrowings – In 2022, the Board of Directors reauthorized the issuance of up to $12.0 billion of debt securities. Under our shelf registration, we may issue, from time to time, any combination of debt securities, preferred stock, common stock, or warrants for debt securities or preferred stock in one or more offerings.

During 2023, we issued the following unsecured, fixed-rate debt securities under our shelf registration:

Date	Description of Securities
February 21, 2023	$0.50 billion of 4.750% Notes due February 21, 2026
	$0.50 billion of 4.950% Notes due May 15, 2053

We used the net proceeds from the offerings for general corporate purposes, including the repurchase of common stock pursuant to our share repurchase programs. These debt securities include change-of-control provisions. At December 31, 2023, we had remaining authority to issue up to $5.6 billion of debt securities under our shelf registration.

Receivables Securitization Facility – As of December 31, 2023 and 2022, we recorded $0 and $100 million, respectively, of borrowings under our Receivables Facility, as secured debt. (See further discussion of our "Receivables Securitization Facility" section in Note 10.)

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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Profit (Loss) from Real Estate Operations

Consolidated Statements of Financial Position (Parentheticals) - $ / shares	Dec. 31, 2023	Dec. 31, 2022
Common shares, par value (in dollars per share)	$ 2.5	$ 2.5
Common stock, authorized (in shares)	1,400,000,000	1,400,000,000
Common shares issued (in shares)	1,112,854,806	1,112,623,886
Common shares outstanding (in shares)	609,703,814	612,393,321

Note 6 - Other Income (Details Textual) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2023

Dec. 31, 2022

Dec. 31, 2021

^[1],[2]

$ 414

$ 381

$ 263

Land [Member] | Illinois State Toll Highway Authority [Member]

Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property

Land [Member] | Colorado Department of Transportation [Member]

Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property

$ 35

$ 50

Real Estate Transaction [Member]

Profit (Loss) from Real Estate Operations

$ 107

[1]	2023 includes a one-time $107 million transaction. 2022 includes a $79 million gain from a land sale to the Illinois State Toll Highway Authority and a $35 million gain from a sale to the Colorado Department of Transportation. 2021 includes a $50 million gain from a sale to the Colorado Department of Transportation.
[2]	Prior periods have been reclassified to conform to the current period disclosure.

Consolidated Statements of Comprehensive Income - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2023

Dec. 31, 2022

Dec. 31, 2021

Foreign currency translation

$ 6,379

$ 6,998

$ 6,523

Other comprehensive income/(loss):

Defined benefit plans

(106)

280

723

(44)

Unrealized gain on derivative instruments

Total other comprehensive income/(loss)

^[1]

(32)

332

679

Comprehensive income

$ 6,347

$ 7,330

$ 7,202

[1]	Net of deferred taxes of $31 million, ($92) million, and ($237) million during 2023, 2022, and 2021, respectively.

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

Note 9 - Accumulated Other Comprehensive Income/Loss

12 Months Ended

Dec. 31, 2023

Comprehensive Income (Loss) Note [Text Block]

9. Accumulated Other Comprehensive Income/Loss

Reclassifications out of accumulated other comprehensive income/loss were as follows (net of tax):

Millions	Defined benefit plans			Foreign currency translation		Unrealized gain on derivative instruments [a]			Total
Balance at January 1, 2023	$	(378	)	$	(204	)	$	-	$	(582	)
Other comprehensive income/(loss) before reclassifications		5			58			16		79
Amounts reclassified from accumulated other comprehensive income/(loss) [b]		(111	)		-			-		(111	)
Net year-to-date other comprehensive income/(loss), net of taxes of $31 million		(106	)		58			16		(32	)
Balance at December 31, 2023	$	(484	)	$	(146	)	$	16	$	(614	)

Balance at January 1, 2022	$	(658	)	$	(256	)	$	-	$	(914	)
Other comprehensive income/(loss) before reclassifications		-			52			-		52
Amounts reclassified from accumulated other comprehensive income/(loss) [b]		280			-			-		280
Net year-to-date other comprehensive income/(loss), net of taxes of ($92) million		280			52			-		332
Balance at December 31, 2022	$	(378	)	$	(204	)	$	-	$	(582	)

[a]	Related to interest rate swaps from equity method investments.
[b]	The accumulated other comprehensive income/loss reclassification components are 1) prior service cost/credit and 2) net actuarial loss, which are both included in the computation of net periodic pension benefit/cost. See Note 5 Retirement Plans for additional details.

Note 15 - Variable Interest Entities (Details Textual) $ in Millions	Dec. 31, 2023 USD ($)
Lessee, Operating Lease, Liability, to be Paid	$ 1,768
Variable Interest Entity, Not Primary Beneficiary [Member]
Lessee, Operating Lease, Liability, to be Paid	$ 831

Note 19 - Related Parties (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounts Payable, Current	$ 856	$ 784
UPRR [Member] \| TTX Company [Member]
Accounts Payable, Current	60	68
UPRR [Member] \| TTX Company [Member] \| Car Hire Expenses [Member]
Related Party Transaction, Amounts of Transaction	$ 399	402	$ 375
TTX Company [Member] \| UPRR [Member]
Equity Method Investment, Ownership Percentage	37.03%
Equity Method Investments	$ 1,800	$ 1,700

Note 5 - Retirement Plans

12 Months Ended

Dec. 31, 2023

Retirement Benefits [Text Block]

5. Retirement Plans

Pension Benefits

We provide defined benefit retirement income to eligible non-union employees through qualified and non-qualified (supplemental) pension plans. Qualified and non-qualified pension benefits are based on years of service and the highest compensation during the latest years of employment, with specific reductions made for early retirements. Non-union employees hired on or after January 1, 2018, are no longer eligible for pension benefits, but are eligible for an enhanced 401(k) benefit as described below in other retirement programs.

Funded Status

We are required by GAAP to separately recognize the overfunded or underfunded status of our pension plans as an asset or liability. The funded status represents the difference between the projected benefit obligation (PBO) and the fair value of the plan assets. Our non-qualified (supplemental) pension plan is unfunded by design. The PBO of the pension plans is the present value of benefits earned to date by plan participants, including the effect of assumed future compensation increases. Plan assets are measured at fair value. We use a December 31 measurement date for plan assets and obligations for all our retirement plans.

Changes in our PBO and plan assets were as follows for the years ended December 31:

*Funded Status*
Millions	*2023*			2022
Projected Benefit Obligation
Projected benefit obligation at beginning of year	$	3,725		$	5,296
Service cost		52			93
Interest cost		187			123
Actuarial loss/(gain)		146			(1,557	)
Gross benefits paid		(230	)		(230	)
Projected benefit obligation at end of year	$	3,880		$	3,725
Plan Assets
Fair value of plan assets at beginning of year	$	4,363		$	5,554
Actual return/(loss) on plan assets		235			(992	)
Non-qualified plan benefit contributions		32			31
Gross benefits paid		(230	)		(230	)
Fair value of plan assets at end of year	$	4,400		$	4,363
Funded status at end of year	$	520		$	638

Actuarial losses that increase the PBO were driven by a decrease in 2023 discount rates from 5.21% to 5.00%. Actuarial gains that decreased the PBO were driven by an increase in 2022 discount rates from 2.80% to 5.21%.

Amounts recognized in the statement of financial position as of December 31, 2023 and 2022, consist of:

Millions	*2023*			2022
Noncurrent assets	$	924		$	1,033
Current liabilities		(31	)		(31	)
Noncurrent liabilities		(373	)		(364	)
Net amounts recognized at end of year	$	520		$	638

Pre-tax amounts recognized in accumulated other comprehensive income/loss consist of $643 million and $493 million net actuarial loss as of December 31, 2023 and 2022, respectively.

Pre-tax changes recognized in other comprehensive income/loss as of December 31, 2023, 2022, and 2021, were as follows:

Millions	*2023*			2022		2021
Net actuarial (loss)/gain	$	(159	)	$	272	$	813
Amortization of:
Actuarial loss		9			86		141
Total	$	(150	)	$	358	$	954

Underfunded Accumulated Benefit Obligation – The accumulated benefit obligation (ABO) is the present value of benefits earned to date, assuming no future compensation growth. The underfunded accumulated benefit obligation represents the difference between the ABO and the fair value of plan assets.

The following table discloses only the PBO, ABO, and fair value of plan assets for pension plans where the accumulated benefit obligation is in excess of the fair value of the plan assets as of December 31:

*Underfunded Accumulated Benefit Obligation*
Millions	*2023*			2022
Projected benefit obligation	$	404		$	394
Accumulated benefit obligation	$	399		$	382
Fair value of plan assets		-			-
Underfunded accumulated benefit obligation	$	(399	)	$	(382	)

The ABO for all defined benefit pension plans was $3.6 billion and $3.5 billion at December 31, 2023 and 2022, respectively.

Assumptions – The weighted-average actuarial assumptions used to determine benefit obligations at December 31:

Percentages	*2023*			2022
Discount rate		5.00	%		5.21	%
Compensation increase		4.00	%		4.10	%

Expense

Pension expense is determined based upon the annual service cost of benefits (the actuarial cost of benefits earned during a period) and the interest cost on those liabilities, less the expected return on plan assets. The expected long-term rate of return on plan assets is applied to a calculated value of plan assets that recognizes changes in fair value over a 5-year period. This practice is intended to reduce year-to-year volatility in pension expense, but it can have the effect of delaying the recognition of differences between actual returns on assets and expected returns based on long-term rate of return assumptions. Differences in actual experience in relation to assumptions are not recognized in net income immediately but are deferred in accumulated other comprehensive income/loss and, if necessary, amortized as pension expense.

The components of our net periodic pension benefit/cost were as follows for the years ended December 31:

Millions	*2023*			2022			2021
Net Periodic Pension Cost:
Service cost	$	52		$	93		$	110
Interest cost		187			123			104
Expected return on plan assets		(248	)		(293	)		(270	)
Amortization of:
Actuarial loss		9			86			141
Net periodic pension cost	$	-		$	9		$	85

Assumptions – The weighted-average actuarial assumptions used to determine expense were as follows:

Percentages	*2023*			2022			2021
Discount rate for benefit obligations		5.21	%		2.80	%		2.42	%
Discount rate for interest on benefit obligations		5.14	%		2.40	%		1.90	%
Discount rate for service cost		5.19	%		2.91	%		2.61	%
Discount rate for interest on service cost		5.21	%		2.86	%		2.53	%
Expected return on plan assets		5.25	%		6.25	%		6.25	%
Compensation increase		4.10	%		4.10	%		4.40	%

We measure the service cost and interest cost components of our net periodic pension benefit/cost by using individual spot discount rates matched with separate cash flows for each future year. The discount rates were based on a yield curve of high-quality corporate bonds. The expected return on plan assets is based on our asset allocation mix and our historical return, taking into account current and expected market conditions. The actual return/(loss) on pension plan assets, net of fees, was approximately 6% in 2023, (18%) in 2022, and 15% in 2021.

Cash Contributions

The following table details cash contributions, if any, for the qualified and non-qualified (supplemental) pension plans:

Millions	Qualified		Non-qualified
2023	$	-	$	32
2022	$	-	$	31

Our policy with respect to funding the qualified pension plans is to fund at least the minimum required by law and not more than the maximum amount deductible for tax purposes.

The non-qualified pension plans are not funded and are not subject to any minimum regulatory funding requirements. Benefit payments for each year represent supplemental pension payments. We anticipate our 2024 supplemental pension payments will be made from cash generated from operations.

Benefit Payments

The following table details expected benefit payments for the years 2024 through 2033:

Millions
2024	$	230
2025		229
2026		229
2027		230
2028		231
Years 2029 - 2033	$	1,188

Asset Allocation Strategy

Our pension plan asset allocation at December 31, 2023 and 2022, and target allocation for 2024, are as follows:

		Percentage of Plan Assets
	Target		December 31,
	Allocation 2024		*2023*			2022
Equity securities		20% to 30%		24	%		48	%
Debt securities		70% to 80%		75			51
Real estate		0% to 2%		1			1
Total				100	%		100	%

The pension plan investments are held in a master trust. The investment strategy for pension plan assets is to maintain a broadly diversified portfolio designed to achieve our target average long-term rate of return of 5.25%. While we believe we can achieve a long-term average rate of return of 5.25%, we cannot be certain that the portfolio will perform to our expectations. Assets are strategically allocated among equity, debt, and other investments in order to achieve a diversification level that reduces fluctuations in investment returns. Asset allocation target ranges for equity, debt, and other portfolios are evaluated at least every three years with the assistance of an independent consulting firm. Actual asset allocations are monitored monthly, and rebalancing actions are executed at least quarterly, as needed.

Since 2020, the asset allocation targets for equity and debt have been adjusted annually to move from equity to debt as a de-risking measure. We met our target endpoint of 25% equity and 75% debt in 2023. The average credit rating of the debt portfolio was AA- and A+ at December 31, 2023 and 2022, respectively. The debt portfolio is also broadly diversified and invested primarily in U.S. Treasury, mortgage, and corporate securities. The weighted-average maturity of the debt portfolio was 22 years and 21 years at December 31, 2023 and 2022, respectively.

The investment of pension plan assets in securities issued by UPC is explicitly prohibited by the plan for both the equity and debt portfolios, other than through index fund holdings.

Fair Value Measurements

The pension plan assets are valued at fair value. The following is a description of the valuation methodologies used for the investments measured at fair value, including the general classification of such instruments pursuant to the valuation hierarchy.

Temporary Cash Investments – These investments consist of U.S. dollars and foreign currencies. Foreign currencies held are reported in terms of U.S. dollars based on currency exchange rates readily available in active markets. U.S. dollars and foreign currencies are classified as Level 1 investments.

Registered Investment Companies – Registered Investment Companies are entities primarily engaged in the business of investing in securities and are registered with the SEC. The plan’s prior holdings of Registered Investment Companies included both public and private fund vehicles. The public vehicles are exchange-traded funds (stocks), which are classified as Level 1 investments. The private vehicles (bonds) do not have published pricing and are valued using Net Asset Value (NAV).

Federal Government Securities – Federal Government Securities consist of bills, notes, bonds, and other fixed income securities issued directly by the U.S. Treasury or by government-sponsored enterprises. These assets are valued using a bid evaluation process with bid data provided by independent pricing sources. Federal Government Securities are classified as Level 2 investments.

Bonds and Debentures – Bonds and debentures consist of debt securities issued by U.S. and non-U.S. corporations as well as state and local governments. These assets are valued using a bid evaluation process with bid data provided by independent pricing sources. Corporate, state, and municipal bonds and debentures are classified as Level 2 investments.

Corporate Stock – This investment category consists of common and preferred stock issued by U.S. and non-U.S. corporations. Most common shares are traded actively on exchanges and price quotes for these shares are readily available. Common stock is classified as a Level 1 investment. Preferred shares included in this category are valued using a bid evaluation process with bid data provided by independent pricing sources. Preferred stock is classified as a Level 2 investment.

Venture Capital and Buyout Partnerships – This investment category is comprised of interests in limited partnerships that invest primarily in privately-held companies. Due to the private nature of the partnership investments, pricing inputs are not readily observable. Asset valuations are developed by the general partners that manage the partnerships. These valuations are based on the application of public market multiples to private company cash flows, market transactions that provide valuation information for comparable companies, and other methods. The fair value recorded by the plan is calculated using each partnership’s NAV.

Real Estate Funds – The plan’s real estate investments are primarily interests in private real estate investment trusts, partnerships, limited liability companies, and similar structures. Valuations for the holdings in this category are not based on readily observable inputs and are primarily derived from property appraisals. The fair value recorded by the plan is calculated using the NAV for each investment.

Collective Trust and Other Funds – Collective trust and other funds are comprised of shares or units in commingled funds and limited liability companies that are not publicly traded. The underlying assets in these entities (global stock funds and short-term investment funds) are publicly traded on exchanges and price quotes for the assets held by these funds are readily available. The fair value recorded by the plan is calculated using NAV for each investment.

As of December 31, 2023, the pension plan assets measured at fair value on a recurring basis were as follows:

	Quoted Prices			Significant
	in Active			Other			Significant
	Markets for			Observable			Unobservable
	Identical Inputs			Inputs			Inputs
Millions	(Level 1)			(Level 2)			(Level 3)			Total
Plan assets at fair value:
Temporary cash investments		$	-		$	-		$	-		$	-
Registered investment companies [a]			-			-			-			-
Federal government securities			-			1,508			-			1,508
Bonds and debentures			-			1,696			-			1,696
Corporate stock			176			5			-			181
Total plan assets at fair value		$	176		$	3,209		$	-		$	3,385
Plan assets at NAV:
Registered investment companies [b]												-
Venture capital and buyout partnerships												554
Real estate funds												30
Collective trust and other funds												382
Total plan assets at NAV											$	966
Other assets/(liabilities) [c]												49
Total plan assets											$	4,400

As of December 31, 2022, the pension plan assets measured at fair value on a recurring basis were as follows:

	Quoted Prices			Significant
	in Active			Other			Significant
	Markets for			Observable			Unobservable
	Identical Inputs			Inputs			Inputs
Millions	(Level 1)			(Level 2)			(Level 3)			Total
Plan assets at fair value:
Temporary cash investments		$	1		$	-		$	-		$	1
Registered investment companies [a]			6			-			-			6
Federal government securities			-			803			-			803
Bonds and debentures			-			1,069			-			1,069
Corporate stock			1,104			7			-			1,111
Total plan assets at fair value		$	1,111		$	1,879		$	-		$	2,990
Plan assets at NAV:
Registered investment companies [b]												68
Venture capital and buyout partnerships												611
Real estate funds												37
Collective trust and other funds												622
Total plan assets at NAV											$	1,338
Other assets/(liabilities) [c]												35
Total plan assets											$	4,363

[a]	Registered investment companies measured at fair value are stock investments.
[b]	Registered investment companies measured at NAV include bond investments.
[c]	Includes accrued receivables, net payables, and pending broker settlements.

The master trust’s investments in limited partnerships and similar structures (used to invest in private equity and real estate) are valued at fair value based on their proportionate share of the partnerships’ fair value as recorded in the limited partnerships’ audited financial statements. The limited partnerships allocate gains, losses, and expenses to the partners based on the ownership percentage as described in the partnership agreements. At December 31, 2023 and 2022, the master trust had future commitments for additional contributions to private equity partnerships totaling $80 million and $91 million, respectively, and to real estate partnerships and funds totaling $5 million and $5 million, respectively.

Other Retirement Programs

Other Post Retirement Benefits – We provide medical and life insurance benefits for eligible retirees hired before January 1, 2004. These benefits are funded as medical claims and life insurance premiums are paid. OPEB expense is determined based upon the annual service cost of benefits and the interest cost on those liabilities plus amortization of net (gain)/loss amounts offset by amortization of prior service credits recorded in AOCI. Our OPEB liability was $104 million and $134 million at December 31, 2023 and 2022, respectively. The liability is based on discount rate assumptions of 4.97% and 5.23% at December 31, 2023 and 2022, respectively. OPEB net periodic (benefit)/cost was ($7) million in 2023, ($2) million in 2022, and ($3) million in 2021.

401(k)/Thrift Plan – For non-union employees hired prior to January 1, 2018, and eligible union employees for whom we make matching contributions, we provide a defined contribution plan (401(k)/thrift plan). We match 50% for each dollar contributed by employees up to the first 6% of compensation contributed. For non-union employees hired on or after January 1, 2018, we match 100% for each dollar, up to the first 6% of compensation contributed, in addition to contributing an annual amount of 3% of the employee’s annual base salary. Our plan contributions were $27 million in 2023, $24 million in 2022, and $21 million in 2021.

Railroad Retirement System – All Railroad employees are covered by the Railroad Retirement System (the System). Contributions made to the System are expensed as incurred and amounted to approximately $711 million in 2023, $586 million in 2022, and $550 million in 2021.

Collective Bargaining Agreements – Under collective bargaining agreements, we participate in multi-employer benefit plans that provide certain post retirement health care and life insurance benefits for eligible union employees. Premiums paid under these plans are expensed as incurred and amounted to $16 million in 2023, $20 million in 2022, and $30 million in 2021.

The entire disclosure for retirement benefits.

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Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating revenues:
Operating revenues	$ 24,119	$ 24,875	$ 21,804
Operating expenses:
Compensation and benefits	4,818	4,645	4,158
Fuel	2,891	3,439	2,049
Purchased services and materials	2,616	2,442	2,016
Depreciation	2,318	2,246	2,208
Equipment and other rents	947	898	859
Other	1,447	1,288	1,176
Total operating expenses	15,037	14,958	12,466
Operating income	9,082	9,917	9,338
Other income, net (Note 6)	491	426	297
Interest expense	(1,340)	(1,271)	(1,157)
Income before income taxes	8,233	9,072	8,478
Income tax expense (Note 7)	(1,854)	(2,074)	(1,955)
Net income	$ 6,379	$ 6,998	$ 6,523
Share and Per Share (Note 8):
Earnings per share - basic (in dollars per share)	$ 10.47	$ 11.24	$ 9.98
Earnings per share - diluted (in dollars per share)	$ 10.45	$ 11.21	$ 9.95
Weighted average number of shares - basic (in shares)	609.2	622.7	653.8
Weighted average number of shares - diluted (in shares)	610.2	624.0	655.4
Cargo and Freight [Member]
Operating revenues:
Operating revenues	$ 22,571	$ 23,159	$ 20,244
Product and Service, Other [Member]
Operating revenues:
Operating revenues	$ 1,548	$ 1,716	$ 1,560

Note 7 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Deferred Tax Assets, Valuation Allowance	$ 0	$ 0
Income Tax Examination, Penalties and Interest Accrued Liabilities (Receivables)	(4,000)	(3,000)
Income Tax Examination, Penalties and Interest Expense (Benefit)	(1,000)	(2,000)	$ (5,000)
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	30,000	31,000	31,000
State and Local Jurisdiction [Member] \| Nebraska, Iowa, Kansas, and Arkansas Department of Revenue [Member]
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability	$ (114,000)
State and Local Jurisdiction [Member] \| Nebraska, Iowa, Arkansas, and Idaho Department of Revenue [Member]
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability		$ (95,000)
State and Local Jurisdiction [Member] \| Nebraska, Oklahoma, Idaho, Louisiana and Arkansas Department of Revenue [Member]
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability			$ (32,000)

Note 2 - Significant Accounting Policies - Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash and cash equivalents	$ 1,055	$ 973	$ 960
Total cash, cash equivalents, and restricted cash equivalents	1,074	987	983
Other Current Assets [Member]
Restricted cash equivalents	10	10	19
Other Noncurrent Assets [Member]
Restricted cash equivalents	$ 9	$ 4	$ 4

Note 4 - Stock Options and Other Stock Plans - Changes in Retention Awards (Details) - Retention Awards [Member] shares in Thousands	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Nonvested, beginning balance (in shares) \| shares	1,069
Nonvested, weighted-average grant-date fair value, beginning balance (in dollars per share) \| $ / shares	$ 196.47
Granted (in shares) \| shares	297
Granted, weighted-average grant-date fair value (in dollars per share) \| $ / shares	$ 202.88
Vested (in shares) \| shares	(317)
Vested, weighted-average grant-date fair value (in dollars per share) \| $ / shares	$ 165.34
Forfeited (in shares) \| shares	(53)
Forfeited, weighted-average grant-date fair value (in dollars per share) \| $ / shares	$ 206.43
Nonvested, ending balance (in shares) \| shares	996
Nonvested, weighted-average grant-date fair value, ending balance (in dollars per share) \| $ / shares	$ 207.76

Note 8 - Earnings Per Share - Schedule of Reconciliation (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Net income	$ 6,379	$ 6,998	$ 6,523
Weighted-average number of shares outstanding:
Basic (in shares)	609.2	622.7	653.8
Diluted (in shares)	610.2	624.0	655.4
Earnings per share - basic (in dollars per share)	$ 10.47	$ 11.24	$ 9.98
Earnings per share - diluted (in dollars per share)	$ 10.45	$ 11.21	$ 9.95
Share-Based Payment Arrangement, Option [Member]
Weighted-average number of shares outstanding:
Dilutive effect of share based payment awards (in shares)	0.4	0.6	0.8
Retention Awards [Member]
Weighted-average number of shares outstanding:
Dilutive effect of share based payment awards (in shares)	0.6	0.7	0.8

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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-Section 45
-Paragraph 60B
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-4

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482662/260-10-50-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

Reference 15: http://www.xbrl.org/2003/role/exampleRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 52
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-52

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-7

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

Cybersecurity Disclosure Information (Details Textual)	12 Months Ended
Cybersecurity Disclosure Information (Details Textual)	Dec. 31, 2023
CIO [Member]
Cybersecurity, Period of Relevant Work Experience (Year)	27 years
CISO [Member]
Cybersecurity, Period of Relevant Work Experience (Year)	28 years
Deputy CISO [Member]
Cybersecurity, Period of Relevant Work Experience (Year)	19 years

Note 2 - Significant Accounting Policies

12 Months Ended

Dec. 31, 2023

Significant Accounting Policies [Text Block]

2. Significant Accounting Policies

Principles of Consolidation – The Consolidated Financial Statements include the accounts of Union Pacific Corporation and all of its subsidiaries. Investments in affiliated companies (20% to 50% owned) are accounted for using the equity method of accounting. All intercompany transactions are eliminated. We currently have no less than majority-owned investments that require consolidation under variable interest entity requirements.

Cash, Cash Equivalents, and Restricted Cash – Cash equivalents consist of investments with original maturities of three months or less. Amounts included in restricted cash represent those required to be set aside by contractual agreement.

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the Consolidated Statements of Financial Position that sum to the total of the same such amounts shown on the Consolidated Statements of Cash Flows:

Millions	*2023*		2022		2021
Cash and cash equivalents	$	1,055	$	973	$	960
Restricted cash equivalents in other current assets		10		10		19
Restricted cash equivalents in other assets		9		4		4
Total cash, cash equivalents, and restricted cash equivalents	$	1,074	$	987	$	983

Accounts Receivable – Accounts receivable includes receivables reduced by an allowance for doubtful accounts. The allowance is based upon historical losses, credit worthiness of customers, and current economic conditions. Receivables not expected to be collected in one year and the associated allowances are classified as other assets in our Consolidated Statements of Financial Position.

Investments – Investments represent our investments in affiliated companies (20% to 50% owned) that are accounted for under the equity method of accounting, and investments in companies (less than 20% owned) accounted for at fair value when there is a readily determined fair value or at cost minus impairment when there are not readily determinable fair values. Our portion of income/loss on equity method investments that are integral to our operations are recorded in operating expenses. Realized and unrealized gains and losses on investments that are not integral to our operations are recorded in other income.

Materials and Supplies – Materials and supplies are carried at the lower of average cost or net realizable value.

Property and Depreciation – Properties and equipment are carried at cost and are depreciated on a straight-line basis over their estimated service lives, which are measured in years, except for rail in high-density traffic corridors (i.e., all rail lines except for those lines subject to abandonment, yard tracks, and switching tracks), where lives are measured in millions of gross tons per mile of track. We use the group method of depreciation where all items with similar characteristics, use, and expected lives are grouped together in asset classes and are depreciated using composite depreciation rates. The group method of depreciation treats each asset class as a pool of resources, not as singular items. We determine the estimated service lives of depreciable railroad assets by means of depreciation studies. Under the group method of depreciation, no gain or loss is recognized when depreciable property is retired or replaced in the ordinary course of business.

Impairment of Long-Lived Assets – We review long-lived assets, including identifiable intangibles, for impairment when events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If impairment indicators are present and the estimated future undiscounted cash flows are less than the carrying value of the long-lived assets, the carrying value is reduced to the estimated fair value.

Revenue Recognition – Freight revenues are derived from contracts with customers. We account for a contract when it has approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance, and collectability of consideration is probable. Our contracts include private agreements, private rate/letter quotes, public circulars/tariffs, and interline/foreign agreements. The performance obligation in our contracts is typically delivering a specific commodity from a place of origin to a place of destination and our commitment begins with the tendering and acceptance of a freight bill of lading and is satisfied upon delivery at destination. We consider each freight shipment to be a distinct performance obligation.

We recognize freight revenues over time as freight moves from origin to destination. The allocation of revenues between reporting periods is based on the relative transit time in each reporting period with expenses recognized as incurred. Outstanding performance obligations related to freight moves in transit totaled $149 million at December 31, 2023, and $194 million at December 31, 2022, and are expected to be recognized in the following quarter as we satisfy our remaining performance obligations and deliver freight to destination. The transaction price is generally specified in a contract and may be dependent on the commodity, origin/destination, and route. Customer incentives, which are primarily provided for shipping to/from specific locations or based on cumulative volumes, are recorded as a reduction to operating revenues. Customer incentives that include variable consideration based on cumulative volumes are estimated using the expected value method, which is based on available historical, current, and forecasted volumes, and recognized as the related performance obligation is satisfied.

Under typical payment terms, our customers pay us after each performance obligation is satisfied and there are no material contract assets or liabilities associated with our freight revenues. Outstanding freight receivables are presented in our Consolidated Statements of Financial Position as accounts receivable, net.

Freight revenues related to interline transportation services that involve other railroads are reported on a net basis. The portion of the gross amount billed to customers that is remitted by the Company to another party is not reflected as freight revenues.

Other revenues consist primarily of revenues earned by our other subsidiaries (primarily logistics and commuter rail operations) and accessorial revenues. Other subsidiary revenues are generally recognized over time as shipments move from origin to destination. The allocation of revenues between reporting periods is based on the relative transit time in each reporting period with expenses recognized as incurred. Accessorial revenues are recognized at a point in time as performance obligations are satisfied.

Translation of Foreign Currency – Our portion of the assets and liabilities related to foreign investments are translated into U.S. dollars at the exchange rates in effect at the balance sheet date. Revenues and expenses are translated at the average rates of exchange prevailing during the year. Unrealized gains or losses are reflected within common shareholders’ equity as accumulated other comprehensive income or loss.

Fair Value Measurements – We use a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. The level in the fair value hierarchy within which the fair value measurement in its entirety falls is determined based on the lowest level input that is significant to the fair value measurement in its entirety. These levels include:

Level 1: Quoted market prices in active markets for identical assets or liabilities.

Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data.

Level 3: Unobservable inputs that are not corroborated by market data.

We have applied fair value measurements to our short-term investments, certain equity investments, pension plan assets, and short- and long-term debt.

Stock-Based Compensation – We issue treasury shares to cover stock option exercises, stock unit vestings, and ESPP shares, while new shares are issued when retention shares are granted.

We measure and recognize compensation expense for all stock-based awards made to employees, including stock options and ESPP awards. Compensation expense is based on the fair value of the awards as measured at the grant date and is expensed ratably over the service period of the awards (generally the vesting period). The fair value of retention awards is the closing stock price on the date of grant, the fair value of stock options is determined by using the Black-Scholes option pricing model, and the fair value of ESPP awards is based on the Company contribution match.

Earnings Per Share – Basic earnings per share are calculated on the weighted-average number of common shares outstanding during each period. Diluted earnings per share include shares issuable upon exercise of outstanding stock options and stock-based awards where the conversion of such instruments would be dilutive.

Income Taxes – We account for income taxes by recording taxes payable or refundable for the current year and deferred tax assets and liabilities for the expected future tax consequences of events that are reported in different periods for financial reporting and income tax purposes. The majority of our deferred tax assets relate to expenses that already have been recorded for financial reporting purposes but not deducted for tax purposes. The majority of our deferred tax liabilities relate to differences between the tax bases and financial reporting amounts of our land and depreciable property, due to accelerated tax depreciation (including bonus depreciation), revaluation of assets in purchase accounting transactions, and differences in capitalization methods. These expected future tax consequences are measured based on current tax law; the effects of future tax legislation are not anticipated.

When appropriate, we record a valuation allowance against deferred tax assets to reflect that these tax assets may not be realized. In determining whether a valuation allowance is appropriate, we consider whether it is more likely than not that all or some portion of our deferred tax assets will not be realized, based on management’s judgments using available evidence for purposes of estimating whether future taxable income will be sufficient to realize a deferred tax asset.

We recognize tax benefits that are more likely than not to be sustained upon examination by tax authorities. The amount recognized is measured as the largest amount of benefit that is greater than 50 percent likely to be realized upon settlement. A liability for “unrecognized tax benefits” is recorded for any tax benefits claimed in our tax returns that do not meet these recognition and measurement standards.

Leases – We determine if an arrangement is or contains a lease at inception. Operating lease assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. When an implicit rate is not available, we use a collateralized incremental borrowing rate for operating leases based on the information available at commencement date, including lease term, in determining the present value of future payments. The operating lease asset also includes any lease payments made and excludes lease incentives and initial direct costs incurred. Our lease terms may include options to extend or terminate the lease when it is reasonably certain that the option will be exercised. Operating leases are included in operating lease assets, accounts payable and other current liabilities, and operating lease liabilities on our Consolidated Statements of Financial Position. Finance leases are included in properties, net, debt due within one year, and debt due after one year on our Consolidated Statements of Financial Position. Operating lease expense is recognized on a straight-line basis over the lease term and primarily reported in equipment and other rents and financing lease expense is recorded as depreciation and interest expense in our Consolidated Statements of Income.

We have lease agreements with lease and non-lease components, and we have elected to not separate lease and non-lease components for all classes of underlying assets. Leases with an initial term of 12 months or less are not recorded on our Consolidated Statements of Financial Position. Leases with initial terms in excess of 12 months are recorded as operating or financing leases in our Consolidated Statements of Financial Position.

Pension Benefits – In order to measure the expense associated with pension benefits, we must make various assumptions including discount rates used to value certain liabilities, expected return on plan assets used to fund these expenses, compensation increases, employee turnover rates, and anticipated mortality rates. The assumptions used by us are based on our historical experience as well as current facts and circumstances. We use an actuarial analysis to measure the expense and liability associated with these benefits.

Personal Injury – The cost of injuries to employees and others on our property is charged to expense based on estimates of the ultimate cost and number of incidents each year. We use an actuarial analysis to measure the expense and liability, including unasserted claims. Our personal injury liability is not discounted to present value due to the uncertainty surrounding the timing of future payments. Legal fees and incidental costs are expensed as incurred.

Environmental – When environmental issues have been identified with respect to property currently or formerly owned, leased, or otherwise used in the conduct of our business, we perform, with the assistance of our consultants, environmental assessments on such property. We expense the cost of the assessments as incurred. We accrue the cost of remediation where our obligation is probable and such costs can be reasonably estimated. We do not discount our environmental liabilities when the timing of the anticipated cash payments is not fixed or readily determinable. Legal fees and incidental costs are expensed as incurred.

Use of Estimates – The preparation of our Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect certain reported assets and liabilities, the disclosure of certain contingent assets and liabilities as of the date of the Consolidated Financial Statements, as well as the reported amounts of revenues and expenses during the reporting period. Actual future results may differ from such estimates.

Consolidated Statements of Changes in Common Shareholders' Equity (Parentheticals) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Dividends per share (in dollars per share)	$ 5.2	$ 5.08	$ 4.29

Note 8 - Earnings Per Share (Details Textual) - shares shares in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-Based Payment Arrangement, Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	0.9	0.3	0.2

Note 11 - Properties

12 Months Ended

Dec. 31, 2023

Property, Plant and Equipment Disclosure [Text Block]

11. Properties

The following tables list the major categories of property and equipment as well as the weighted-average estimated useful life for each category (in years):

Millions, Except Estimated Useful Life			Accumulated		Net Book		Estimated
As of December 31, 2023	Cost		Depreciation		Value		Useful Life
Land	$	5,426	$	N/A	$	5,426		N/A
Road:
Rail and other track material		18,837		7,344		11,493		42
Ties		11,985		3,895		8,090		34
Ballast		6,345		2,061		4,284		34
Other roadway [a]		23,175		5,368		17,807		47
Total road		60,342		18,668		41,674		N/A
Equipment:
Locomotives		9,295		3,591		5,704		18
Freight cars		2,765		956		1,809		23
Work equipment and other		1,344		546		798		17
Total equipment		13,404		5,093		8,311		N/A
Technology and other		1,388		574		814		12
Construction in progress		1,173		-		1,173		N/A
Total	$	81,733	$	24,335	$	57,398		N/A

Millions, Except Estimated Useful Life			Accumulated		Net Book		Estimated
As of December 31, 2022	Cost		Depreciation		Value		Useful Life
Land	$	5,344	$	N/A	$	5,344		N/A
Road:
Rail and other track material		18,419		7,096		11,323		43
Ties		11,676		3,699		7,977		34
Ballast		6,222		1,950		4,272		34
Other roadway [a]		22,411		4,970		17,441		47
Total road		58,728		17,715		41,013		N/A
Equipment:
Locomotives		9,166		3,606		5,560		18
Freight cars		2,562		898		1,664		23
Work equipment and other		1,253		473		780		17
Total equipment		12,981		4,977		8,004		N/A
Technology and other		1,254		525		729		12
Construction in progress		948		-		948		N/A
Total	$	79,255	$	23,217	$	56,038		N/A

[a]

Other roadway includes grading, bridges and tunnels, signals, buildings, and other road assets.

Property and Depreciation – Our railroad operations are highly capital-intensive, and our large base of homogeneous, network-type assets turns over on a continuous basis. Each year we develop a capital program for the replacement of assets and for the acquisition or construction of assets that enable us to enhance our operations or provide new service offerings to customers. We currently have more than 60 depreciable asset classes, and we may increase or decrease the number of asset classes due to changes in technology, asset strategies, or other factors.

We determine the estimated service lives of depreciable railroad assets by means of depreciation studies. We perform depreciation studies at least every 3 years for equipment and every 6 years for track assets (i.e., rail and other track material, ties, and ballast) and other road property. Our depreciation studies take into account the following factors:

●	Statistical analysis of historical patterns of use and retirements of each of our asset classes,
●	Evaluation of any expected changes in current operations and the outlook for continued use of the assets,
●	Evaluation of technological advances and changes to maintenance practices, and
●	Expected salvage to be received upon retirement.

For rail in high-density traffic corridors, we measure estimated service lives in millions of gross tons per mile of track. It has been our experience that the lives of rail in high-density traffic corridors are closely correlated to usage (i.e., the amount of weight carried over the rail). The service lives also vary based on rail weight, rail condition (e.g., new or secondhand), and rail type (e.g., straight or curve). Our depreciation studies for rail in high-density traffic corridors consider each of these factors in determining the estimated service lives. For rail in high-density traffic corridors, we calculate depreciation rates annually by dividing the number of gross ton-miles carried over the rail (i.e., the weight of loaded and empty freight cars, locomotives, and maintenance of way equipment transported over the rail) by the estimated service lives of the rail measured in millions of gross tons per mile. For all other depreciable assets, we compute depreciation based on the estimated service lives of our assets as determined from the analysis of our depreciation studies. Changes in the estimated service lives of our assets and their related depreciation rates are implemented prospectively.

Under the group method of depreciation, the historical cost (net of salvage) of depreciable property that is retired or replaced in the ordinary course of business is charged to accumulated depreciation and no gain or loss is recognized. The historical cost of certain track assets is estimated by multiplying the current replacement cost of track assets by a historical index factor derived from (a) inflation indices published by the Bureau of Labor Statistics and (b) the estimated useful lives of the assets as determined by our depreciation studies. The indices were selected because they closely correlate with the major costs of the properties comprising the applicable track asset classes. Because of the number of estimates inherent in the depreciation and retirement processes and because it is impossible to precisely estimate each of these variables until a group of property is completely retired, we continually monitor the estimated service lives of our assets and the accumulated depreciation associated with each asset class to ensure our depreciation rates are appropriate. In addition, we determine if the recorded amount of accumulated depreciation is deficient (or in excess) of the amount indicated by our depreciation studies. Any deficiency (or excess) is amortized as a component of depreciation expense over the remaining service lives of the applicable classes of assets.

For retirements of depreciable railroad properties that do not occur in the normal course of business, a gain or loss may be recognized if the retirement meets each of the following three conditions: (a) is unusual, (b) is material in amount, and (c) varies significantly from the retirement profile identified through our depreciation studies. A gain or loss is recognized in other income when we sell land or dispose of assets that are not part of our railroad operations.

We review construction in progress assets that have not yet been placed into service, for impairment when events or changes in circumstances indicate that the carrying amount of a long-lived asset or assets may not be recoverable. If impairment indicators are present and the estimated future undiscounted cash flows are less than the carrying value of construction in progress assets when grouped with other assets and liabilities at the lowest level where identifiable cash flows are largely independent, the carrying value is reduced to the estimated fair value.

When we purchase an asset, we capitalize all costs necessary to make the asset ready for its intended use. However, many of our assets are self-constructed. A large portion of our capital expenditures is for replacement of existing track assets and other road properties, which is typically performed by our employees, and for track line expansion and other capacity projects. Costs that are directly attributable to capital projects (including overhead costs) are capitalized. Direct costs that are capitalized as part of self-constructed assets include material, labor, and work equipment. Indirect costs are capitalized if they clearly relate to the construction of the asset.

Costs incurred that extend the useful life of an asset, improve the safety of our operations, or improve operating efficiency are capitalized, while normal repairs and maintenance are expensed as incurred. These costs are allocated using appropriate statistical bases. Total expense for repairs and maintenance incurred was $2.5 billion for 2023, $2.4 billion for 2022, and $2.1 billion for 2021.

Assets held under finance leases are recorded at the lower of the net present value of the minimum lease payments or the fair value of the leased asset at the inception of the lease. Amortization expense is computed using the straight-line method over the shorter of the estimated useful lives of the assets or the period of the related lease.

Note 17 - Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2023

Schedule of Loss Contingencies by Contingency, Environmental [Table Text Block]

Millions	*2023*			2022			2021
Beginning balance	$	253		$	243		$	233
Accruals		99			84			69
Payments		(107	)		(74	)		(59	)
Ending balance at December 31	$	245		$	253		$	243
Current portion, ending balance at December 31	$	91		$	67		$	60

Personal Injury [Member]

Schedule of Loss Contingencies by Contingency [Table Text Block]

Millions	*2023*			2022			2021
Beginning balance	$	361		$	325		$	270
Current year accruals		112			107			93
Changes in estimates for prior years		89			55			48
Payments		(179	)		(126	)		(86	)
Ending balance at December 31	$	383		$	361		$	325
Current portion, ending balance at December 31	$	113		$	84		$	64

Note 1 - Nature of Operations (Details Textual) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Network Route Miles	32,693
Route Miles Owned	26,110
Number of Reportable Segments	1
Number of Operating Segments	1
Revenue from Contract with Customer, Excluding Assessed Tax	$ 24,119	$ 24,875	$ 21,804
MEXICO
Revenue from Contract with Customer, Excluding Assessed Tax	$ 2,800	$ 2,700	$ 2,400

Total current tax expense

Note 7 - Income Taxes - Schedule of Income Tax Expense Components (Details) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2023

Dec. 31, 2022

Dec. 31, 2021

Federal, current

$ 1,417

$ 1,465

$ 1,446

State, current

314

340

347

Foreign, current

1,737

1,812

1,801

Federal, deferred

219

320

199

State, deferred [a]

^[1]

(104)

(59)

(44)

Foreign, deferred

(1)

Total deferred and other tax expense

117

262

154

Total income tax expense

$ 1,854

$ 2,074

$ 1,955

[1]

In 2023, Nebraska, Iowa, Kansas, and Arkansas enacted corporate income tax legislation that resulted in a $114 million reduction of our deferred tax expense. In 2022, Nebraska, Iowa, Arkansas, and Idaho enacted corporate income tax legislation that resulted in a $95 million reduction of our deferred tax expense.

Amortization of leased assets [b]

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Note 16 - Leases - Schedule of Lease Costs (Details) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2023

Dec. 31, 2022

Operating lease cost [a]

^[1]

$ 369

$ 338

Short-term lease cost

Variable lease cost

^[2]

Interest on lease liabilities [c]

^[3]

Net lease cost

$ 480

$ 433

[1]	Operating lease cost is primarily reported in equipment and other rents in our Consolidated Statements of Income.
[2]	Amortization of leased assets is reported in depreciation in our Consolidated Statements of Income.
[3]	Interest on lease liabilities is reported in interest expense in our Consolidated Statements of Income.

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating Activities
Net income	$ 6,379	$ 6,998	$ 6,523
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	2,318	2,246	2,208
Deferred and other income taxes	117	262	154
Other operating activities, net	(132)	(152)	(56)
Changes in current assets and liabilities:
Accounts receivable, net	(177)	(169)	(217)
Materials and supplies	(2)	(120)	17
Other current assets	(38)	5	31
Accounts payable and other current liabilities	(215)	565	184
Income and other taxes	129	(273)	188
Cash provided by operating activities	8,379	9,362	9,032
Investing Activities
Capital investments	(3,606)	(3,620)	(2,936)
Other investing activities, net	(61)	149	227
Cash used in investing activities	(3,667)	(3,471)	(2,709)
Financing Activities
Dividends paid	(3,173)	(3,159)	(2,800)
Debt repaid	(2,190)	(2,291)	(1,299)
Debt issued (Note 14)	1,599	6,080	4,201
Share repurchase programs (Note 18)	(705)	(6,282)	(7,291)
Other financing activities, net	(156)	(235)	31
Cash used in financing activities	(4,625)	(5,887)	(7,158)
Net change in cash, cash equivalents, and restricted cash	87	4	(835)
Cash, cash equivalents, and restricted cash at beginning of year	987	983	1,818
Cash, cash equivalents, and restricted cash at end of year	1,074	987	983
Non-cash investing and financing activities:
Capital investments accrued but not yet paid	137	152	263
Term loan renewals	0	0	100
Common shares repurchased but not yet paid	5	0	0
Cash paid during the year for:
Income taxes, net of refunds	(1,486)	(2,060)	(1,658)
Interest, net of amounts capitalized	$ (1,268)	$ (1,156)	$ (1,087)

Note 17 - Commitments and Contingencies - Environmental Liability Activity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Balance	$ 253	$ 243	$ 233
Accruals	99	84	69
Payments	(107)	(74)	(59)
Balance	245	253	243
Balance, Current	$ 91	$ 67	$ 60

Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Consolidation, Policy [Policy Text Block]

Cash and Cash Equivalents, Policy [Policy Text Block]

Millions	*2023*		2022		2021
Cash and cash equivalents	$	1,055	$	973	$	960
Restricted cash equivalents in other current assets		10		10		19
Restricted cash equivalents in other assets		9		4		4
Total cash, cash equivalents, and restricted cash equivalents	$	1,074	$	987	$	983

Receivable [Policy Text Block]

Investment, Policy [Policy Text Block]

Inventory, Policy [Policy Text Block]

Materials and Supplies – Materials and supplies are carried at the lower of average cost or net realizable value.

Property, Plant and Equipment, Policy [Policy Text Block]

Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]

Revenue [Policy Text Block]

Foreign Currency Transactions and Translations Policy [Policy Text Block]

Fair Value Measurement, Policy [Policy Text Block]

Level 1: Quoted market prices in active markets for identical assets or liabilities.

Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data.

Level 3: Unobservable inputs that are not corroborated by market data.

We have applied fair value measurements to our short-term investments, certain equity investments, pension plan assets, and short- and long-term debt.

Share-Based Payment Arrangement [Policy Text Block]

Stock-Based Compensation – We issue treasury shares to cover stock option exercises, stock unit vestings, and ESPP shares, while new shares are issued when retention shares are granted.

Earnings Per Share, Policy [Policy Text Block]

Income Tax, Policy [Policy Text Block]

Lessee, Leases [Policy Text Block]

Pension and Other Postretirement Plans, Pensions, Policy [Policy Text Block]

Personal Injury [Policy Text Block]

Environmental Costs, Policy [Policy Text Block]

Use of Estimates, Policy [Policy Text Block]

Note 5 - Retirement Plans - Pre-tax Changes Recognized in Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Net actuarial (loss)/gain	$ (159)	$ 272	$ 813
Actuarial loss	9	86	141
Total	$ (150)	$ 358	$ 954

Note 18 - Share Repurchase Programs - Schedule of Share Repurchase Programs (Details) - $ / shares

3 Months Ended

12 Months Ended

21 Months Ended

36 Months Ended

Dec. 31, 2023

Sep. 30, 2023

Jun. 30, 2023

Mar. 31, 2023

Dec. 31, 2022

Sep. 30, 2022

Jun. 30, 2022

^[1]

Mar. 31, 2022

^[2]

Dec. 31, 2023

Dec. 31, 2022

Dec. 31, 2023

Mar. 31, 2022

Treasury Stock, Number of Shares Purchased (in shares)

606,581

2,908,703

3,501,667

9,490,339

3,100,683

11,014,201

3,515,284

27,106,890

19,600,000

83,300,000

Treasury Stock, Average Price per Share (in dollars per share)

$ 0

$ 199.81

$ 203.19

$ 201.33

$ 221.52

$ 232.87

^[3]

$ 249.95

^[3]

$ 202.61

$ 231.76

Remaining number of shares that may be repurchased under current authority (in shares)

80,392,027

[1]	Includes 1,847,185 shares repurchased in 2022 under accelerated share repurchase programs.
[2]	Includes 7,012,232 shares repurchased in 2022 under accelerated share repurchase programs.
[3]	In the period of the final settlement, the average price paid under the accelerated share repurchase programs is calculated based on the total program value less the value assigned to the initial delivery of shares. The average price of the completed 2022 accelerated share repurchase programs was $248.32.

Note 5 - Retirement Plans (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate		5.00%	5.21%	2.80%
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax		$ 643	$ 493
Defined Benefit Plan, Accumulated Benefit Obligation		$ 3,600	$ 3,500
Defined Benefit Plan, Expected Return on Plan Assets, Changes In Fair Value, Period (Year)		5 years
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-Term Rate of Return on Plan Assets		5.25%	6.25%	6.25%
Weighted-average Maturity of Pension Plan Debt Portfolio (Year)		22 years	21 years
Pension Plan Master Trust, Future Commitments for Additional Contributions, Private Equity Partnerships		$ 80	$ 91
Pension Plan Master Trust, Future Commitments for Additional Contributions, Real Estate Partnerships and Funds		5	5
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)		0	9	$ 85
Defined Contribution Plan, Cost		27	24	21
Railroad Retirement System Contributions		711	586	550
Collective-Bargaining Arrangement, Other [Member]
Multiple-Employer Plan Accounted for as Multiemployer Plan, Contribution by Participating Entity		$ 16	$ 20	$ 30
Forecast [Member]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-Term Rate of Return on Plan Assets	5.25%
Pension Plan [Member]
Actual Return (Loss) on Pension Plan Assets, Net of Fees		6.00%	(18.00%)	15.00%
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position		$ 520	$ 638
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate		4.97%	5.23%
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position		$ (104)	$ (134)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)		$ (7)	$ (2)	$ (3)
Four Zero One Thrift Plan Before 2018 [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match		50.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay		6.00%
Four Zero One Thrift Plan 2018 Beyond [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match		100.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay		6.00%
Defined Contribution Plan, Additional Annual Employer Contribution, Percent of Employees Gross Pay		3.00%

Note 10 - Accounts Receivable

12 Months Ended

Dec. 31, 2023

Loans, Notes, Trade and Other Receivables Disclosure [Text Block]

10. Accounts Receivable

Accounts receivable includes freight and other receivables reduced by an allowance for doubtful accounts. At December 31, 2023 and 2022, our accounts receivable were reduced by $9 million and $10 million, respectively. Receivables not expected to be collected in one year and the associated allowances are classified as other assets in our Consolidated Statements of Financial Position. At December 31, 2023 and 2022, receivables classified as other assets were reduced by allowances of $71 million and $58 million, respectively.

Receivables Securitization Facility – The Railroad maintains an $800 million, 3-year receivables securitization facility (the Receivables Facility) maturing in July 2025. Under the Receivables Facility, the Railroad sells most of its eligible third-party receivables to Union Pacific Receivables, Inc. (UPRI), a consolidated, wholly-owned, bankruptcy-remote subsidiary that may subsequently transfer, without recourse, an undivided interest in accounts receivable to investors. The investors have no recourse to the Railroad’s other assets except for customary warranty and indemnity claims. Creditors of the Railroad do not have recourse to the assets of UPRI.

The amount recorded under the Receivables Facility was $0 and $100 million at December 31, 2023 and 2022, respectively. The Receivables Facility was supported by $1.7 billion and $1.6 billion of accounts receivable as collateral at December 31, 2023 and 2022, respectively, which, as a retained interest, is included in accounts receivable, net in our Consolidated Statements of Financial Position.

The outstanding amount the Railroad maintains under the Receivables Facility may fluctuate based on current cash needs. The maximum allowed under the Receivables Facility is $800 million with availability directly impacted by eligible receivables, business volumes, and credit risks, including receivables payment quality measures such as default and dilution ratios. If default or dilution ratios increase one percent, the allowable outstanding amount under the Receivables Facility would not materially change.

The costs of the Receivables Facility include interest, which will vary based on prevailing benchmark and commercial paper rates, program fees paid to participating banks, commercial paper issuance costs, and fees of participating banks for unused commitment availability. The costs of the Receivables Facility are included in interest expense and were $9 million, $10 million, and $4 million for 2023, 2022, and 2021, respectively.

Note 4 - Stock Options and Other Stock Plans - Changes in Performance Retention Awards (Details) - Performance Retention Awards [Member] shares in Thousands	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Nonvested, beginning balance (in shares) \| shares	594
Nonvested, weighted-average grant-date fair value, beginning balance (in dollars per share) \| $ / shares	$ 199.82
Granted (in shares) \| shares	251
Granted, weighted average grant-date fair value (in dollars per share) \| $ / shares	$ 202.81
Vested (in shares) \| shares	(78)
Vested, weighted average grant-date fair value (in dollars per share) \| $ / shares	$ 189.29
Unearned (in shares) \| shares	(127)
Unearned, weighted average grant-date fair value (in dollars per share) \| $ / shares	$ 186.11
Forfeited (in shares) \| shares	(23)
Forfeited, weighted average grant-date fair value (in dollars per share) \| $ / shares	$ 218.31
Nonvested, ending balance (in shares) \| shares	617
Nonvested, weighted-average grant-date fair value, ending balance (in dollars per share) \| $ / shares	$ 204.5

Note 8 - Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2023

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

Millions, Except Per Share Amounts	*2023*		2022		2021
Net income	$	6,379	$	6,998	$	6,523
Weighted-average number of shares outstanding:
Basic		609.2		622.7		653.8
Dilutive effect of stock options		0.4		0.6		0.8
Dilutive effect of retention shares and units		0.6		0.7		0.8
Diluted		610.2		624.0		655.4
Earnings per share - basic	$	10.47	$	11.24	$	9.98
Earnings per share - diluted	$	10.45	$	11.21	$	9.95

Note 5 - Retirement Plans - Accumulated Benefit Obligation (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Projected benefit obligation	$ 404	$ 394
Accumulated benefit obligation	399	382
Fair value of plan assets	0	0
Underfunded accumulated benefit obligation	$ (399)	$ (382)

Note 5 - Retirement Plans - Pension Plan Asset Allocation (Details)	Dec. 31, 2023	Dec. 31, 2022
Asset allocation percentage	100.00%	100.00%
Defined Benefit Plan, Equity Securities [Member]
Asset allocation percentage	24.00%	48.00%
Defined Benefit Plan, Equity Securities [Member] \| Minimum [Member]
Target Allocation	20.00%
Defined Benefit Plan, Equity Securities [Member] \| Maximum [Member]
Target Allocation	30.00%
Defined Benefit Plan, Debt Security [Member]
Asset allocation percentage	75.00%	51.00%
Defined Benefit Plan, Debt Security [Member] \| Minimum [Member]
Target Allocation	70.00%
Defined Benefit Plan, Debt Security [Member] \| Maximum [Member]
Target Allocation	80.00%
Defined Benefit Plan, Real Estate [Member]
Asset allocation percentage	1.00%	1.00%
Defined Benefit Plan, Real Estate [Member] \| Minimum [Member]
Target Allocation	0.00%
Defined Benefit Plan, Real Estate [Member] \| Maximum [Member]
Target Allocation	2.00%

Note 6 - Other Income (Tables)

12 Months Ended

Dec. 31, 2023

Schedule of Other Nonoperating Income, by Component [Table Text Block]

Millions	*2023*			2022			2021
Real estate income [a] [b]	$	414		$	381		$	263
Net periodic pension benefit/(costs)		52			84			25
Interest income [a]		52			23			4
Environmental remediation and restoration		(37	)		(47	)		(17	)
Gain from sale of investment		-			-			36
Other [a]		10			(15	)		(14	)
Total	$	491		$	426		$	297

Note 16 - Leases - Schedule of Other Lease Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating cash flows from operating leases	$ 323	$ 319
Investing cash flows from operating leases	33	31
Operating cash flows from finance leases	9	15
Financing cash flows from finance leases	65	91
Leased assets obtained in exchange for finance lease liabilities	0	0
Leased assets obtained in exchange for operating lease liabilities	$ 241	$ 173

Note 6 - Other Income - Schedule of Other Income (Details) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2023

Dec. 31, 2022

Dec. 31, 2021

Real estate income [a] [b]

^[1],[2]

$ 414

$ 381

$ 263

Net periodic pension benefit/(costs)

Interest income [a]

^[2]

Environmental remediation and restoration

(37)

(47)

(17)

Gain from sale of investment

Other [a]

^[2]

(15)

(14)

Total

$ 491

$ 426

$ 297

[1]	2023 includes a one-time $107 million transaction. 2022 includes a $79 million gain from a land sale to the Illinois State Toll Highway Authority and a $35 million gain from a sale to the Colorado Department of Transportation. 2021 includes a $50 million gain from a sale to the Colorado Department of Transportation.
[2]	Prior periods have been reclassified to conform to the current period disclosure.

Note 7 - Income Taxes - Schedule of Unrecognized Tax Benefits Assets (Liabilities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Balance, Unrecognized tax benefits	$ 34	$ 38	$ 74
Lapse of statutes of limitations	(4)	(3)	(1)
Decreases for positions taken in prior years	(1)	(4)	(24)
Increases for positions taken in current year	1	3	3
Refunds from/(payments to) and settlements with taxing authorities	0	0	(12)
Increases/(decreases) for interest and penalties	0	0	(3)
Increases for positions taken in prior years	0	0	1
Balance, Unrecognized tax benefits	$ 30	$ 34	$ 38

Note 4 - Stock Options and Other Stock Plans - Stock Option Assumption (Details) - Share-Based Payment Arrangement, Option [Member] - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Risk-free interest rate	3.90%	1.60%	0.40%
Dividend yield	2.60%	1.90%	1.90%
Expected life (years) (Year)	4 years 6 months	4 years 4 months 24 days	4 years 7 months 6 days
Volatility	29.30%	28.70%	28.30%
Weighted-average grant-date fair value of options granted (in dollars per share)	$ 48.31	$ 51.92	$ 39.97

Note 4 - Stock Options and Other Stock Plans (Tables)

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement, Cost by Plan [Table Text Block]

Millions	*2023*		2022		2021
Stock-based compensation expense, before tax:
Stock options	$	16	$	14	$	15
Retention awards		71		68		66
ESPP		20		17		7
Total stock-based compensation expense, before tax	$	107	$	99	$	88
Excess income tax benefits from equity compensation plans	$	11	$	21	$	26

Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

Weighted-Average Assumptions	*2023*			2022			2021
Risk-free interest rate		3.9	%		1.6	%		0.4	%
Dividend yield		2.6	%		1.9	%		1.9	%
Expected life (years)		4.5			4.4			4.6
Volatility		29.3	%		28.7	%		28.3	%
Weighted-average grant-date fair value of options granted	$	48.31		$	51.92		$	39.97

Share-Based Payment Arrangement, Option, Activity [Table Text Block]

	Options (thous.)		Weighted-Average Exercise Price			Weighted-Average Remaining Contractual Term (yrs.)		Aggregate Intrinsic Value (millions)
Outstanding at January 1, 2023		1,974		$	169.64		6.0		$	86
Granted		351			202.81		N/A			N/A
Exercised		(233	)		118.29		N/A			N/A
Forfeited or expired		(20	)		218.46		N/A			N/A
Outstanding at December 31, 2023		2,072		$	180.56		5.9		$	135
Vested or expected to vest at December 31, 2023		2,053		$	180.23		5.9		$	134
Options exercisable at December 31, 2023		1,423		$	164.48		4.8		$	115

Cash Proceeds Received and Tax Benefit from Share-Based Payment Awards [Table Text Block]

Millions	*2023*			2022			2021
Intrinsic value of stock options exercised	$	23		$	53		$	84
Cash received from option exercises		27			27			58
Treasury shares repurchased for employee payroll taxes		(5	)		(8	)		(15	)
Income tax benefit realized from option exercises		5			8			16
Aggregate grant-date fair value of stock options vested	$	14		$	13		$	14

Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]

	Shares (thous.)		Weighted-Average Grant-Date Fair Value
Nonvested at January 1, 2023		1,069		$	196.47
Granted		297			202.88
Vested		(317	)		165.34
Forfeited		(53	)		206.43
Nonvested at December 31, 2023		996		$	207.76

Schedule of Nonvested Performance-Based Units Activity [Table Text Block]

	Shares (thous.)		Weighted-Average Grant-Date Fair Value
Nonvested at January 1, 2023		594		$	199.82
Granted		251			202.81
Vested		(78	)		189.29
Unearned		(127	)		186.11
Forfeited		(23	)		218.31
Nonvested at December 31, 2023		617		$	204.50

Note 18 - Share Repurchase Programs (Tables)

12 Months Ended

Dec. 31, 2023