Union Pacific (UNP) 10-Q 22 Apr 21 2021 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	Apr. 16, 2021
Cover [Abstract]
Document type	10-Q
Document period end date	Mar. 31, 2021
Amendment flag	false
Entity registrant name	UNION PACIFIC CORPORATION
Entity central index key	0000100885
Entity current reporting status	Yes
Current fiscal year end date	--12-31
Entity filer category	Large Accelerated Filer
Document fiscal year focus	2021
Document fiscal period focus	Q1
Trading Symbol	UNP
Entity common stock shares outstanding		664,302,521
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Address, Address Line One	1400 Douglas Street
Entity Address, City or Town	Omaha
Entity Address, Postal Zip Code	68179
Entity Address, State or Province	NE
City Area Code	402
Local Phone Number	544-5000
Entity File Number	1-6075
Entity Tax Identification Number	13-2626465
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock (Par Value $2.50 per share)
Entity Incorporation, State or Country Code	UT
Security Exchange Name	NYSE
Document Quarterly Report	true
Document Transition Report	false

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating revenues:
Revenue from contract with customer excluding assessed tax	$ 4,649	$ 4,880
Total operating revenues	5,001	5,229
Operating expenses:
Compensation and benefits	1,026	1,059
Depreciation	549	547
Purchased services and materials	490	521
Fuel	411	434
Equipment and other rents	212	227
Other	320	298
Total operating expenses	3,008	3,086
Operating income	1,993	2,143
Other income (Note 6)	51	53
Interest expense	(290)	(278)
Income before income taxes	1,754	1,918
Income taxes	(413)	(444)
Net income	$ 1,341	$ 1,474
Share and Per Share (Note 7):
Earnings per share - basic	$ 2.01	$ 2.15
Earnings per share - diluted	$ 2	$ 2.15
Weighted average number of shares - basic	667.6	684.3
Weighted average number of shares - diluted	669.2	686.2
Cargo and Freight [Member]
Operating revenues:
Revenue from contract with customer excluding assessed tax	$ 4,649	$ 4,880
Other [Member]
Operating revenues:
Revenue from contract with customer excluding assessed tax	$ 352	$ 349

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Condensed Consolidated Statements of Comprehensive Income [Abstract]
Net income		$ 1,341	$ 1,474
Other comprehensive income/(loss):
Defined benefit plans		25	22
Foreign currency translation		(26)	5
Total other comprehensive income/(loss)	[1]	(1)	27
Comprehensive income		$ 1,340	$ 1,501
[1]	Net of deferred taxes of ($ 8 ) million and ($ 7 ) million during the three months ended March 31, 2021 and 2020, respectively.

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Parentheticals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Consolidated Statements of Comprehensive Income (Parentheticals) [Abstract]
Deferred taxes activity other comprehensive income/(loss)	$ (8)	$ (7)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Financial Position - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 1,183	$ 1,799
Short-term investments (Note 12)	60	60
Accounts receivable, net (Note 9)	1,610	1,505
Materials and supplies	659	638
Other current assets	207	212
Total current assets	3,719	4,214
Investments	2,167	2,164
Properties, net (Note 10)	54,062	54,161
Operating lease assets	1,581	1,610
Other assets	264	249
Total assets	61,793	62,398
Current liabilities:
Accounts payable and other current liabilities (Note 11)	3,306	3,104
Debt due within one year (Note 13)	1,565	1,069
Total current liabilities	4,871	4,173
Debt due after one year (Note 13)	25,117	25,660
Operating lease liabilities	1,171	1,283
Deferred income taxes	12,307	12,247
Other long-term liabilities	2,073	2,077
Commitments and contingencies (Note 14)
Total liabilities	45,539	45,440
Common shareholders' equity:
Common shares, $2.50 par value, 1,400,000,000 authorized; 1,112,478,704 and 1,112,227,784 issued; 665,134,519 and 671,351,360 outstanding, respectively	2,781	2,781
Paid-in-surplus	4,874	4,864
Retained earnings	52,019	51,326
Treasury stock	(41,826)	(40,420)
Accumulated other comprehensive loss (Note 8)	(1,594)	(1,593)
Total common shareholders' equity	16,254	16,958
Total liabilities and common shareholders' equity	$ 61,793	$ 62,398

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Financial Position (Parentheticals) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Consolidated Statements of Financial Position (Parentheticals) [Abstract]
Common shares, par value	$ 2.50	$ 2.50
Common shares authorized	1,400,000,000	1,400,000,000
Common shares issued	1,112,478,704	1,112,227,784
Common shares outstanding	665,134,519	671,351,360

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating Activities
Net income	$ 1,341	$ 1,474
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	549	547
Deferred and other income taxes	54	91
Other operating activities, net	(131)	(64)
Changes in current assets and liabilities:
Accounts receivable, net	(105)	(74)
Materials and supplies	(21)	59
Other current assets	(1)	1
Accounts payable and other current liabilities	(67)	(168)
Income and other taxes	339	289
Cash provided by operating activities	1,958	2,155
Investing Activities
Capital investments	(536)	(807)
Maturities of short-term investments (Note 12)	24	70
Purchases of short-term investments (Note 12)	(24)	(70)
Proceeds from asset sales	17	8
Other investing activities, net	14	(8)
Cash used in investing activities	(505)	(807)
Financing Activities
Share repurchase programs (Note 15)	(1,347)	(2,556)
Dividends paid	(650)	(660)
Debt repaid	(47)	(305)
Net issuance/(repayment) of commercial paper (Note 13)	(15)	(1)
Debt issued (Note 13)		2,996
Other financing activities, net	(14)	(71)
Cash used in financing activities	(2,073)	(997)
Net change in cash, cash equivalents, and restricted cash	(620)	351
Cash, cash equivalents, restricted cash, beginning balance	1,818	856
Cash, cash equivalents, restricted cash, ending balance	1,198	1,207
Non-cash investing and financing activities:
Capital investments accrued but not yet paid	99	169
Common shares repurchased but not yet paid	55
Cash (paid for)/received from:
Income taxes, net of refunds	(1)	(11)
Interest, net of amounts capitalized	(394)	(349)
Reconciliation of cash, cash equivalents, and restricted cash to the Condensed Consolidated Statement of Financial Position
Cash and cash equivalents, at carry value	1,183	1,130
Cash, cash equivalents, restricted cash, ending balance	1,198	1,207
Accelerated Share Repurchase Agreement [Member]
Financing Activities
Share repurchase programs (Note 15)		(400)
Other Current Assets [Member]
Reconciliation of cash, cash equivalents, and restricted cash to the Condensed Consolidated Statement of Financial Position
Restricted Cash and Cash Equivalents	3	65
Other Noncurrent Assets [Member]
Reconciliation of cash, cash equivalents, and restricted cash to the Condensed Consolidated Statement of Financial Position
Restricted Cash and Cash Equivalents	$ 12	$ 12

Condensed Consolidated Statem_7

Condensed Consolidated Statements of Changes in Common Shareholders' Equity - USD ($) $ in Millions	Common Shares [Member]	Paid-in-Surplus [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income/(Loss) (Note 9) [Member]	[1]	Total
Shareholders' equity, beginning balance at Dec. 31, 2019	$ 2,780	$ 4,523	$ 48,605	$ (36,424)	$ (1,356)		$ 18,128
Common shares, beginning balance at Dec. 31, 2019	1,112,000,000			(419,900,000)
Net income			1,474				1,474
Other comprehensive income/(loss)					27		27	[2]
Conversion, stock option exercises, forfeitures, and other	$ 1	(11)		$ (12)			(22)
Conversion, stock option exercises, forfeitures, and other (shares)	300,000			500,000
Share repurchases (Note 15)		(400)		$ (2,556)			$ (2,956)
Share repurchases (Note 15) (shares)				(14,300,000)			(14,305,793)	[3]
Cash dividends declared			(660)				$ (660)
Shareholders' equity, ending balance at Mar. 31, 2020	$ 2,781	4,112	49,419	$ (38,992)	(1,329)		15,991
Common shares, ending balance at Mar. 31, 2020	1,112,300,000			(433,700,000)
Shareholders' equity, beginning balance at Dec. 31, 2020	$ 2,781	4,864	51,326	$ (40,420)	(1,593)		$ 16,958
Common shares, beginning balance at Dec. 31, 2020	1,112,200,000			(440,900,000)			671,351,360
Net income			1,341				$ 1,341
Other comprehensive income/(loss)					(1)		(1)	[2]
Conversion, stock option exercises, forfeitures, and other		10		$ (4)			6
Conversion, stock option exercises, forfeitures, and other (shares)	300,000			200,000
Share repurchases (Note 15)				$ (1,402)			$ (1,402)
Share repurchases (Note 15) (shares)				(6,700,000)			(6,691,421)	[3]
Cash dividends declared			(648)				$ (648)
Shareholders' equity, ending balance at Mar. 31, 2021	$ 2,781	$ 4,874	$ 52,019	$ (41,826)	$ (1,594)		$ 16,254
Common shares, ending balance at Mar. 31, 2021	1,112,500,000			(447,400,000)			665,134,519
[1]	AOCI = Accumulated Other Comprehensive Income/Loss (Note 8)
[2]	Net of deferred taxes of ($ 8 ) million and ($ 7 ) million during the three months ended March 31, 2021 and 2020, respectively.
[3]	Includes 8,786,380 shares repurchased in February 2020 under accelerated share repurchase programs.

Condensed Consolidated Statem_8

Condensed Consolidated Statements of Changes in Common Shareholders' Equity (Parentheticals) - $ / shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Stockholders' Equity [Abstract]
Cash dividends declared per share	$ 0.97	$ 0.97

Basis Of Presentation

Basis Of Presentation	3 Months Ended
	Mar. 31, 2021
Basis of Presentation [Abstract]
Basis of Presentation	For purposes of this report, unless the context otherwise requires, all references herein to the “Corporation”, “Company”, “UPC”, “we”, “us”, and “our” mean Union Pacific Corporation and its subsidiaries, including Union Pacific Railroad Company, which will be separately referred to herein as “UPRR” or the “Railroad”. 1. Basis of Presentation Our Condensed Consolidated Financial Statements are unaudited and reflect all adjustments (consisting of normal and recurring adjustments) that are, in the opinion of management, necessary for their fair presentation in conformity with accounting principles generally accepted in the United States of America (GAAP). Pursuant to the rules and regulations of the Securities and Exchange Commission (SEC), certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted. Accordingly, this Quarterly Report on Form 10-Q should be read in conjunction with our Consolidated Financial Statements and notes thereto contained in our 2020 Annual Report on Form 10-K. Our Consolidated Statement of Financial Position at December 31, 2020, is derived from audited financial statements. The results of operations for the three months ended March 31, 2021, are not necessarily indicative of the results for the entire year ending December 31, 2021. The Condensed Consolidated Financial Statements are presented in accordance with GAAP as codified in the Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC).

Accounting Pronouncements

Accounting Pronouncements	3 Months Ended
	Mar. 31, 2021
Accounting Pronouncements [Abstract]
Accounting Pronouncements	2. Accounting Pronouncements In December 2019, the FASB issued Accounting Standards Update No. 2019-12 (ASU 2019-12), Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes , which simplifies the accounting and disclosure requirements for income taxes by clarifying existing guidance to improve consistency in application of Accounting Standards Codification (ASC) 740. The company adopted the ASU on January 1, 2021 (the effective date) , and it did not have a material impact on the Company’s consolidated financial statements and related disclosures. In March 2020, the FASB issued Accounting Standards Update No. 2020-04 (ASU 2020-04), Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting , which provides optional expedients and exceptions for applying GAAP principles to contracts, hedging relationships, and other transactions that reference London Interbank Offered Rate (LIBOR) or another reference rate expected to be discontinued due to reference rate reform. This guidance was effective beginning on March 12, 2020, and can be adopted on a prospective basis no later than December 31, 2022, with early adoption permitted. The Company is currently evaluating the effect that the new guidance will have on our consolidated financial statements and related disclosures.

Operations and Segmentation

Operations and Segmentation	3 Months Ended
	Mar. 31, 2021
Operations and Segmentation [Abstract]
Operations and Segmentation	3. Operations and Segmentation The Railroad, along with its subsidiaries and rail affiliates, is our one reportable operating segment. Although we provide and analyze revenue by three commodity groups, 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, for the Three Months Ended March 31, 2021 2020 Bulk $ 1,512 $ 1,534 Industrial 1,656 1,894 Premium 1,481 1,452 Total freight revenues $ 4,649 $ 4,880 Other subsidiary revenues 177 214 Accessorial revenues 161 117 Other 14 18 Total operating revenues $ 5,001 $ 5,229 Although our revenues are principally derived from customers domiciled in the U.S., the ultimate points of origin or destination for some products we transport are outside the U.S. Each of our commodity groups includes revenue from shipments to and from Mexico. Included in the above table are freight revenues from our Mexico business which amounted to $ 565 million and $ 583 million, respectively, for the three months ended March 31, 2021 and 2020 .

Stock-based Compensation

Stock-based Compensation	3 Months Ended
	Mar. 31, 2021
Stock-based compensation [Abstract]
Stock-based Compensation	4. Stock-Based Compensation We have several stock-based compensation plans under which 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”. We issue treasury shares to cover option exercises and stock unit vestings, while new shares are issued when retention shares are granted. Information regarding stock-based compensation appears in the table below: Millions, for the Three Months Ended March 31, 2021 2020 Stock-based compensation, before tax: Stock options $ 4 $ 4 Retention awards 16 18 Total stock-based compensation, before tax $ 20 $ 22 Excess tax benefits from equity compensation plans $ 15 $ 33 Stock Options – We estimate the fair value of our stock option awards using the Black-Scholes option pricing model. The table below shows the annual weighted-average assumptions used for valuation purposes: Weighted-Average Assumptions 2021 2020 Risk-free interest rate 0.4 % 1.5 % Dividend yield 1.9 % 2.1 % Expected life (years) 4.6 4.9 Volatility 28.3 % 23.4 % Weighted-average grant-date fair value of options granted $ 39.97 $ 32.20 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 option. A summary of stock option activity during the three months ended March 31, 2021, is presented below: Options (thous.) Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value (millions) Outstanding at January 1, 2021 2,569 $ 132.49 6.4 yrs. $ 195 Granted 387 204.45 N/A N/A Exercised ( 252 ) 122.76 N/A N/A Forfeited or expired ( 34 ) 136.24 N/A N/A Outstanding at March 31, 2021 2,670 $ 143.79 6.7 yrs. $ 204 Vested or expected to vest at March 31, 2021 2,644 $ 143.51 6.7 yrs. $ 203 Options exercisable at March 31, 2021 1,814 $ 123.73 5.6 yrs. $ 175 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 March 31, 2021, are subject to performance or market-based vesting conditions. At March 31, 2021, there was $ 27 million of unrecognized compensation expense related to nonvested stock options, which is expected to be recognized over a weighted-average period of 1.7 years. Additional information regarding stock option exercises appears in the following table: Millions, for the Three Months Ended March 31, 2021 2020 Intrinsic value of stock options exercised $ 23 $ 48 Cash received from option exercises 30 33 Treasury shares repurchased for employee taxes ( 6 ) ( 8 ) Tax benefit realized from option exercises 4 11 Aggregate grant-date fair value of stock options vested 14 14 Retention Awards – The fair value of retention awards is based on the closing price of the stock on the grant date. Dividends and dividend equivalents are paid to participants during the vesting periods. Changes in our retention awards during the three months ended March 31, 2021, were as follows: Shares (thous.) Weighted-Average Grant-Date Fair Value Nonvested at January 1, 2021 1,476 $ 141.06 Granted 279 204.55 Vested ( 409 ) 107.82 Forfeited ( 16 ) 156.98 Nonvested at March 31, 2021 1,330 $ 164.41 Retention awards are granted at no cost to the employee and vest over periods lasting up to 4 years. At March 31, 2021, there was $ 129 million of total unrecognized compensation expense related to nonvested retention awards, which is expected to be recognized over a weighted-average period of 2.2 years. Performance Retention Awards – In February 2021, our Board of Directors approved performance stock unit grants. This plan is based on performance targets for annual return on invested capital (ROIC) and operating income growth (OIG) compared to companies in the S&P 100 Industries 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 2021 stock units awarded to selected employees 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 3 -year performance period, and with respect to the third year of the plan, the remaining one-third of the fair value is subject to the relative three-year OIG. We measure the fair value of these 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 retention awards during the three months ended March 31, 2021, were as follows: Shares (thous.) Weighted-Average Grant-Date Fair Value Nonvested at January 1, 2021 773 $ 148.17 Granted 227 204.45 Vested ( 140 ) 129.60 Unearned ( 150 ) 128.78 Forfeited ( 13 ) 185.87 Nonvested at March 31, 2021 697 $ 173.70 At March 31, 2021, there was $ 34 million of total unrecognized compensation expense related to nonvested performance retention awards, which is expected to be recognized over a weighted-average period of 1.9 years. This expense is subject to achievement of the performance measures established for the performance stock unit grants.

Retirement Plans

Retirement Plans	3 Months Ended
	Mar. 31, 2021
Retirement Plans [Abstract]
Retirement Plans	5. Retirement Plans Pension and Other Postretirement Benefits Pension Plans – 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) plan. Other Postretirement Benefits (OPEB) – 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. Expense Both pension and OPEB expense are 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 or OPEB expense. The components of our net periodic pension and OPEB costs were as follows for the three months ended March 31: Millions, Pension OPEB for the Three Months Ended March 31, 2021 2020 2021 2020 Service cost $ 30 $ 27 $ - $ - Interest cost 26 34 1 1 Expected return on plan assets ( 67 ) ( 70 ) - - Amortization of: Prior service cost/(credit) - - ( 4 ) ( 3 ) Actuarial loss 36 28 2 2 Net periodic benefit cost $ 25 $ 19 $ ( 1 ) $ - 0 Cash Contributions For the three months ended March 31, 2021, cash contributions totaled $ 0 to the qualified pension plan. Any contributions made during 2021 will be based on cash generated from operations and financial market considerations. Our policy with respect to funding the qualified plans is to fund at least the minimum required by law and not more than the maximum amount deductible for tax purposes. At March 31, 2021, we do not have minimum cash funding requirements for 2021.

Other Income

Other Income	3 Months Ended
	Mar. 31, 2021
Other Income [Abstract]
Other Income	6. Other Income Other income included the following: Millions, for the Three Months Ended March 31, 2021 2020 Rental income $ 33 $ 31 Gain on non-operating asset dispositions 9 11 Net periodic pension and OPEB costs 6 8 Interest income 1 6 Non-operating environmental costs and other 2 ( 3 ) Total $ 51 $ 53

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Earnings Per Share	7. Earnings Per Share The following table provides a reconciliation between basic and diluted earnings per share: Millions, Except Per Share Amounts, for the Three Months Ended March 31, 2021 2020 Net income $ 1,341 $ 1,474 Weighted-average number of shares outstanding: Basic 667.6 684.3 Dilutive effect of stock options 0.8 0.9 Dilutive effect of retention shares and units 0.8 1.0 Diluted 669.2 686.2 Earnings per share – basic $ 2.01 $ 2.15 Earnings per share – diluted $ 2.00 $ 2.15 Stock options excluded as their inclusion would be anti-dilutive 0.3 0.7

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income/(Loss)	3 Months Ended
	Mar. 31, 2021
Accumulated Other Comprehensive Income/(Loss) [Abstract]
Accumulated Other Comprehensive Income/(Loss)	8. Accumulated Other Comprehensive Income/Loss Reclassifications out of accumulated other comprehensive income/loss for the three months ended March 31, 2021 and 2020, were as follows (net of tax): Millions Defined benefit plans Foreign currency translation Total Balance at January 1, 2021 $ ( 1,381 ) $ ( 212 ) $ ( 1,593 ) Other comprehensive income/(loss) before reclassifications ( 1 ) ( 26 ) ( 27 ) Amounts reclassified from accumulated other comprehensive income/(loss) [a] 26 - 26 Net year-to-date other comprehensive income/(loss), net of taxes of ($8) million 25 ( 26 ) ( 1 ) Balance at March 31, 2021 $ ( 1,356 ) $ ( 238 ) $ ( 1,594 ) Balance at January 1, 2020 $ ( 1,150 ) $ ( 206 ) $ ( 1,356 ) Other comprehensive income/(loss) before reclassifications 2 5 7 Amounts reclassified from accumulated other comprehensive income/(loss) [a] 20 - 20 Net year-to-date other comprehensive income/(loss), net of taxes of ($7) million 22 5 27 Balance at March 31, 2020 $ ( 1,128 ) $ ( 201 ) $ ( 1,329 ) [a] 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 cost. See Note 5 Retirement Plans for additional details.

Accounts Receivable

Accounts Receivable	3 Months Ended
	Mar. 31, 2021
Accounts Receivable [Abstract]
Accounts Receivable	9. Accounts Receivable Accounts receivable includes freight and other receivables reduced by an allowance for doubtful accounts. The allowance is based upon historical losses, creditworthiness of customers, and current economic conditions. At both March 31, 2021, and December 31, 2020, our accounts receivable were reduced by $ 17 million. Receivables not expected to be collected in one year and the associated allowances are classified as other assets in our Condensed Consolidated Statements of Financial Position. At March 31, 2021, and December 31, 2020, receivables classified as other assets were reduced by allowances of $ 43 million and $ 51 million, respectively. Receivables Securitization Facility – The Railroad maintains an $ 800 million, 3 -year receivables securitization facility (the Receivables Facility) maturing in July 2022 . 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 at both March 31, 2021, and December 31, 2020. The Receivables Facility was supported by $ 1.3 billion and $ 1.2 billion of accounts receivable as collateral at March 31, 2021, and December 31, 2020, respectively, which, as a retained interest, is included in accounts receivable, net in our Condensed Consolidated Statements of Financial Position. The outstanding amount the Railroad is allowed to maintain under the Receivables Facility, with a maximum of $800 million, may fluctuate based on the availability of eligible receivables and is directly affected by 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 $ 1 million and $ 3 million for the three months ended March 31, 2021 and 2020, respectively. Subsequent Event – On April 12, 2021, we drew $ 400 million on our Receivables Facility, increasing the amount recorded to $ 400 million in the second quarter. We used the net proceeds for general corporate purposes, including the repurchase of common stock pursuant to our share repurchase programs.

Properties

Properties	3 Months Ended
	Mar. 31, 2021
Properties [Abstract]
Properties	10. 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 March 31, 2021 Cost Depreciation Value Useful Life Land $ 5,245 $ N/A $ 5,245 N/A Road: Rail and other track material 17,693 6,698 10,995 43 Ties 11,121 3,387 7,734 34 Ballast 5,956 1,785 4,171 34 Other roadway [a] 21,058 4,386 16,672 48 Total road 55,828 16,256 39,572 N/A Equipment: Locomotives 9,322 3,605 5,717 17 Freight cars 2,157 801 1,356 25 Work equipment and other 1,108 361 747 18 Total equipment 12,587 4,767 7,820 N/A Technology and other 1,211 535 676 12 Construction in progress 749 - 749 N/A Total $ 75,620 $ 21,558 $ 54,062 N/A Millions, Except Estimated Useful Life Accumulated Net Book Estimated As of December 31, 2020 Cost Depreciation Value Useful Life Land $ 5,246 $ N/A $ 5,246 N/A Road: Rail and other track material 17,620 6,631 10,989 42 Ties 11,051 3,331 7,720 34 Ballast 5,926 1,753 4,173 34 Other roadway [a] 21,030 4,329 16,701 48 Total road 55,627 16,044 39,583 N/A Equipment: Locomotives 9,375 3,555 5,820 17 Freight cars 2,118 789 1,329 25 Work equipment and other 1,107 351 756 18 Total equipment 12,600 4,695 7,905 N/A Technology and other 1,199 520 679 13 Construction in progress 748 - 748 N/A Total $ 75,420 $ 21,259 $ 54,161 N/A [a] Other roadway includes grading, bridges and tunnels, signals, buildings, and other road assets.

Accounts Payable and Other Curr

Accounts Payable and Other Current Liabilities	3 Months Ended
	Mar. 31, 2021
Accounts Payable and Other Current Liabilties [Abstract]
Accounts Payable and Other Current Liabilities	11. Accounts Payable and Other Current Liabilities Mar. 31, Dec. 31, Millions 2021 2020 Income and other taxes payable $ 974 $ 635 Accounts payable 634 612 Accrued wages and vacation 345 340 Current operating lease liabilities 294 321 Interest payable 205 326 Accrued casualty costs 177 177 Equipment rents payable 101 101 Other 576 592 Total accounts payable and other current liabilities $ 3,306 $ 3,104

Financial Instruments

Financial Instruments	3 Months Ended
	Mar. 31, 2021
Financial Instruments[Abstract]
Financial Instruments	12. 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 March 31, 2021, the Company had $ 70 million of short-term investments, of which $ 10 million are in a trust for the purpose of providing collateral for payment of certain other long-term liabilities, and as such are classified as other assets. 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 March 31, 2021, the fair value of total debt was $ 29.3 billion, approximately $ 2.6 billion more than the carrying value. At December 31, 2020, the fair value of total debt was $ 31.9 billion, approximately $ 5.1 billion more 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.

Debt

Debt	3 Months Ended
	Mar. 31, 2021
Debt [Abstract]
Debt	13. Debt Credit Facilities – At March 31, 2021, we had $ 2.0 billion of credit available under our revolving credit facility (the Facility), which is designated for general corporate purposes and can be used to support the issuance of commercial paper. Credit facility withdrawals totaled $ 0 during the three months ended March 31, 2021. 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 LIBOR, plus a spread, depending upon credit ratings for our senior unsecured debt. The 5 year facility, set to expire on June 8, 2023 , requires UPC to maintain a debt-to-EBITDA (earnings before interest, taxes, depreciation, and amortization) coverage ratio. The definition of debt used for purposes of calculating the 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 March 31, 2021, the Company was in compliance with the debt-to-EBITDA coverage ratio, which allows us to carry up to $ 36.2 billion of debt (as defined in the Facility), and we had $ 28.2 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 the three months ended March 31, 2021, we issued $ 300 million and repaid $ 315 million of commercial paper with maturities ranging from 20 to 48 days, and at March 31, 2021, we had $ 60 million of commercial paper outstanding. Our revolving credit facility can be used to support 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. In May 2020, we entered into three bilateral revolving credit lines which mature by May 18, 2021 , totaling $ 600 million of available credit. During the three months ended March 31, 2021, we drew $ 0 and repaid $ 0 , and at March 31, 2021, we had $ 0 outstanding. Shelf Registration Statement and Significant New Borrowings – We filed an automatic shelf registration statement with the SEC that became effective on February 10, 2021. The Board of Directors authorized the issuance of up to $ 6 billion of debt securities, replacing the prior Board authorization in November 2019, which had $ 2.25 billion of authority remaining. 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 the three months ended March 31, 2021, we did not issue any debt securities under this registration statement. At March 31, 2021 , we had remaining authority from the Board of Directors to issue up to $ 6 billion of debt securities under our shelf registration. Receivables Securitization Facility – As of both March 31, 2021, and December 31, 2020, we recorded $ 0 of borrowings under our Receivables Facility as secured debt. (See further discussion of our receivables securitization facility in Note 9). Subsequent Event – On April 6, 2021 , we exchanged approximately $ 1.7 billion of various outstanding notes and debentures due between 2028 and 2065 (Existing Notes) for $ 701 million of 2.891 % notes due April 6, 2036 (New 2036 Notes) and $ 1.0 billion of 3.799 % notes due April 6, 2071 (New 2071 Notes), plus cash consideration of approximately $ 257 million in addition to $ 14 million for accrued and unpaid interest on the Existing Notes. In accordance with ASC 470-50-40, Debt-Modifications and Extinguishments-Derecognition , this transaction was accounted for as a debt exchange, as the exchanged debt instruments are not considered to be substantially different. The cash consideration was recorded as an adjustment to the carrying value of debt, and the balance of the unamortized discount and issue costs from the Existing Notes is being amortized as an adjustment of interest expense over the terms of the new notes. No gain or loss was recognized as a result of the exchange. Costs related to the debt exchange that were payable to parties other than the debt holders totaled approximately $ 12 million and were included in interest expense during the quarter ended March 31, 2021.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Commitments And Contingencies [Abstract]
Commitments and Contingencies	14. 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. To the extent possible, we have recorded a liability where asserted and unasserted claims are considered probable and where such claims can be reasonably estimated. We 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. Personal Injury – The cost of personal injuries to employees and others related to our activities 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. 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. Our personal injury liability is not discounted to present value due to the uncertainty surrounding the timing of future payments. Approximately 94 % of the recorded liability is related to asserted claims and approximately 6 % is related to unasserted claims at March 31, 2021. 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 $ 293 million to $ 320 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, for the Three Months Ended March 31, 2021 2020 Beginning balance $ 270 $ 265 Current year accruals 18 18 Changes in estimates for prior years 21 2 Payments ( 16 ) ( 15 ) Ending balance at March 31 $ 293 $ 270 Current portion, ending balance at March 31 $ 60 $ 62 We reassess our estimated insurance recoveries annually and have recognized an asset for estimated insurance recoveries at both March 31, 2021, and December 31, 2020. Any changes to recorded insurance recoveries are included in the above table in the changes in estimates for prior years category. Environmental Costs – We are subject to federal, state, and local environmental laws and regulations. We have identified 368 sites where we are or may be liable for remediation costs associated with alleged contamination or for violations of environmental requirements. This includes 26 sites that are the subject of actions taken by the U.S. government, 16 of which 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. When we identify an environmental issue with respect to property owned, leased, or otherwise used in our business, we perform, with assistance of our consultants, environmental assessments on the 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. Our environmental liability is not discounted to present value due to the uncertainty surrounding the timing of future payments. Our environmental liability activity was as follows: Millions, for the Three Months Ended March 31, 2021 2020 Beginning balance $ 233 $ 227 Accruals 12 15 Payments ( 11 ) ( 16 ) Ending balance at March 31 $ 234 $ 226 Current portion, ending balance at March 31 $ 63 $ 64 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 FELA claims and property coverage which 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 Condensed 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 Condensed 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 – We are contingently obligated under a variety of indemnification arrangements, although in some cases the extent of our potential liability is limited, 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.

Share Repurchase Program

Share Repurchase Program	3 Months Ended
	Mar. 31, 2021
Share Repurchase Program [Abstract]
Share Repurchase Program	15. Share Repurchase Programs Effective April 1, 2019, our Board of Directors authorized the repurchase of up to 150 million shares of our common stock by March 31, 2022 . 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. As of March 31, 2021, we repurchased a total of $ 42.3 billion of our common stock since commencement of our repurchase programs in 2007. The table below represents shares repurchased under repurchase programs in the first quarter of 2021 and 2020: Number of Shares Purchased Average Price Paid [a] 2021 2020 2021 2020 First quarter [b] 6,691,421 14,305,793 $ 209.50 $ 178.66 Remaining number of shares that may be repurchased under current authority 104,331,549 [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 2020 accelerated share repurchase programs was $ 155.86 . [b] Includes 8,786,380 shares repurchased in February 2020 under accelerated share repurchase programs. Management's assessments of market conditions and other pertinent factors guide the timing 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 and fees. From April 1, 2021, through April 21, 2021, we repurchased 1.1 million shares at an aggregate cost of approximately $ 237 million. 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 19, 2020, the Company received 8,786,380 shares of its common stock repurchased under ASRs for an aggregate of $ 2.0 billion. Upon settlement of these ASRs in the third quarter of 2020, we received 4,045,575 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.

Related Parties

Related Parties	3 Months Ended
	Mar. 31, 2021
Related Parties [Abstract]
Related Parties	16. Related Parties UPRR and other North American railroad companies jointly own TTX Company (TTX). UPRR has a 36.79 % 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 $ 1.5 billion recognized as investments related to TTX in our Condensed Consolidated Statements of Financial Position as of both March 31, 2021, and December 31, 2020. TTX car hire expenses of $ 96 million for both the three months ended March 31, 2021 and 2020, are included in equipment and other rents in our Condensed Consolidated Statements of Income. In addition, UPRR had accounts payable to TTX of $ 64 million and $ 59 million as of March 31, 2021, and December 31, 2020, respectively.

Operations and Segmentation (Ta

Operations and Segmentation (Tables)	3 Months Ended
	Mar. 31, 2021
Operations and Segmentation [Abstract]
Freight Revenue By Commodity Group	The following table represents a disaggregation of our freight and other revenues: Millions, for the Three Months Ended March 31, 2021 2020 Bulk $ 1,512 $ 1,534 Industrial 1,656 1,894 Premium 1,481 1,452 Total freight revenues $ 4,649 $ 4,880 Other subsidiary revenues 177 214 Accessorial revenues 161 117 Other 14 18 Total operating revenues $ 5,001 $ 5,229

Stock-based Compensation (Table

Stock-based Compensation (Tables)	3 Months Ended
	Mar. 31, 2021
Stock-based compensation [Abstract]
Stock-Based Compensation	Information regarding stock-based compensation appears in the table below: Millions, for the Three Months Ended March 31, 2021 2020 Stock-based compensation, before tax: Stock options $ 4 $ 4 Retention awards 16 18 Total stock-based compensation, before tax $ 20 $ 22 Excess tax benefits from equity compensation plans $ 15 $ 33
Stock Options Weight Average Assumptions	The table below shows the annual weighted-average assumptions used for valuation purposes: Weighted-Average Assumptions 2021 2020 Risk-free interest rate 0.4 % 1.5 % Dividend yield 1.9 % 2.1 % Expected life (years) 4.6 4.9 Volatility 28.3 % 23.4 % Weighted-average grant-date fair value of options granted $ 39.97 $ 32.20
Stock Options Activity	A summary of stock option activity during the three months ended March 31, 2021, is presented below: Options (thous.) Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value (millions) Outstanding at January 1, 2021 2,569 $ 132.49 6.4 yrs. $ 195 Granted 387 204.45 N/A N/A Exercised ( 252 ) 122.76 N/A N/A Forfeited or expired ( 34 ) 136.24 N/A N/A Outstanding at March 31, 2021 2,670 $ 143.79 6.7 yrs. $ 204 Vested or expected to vest at March 31, 2021 2,644 $ 143.51 6.7 yrs. $ 203 Options exercisable at March 31, 2021 1,814 $ 123.73 5.6 yrs. $ 175
Stock Option Exercises	Additional information regarding stock option exercises appears in the following table: Millions, for the Three Months Ended March 31, 2021 2020 Intrinsic value of stock options exercised $ 23 $ 48 Cash received from option exercises 30 33 Treasury shares repurchased for employee taxes ( 6 ) ( 8 ) Tax benefit realized from option exercises 4 11 Aggregate grant-date fair value of stock options vested 14 14
Retention Awards Activity	Changes in our retention awards during the three months ended March 31, 2021, were as follows: Shares (thous.) Weighted-Average Grant-Date Fair Value Nonvested at January 1, 2021 1,476 $ 141.06 Granted 279 204.55 Vested ( 409 ) 107.82 Forfeited ( 16 ) 156.98 Nonvested at March 31, 2021 1,330 $ 164.41
Performance Based Units Activity	Changes in our performance retention awards during the three months ended March 31, 2021, were as follows: Shares (thous.) Weighted-Average Grant-Date Fair Value Nonvested at January 1, 2021 773 $ 148.17 Granted 227 204.45 Vested ( 140 ) 129.60 Unearned ( 150 ) 128.78 Forfeited ( 13 ) 185.87 Nonvested at March 31, 2021 697 $ 173.70

Retirement Plans (Tables)

Retirement Plans (Tables)	3 Months Ended
	Mar. 31, 2021
Retirement Plans [Abstract]
Net Periodic Pension And OPEB Cost/(Benefit)	The components of our net periodic pension and OPEB costs were as follows for the three months ended March 31: Millions, Pension OPEB for the Three Months Ended March 31, 2021 2020 2021 2020 Service cost $ 30 $ 27 $ - $ - Interest cost 26 34 1 1 Expected return on plan assets ( 67 ) ( 70 ) - - Amortization of: Prior service cost/(credit) - - ( 4 ) ( 3 ) Actuarial loss 36 28 2 2 Net periodic benefit cost $ 25 $ 19 $ ( 1 ) $ - 0

Other Income (Tables)

Other Income (Tables)	3 Months Ended
	Mar. 31, 2021
Other Income [Abstract]
Other Income	Other income included the following: Millions, for the Three Months Ended March 31, 2021 2020 Rental income $ 33 $ 31 Gain on non-operating asset dispositions 9 11 Net periodic pension and OPEB costs 6 8 Interest income 1 6 Non-operating environmental costs and other 2 ( 3 ) Total $ 51 $ 53

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Earnings Per Share	The following table provides a reconciliation between basic and diluted earnings per share: Millions, Except Per Share Amounts, for the Three Months Ended March 31, 2021 2020 Net income $ 1,341 $ 1,474 Weighted-average number of shares outstanding: Basic 667.6 684.3 Dilutive effect of stock options 0.8 0.9 Dilutive effect of retention shares and units 0.8 1.0 Diluted 669.2 686.2 Earnings per share – basic $ 2.01 $ 2.15 Earnings per share – diluted $ 2.00 $ 2.15 Stock options excluded as their inclusion would be anti-dilutive 0.3 0.7

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income/(Loss) (Tables)	3 Months Ended
	Mar. 31, 2021
Accumulated Other Comprehensive Income/(Loss) [Abstract]
After-Tax Components Of Accumulated Other Comprehensive Loss	Reclassifications out of accumulated other comprehensive income/loss for the three months ended March 31, 2021 and 2020, were as follows (net of tax): Millions Defined benefit plans Foreign currency translation Total Balance at January 1, 2021 $ ( 1,381 ) $ ( 212 ) $ ( 1,593 ) Other comprehensive income/(loss) before reclassifications ( 1 ) ( 26 ) ( 27 ) Amounts reclassified from accumulated other comprehensive income/(loss) [a] 26 - 26 Net year-to-date other comprehensive income/(loss), net of taxes of ($8) million 25 ( 26 ) ( 1 ) Balance at March 31, 2021 $ ( 1,356 ) $ ( 238 ) $ ( 1,594 ) Balance at January 1, 2020 $ ( 1,150 ) $ ( 206 ) $ ( 1,356 ) Other comprehensive income/(loss) before reclassifications 2 5 7 Amounts reclassified from accumulated other comprehensive income/(loss) [a] 20 - 20 Net year-to-date other comprehensive income/(loss), net of taxes of ($7) million 22 5 27 Balance at March 31, 2020 $ ( 1,128 ) $ ( 201 ) $ ( 1,329 ) [a] 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 cost. See Note 5 Retirement Plans for additional details.

Properties (Tables)

Properties (Tables)	3 Months Ended
	Mar. 31, 2021
Properties [Abstract]
Schedule Of 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 March 31, 2021 Cost Depreciation Value Useful Life Land $ 5,245 $ N/A $ 5,245 N/A Road: Rail and other track material 17,693 6,698 10,995 43 Ties 11,121 3,387 7,734 34 Ballast 5,956 1,785 4,171 34 Other roadway [a] 21,058 4,386 16,672 48 Total road 55,828 16,256 39,572 N/A Equipment: Locomotives 9,322 3,605 5,717 17 Freight cars 2,157 801 1,356 25 Work equipment and other 1,108 361 747 18 Total equipment 12,587 4,767 7,820 N/A Technology and other 1,211 535 676 12 Construction in progress 749 - 749 N/A Total $ 75,620 $ 21,558 $ 54,062 N/A Millions, Except Estimated Useful Life Accumulated Net Book Estimated As of December 31, 2020 Cost Depreciation Value Useful Life Land $ 5,246 $ N/A $ 5,246 N/A Road: Rail and other track material 17,620 6,631 10,989 42 Ties 11,051 3,331 7,720 34 Ballast 5,926 1,753 4,173 34 Other roadway [a] 21,030 4,329 16,701 48 Total road 55,627 16,044 39,583 N/A Equipment: Locomotives 9,375 3,555 5,820 17 Freight cars 2,118 789 1,329 25 Work equipment and other 1,107 351 756 18 Total equipment 12,600 4,695 7,905 N/A Technology and other 1,199 520 679 13 Construction in progress 748 - 748 N/A Total $ 75,420 $ 21,259 $ 54,161 N/A [a] Other roadway includes grading, bridges and tunnels, signals, buildings, and other road assets.

Accounts Payable And Other Cu_2

Accounts Payable And Other Current Liabilities (Tables)	3 Months Ended
	Mar. 31, 2021
Accounts Payable and Other Current Liabilties [Abstract]
Schedule of Accounts Payable and Accrued Liabilities	Mar. 31, Dec. 31, Millions 2021 2020 Income and other taxes payable $ 974 $ 635 Accounts payable 634 612 Accrued wages and vacation 345 340 Current operating lease liabilities 294 321 Interest payable 205 326 Accrued casualty costs 177 177 Equipment rents payable 101 101 Other 576 592 Total accounts payable and other current liabilities $ 3,306 $ 3,104

Commitments And Contingencies (

Commitments And Contingencies (Tables)	3 Months Ended
	Mar. 31, 2021
Commitments And Contingencies [Abstract]
Commitments And Contingencies Activity	Our personal injury liability activity was as follows : Millions, for the Three Months Ended March 31, 2021 2020 Beginning balance $ 270 $ 265 Current year accruals 18 18 Changes in estimates for prior years 21 2 Payments ( 16 ) ( 15 ) Ending balance at March 31 $ 293 $ 270 Current portion, ending balance at March 31 $ 60 $ 62
Commitments And Contingencies Activity.	Our environmental liability activity was as follows: Millions, for the Three Months Ended March 31, 2021 2020 Beginning balance $ 233 $ 227 Accruals 12 15 Payments ( 11 ) ( 16 ) Ending balance at March 31 $ 234 $ 226 Current portion, ending balance at March 31 $ 63 $ 64

Share Repurchase Program (Table

Share Repurchase Program (Tables)	3 Months Ended
	Mar. 31, 2021
Share Repurchase Program [Abstract]
Share Repurchase Program	The table below represents shares repurchased under repurchase programs in the first quarter of 2021 and 2020: Number of Shares Purchased Average Price Paid [a] 2021 2020 2021 2020 First quarter [b] 6,691,421 14,305,793 $ 209.50 $ 178.66 Remaining number of shares that may be repurchased under current authority 104,331,549 [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 2020 accelerated share repurchase programs was $ 155.86 . [b] Includes 8,786,380 shares repurchased in February 2020 under accelerated share repurchase programs.

Operations and Segmentation (De

Operations and Segmentation (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Commodity Group Information [Line Items]
Freight revenues	$ 4,649	$ 4,880
Subsidiary revenue	177	214
Accessorial revenues	161	117
Other revenues	14	18
Total operating revenues	5,001	5,229
Cargo and Freight [Member]
Commodity Group Information [Line Items]
Freight revenues	4,649	4,880
Bulk [Member]
Commodity Group Information [Line Items]
Freight revenues	1,512	1,534
Industrial [Member]
Commodity Group Information [Line Items]
Freight revenues	1,656	1,894
Premium [Member]
Commodity Group Information [Line Items]
Freight revenues	1,481	1,452
Mexico [Member]
Commodity Group Information [Line Items]
Freight revenues	$ 565	$ 583

Stock-based Compensation (Narra

Stock-based Compensation (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)
Stock Options [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
Contractual term	10 years
Years until vest	3 years
Stock options, subject to performance or market-based vesting conditions	None
Unrecognized compensation expense	$ 27
Expected weighted average period (in years) of nonvested stock options to be recognized	1 year 8 months 12 days
Retention Awards [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
Years until vest	4 years
Unrecognized compensation expense	$ 129
Expected weighted average period (in years) of nonvested stock options to be recognized	2 years 2 months 12 days
Performance Retention Awards [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
Requisite service period	37 months
Contractual terms of award	We expense two-thirds of the fair value of the units that are probable of being earned based on our forecasted ROIC over the 3-year performance period, and with respect to the third year of the plan, the remaining one-third of the fair value is subject to the relative three-year OIG.
ROIC performance period	3 years
Unrecognized compensation expense	$ 34
Expected weighted average period (in years) of nonvested stock options to be recognized	1 year 10 months 24 days

Stock-based Compensation (Sched

Stock-based Compensation (Schedule Of Compensation) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Stock-Based Compensation, Before Tax: [Abstract]
Stock options	$ 4	$ 4
Retention awards	16	18
Total stock-based compensation, before tax	20	22
Excess tax benefits from equity compensation plans	$ 15	$ 33

Stock-based Compensation (Sch_2

Stock-based Compensation (Schedule of Stock Options Weight Average Assumptions) (Details) - Stock Options [Member] - $ / shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Assumptions For Stock Awards [Abstract]
Risk-free interest rate at date of grant	0.40%	1.50%
Dividend yield	1.90%	2.10%
Expected life (years)	4 years 7 months 6 days	4 years 10 months 24 days
Volatility	28.30%	23.40%
Weighted-average grant-date fair value of options granted	$ 39.97	$ 32.20

Stock-based Compensation (Sch_3

Stock-based Compensation (Schedule of Stock Option Activities) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Stock Options [Member]
Stock Option Activity [Abstract]
Stock options, shares outstanding at January 1, 2021	2,569
Stock options, shares granted	387
Stock options, shares exercised	(252)
Stock options, shares forfeited or expired	(34)
Stock options, shares outstanding at March 31, 2021	2,670	2,569
Stock options, shares vested or expected to vest at March 31, 2021	2,644
Stock options, shares exercisable at March 31, 2021	1,814
Stock options weighted-average exercise price, outstanding at January 1, 2021	$ 132.49
Stock options weighted-average exercise price, granted	204.45
Stock options weighted-average exercise price, exercised	122.76
Stock options weighted-average exercise price, forfeited or expired	136.24
Stock options weighted-average exercise price, outstanding at March 31, 2021	143.79	$ 132.49
Stock options weighted-average exercise price, vested or expected to vest at March 31, 2021	143.51
Stock options weighted-average exercise price, options exercisable at March 31, 2021	$ 123.73
Stock options weighted-average remaining contractual term in years, outstanding at January 1, 2021	6 years 8 months 12 days	6 years 4 months 24 days
Stock options weighted-average remaining contractual term in years, outstanding at March 31, 2021	6 years 8 months 12 days	6 years 4 months 24 days
Stock options weighted-average remaining contractual term in years, vested or expected to vest at March 31, 2021	6 years 8 months 12 days
Stock options weighted-average remaining contractual term in years, options exercisable at March 31, 2021	5 years 7 months 6 days
Stock options aggregate intrinsic value, outstanding at January 1, 2021	$ 195
Stock options aggregate intrinsic value, outstanding at March 31, 2021	204	$ 195
Stock options aggregate intrinsic value, vested or expected to vest at March 31, 2021	203
Stock options aggregate intrinsic value, options exercisable at March 31, 2021	$ 175
Retention Awards [Member]
Awards Activity [Abstract]
Awards, shares nonvested at January 1, 2021	1,476
Awards, shares granted	279
Awards, shares vested	(409)
Awards, shares forfeited	(16)
Awards, shares nonvested at March 31, 2021	1,330	1,476
Awards weighted-average grant-date fair value, nonvested at January 1, 2021	$ 141.06
Awards weighted-average grant-date fair value, granted	204.55
Awards weighted-average grant-date fair value, vested	107.82
Awards weighted-average grant-date fair value, forfeited	156.98
Awards weighted-average grant-date fair value, nonvested at March 31, 2021	$ 164.41	$ 141.06
Performance Retention Awards [Member]
Awards Activity [Abstract]
Awards, shares nonvested at January 1, 2021	773
Awards, shares granted	227
Awards, shares vested	(140)
Awards, shares unearned	(150)
Awards, shares forfeited	(13)
Awards, shares nonvested at March 31, 2021	697	773
Awards weighted-average grant-date fair value, nonvested at January 1, 2021	$ 148.17
Awards weighted-average grant-date fair value, granted	204.45
Awards weighted-average grant-date fair value, vested	129.60
Awards weighted-average grant-date fair value, unearned	128.78
Awards weighted-average grant-date fair value, forfeited	185.87
Awards weighted-average grant-date fair value, nonvested at March 31, 2021	$ 173.70	$ 148.17

Stock-based Compensation (Sch_4

Stock-based Compensation (Schedule of Stock Option Exercises) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Stock Option Aggregate Disclosures [Abstract]
Intrinsic value of stock options exercised	$ 23	$ 48
Cash received from option exercises	30	33
Treasury shares repurchased for employee payroll taxes	(6)	(8)
Tax benefit realized from option exercises	4	11
Aggregate grant-date fair value of stock options vested	$ 14	$ 14

Retirement Plans (Details)

Retirement Plans (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net Periodic Pension And OPEB Cost [Abstract]
Changes in fair value	5 years
Other comprehensive income defined benefit plans	$ (25,000,000)	$ (22,000,000)
Defined Benefit Plans [Member]
Net Periodic Pension And OPEB Cost [Abstract]
Service cost	30,000,000	27,000,000
Interest cost	26,000,000	34,000,000
Expected return on plan assets	(67,000,000)	(70,000,000)
Amortization of actuarial loss	36,000,000	28,000,000
Net periodic cost	25,000,000	19,000,000
Voluntary cash contributions to qualified pension plan	0
OPEB [Member]
Net Periodic Pension And OPEB Cost [Abstract]
Interest cost	1,000,000	1,000,000
Amortization of prior service cost	(4,000,000)	(3,000,000)
Amortization of actuarial loss	2,000,000	$ 2,000,000
Net periodic cost	$ (1,000,000)

Other Income (Details)

Other Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Other Income [Abstract]
Rental income	$ 33	$ 31
Net gain on non-operating asset dispositions.	9	11
Net periodic pension and OPEB costs	6	8
Interest Income	1	6
Non-operating environmental costs and other	2	(3)
Total	$ 51	$ 53

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share Details [Abstract]
Net income	$ 1,341	$ 1,474
Weighted-Average Number Of Shares Outstanding
Basic	667.6	684.3
Dilutive effect of stock options	0.8	0.9
Dilutive effect of retention shares and units	0.8	1
Diluted	669.2	686.2
Earnings per share - basic	$ 2.01	$ 2.15
Earnings per share - diluted	$ 2	$ 2.15
Stock options excluded as their inclusion would be anti-dilutive	0.3	0.7

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income/(Loss) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance		$ (1,593)	$ (1,356)
Other comprehensive income/(loss) before reclassifications		(27)	7
Amounts reclassified from accumulated other comprehensive income/(loss)	[1]	26	20
Net to-date other comprehensive income/(loss), net of taxes	[2]	(1)	27
Balance at March 31		(1,594)	(1,329)
Deferred taxes activity other comprehensive income/(loss)		(8)	(7)
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance		(1,381)	(1,150)
Other comprehensive income/(loss) before reclassifications		(1)	2
Amounts reclassified from accumulated other comprehensive income/(loss)	[1]	26	20
Net to-date other comprehensive income/(loss), net of taxes		25	22
Balance at March 31		(1,356)	(1,128)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance		(212)	(206)
Other comprehensive income/(loss) before reclassifications		(26)	5
Net to-date other comprehensive income/(loss), net of taxes		(26)	5
Balance at March 31		$ (238)	$ (201)
[1]	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 cost. See Note 5 Retirement Plans for additional details.
[2]	Net of deferred taxes of ($ 8 ) million and ($ 7 ) million during the three months ended March 31, 2021 and 2020, respectively.

Accounts Receivable (Details)

Accounts Receivable (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Apr. 12, 2021	Dec. 31, 2020
Accounts Receivable Details [Abstract]
Allowance for doubtful accounts	$ 17			$ 17
Allowance for doubtful accounts - receivables not expected to be collected in one year	43			51
Receivables Securitization Facility [Abstract]
Total capacity to transfer undivided interests to investors under the receivables securitization facility	$ 800
Receivables securitization facility maturity date	2022-07
Receivables securitization facility duration	3 years
Value of the outstanding undivided interest held by investors under the receivables securitization facility	$ 0			0
Accounts receivable supporting the undivided interest held by investors	1,300			$ 1,200
Cost of the receivables securitization facility - interest expense	$ 1	$ 3
Subsequent Event [Member]
Receivables Securitization Facility [Abstract]
Value of the outstanding undivided interest held by investors under the receivables securitization facility			$ 400

Properties (Details)

Properties (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Mar. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Cost		$ 75,620	$ 75,420
Accumulated depreciation		21,558	21,259
Net book value		54,062	54,161
Land [Member]
Property, Plant and Equipment [Line Items]
Cost		5,245	5,246
Net book value		5,245	5,246
Road: Rail and Other Track Material [Member]
Property, Plant and Equipment [Line Items]
Cost		17,693	17,620
Accumulated depreciation		6,698	6,631
Net book value		$ 10,995	$ 10,989
Estimated useful life		43 years	42 years
Road: Ties [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 11,121	$ 11,051
Accumulated depreciation		3,387	3,331
Net book value		$ 7,734	$ 7,720
Estimated useful life		34 years	34 years
Road: Ballast [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 5,956	$ 5,926
Accumulated depreciation		1,785	1,753
Net book value		$ 4,171	$ 4,173
Estimated useful life		34 years	34 years
Road: Other Roadway [Member]
Property, Plant and Equipment [Line Items]
Cost	[1]	$ 21,058	$ 21,030
Accumulated depreciation	[1]	4,386	4,329
Net book value	[1]	$ 16,672	$ 16,701
Estimated useful life	[1]	48 years	48 years
Total Road [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 55,828	$ 55,627
Accumulated depreciation		16,256	16,044
Net book value		39,572	39,583
Equipment: Locomotives [Member]
Property, Plant and Equipment [Line Items]
Cost		9,322	9,375
Accumulated depreciation		3,605	3,555
Net book value		$ 5,717	$ 5,820
Estimated useful life		17 years	17 years
Equipment: Freight Cars [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 2,157	$ 2,118
Accumulated depreciation		801	789
Net book value		$ 1,356	$ 1,329
Estimated useful life		25 years	25 years
Equipment: Work Equipment and Other [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 1,108	$ 1,107
Accumulated depreciation		361	351
Net book value		$ 747	$ 756
Estimated useful life		18 years	18 years
Total Equipment [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 12,587	$ 12,600
Accumulated depreciation		4,767	4,695
Net book value		7,820	7,905
Technology and Other [Member]
Property, Plant and Equipment [Line Items]
Cost		1,211	1,199
Accumulated depreciation		535	520
Net book value		$ 676	$ 679
Estimated useful life		12 years	13 years
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 749	$ 748
Net book value		$ 749	$ 748
[1]	Other roadway includes grading, bridges and tunnels, signals, buildings, and other road assets.

Accounts Payable And Other Cu_3

Accounts Payable And Other Current Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Accounts Payable and Other Current Liabilities Details [Abstract]
Income and other taxes payable	$ 974	$ 635
Accounts payable	634	612
Accrued wages and vacation	345	340
Current liabilities operating leases	294	321
Interest payable	205	326
Accrued casualty costs	177	177
Equipment rents payable	101	101
Other	576	592
Total accounts payable and other current liabilities	$ 3,306	$ 3,104

Financial Instruments (Details)

Financial Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Short-Term Investments [Abstract]
Short-term investments	$ 60	$ 60
Short-term investments reclassified as other assets	10
Fair Value of Debt Instruments [Abstract]
Fair value of total debt	29,300	31,900
Fair value of total debt in excess of (less than) carrying value	2,600	$ 5,100
Significant Other Observable Inputs (Level 2) [Member] | Time Deposits [Member]
Short-Term Investments [Abstract]
Short-term investments	$ 70

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($)	1 Months Ended	3 Months Ended
	Feb. 09, 2021	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Facility expiration date		May 18, 2021
Commercial paper issued		$ 300,000,000
Commercial paper repaid		$ 315,000,000
Commercial paper maturity duration minimum		20 days
Commercial paper maturity duration maximum		48 days
Commercial paper outstanding		$ 60,000,000
Credit available under line of credit		600,000,000
Amount drawn under line of credit		0
Repayments of line of credit		0
Amount outstanding under line of credit		0
Board of Directors authorized debt issuance		6,000,000,000
Previous Board Of Directors Remaining Debt Issuance	$ 2,250,000,000
Board of Directors remaining debt issuance		6,000,000,000
Secured debt under receivables securitization facility		0	$ 0
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Revolving credit facility available credit		$ 2,000,000,000
Facility expiration date		Jun. 8, 2023
Credit facility term		5 years
Revolving credit facility withdrawals		$ 0
Allowable debt per debt to earnings before interest taxes depreciation and amortization coverage ratio (as defined in the facility)		36,200,000,000
Outstanding debt (as defined by facility)		28,200,000,000
Cross-default provision (as defined by facility)		$ 150,000,000

Debt (Debt Exchange) (Narrative

Debt (Debt Exchange) (Narrative) (Details) - Subsequent Event [Member] $ in Millions	Apr. 06, 2021USD ($)
Debt Conversion [Line Items]
Original debt	$ 1,700
Date of exchange	Apr. 6, 2021
Cash consideration	$ 257
Accrued and unpaid interest	14
Debt exchange fees	$ 12
Minimum [Member]
Debt Conversion [Line Items]
Original due date year	2028
Maximum [Member]
Debt Conversion [Line Items]
Original due date year	2065
2.891% Notes Due 2036 [Member]
Debt Conversion [Line Items]
New debt	$ 701
New rate	2.891%
New due date	Apr. 6, 2036
3.799% Notes Due 2071 [Member]
Debt Conversion [Line Items]
New debt	$ 1,000
New rate	3.799%
New due date	Apr. 6, 2071

Commitments And Contingencies_2

Commitments And Contingencies (Narrative) (Details) $ in Millions	Mar. 31, 2021USD ($)item
Commitments and Contingencies [Line Items]
Sites identified which we are or may be liable for remediation costs	368
Sites subject of actions taken by the U.S. government	26
Sites on the Superfund National Priorities List	16
Personal Injury [Member]
Commitments and Contingencies [Line Items]
Percent of liability recorded related to asserted claims	94.00%
Percent of liability recorded related to unasserted claims	6.00%
Personal Injury [Member] | Minimum [Member]
Commitments and Contingencies [Line Items]
Reasonably possible outcome of related claims | $	$ 293
Personal Injury [Member] | Maximum [Member]
Commitments and Contingencies [Line Items]
Reasonably possible outcome of related claims | $	$ 320

Commitments And Contingencies_3

Commitments And Contingencies (Commitments And Contingencies Activity) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Liability Activity [Abstract]
Current portion, ending balance at March 31	$ 177
Environmental [Abstract]
Beginning balance.	233	$ 227
Accruals	12	15
Payments	(11)	(16)
Ending balance at March 31.	234	226
Current portion, ending balance at March 31.	63	64
Personal Injury [Member]
Liability Activity [Abstract]
Beginning balance	270	265
Current year accruals	18	18
Changes in estimates for prior years	21	2
Payments	(16)	(15)
Ending balance at March 31	293	270
Current portion, ending balance at March 31	$ 60	$ 62

Share Repurchase Program (Detai

Share Repurchase Program (Details) - USD ($) $ / shares in Units, $ in Millions		1 Months Ended	3 Months Ended			10 Months Ended	171 Months Ended
		Apr. 21, 2021	Mar. 31, 2021	Sep. 30, 2020	Mar. 31, 2020	Dec. 31, 2020	Mar. 31, 2021	Apr. 01, 2019
Shares Repurchased [Line Items]
BOD authorized								150,000,000
Stock repurchase program expiration date			Mar. 31, 2022
Aggregate cost			$ 1,402		$ 2,956		$ 42,300
Shares repurchased	[1]		6,691,421		14,305,793
Average purchase price	[1],[2]		$ 209.50		$ 178.66
Remaining number of shares that may be repurchased under current authority			104,331,549				104,331,549
Treasury stock, value			$ 41,826			$ 40,420	$ 41,826
Accelerated Share Repurchase Agreement [Member]
Shares Repurchased [Line Items]
Aggregate cost						$ 2,000
Shares repurchased				4,045,575	8,786,380	8,786,380
Average purchase price					$ 155.86
Subsequent Event [Member]
Shares Repurchased [Line Items]
Aggregate cost		$ 237
Shares repurchased		1,100,000
[1]	Includes 8,786,380 shares repurchased in February 2020 under accelerated share repurchase programs.
[2]	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 2020 accelerated share repurchase programs was $ 155.86 .

Related Parties (Details)

Related Parties (Details) - TTX Company [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Related Party Transaction [Line Items]
Equity Method Investment, Ownership Percentage	36.79%
Equity Method Investments	$ 1,500		$ 1,500
Related Party Transaction, Expenses from Transactions with Related Party	96	$ 96
Accounts Payable, Related Parties, Current	$ 64		$ 59