Union Pacific (UNP) 10-Q 26 Apr 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 20, 2018
Document and Entity Information [Abstract]
Document type	10-Q
Document period end date	Mar. 31, 2018
Amendment flag	false
Entity registrant name	UNION PACIFIC CORP
Entity central index key	100,885
Entity current reporting status	Yes
Entity voluntary filers	No
Current fiscal year end date	--12-31
Entity filer category	Large Accelerated Filer
Entity well known seasoned issuer	Yes
Document fiscal year focus	2,018
Document fiscal period focus	Q1
Trading Symbol	unp
Entity common stock shares outstanding		770,245,910

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating revenues:
Freight revenues	$ 5,122	$ 4,794
Other revenues	353	338
Total operating revenues	5,475	5,132
Operating expenses:
Compensation and benefits	1,273	1,262
Purchased services and materials	599	566
Fuel	589	460
Depreciation	543	520
Equipment and other rents	266	276
Other	266	260
Total operating expenses	3,536	3,344
Operating income	1,939	1,788
Other income (Note 7)	(42)	72
Interest expense	(186)	(172)
Income before income taxes	1,711	1,688
Income taxes	(401)	(616)
Net income	$ 1,310	$ 1,072
Share and Per Share (Note 9):
Earnings per share - basic	$ 1.69	$ 1.32
Earnings per share - diluted	$ 1.68	$ 1.32
Weighted average number of shares - basic	776.4	811.5
Weighted average number of shares - diluted	779.6	814.8
Dividends declared per share	$ 0.73	$ 0.605

Condensed Consolidated Stateme3

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Condensed Consolidated Statements of Comprehensive Income [Abstract]
Net income		$ 1,310	$ 1,072
Other comprehensive income/(loss):
Defined benefit plans		19	11
Foreign currency translation			9
Total other comprehensive income/(loss)	[1]	19	20
Comprehensive income		$ 1,329	$ 1,092
[1]	Net of deferred taxes of $(6) million and $(14) million during the three months ended March 31, 2018, and 2017, respectively.

Condensed Consolidated Stateme4

Condensed Consolidated Statements of Comprehensive Income (Parentheticals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Consolidated Statements of Comprehensive Income (Parentheticals) [Abstract]
Deferred taxes activity other comprehensive income/(loss)	$ (6)	$ (14)

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Financial Position - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 1,048	$ 1,275
Short-term investments (Note 14)	90	90
Accounts receivable, net (Note 11)	1,571	1,493
Materials and supplies	808	749
Other current assets	380	399
Total current assets	3,897	4,006
Investments	1,810	1,809
Net properties (Note 12)	51,696	51,605
Other assets	386	386
Total assets	57,789	57,806
Current liabilities:
Accounts payable and other current liabilities (Note 13)	2,855	3,139
Debt due within one year (Note 15)	1,891	800
Total current liabilities	4,746	3,939
Debt due after one year (Note 15)	15,697	16,144
Deferred income taxes	11,050	10,936
Other long-term liabilities	1,907	1,931
Commitments and contingencies (Note 17)
Total liabilities	33,400	32,950
Common shareholders' equity:
Common shares, $2.50 par value, 1,400,000,000 authorized; 1,111,814,739 and 1,111,371,304 issued; 772,517,399 and 780,917,756 outstanding, respectively	2,779	2,778
Paid-in-surplus	4,473	4,476
Retained earnings	42,359	41,317
Treasury stock	(23,800)	(22,574)
Accumulated other comprehensive loss (Note 10)	(1,422)	(1,141)
Total common shareholders' equity	24,389	24,856
Total liabilities and common shareholders' equity	$ 57,789	$ 57,806

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Financial Position (Parentheticals) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
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	1,111,814,739	1,111,371,304
Common shares outstanding	772,517,399	780,917,756

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating Activities
Net income	$ 1,310	$ 1,072
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	543	520
Deferred and other income taxes	112	145
Other operating activities, net	339	94
Changes in current assets and liabilities:
Accounts receivable, net	(78)	(21)
Materials and supplies	(59)	(43)
Other current assets	(112)	(132)
Accounts payable and other current liabilities	(379)	(186)
Income and other taxes	225	434
Cash provided by operating activities	1,901	1,883
Investing Activities
Capital investments	(910)	(811)
Purchases of short-term investments (Note 14)	(60)	(90)
Maturities of short-term investments (Note 14)	60	60
Proceeds from asset sales	12	17
Other investing activities, net	(21)	(19)
Cash used in investing activities	(919)	(843)
Financing Activities
Debt issued (Note 15)	1,706	200
Common share repurchases (Note 18)	(1,166)	(759)
Debt repaid	(1,157)	(184)
Dividends paid	(568)	(492)
Other financing activities, net	(24)	(33)
Cash used in financing activities	(1,209)	(1,268)
Net change in cash and cash equivalents	(227)	(228)
Cash and cash equivalents at beginning of year	1,275	1,277
Cash and cash equivalents at end of period	1,048	1,049
Non-cash investing and financing activities:
Capital investments accrued but not yet paid	74	94
Common shares repurchased but not yet paid	64	43
Cash (paid for)/received from:
Income taxes, net of refunds	2	(3)
Interest, net of amounts capitalized	$ (230)	$ (203)

Condensed Consolidated Stateme8

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]	AOCI [Member]	[1]	Total
Shareholders' equity, beginning balance at Dec. 31, 2016	$ 2,777	$ 4,421	$ 32,587	$ (18,581)	$ (1,272)		$ 19,932
Common shares, beginning balance at Dec. 31, 2016	1,111,000,000			(295,200,000)
Net income			1,072				1,072
Other comprehensive income/(loss)					20		20	[2]
Conversion, stock option exercises, forfeitures, and other	$ 2	(15)		$ 6			(7)
Conversion, stock option exercises, forfeitures, and other (shares)	400,000			500,000
Share repurchases (Note 18)				$ (802)			$ (802)
Share repurchases (Note 18) (shares)				(7,500,000)			(7,531,300)
Cash dividends declared			(492)				$ (492)
Shareholders' equity, ending balance at Mar. 31, 2017	$ 2,779	4,406	33,167	$ (19,377)	(1,252)		19,723
Common shares, ending balance at Mar. 31, 2017	1,111,400,000			(302,200,000)
Shareholders' equity, beginning balance at Dec. 31, 2017	$ 2,778	4,476	41,317	$ (22,574)	(1,141)		$ 24,856
Common shares, beginning balance at Dec. 31, 2017	1,111,400,000			(330,500,000)			780,917,756
Net income			1,310				$ 1,310
Other comprehensive income/(loss)					19		19	[2]
Conversion, stock option exercises, forfeitures, and other	$ 1	(3)		$ 4			2
Conversion, stock option exercises, forfeitures, and other (shares)	400,000			500,000
Share repurchases (Note 18)				$ (1,230)			$ (1,230)
Share repurchases (Note 18) (shares)				(9,300,000)			(9,259,004)
Cash dividends declared			(568)				$ (568)
Reclassification due to ASU 2018-02 adoption (Note 2)			300		(300)
Shareholders' equity, ending balance at Mar. 31, 2018	$ 2,779	$ 4,473	$ 42,359	$ (23,800)	$ (1,422)		$ 24,389
Common shares, ending balance at Mar. 31, 2018	1,111,800,000			(339,300,000)			772,517,399
[1]	AOCI = Accumulated Other Comprehensive Income/(Loss) (Note 10)
[2]	Net of deferred taxes of $(6) million and $(14) million during the three months ended March 31, 2018, and 2017, respectively.

Condensed Consolidated Stateme9

Condensed Consolidated Statements of Changes in Common Shareholders' Equity (Parentheticals) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Stockholders' Equity [Abstract]
Cash dividends declared per share	$ 0.73	$ 0.605

Basis Of Presentation

Basis Of Presentation	3 Months Ended
	Mar. 31, 2018
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 2017 Annual Report on Form 10-K. Our Consolidated Statement of Financial Position at December 31, 2017 , is derived from audited financial statements. The results of operations for the three months ended March 31, 2018 , are not necessarily indicative of the results for the entire year ending December 31, 2018 .  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, 2018
Accounting Pronouncements [Abstract]
Accounting Pronouncements	2. Accounting Pronouncements  In May 2014, the FASB issued Accounting Standards Update No. 2014-09 (ASU 2014-09), Revenue from Contracts with Customers (Topic 606). ASU 2014-09 supersedes the revenue recognition guidance in Topic 605, Revenue Recognition. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods and services to customers in an amount that reflects the consideration to which the entity expects to be entitled in the exchange for those goods or services. This may require the use of more judgment and estimates in order to correctly recognize the revenue expected as an outcome of each specific performance obligation. Additionally, this guidance will require the disclosure of the nature, amount, and timing of revenue arising from contracts so as to aid in the understanding of the users of financial statements.  Effective January 1, 2018, the Company adopted ASU 2014-09 using the modified retrospective transition method. The Company analyzed its freight and other revenues and recognize s freight revenues as freight moves fr om origin to destination and recognize s other revenues as identified performance obl igations are satisfied. We also analyzed freight and other revenues in the context of the new guidance on principal versus agent considerations and evaluated the required new disclosures. The ASU did not have an impact on our consolidated financial position, results of operations, or cash flows.  In January 2016, the FASB issued Accounting Standards Update No. 2016-01 (ASU 2016-01), Recognition and Measurement of Financial Assets and Financial Liabilities (Subtopic 825-10) . ASU 2016-01 provides guidance for the recognition, measurement, presentation, and disclosure of financial instruments. This guidance is effective for annual and interim periods beginning after December 15, 2017, and early adoption is not permitted. Effective January 1, 2018, the Company adopted the ASU and it did not have an impact on our consolidated financial position, results of operations, or cash flows.  In March 2017, the FASB issued Accounting Standards Update No. 2017-07 (ASU 2017-07), Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost (Topic 715) . ASU 2017-07 requires the service cost component be reported separately from the other components of net benefit costs in the income statement, provides explicit guidance on the presentation of the service cost component and the other components of net benefit cost in the income statement, and allows only the service cost component of net benefit cost to be eligible for capitalization. Effective January 1, 2018, we adopted the standard on a retrospective basis . As a result of the adoption, only service costs are recorded within compensation and ben efits expense, and the other components of net benefit costs are now recorded within other income /(expense) . The retrospective adoption of ASU 2017-07 decreased operating income by $4 million and $5 million for the three months ended March 31, 2018 and 2017, respectively, and increased other income by $4 million and $5 million for the same periods.  On February 14, 2018, the FASB issued Accounting Standards Update 2018-02, (ASU 2018-02), Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income , which allows entities the option to reclassify from accumulated other comprehensive income (“AOCI”) to retained earnings the income tax effects that remain in AOCI resulting from the application of the Tax Act. ASU 2018-02 is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2018. Early adoption of the ASU is permitted, including adoption in any interim period. We have adopted ASU 2018-02 during the first quarter of 2018. As a result of this adoption, we have elected to reclassify $30 0 m illion from AOCI to retained earnings. UP has adopted the policy that future income tax effects that are stranded in AOCI will be released only when the entire portfolio of the type of item is liquidated.  In February 2016, the FASB issued Accounting Standards Update No. 2016-02 (ASU 2016-02), Leases (Subtopic 842) . ASU 2016-02 will require companies to recognize lease assets and lease liabilities on the balance sheet and disclose key information about leasing arrangements. For public companies, this standard is effective for annual reporting periods beginning after December 15, 2018, and early adoption is permitted. Management is currently evaluating the impact of this standard on our consolidated financial position, results of operations, and cash flows, but expects that the adoption will result in a n increase in the Company’s assets and liabilities of over $2 billion. 

Significant Accounting Policies

Significant Accounting Policies Update	3 Months Ended
	Mar. 31, 2018
Significant Accounting Policies [Abstract]
Significant Accounting Policies Update [Text Block]	 3. Significant Accounting Policies Update  Our significant accounting policies are detailed in Note 2 of our Annual Report on Form 10-K for the year ended December 31, 2017. Changes to our accounting policies as a result of adopting ASU 2014-09 are discussed below.  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 revenue 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 $161 million at March 31, 2018 and $154 million at December 31, 2017 and are expected to be recognized in the next 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 a specified cumulative volume or shipping to/from specific locations, are recorded as a reduction to operating revenues based on actual or projected future customer shipments.  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 Statement of Financial Position as Accounts Receivables, net.  Freight revenue 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 revenue.  Other revenues consist primarily of revenues earned by our subsidiaries and accessorial revenues. Non-rail subsidiary revenues are generally recognized over time as shipments move from origin to destination. The allocation of revenue 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.  

Operations and Segmentation

Operations and Segmentation	3 Months Ended
	Mar. 31, 2018
Operations and Segmentation [Abstract]
Operations and Segmentation	4 . 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 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 :     Three Months Ended  March 31,  Millions 2018 2017  Agricultural Products $ 1,098 $ 1,094  Energy 1,173 1,024  Industrial 1,340 1,264  Premium 1,511 1,412  Total freight revenues $ 5,122 $ 4,794  Subsidiary revenues 217 215  Accessorial revenues 121 106  Other revenues 15 17  Total operating revenues $ 5,475 $ 5,132 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 revenue from shipments to and from Mexico. Included in the above table are freight revenues from our Mexico business which amounted to $ 579 million and $566 million, respectively, for the three months ended March 31, 2018, and March 31, 2017 .

Stock-based Compensation

Stock-based Compensation	3 Months Ended
	Mar. 31, 2018
Stock-based compensation [Abstract]
Stock-based Compensation	5 . Stock-Based Compensation  We have several stock-based compensation plans under which employees and non-employee directors receive stock options, nonvested retention shares, and nonvested stock units. We refer to the nonvested shares and stock units collectively as “retention awards”. We have elected to 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:     Three Months Ended  March 31,  Millions 2018 2017  Stock-based compensation, before tax:  Stock options $ 4 $ 4  Retention awards 21 22  Total stock-based compensation, before tax $ 25 $ 26  Excess tax benefits from equity compensation plans $ 15 $ 22 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 2018 2017  Risk-free interest rate 2.6% 2.0%  Dividend yield 2.3% 2.3%  Expected life (years) 5.3 5.3  Volatility 21.1% 21.7%  Weighted-average grant-date fair value of options granted $ 21.70 $ 18.19 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, 2018 , is presented below:    Options (thous.) Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value (millions)  Outstanding at January 1, 2018 5,630 $ 83.37 5.8 yrs. $ 286  Granted 800 124.86 N/A N/A  Exercised (446) 62.14 N/A N/A  Forfeited or expired (8) 86.57 N/A N/A  Outstanding at March 31, 2018 5,976 $ 90.50 6.2 yrs. $ 263  Vested or expected to vest at March 31, 2018 5,918 $ 90.33 6.2 yrs. $ 261  Options exercisable at March 31, 2018 4,045 $ 82.73 5.0 yrs. $ 209 Stock options are granted at the closing price on the date of grant, have ten -year contractual terms, and vest no later than three years from the date of grant . None of the stock options outstanding at March 31, 2018 , are subject to performance or market-based vesting conditions.  At March 31, 2018 , there was $32 million of unrecognized compensation expense related to nonvested stock options, which is expected to be recognized over a weighted-average period of 1.6 years. Additional information regarding stock option exercises appears in the table below:     Three Months Ended  March 31,  Millions 2018 2017  Intrinsic value of stock options exercised $ 33 $ 23  Cash received from option exercises 26 20  Treasury shares repurchased for employee payroll taxes (8) (7)  Tax benefit realized from option exercises 8 9  Aggregate grant-date fair value of stock options vested 18 19 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, 2018 , were as follows:     Shares (thous.) Weighted-Average Grant-Date Fair Value  Nonvested at January 1, 2018 2,313 $ 95.04  Granted 532 125.08  Vested (611) 87.94  Forfeited (24) 97.76  Nonvested at March 31, 2018 2,210 $ 104.20 Retention awards are granted at no cost to the employee or non-employee director and vest over periods lasting up to four years. At March 31, 2018 , there was $133 million of total unrecognized compensation expense related to nonvested retention awards, which is expected to be recognized over a weighted-average period of 2.4 years.  Performance Retention Awards – In February 2018, our Board of Directors approved performance stock unit grants. The basic terms of these performance stock units are identical to those granted in February 2017, except for different annual return on invested capital (ROIC) performance targets. The plan also includes relative operating income growth (OIG) as a modifier compared to the companies included in the S&P 500 Industrials Index. We define ROIC as net operating profit adjusted for interest expense (including interest on the present value of operating leases) and taxes on interest divided by average invested capital adjusted for the present value of operating leases. The modifier can be up to +/- 25% of the award earned based on the ROIC achieved.  Stock units awarded to selected employees under these grants are subject to continued employment for 37 months and the attainment of cert ain levels of ROIC , modified for the relative OIG. We expense 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 relative OIG modifier. 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, reduced by the present value of estimated future dividends. Dividend equivalents are paid to participants only after the units are earned.  The assumptions used to calculate the present value of estimated future dividends related to the February 2018 grant were as follows:     2018  Dividend per share per quarter $ 0.73  Risk-free interest rate at date of grant 2.3% Changes in our performance retention awards during the three months ended March 31, 2018 , were as follows:     Shares (thous.) Weighted-Average Grant-Date Fair Value  Nonvested at January 1, 2018 1,138 $ 92.92  Granted 348 117.80  Vested (94) 112.19  Unearned (201) 114.97  Forfeited (5) 78.20  Nonvested at March 31, 2018 1,186 $ 95.02 At March 31, 2018 , there was $56 million of total unrecognized compensation expense related to nonvested performance retention awards, which is expected to be recognized over a weighted-average period of 1.8 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, 2018
Retirement Plans [Abstract]
Retirement Plans	6 . 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.  Other Postretirement Benefits (OPEB) – We provide medical and life insurance benefits for eligible retirees. 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 five -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 and, if necessary, amortized as pension or OPEB expense.  The components of our net periodic pension and OPEB cost were as follows for the three months ended March 31:     Pension OPEB  Millions 2018 2017 2018 2017  Service cost $ 27 $ 23 $ - $ -  Interest cost 36 35 3 3  Expected return on plan assets (68) (66) - -  Amortization of actuarial loss 23 20 2 3  Net periodic benefit cost $ 18 $ 12 $ 5 $ 6  As a result of the adoption of ASU 2017-07 effective January 1, 2018, only service costs are recorded within compensation and ben efits expense, and the other components of net benefit costs are now recorded within other income /(expense) .  Cash Contributions  For the three months ended March 31, 2018 , we did not make any cash contributions to the qualified pension plan. Any contributions made during 2018 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, 2018 , we do not have minimum cash funding requirements for 2018 .

Other Income

Other Income	3 Months Ended
	Mar. 31, 2018
Other Income [Abstract]
Other Income	7. Other Income / (Expense)  Other income / (expense) included the following:     Three Months Ended  March 31 ,  Millions 2018 2017  Early extinguishment of debt [a] $ (85) $ -  Rental income 28 37  Net gain on non-operating asset dispositions [b] 6 34  Interest income 4 2  Net periodic pension and OPEB costs 4 5  Non-operating environmental costs and other 1 (6)  Total $ (42) $ 72  [a] 2018 includes a debt extinguishment charge for the early redemption of certain bonds and debentures (Note 15) . [b] 2017 includes $26 million related to a real estate sale in the first quarter .

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Tax [Abstract]
Income Taxes	8. Income Taxes  On December 22, 2017, The Tax Cuts and Jobs Act (the “Tax Act”) was enacted. The Tax Act made significant changes to federal tax law, including a reduction in the federal income tax rate from 35% to 21% effective January 1, 2018, 100% bonus depreciation for certain capital expenditures, stricter limits on deductions for interest and certain executive compensation, and a one-time transition tax on previously deferred earnings of certain foreign subsidiaries. As a result of our initial analysis of the Tax Act and existing implementation guidance, we remeasured our deferred tax assets and liabilities and computed our transition tax liability net of offsetting foreign tax credits. This resulted in a $5.9 billion reduction in our income tax expense in the fourth quarter of 2017. We also recorded a $212 million reduction to our operating expense related to income tax adjustments at equity-method affiliates in the fourth quarter of 2017.  The SEC provided guidance in SAB 118 on accounting for the tax effects of the Tax Act. In accordance with that guidance, some of the income tax effects recorded in 2017 are provisional, including those related to our analysis of 100% bonus depreciation for certain capital expenditures, stricter limits on deductions for certain executive compensation, the one-time transition tax, and the reduction to our operating expense related to income tax adjustments at equity-method affiliates. The accounting for the income tax effects may be adjusted during 2018 as a result of continuing analysis of the Tax Act; additional implementation guidance from the IRS, state tax authorities, the SEC, the FASB, or the Joint Committee on Taxation; and new information from domestic or foreign equity affiliates. We had no material adjustments to our initial analysis of the Tax Act during the first quarter of 2018.  UPC is not currently under examination by the Internal Revenue Service. The statute of limitations has run for all years prior to 2014. In 2017, UPC amended its 2013 income tax return, primarily to claim deductions resulting from the resolution of prior year IRS examinations. The IRS and Joint Committee on Taxation have completed their review of this return and we anticipate receiving a refund of $18 million in the second quarter of 2018.  Several state tax authorities are examining our state tax returns for years 2010 through 2015.  At March 31, 2018, we had a net liability for unrecognized tax benefits of $182 million. 

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Share	9 . 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, 2018 2017  Net income $ 1,310 $ 1,072  Weighted-average number of shares outstanding:  Basic 776.4 811.5  Dilutive effect of stock options 1.8 1.8  Dilutive effect of retention shares and units 1.4 1.5  Diluted 779.6 814.8  Earnings per share – basic $ 1.69 $ 1.32  Earnings per share – diluted $ 1.68 $ 1.32  Stock options excluded as their inclusion would be anti-dilutive 0.5 1.6

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income/(Loss)	3 Months Ended
	Mar. 31, 2018
Accumulated Other Comprehensive Income/(Loss) [Abstract]
Accumulated Other Comprehensive Income/(Loss)	10 . Accumulated Other Comprehensive Income/(Loss)  Reclassifications out of accumulated other comprehensive income/(loss) for the three months ended March 31, 2018 , and 2017 , were as follows (net of tax):      Millions Defined benefit plans Foreign currency translation Total  Balance at January 1, 2018 $ (1,029) $ (112) $ (1,141)  Other comprehensive income/(loss) before reclassifications - - -  Amounts reclassified from accumulated other comprehensive income/(loss) [a] 19 - 19  Net year-to-date other comprehensive income/(loss), net of taxes of $(6) million 19 - 19  Reclassification due to ASU 2018-02 adoption (Note 2) (225) (75) (300)  Balance at March 31, 2018 $ (1,235) $ (187) $ (1,422)   Balance at January 1, 2017 $ (1,132) $ (140) $ (1,272)  Other comprehensive income/(loss) before reclassifications (3) 9 6  Amounts reclassified from accumulated other comprehensive income/(loss) [a] 14 - 14  Net year-to-date other comprehensive income/(loss), net of taxes of $(14) million 11 9 20  Balance at March 31, 2017 $ (1,121) $ (131) $ (1,252)  [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 p eriodic pension cost. See Note 6 Retirement Plans for additional details.   

Accounts Receivable

Accounts Receivable	3 Months Ended
	Mar. 31, 2018
Accounts Receivable [Abstract]
Accounts Receivable	11 . Accounts Receivable  Accounts receivable includes freight and other receivables reduced by an allowance for doubtful accounts. The allowance is based upon historical losses, credit worthiness of customers, and current economic conditions. At both March 31, 2018 , and December 31, 2017 , our accounts receivable were reduced by $3 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 , 2018 , and December 31, 2017 , receivables classified as other assets were reduced by allowances of $19 million and $17 million, respectively .  Receivables Securitization Facility – The Railroad maintains a $650 million, 3 -year receivables securitiz ation facility (the Receivables Facility) maturing in July 2019 . 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 outstanding under the Receivables Facility was $ 650 million and $500 at March 31, 2018 , and December 31, 2017 , respectively. The Receivables Facility was supported by $1.2 billion and $1.1 billion of accounts receivable as collateral at March 31, 2018 , and December 31, 2017 , 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 all owed to maintain under the Receivables Facility, with a maximum of $650 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 $4 million and $1 million for the three months ended March 31, 2018 , and 2017 , respectively.

Properties

Properties	3 Months Ended
	Mar. 31, 2018
Properties [Abstract]
Properties	12 . 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, 2018 Cost Depreciation Value Useful Life  Land $ 5,271 $ N/A $ 5,271 N/A  Road:  Rail and other track material 16,439 5,997 10,442 43  Ties 10,227 2,935 7,292 33  Ballast 5,442 1,533 3,909 34  Other roadway [a] 19,143 3,549 15,594 47  Total road 51,251 14,014 37,237 N/A  Equipment:  Locomotives 9,667 3,737 5,930 19  Freight cars 2,295 985 1,310 24  Work equipment and other 941 277 664 19  Total equipment 12,903 4,999 7,904 N/A  Technology and other 1,099 462 637 11  Construction in progress 647 - 647 N/A  Total $ 71,171 $ 19,475 $ 51,696 N/A [a] Other roadway includes grading, bridges and tunnels, signals, buildings, and other road assets.      Millions, Except Estimated Useful Life Accumulated Net Book Estimated  As of December 31, 2017 Cost Depreciation Value Useful Life  Land $ 5,258 $ N/A $ 5,258 N/A  Road:  Rail and other track material 16,327 5,929 10,398 43  Ties 10,132 2,881 7,251 33  Ballast 5,406 1,509 3,897 34  Other roadway [a] 18,972 3,482 15,490 47  Total road 50,837 13,801 37,036 N/A  Equipment:  Locomotives 9,686 3,697 5,989 19  Freight cars 2,255 983 1,272 24  Work equipment and other 936 267 669 19  Total equipment 12,877 4,947 7,930 N/A  Technology and other 1,105 460 645 11  Construction in progress 736 - 736 N/A  Total $ 70,813 $ 19,208 $ 51,605 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, 2018
Accounts Payable and Other Current Liabilties [Abstract]
Accounts Payable and Other Current Liabilities	13 . Accounts Payable and Other Current Liabilities     Mar. 31, Dec. 31,  Millions 2018 2017  Accounts payable $ 768 $ 1,013  Income and other taxes payable 641 547  Accrued wages and vacation 388 384  Accrued casualty costs 189 194  Interest payable 165 220  Equipment rents payable 113 110  Other 591 671  Total accounts payable and other current liabilities $ 2,855 $ 3,139

Financial Instruments

Financial Instruments	3 Months Ended
	Mar. 31, 2018
Financial Instruments[Abstract]
Financial Instruments	14 . Financial Instruments  Short-Term Investments – The Company’s short-term investments consist of time deposits ( $90 million as of March 31, 2018 ). These investments are considered level 2 investments and are valued at amortized cost, which approximates fair value . All short-term investments have a maturity of less than one year and are classified as held-to-maturity. There were no transfers out of Level 2 during the three months ended March 31, 2018 .  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, 2018 , the fair value of total debt was $18.0 billion, approximately $0.4 billion more than the carrying value. At December 31, 2017 , the fair value of total debt was $18.2 billion, approximately $1.3 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. It does not impact the financial statements under current accounting rules. At March 31, 2018 , and December 31, 2017 , approxim ately $0 and $155 million , respectively of debt securities contained call provisions that allow us to retire the debt instruments prior to final maturity, with the payment of fixed call premiums, or in certain cases, at par. 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, 2018
Debt [Abstract]
Debt	15 . Debt  Credit Facilities – At March 31, 2018 , we had $ 1.7 billion of credit available under our revolving credit facility, which is designated for general corporate purposes and supports the issuance of commercial paper. We did not draw on the facility during the three months ended March 31, 2018 . 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 London Interbank Offered Rates, plus a spread, depending upon credit ratings for our senior unsecured debt. The facility matures in May 2019 under a five -year term and requires UPC to maintain a debt-to-net-worth coverage ratio.  The definition of debt used for purposes of calculating the debt-to-net-worth coverage ratio includes, among other things, certain credit arrangements, capital leases, guarantees and unfunded and vested pension benefits under Title IV of ERISA. At March 31, 2018 , the Company was in compliance with the debt-to-net-worth coverage ratio, which allows us to carry up to $48.8 billion of debt (as defined in the facility), and we had $17.6 billion of debt (as defined in the facility) outstanding at that date. Under our current financial plans, we expect to continue to satisfy the debt-to-net-worth coverage ratio; however, many factors beyond our reasonable control could affect our ability to comply with this provision in the future. 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 $125 million cross-default provision and a change-of-control provision.  Duri ng the three months ended March 31, 2018, we issued $1.56 billion and repaid $920 million of commercial pape r with maturities ranging from 1 to 34 days, and at March 31, 2018, we had $637 million of commercial paper outstanding. 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 – We filed an automatic shelf registration statement with the SEC that became effective on February 12, 2018. The Board of Directors authorized the issuance of up to $6 billion of debt securities, replacing the prior Board authorization in July 2016 , which had $1.55 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, 2018, we did not issue any debt securities under this registration statement. At March 31, 2018 , we had remaining authority to issue up to $6 billion of debt securities under our shelf registration.  Receivables Securitization Facility – As of March 31, 2018 , and December 31, 2017 , we recorded $650 million and $500 million , respectively, of borrowings under our Receivables Facility as secured debt. (See further discussion of our receivables securitization facility in Note 1 1 ).  Debt Redemption – On March 15, 2018 , we effectively redeemed, in entirety, the Missouri Pacific 5% Income Debentures due 2045 , the Chicago and Eastern Illinois 5% Income Debentures due 2054 , and the Missouri Pacific 4.75% General Mortgage Income Bonds Series A due 2020 and Series B due 2030 . The debentures had principal outstanding of $96 million and $2 million, respectively, and the bonds had principal outstanding of $30 million and $27 million, respectively. The bonds and debentures were assumed by the Railroad in the 1982 acquisition of the Missouri Pacific Railroad Company, with a weighted average interest rate of 4.9% . The carrying value of all four bonds and debentures at the time of redemption was $70 million, due to fair value purchase accounting adjustments related to the acquisition. The redemption resulted in an early extinguishment charge of $85 million in the first quarter of 2018 .

Variable Interest Entities

Variable Interest Entities	3 Months Ended
	Mar. 31, 2018
Variable Interest Entities [Abstract]
Variable Interest Entities	16 . 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 $ 1.8 billion as of March 31, 2018 .

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies [Abstract]
Commitments and Contingencies	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. 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 95% of the recorded liability is related to asserted claims and approximately 5% is related to unasserted claims at March 31, 2018 . 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 $272 million to $296 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, 2018 2017  Beginning balance $ 285 $ 290  Current year accruals 19 19  Changes in estimates for prior years (11) 4  Payments (21) (22)  Ending balance at March 31 $ 272 $ 291  Current portion, ending balance at March 31 $ 70 $ 65 We have insurance coverage for a portion of the costs incurred to resolve personal injury-related claims, and we have recognized an asset for estimated insurance recoveries at March 31, 2018 , and December 31, 2017 . 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 310 sites at which we are or may be liable for remediation costs associated with alleged contamination or for violations of environmental requirements. This includes 33 sites that are the subject of actions taken by the U.S. government, 21 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, 2018 2017  Beginning balance $ 196 $ 212  Accruals 16 2  Payments (14) (11)  Ending balance at March 31 $ 198 $ 203  Current portion, ending balance at March 31 $ 57 $ 53 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. In the event the Company leaves the reinsurance program, the Company is not relieved of its primary obligation to the policyholders for activity prior to the termination of the treaty agreements. We record both liabilities and reinsurance receivables using an actuarial analysis based on historical experience in our Condensed Consolidated Statements of Financial Position.  Guarantees – At both March 31, 2018 , and December 31, 2017 , we were contingently liable for $33 million in guarantees. The fair value of these obligations as of both March 31 , 2018 , and December 31, 2017 was $0 . We entered into these contingent guarantees in the normal course of business, and they include guaranteed obligations related to our affiliated operations. The final guarantee expires in 2022 . We are not aware of any existing event of default that would require us to satisfy these guarantees . We do not expect that these guarantees will have a material adverse effect on our consolidated financial condition, results of operations, or liquidity.  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 .  Operating Leases – At March 31, 2018 , we had commitments for future minimum lease payments under operating leases with initial or remaining non-cancelable lease terms in excess of one year of approximately $2.4 billion.

Share Repurchase Program

Share Repurchase Program	3 Months Ended
	Mar. 31, 2018
Share Repurchase Program [Abstract]
Share Repurchase Program	18. Share Repurchase Program  Effective January 1, 2017, our Board of Directors authorized the repurchase of up to 120 million shares of our common stock by December 31, 2020 , replacing our previous repurchase program. As of March 31, 2018, we repurchased a total of $24.4 billion of our common stock since the commencement of our repurchase programs in 2007. The table below represents shares repurchased under this repurchase program during this reporting period.     Number of Shares Purchased Average Price Paid  2018 2017 2018 2017  First quarter 9,259,004 7,531,300 $ 132.84 $ 106.55  Remaining number of shares that may be repurchased under current authority 74,388,148 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. Repurchased shares are recorded in treasury stock at cost, which includes any applicable commissions and fees.  From April 1, 2018, through April 25, 2018, we repurchased 2.8 million shares at an aggregate cost of approximately $375 million.

Related Parties

Related Parties	3 Months Ended
	Mar. 31, 2018
Related Parties [Abstract]
Related Parties	19 . 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 oth er North American railroads own the remaining interest. In accordance with ASC 323 Investments - Equity Method and Joint Venture , UPRR applies the equ ity method of accounting to our investment in TTX.  TTX is a railcar pooling company that owns railcars and intermodal wells to serve North America’s railroads. TTX assists railroads in meeting the needs of their customers by providing railcars in an efficient, pooled environment. All railroads have the ability to utilize TTX railcars through car hire by renting railcars at stated rates.  UPRR had $1.2 b illion recognized as investments related to TTX in our Condensed Consolidated Statements of Financial Position as of both March 31, 2018 , and December 31, 2017. TTX car hire expenses of $105 million and $86 million for the three months ended March 31, 2018 , and 2017 , respectively , are included in equipment and other rents in our Condensed Consolidated Statements of Income. In addition, UPRR had accounts payable to TTX of $68 million and $69 million as of March 31, 2018 , and December 31, 2017 , respectively.

Significant Accounting Polici29

Significant Accounting Policies Update (Policies)	3 Months Ended
	Mar. 31, 2018
Significant Accounting Policies [Abstract]
Revenue Recognition Policy [Text Block]	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 revenue 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 $161 million at March 31, 2018 and $154 million at December 31, 2017 and are expected to be recognized in the next 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 a specified cumulative volume or shipping to/from specific locations, are recorded as a reduction to operating revenues based on actual or projected future customer shipments.  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 Statement of Financial Position as Accounts Receivables, net.  Freight revenue 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 revenue.  Other revenues consist primarily of revenues earned by our subsidiaries and accessorial revenues. Non-rail subsidiary revenues are generally recognized over time as shipments move from origin to destination. The allocation of revenue 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.

Operations and Segmentation (Ta

Operations and Segmentation (Tables)	3 Months Ended
	Mar. 31, 2018
Operations and Segmentation [Abstract]
Freight Revenue By Commodity Group	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 :     Three Months Ended  March 31,  Millions 2018 2017  Agricultural Products $ 1,098 $ 1,094  Energy 1,173 1,024  Industrial 1,340 1,264  Premium 1,511 1,412  Total freight revenues $ 5,122 $ 4,794  Subsidiary revenues 217 215  Accessorial revenues 121 106  Other revenues 15 17  Total operating revenues $ 5,475 $ 5,132

Stock-based Compensation (Table

Stock-based Compensation (Tables)	3 Months Ended
	Mar. 31, 2018
Stock-based compensation [Abstract]
Stock-Based Compensation	Information regarding stock-based compensation appears in the table below:     Three Months Ended  March 31,  Millions 2018 2017  Stock-based compensation, before tax:  Stock options $ 4 $ 4  Retention awards 21 22  Total stock-based compensation, before tax $ 25 $ 26  Excess tax benefits from equity compensation plans $ 15 $ 22 
Stock Options Weight Average Assumptions	The table below shows the annual weighted-average assumptions used for valuation purposes:     Weighted-Average Assumptions 2018 2017  Risk-free interest rate 2.6% 2.0%  Dividend yield 2.3% 2.3%  Expected life (years) 5.3 5.3  Volatility 21.1% 21.7%  Weighted-average grant-date fair value of options granted $ 21.70 $ 18.19
Stock Options Activity	A summary of stock option activity during the three months ended March 31, 2018 , is presented below:    Options (thous.) Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value (millions)  Outstanding at January 1, 2018 5,630 $ 83.37 5.8 yrs. $ 286  Granted 800 124.86 N/A N/A  Exercised (446) 62.14 N/A N/A  Forfeited or expired (8) 86.57 N/A N/A  Outstanding at March 31, 2018 5,976 $ 90.50 6.2 yrs. $ 263  Vested or expected to vest at March 31, 2018 5,918 $ 90.33 6.2 yrs. $ 261  Options exercisable at March 31, 2018 4,045 $ 82.73 5.0 yrs. $ 209
Stock Option Exercises	Additional information regarding stock option exercises appears in the table below:     Three Months Ended  March 31,  Millions 2018 2017  Intrinsic value of stock options exercised $ 33 $ 23  Cash received from option exercises 26 20  Treasury shares repurchased for employee payroll taxes (8) (7)  Tax benefit realized from option exercises 8 9  Aggregate grant-date fair value of stock options vested 18 19
Retention Awards Activity	Changes in our retention awards during the three months ended March 31, 2018 , were as follows:     Shares (thous.) Weighted-Average Grant-Date Fair Value  Nonvested at January 1, 2018 2,313 $ 95.04  Granted 532 125.08  Vested (611) 87.94  Forfeited (24) 97.76  Nonvested at March 31, 2018 2,210 $ 104.20
Performance Retention Awards Present Value Calculation Assumptions	The assumptions used to calculate the present value of estimated future dividends related to the February 2018 grant were as follows:     2018  Dividend per share per quarter $ 0.73  Risk-free interest rate at date of grant 2.3%
Performance Based Units Activity	Changes in our performance retention awards during the three months ended March 31, 2018 , were as follows:     Shares (thous.) Weighted-Average Grant-Date Fair Value  Nonvested at January 1, 2018 1,138 $ 92.92  Granted 348 117.80  Vested (94) 112.19  Unearned (201) 114.97  Forfeited (5) 78.20  Nonvested at March 31, 2018 1,186 $ 95.02 

Retirement Plans (Tables)

Retirement Plans (Tables)	3 Months Ended
	Mar. 31, 2018
Retirement Plans [Abstract]
Net Periodic Pension And OPEB Cost/(Benefit)	The components of our net periodic pension and OPEB cost were as follows for the three months ended March 31:     Pension OPEB  Millions 2018 2017 2018 2017  Service cost $ 27 $ 23 $ - $ -  Interest cost 36 35 3 3  Expected return on plan assets (68) (66) - -  Amortization of actuarial loss 23 20 2 3  Net periodic benefit cost $ 18 $ 12 $ 5 $ 6 

Other Income (Tables)

Other Income (Tables)	3 Months Ended
	Mar. 31, 2018
Other Income [Abstract]
Other Income	Other income / (expense) included the following:     Three Months Ended  March 31 ,  Millions 2018 2017  Early extinguishment of debt [a] $ (85) $ -  Rental income 28 37  Net gain on non-operating asset dispositions [b] 6 34  Interest income 4 2  Net periodic pension and OPEB costs 4 5  Non-operating environmental costs and other 1 (6)  Total $ (42) $ 72  [a] 2018 includes a debt extinguishment charge for the early redemption of certain bonds and debentures (Note 15) . [b] 2017 includes $26 million related to a real estate sale in the first quarter .

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2018
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, 2018 2017  Net income $ 1,310 $ 1,072  Weighted-average number of shares outstanding:  Basic 776.4 811.5  Dilutive effect of stock options 1.8 1.8  Dilutive effect of retention shares and units 1.4 1.5  Diluted 779.6 814.8  Earnings per share – basic $ 1.69 $ 1.32  Earnings per share – diluted $ 1.68 $ 1.32  Stock options excluded as their inclusion would be anti-dilutive 0.5 1.6 

Accumulated Other Comprehensi35

Accumulated Other Comprehensive Income/(Loss) (Tables)	3 Months Ended
	Mar. 31, 2018
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, 2018 , and 2017 , were as follows (net of tax):      Millions Defined benefit plans Foreign currency translation Total  Balance at January 1, 2018 $ (1,029) $ (112) $ (1,141)  Other comprehensive income/(loss) before reclassifications - - -  Amounts reclassified from accumulated other comprehensive income/(loss) [a] 19 - 19  Net year-to-date other comprehensive income/(loss), net of taxes of $(6) million 19 - 19  Reclassification due to ASU 2018-02 adoption (Note 2) (225) (75) (300)  Balance at March 31, 2018 $ (1,235) $ (187) $ (1,422)   Balance at January 1, 2017 $ (1,132) $ (140) $ (1,272)  Other comprehensive income/(loss) before reclassifications (3) 9 6  Amounts reclassified from accumulated other comprehensive income/(loss) [a] 14 - 14  Net year-to-date other comprehensive income/(loss), net of taxes of $(14) million 11 9 20  Balance at March 31, 2017 $ (1,121) $ (131) $ (1,252)  [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 p eriodic pension cost. See Note 6 Retirement Plans for additional details.   

Properties (Tables)

Properties (Tables)	3 Months Ended
	Mar. 31, 2018
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, 2018 Cost Depreciation Value Useful Life  Land $ 5,271 $ N/A $ 5,271 N/A  Road:  Rail and other track material 16,439 5,997 10,442 43  Ties 10,227 2,935 7,292 33  Ballast 5,442 1,533 3,909 34  Other roadway [a] 19,143 3,549 15,594 47  Total road 51,251 14,014 37,237 N/A  Equipment:  Locomotives 9,667 3,737 5,930 19  Freight cars 2,295 985 1,310 24  Work equipment and other 941 277 664 19  Total equipment 12,903 4,999 7,904 N/A  Technology and other 1,099 462 637 11  Construction in progress 647 - 647 N/A  Total $ 71,171 $ 19,475 $ 51,696 N/A [a] Other roadway includes grading, bridges and tunnels, signals, buildings, and other road assets.      Millions, Except Estimated Useful Life Accumulated Net Book Estimated  As of December 31, 2017 Cost Depreciation Value Useful Life  Land $ 5,258 $ N/A $ 5,258 N/A  Road:  Rail and other track material 16,327 5,929 10,398 43  Ties 10,132 2,881 7,251 33  Ballast 5,406 1,509 3,897 34  Other roadway [a] 18,972 3,482 15,490 47  Total road 50,837 13,801 37,036 N/A  Equipment:  Locomotives 9,686 3,697 5,989 19  Freight cars 2,255 983 1,272 24  Work equipment and other 936 267 669 19  Total equipment 12,877 4,947 7,930 N/A  Technology and other 1,105 460 645 11  Construction in progress 736 - 736 N/A  Total $ 70,813 $ 19,208 $ 51,605 N/A  [a] Other roadway includes grading, bridges and tunnels, signals, buildings, and other road assets.

Accounts Payable And Other Cu37

Accounts Payable And Other Current Liabilities (Tables)	3 Months Ended
	Mar. 31, 2018
Accounts Payable and Other Current Liabilties [Abstract]
Schedule of Accounts Payable and Accrued Liabilities	   Mar. 31, Dec. 31,  Millions 2018 2017  Accounts payable $ 768 $ 1,013  Income and other taxes payable 641 547  Accrued wages and vacation 388 384  Accrued casualty costs 189 194  Interest payable 165 220  Equipment rents payable 113 110  Other 591 671  Total accounts payable and other current liabilities $ 2,855 $ 3,139 

Commitments And Contingencies (

Commitments And Contingencies (Tables)	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies [Abstract]
Commitments And Contingencies Activity	Our personal injury liability activity was as follows:      Millions,  for the Three Months Ended March 31, 2018 2017  Beginning balance $ 285 $ 290  Current year accruals 19 19  Changes in estimates for prior years (11) 4  Payments (21) (22)  Ending balance at March 31 $ 272 $ 291  Current portion, ending balance at March 31 $ 70 $ 65  Our environmental liability activity was as follows:    Millions,  for the Three Months Ended March 31, 2018 2017  Beginning balance $ 196 $ 212  Accruals 16 2  Payments (14) (11)  Ending balance at March 31 $ 198 $ 203  Current portion, ending balance at March 31 $ 57 $ 53  

Share Repurchase Program (Table

Share Repurchase Program (Tables)	3 Months Ended
	Mar. 31, 2018
Share Repurchase Program [Abstract]
Share Repurchase Program	The table below represents shares repurchased under this repurchase program during this reporting period.     Number of Shares Purchased Average Price Paid  2018 2017 2018 2017  First quarter 9,259,004 7,531,300 $ 132.84 $ 106.55  Remaining number of shares that may be repurchased under current authority 74,388,148 

Accounting Pronouncements (Deta

Accounting Pronouncements (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating Income (Loss) [Member] | ASU 2017-07 Adopted [Member}
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ (4)	$ (5)
Other Income [Member] | ASU 2017-07 Adopted [Member}
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	4	$ 5
ASU 2018-02 Early Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of AOCI to retained earnings	300
Assets, Total [Member] | ASU 2016-02 Prospective Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	(2,000)
Liabilities, Total [Member] | ASU 2016-02 Prospective Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 2,000

Significant Accounting Polici41

Significant Accounting Policies Update (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Revenue, Performance Obligation Satisfied over Time [Abstract]
Revenue, remaining performance obligation	$ 161	$ 154

Operations and Segmentation (De

Operations and Segmentation (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Commodity Group Information [Line Items]
Freight revenues	$ 5,122	$ 4,794
Subsidiary revenue	217	215
Accessorial revenues	121	106
Other revenues	15	17
Total operating revenues	5,475	5,132
Agricultural Products [Member]
Commodity Group Information [Line Items]
Freight revenues	1,098	1,094
Energy [Member]
Commodity Group Information [Line Items]
Freight revenues	1,173	1,024
Industrial [Member]
Commodity Group Information [Line Items]
Freight revenues	1,340	1,264
Premium [Member]
Commodity Group Information [Line Items]
Freight revenues	1,511	1,412
Mexico [Member]
Commodity Group Information [Line Items]
Freight revenues	$ 579	$ 566

Stock-based Compensation (Narra

Stock-based Compensation (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
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	0
Unrecognized compensation expense	$ 32
Expected weighted average period (in years) of nonvested stock options to be recognized	1 year 7 months 6 days
Retention Awards [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
Years until vest	4 years
Unrecognized compensation expense	$ 133
Expected weighted average period (in years) of nonvested stock options to be recognized	2 years 4 months 24 days
Performance Retention Awards [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
Operating income growth modifier range	The modifier can be up to +/- 25% of the award earned based on the ROIC achieved.
Requisite service period	37 months
Contractual terms of award	We expense 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 relative OIG modifier.
ROIC performance period	3 years
Unrecognized compensation expense	$ 56
Expected weighted average period (in years) of nonvested stock options to be recognized	1 year 9 months 18 days

Stock-based Compensation (Sched

Stock-based Compensation (Schedule Of Compensation) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Stock-Based Compensation, Before Tax: [Abstract]
Stock options	$ 4	$ 4
Retention awards	21	22
Total stock-based compensation, before tax	25	26
Excess tax benefits from equity compensation plans	$ 15	$ 22

Stock-based Compensation (Sch45

Stock-based Compensation (Schedule of Stock Options Weight Average Assumptions) (Details) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Stock Options [Member]
Assumptions For Stock Awards [Abstract]
Risk-free interest rate at date of grant	2.60%	2.00%
Dividend yield	2.30%	2.30%
Expected life (years)	5 years 3 months 18 days	5 years 3 months 18 days
Volatility	21.10%	21.70%
Weighted-average grant-date fair value of options granted	$ 21.70	$ 18.19
Performance Retention Awards [Member]
Assumptions For Stock Awards [Abstract]
Dividend per share per quarter	$ 0.73
Risk-free interest rate at date of grant	2.30%

Stock-based Compensation (Sch46

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, 2018	Dec. 31, 2017
Stock Options [Member]
Stock Option Activity [Abstract]
Stock options, shares outstanding at January 1, 2018	5,630
Stock options, shares granted	800
Stock options, shares exercised	(446)
Stock options, shares forfeited or expired	(8)
Stock options, shares outstanding at March 31, 2018	5,976	5,630
Stock options, shares vested or expected to vest at March 31, 2018	5,918
Stock options, shares exercisable at March 31, 2018	4,045
Stock options weighted-average exercise price, outstanding at January 1, 2018	$ 83.37
Stock options weighted-average exercise price, granted	124.86
Stock options weighted-average exercise price, exercised	62.14
Stock options weighted-average exercise price, forfeited or expired	86.57
Stock options weighted-average exercise price, outstanding at March 31, 2018	90.50	$ 83.37
Stock options weighted-average exercise price, vested or expected to vest at March 31, 2018	90.33
Stock options weighted-average exercise price, options exercisable at March 31, 2018	$ 82.73
Stock options weighted-average remaining contractual term in years, outstanding at January 1, 2018	6 years 2 months 12 days	5 years 9 months 18 days
Stock options weighted-average remaining contractual term in years, outstanding at March 31, 2018	6 years 2 months 12 days	5 years 9 months 18 days
Stock options weighted-average remaining contractual term in years, vested or expected to vest at March 31, 2018	6 years 2 months 12 days
Stock options weighted-average remaining contractual term in years, options exercisable at March 31, 2018	5 years
Stock options aggregate intrinsic value, outstanding at January 1, 2018	$ 286
Stock options aggregate intrinsic value, outstanding at March 31, 2018	263	$ 286
Stock options aggregate intrinsic value, vested or expected to vest at March 31, 2018	261
Stock options aggregate intrinsic value, options exercisable at March 31, 2018	$ 209
Retention Awards [Member]
Awards Activity [Abstract]
Awards, shares nonvested at January 1, 2018	2,313
Awards, shares granted	532
Awards, shares vested	(611)
Awards, shares forfeited	(24)
Awards, shares nonvested at March 31, 2018	2,210	2,313
Awards weighted-average grant-date fair value, nonvested at January 1, 2018	$ 95.04
Awards weighted-average grant-date fair value, granted	125.08
Awards weighted-average grant-date fair value, vested	87.94
Awards weighted-average grant-date fair value, forfeited	97.76
Awards weighted-average grant-date fair value, nonvested at March 31, 2018	$ 104.20	$ 95.04
Performance Retention Awards [Member]
Awards Activity [Abstract]
Awards, shares nonvested at January 1, 2018	1,138
Awards, shares granted	348
Awards, shares vested	(94)
Awards, shares unearned	(201)
Awards, shares forfeited	(5)
Awards, shares nonvested at March 31, 2018	1,186	1,138
Awards weighted-average grant-date fair value, nonvested at January 1, 2018	$ 92.92
Awards weighted-average grant-date fair value, granted	117.80
Awards weighted-average grant-date fair value, vested	112.19
Awards weighted-average grant-date fair value, unearned	114.97
Awards weighted-average grant-date fair value, forfeited	78.20
Awards weighted-average grant-date fair value, nonvested at March 31, 2018	$ 95.02	$ 92.92

Stock-based Compensation (Sch47

Stock-based Compensation (Schedule of Stock Option Exercises) (Details) - Stock Options [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Stock Option Aggregate Disclosures [Abstract]
Intrinsic value of stock options exercised	$ 33	$ 23
Cash received from option exercises	26	20
Treasury shares repurchased for employee payroll taxes	(8)	(7)
Tax benefit realized from option exercises	8	9
Aggregate grant-date fair value of stock options vested	$ 18	$ 19

Retirement Plans (Details)

Retirement Plans (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net Periodic Pension And OPEB Cost [Abstract]
Changes in fair value	5 years
Pension [Member]
Net Periodic Pension And OPEB Cost [Abstract]
Service cost	$ 27,000,000	$ 23,000,000
Interest cost	36,000,000	35,000,000
Expected return on plan assets	(68,000,000)	(66,000,000)
Amortization of actuarial loss	23,000,000	20,000,000
Net periodic cost	18,000,000	12,000,000
Voluntary cash contributions to qualified pension plan	0
OPEB [Member]
Net Periodic Pension And OPEB Cost [Abstract]
Interest cost	3,000,000	3,000,000
Amortization of actuarial loss	2,000,000	3,000,000
Net periodic cost	$ 5,000,000	$ 6,000,000

Other Income (Details)

Other Income (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Other Income [Abstract]
Early extinguishment of debt	[1]	$ (85)
Rental income		28	$ 37
Net gain on non-operating asset dispositions.	[2]	6	34
Interest Income		4	2
Net periodic pension and OPEB costs		4	5
Non-operating environmental costs and other		1	(6)
Total		$ (42)	72
Real estate sale			$ 26
[1]	2018 includes a debt extinguishment charge for the early redemption of certain bonds and debentures (Note 15).
[2]	2017 includes $26 million related to a real estate sale in the first quarter

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Income Tax Reform [Abstract]
Federal statutory tax rate	21.00%	35.00%
Tax Cuts and Jobs Act of 2017, bonus depreciation on certain capital expenditures, percentage	100.00%
Tax Cuts and Jobs Act of 2017, deferred tax liability, income tax expense (benefit) total		$ 5,900
Tax Cuts and Jobs Act of 2017, operating expense (benefit) from equity method affiliates adjustments		$ 212
Unrecognized Tax Benefits [Abstract]
Net unrecognized tax benefit liability	$ 182

Income Taxes (Settlement) (Deta

Income Taxes (Settlement) (Details) $ in Millions	Mar. 31, 2018USD ($)
Taxes And Interest - Income Taxes [Abstract]
Future tax refund in connection to settlement	$ 18

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share Details [Abstract]
Net income	$ 1,310	$ 1,072
Weighted-Average Number Of Shares Outstanding
Basic	776.4	811.5
Dilutive effect of stock options	1.8	1.8
Dilutive effect of retention shares and units	1.4	1.5
Diluted	779.6	814.8
Earnings per share - basic	$ 1.69	$ 1.32
Earnings per share - diluted	$ 1.68	$ 1.32
Stock options excluded as their inclusion would be anti-dilutive	0.5	1.6

Accumulated Other Comprehensi53

Accumulated Other Comprehensive Income/(Loss) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance		$ (1,141)	$ (1,272)
Other comprehensive income/(loss) before reclassifications			6
Amounts reclassified from accumulated other comprehensive income/(loss)	[1]	19	14
Net to-date other comprehensive income/(loss), net of taxes	[2]	19	20
Reclassification of AOCI to retained earnings due to ASU 2018-02		(300)
Balance at March 31		(1,422)	(1,252)
Deferred taxes activity other comprehensive income/(loss)		(6)	(14)
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance		(1,029)	(1,132)
Other comprehensive income/(loss) before reclassifications			(3)
Amounts reclassified from accumulated other comprehensive income/(loss)	[1]	19	14
Net to-date other comprehensive income/(loss), net of taxes		19	11
Reclassification of AOCI to retained earnings due to ASU 2018-02		(225)
Balance at March 31		(1,235)	(1,121)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance		(112)	(140)
Other comprehensive income/(loss) before reclassifications			9
Amounts reclassified from accumulated other comprehensive income/(loss)
Net to-date other comprehensive income/(loss), net of taxes			9
Reclassification of AOCI to retained earnings due to ASU 2018-02		(75)
Balance at March 31		$ (187)	$ (131)
[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 6 Retirement Plans for additional details.
[2]	Net of deferred taxes of $(6) million and $(14) million during the three months ended March 31, 2018, and 2017, respectively.

Accounts Receivable (Details)

Accounts Receivable (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Accounts Receivable Details [Abstract]
Allowance for doubtful accounts	$ 3		$ 3
Allowance for doubtful accounts - receivables not expected to be collected in one year	19		17
Receivables Securitization Facility [Abstract]
Total capacity to transfer undivided interests to investors under the receivables securitization facility	$ 650
Receivables securitization facility maturity date	2019-07
Receivables securitization facility duration	3 years
Value of the outstanding undivided interest held by investors under the receivables securitization facility	$ 650		500
Accounts receivable supporting the undivided interest held by investors	1,200		$ 1,100
Cost of the receivables securitization facility - interest expense	$ 4	$ 1

Properties (Details)

Properties (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Mar. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Cost		$ 71,171	$ 70,813
Accumulated depreciation		19,475	19,208
Net book value		51,696	51,605
Land [Member]
Property, Plant and Equipment [Line Items]
Cost		5,271	5,258
Net book value		5,271	5,258
Road: Rail and Other Track Material [Member]
Property, Plant and Equipment [Line Items]
Cost		16,439	16,327
Accumulated depreciation		5,997	5,929
Net book value		$ 10,442	$ 10,398
Estimated useful life		43 years	43 years
Road: Ties [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 10,227	$ 10,132
Accumulated depreciation		2,935	2,881
Net book value		$ 7,292	$ 7,251
Estimated useful life		33 years	33 years
Road: Ballast [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 5,442	$ 5,406
Accumulated depreciation		1,533	1,509
Net book value		$ 3,909	$ 3,897
Estimated useful life		34 years	34 years
Road: Other Roadway [Member]
Property, Plant and Equipment [Line Items]
Cost	[1]	$ 19,143	$ 18,972
Accumulated depreciation	[1]	3,549	3,482
Net book value	[1]	$ 15,594	$ 15,490
Estimated useful life	[1]	47 years	47 years
Total Road [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 51,251	$ 50,837
Accumulated depreciation		14,014	13,801
Net book value		37,237	37,036
Equipment: Locomotives [Member]
Property, Plant and Equipment [Line Items]
Cost		9,667	9,686
Accumulated depreciation		3,737	3,697
Net book value		$ 5,930	$ 5,989
Estimated useful life		19 years	19 years
Equipment: Freight Cars [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 2,295	$ 2,255
Accumulated depreciation		985	983
Net book value		$ 1,310	$ 1,272
Estimated useful life		24 years	24 years
Equipment: Work Equipment and Other [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 941	$ 936
Accumulated depreciation		277	267
Net book value		$ 664	$ 669
Estimated useful life		19 years	19 years
Total Equipment [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 12,903	$ 12,877
Accumulated depreciation		4,999	4,947
Net book value		7,904	7,930
Technology and Other [Member]
Property, Plant and Equipment [Line Items]
Cost		1,099	1,105
Accumulated depreciation		462	460
Net book value		$ 637	$ 645
Estimated useful life		11 years	11 years
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 647	$ 736
Net book value		$ 647	$ 736
[1]	Other roadway includes grading, bridges and tunnels, signals, buildings, and other road assets.

Accounts Payable And Other Cu56

Accounts Payable And Other Current Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Accounts Payable and Other Current Liabilities Details [Abstract]
Accounts payable	$ 768	$ 1,013
Income and other taxes payable	641	547
Accrued wages and vacation	388	384
Accrued casualty costs	189	194
Interest payable	165	220
Equipment rents payable	113	110
Other	591	671
Total accounts payable and other current liabilities	$ 2,855	$ 3,139

Financial Instruments (Details)

Financial Instruments (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Short-Term Investments [Abstract]
Short-term investments	$ 90,000,000	$ 90,000,000
Transfers out of level 2	0
Fair Value of Debt Instruments [Abstract]
Fair value of total debt	18,000,000,000	18,200,000,000
Fair value of total debt in excess of carrying value	400,000,000	1,300,000,000
Fixed rate debt securities containing call provisions	0	$ 155,000,000
Significant Other Observable Inputs (Level 2) [Member] | Time Deposits [Member]
Short-Term Investments [Abstract]
Short-term investments	$ 90,000,000

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($)		Mar. 15, 2018	Mar. 15, 2018	Mar. 31, 2018	Feb. 12, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Commercial paper issued				$ 1,560,000,000
Commercial paper repaid				$ 920,000,000
Commercial paper maturity duration minimum				1 day
Commercial paper matrutiy duration maximum				34 days
Commercial paper outstanding				$ 637,000,000
Board of Directors authorized debt issuance					$ 6,000,000,000
Previous Board Of Directors Remaining Debt Issuance				1,550,000,000
Board of Directors remaining debt issuance				6,000,000,000
Secured debt under receivables securitization facility				650,000,000		$ 500,000,000
Early extinguishment charge	[1]			85,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Revolving credit facility available credit				$ 1,700,000,000
Facility expiration date				May 25, 2019
Credit facility term				5 years
Revolving credit facility withdrawals				$ 0
Allowable debt per debt-to-net-worth coverage ratio (as defined in the facility)				48,800,000,000
Outstanding debt (as defined by facility)				17,600,000,000
Cross-default provision (as defined by facility)				125,000,000
Debt Redemption [Member]
Debt Instrument [Line Items]
Redemption date		Mar. 15, 2018
Weighted average interest rate of bonds and debentures		4.90%	4.90%
Fixed rate debt securities carrying value		$ 70,000,000	$ 70,000,000
Early extinguishment charge				$ 85,000,000
Missouri Pacific 5 Percent Income Debentures due 2045 [Member]
Debt Instrument [Line Items]
Interest rate		5.00%	5.00%
Maturity date			Jan. 1, 2045
Principal outstanding		$ 96,000,000	$ 96,000,000
Chicago and Eastern Illinois 5 Percent Income Debentures Due 2054 [Member]
Debt Instrument [Line Items]
Interest rate		5.00%	5.00%
Maturity date			Jan. 1, 2054
Principal outstanding		$ 2,000,000	$ 2,000,000
Missouri Pacific 4.75 Percent General Mortgage Income Bonds Series A Due 2020 [Member]
Debt Instrument [Line Items]
Interest rate		4.75%	4.75%
Maturity date			Jan. 1, 2020
Principal outstanding		$ 30,000,000	$ 30,000,000
Missouri Pacific 4.75 Percent General Mortgage Income Bonds Series B Due 2030 [Member]
Debt Instrument [Line Items]
Interest rate		4.75%	4.75%
Maturity date			Jan. 1, 2030
Principal outstanding		$ 27,000,000	$ 27,000,000
[1]	2018 includes a debt extinguishment charge for the early redemption of certain bonds and debentures (Note 15).

Variable Interest Entities (Det

Variable Interest Entities (Details) $ in Billions	Mar. 31, 2018USD ($)
Future minimum lease payments	$ 2.4
Variable Interest Entity (VIEs) [Member]
Future minimum lease payments	$ 1.8

Commitments And Contingencies60

Commitments And Contingencies (Narrative) (Details)	3 Months Ended
	Mar. 31, 2018USD ($)item	Dec. 31, 2017USD ($)
Commitments and Contingencies [Line Items]
Sites identified which we are or may be liable for remediation costs | item	310
Sites subject of actions taken by the U.S. government | item	33
Sites on the Superfund National Priorities List | item	21
Future minimum lease payments	$ 2,400,000,000
Personal Injury [Member]
Commitments and Contingencies [Line Items]
Percent of liability recorded related to asserted claims	95.00%
Percent of liability recorded related to unasserted claims	5.00%
Personal Injury [Member] | Minimum [Member]
Commitments and Contingencies [Line Items]
Reasonably possible outcome of related claims	$ 272,000,000
Personal Injury [Member] | Maximum [Member]
Commitments and Contingencies [Line Items]
Reasonably possible outcome of related claims	296,000,000
Guarantees [Member]
Commitments and Contingencies [Line Items]
Maximum potential amount of guarantee payments	33,000,000	$ 33,000,000
Recorded liability for fair value of guarantees	$ 0	$ 0
Expiration year of final guarantee	The final guarantee expires in 2022

Commitments And Contingencies61

Commitments And Contingencies (Commitments And Contingencies Activity) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Liability Activity [Abstract]
Current portion, ending balance at March 31	$ 189
Environmental [Abstract]
Beginning balance.	196	$ 212
Accruals	16	2
Payments	(14)	(11)
Ending balance at March 31.	198	203
Current portion, ending balance at March 31.	57	53
Personal Injury [Member]
Liability Activity [Abstract]
Beginning balance	285	290
Current year accruals	19	19
Changes in estimates for prior years	(11)	4
Payments	(21)	(22)
Ending balance at March 31	272	291
Current portion, ending balance at March 31	$ 70	$ 65

Share Repurchase Program (Detai

Share Repurchase Program (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended		135 Months Ended
	Apr. 25, 2018	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Jan. 01, 2017
Shares Repurchased [Line Items]
BOD authorized					120,000,000
Stock repurchase program expiration date		Dec. 31, 2020
Aggregate cost		$ 1,230	$ 802	$ 24,400
Shares repurchased		9,259,004	7,531,300
Average purchase price		$ 132.84	$ 106.55
Remaining number of shares that may be repurchased under current authority		74,388,148		74,388,148
Subsequent Event [Member]
Shares Repurchased [Line Items]
Aggregate cost	$ 375
Shares repurchased	2,800,000

Related Parties (Details)

Related Parties (Details) - TTX Company [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Related Party Transaction [Line Items]
Equity Method Investment, Ownership Percentage	36.79%
Equity Method Investments	$ 1,200		$ 1,200
Related Party Transaction, Expenses from Transactions with Related Party	105	$ 86
Accounts Payable, Related Parties, Current	$ 68		$ 69