Union Pacific (UNP) 10-K 3 Feb 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2016	Jan. 27, 2017	Jun. 30, 2016
Document and Entity Information [Abstract]
Document type	10-K
Document period end date	Dec. 31, 2016
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
Entity public float			$ 72.7
Document fiscal year focus	2,016
Document fiscal period focus	FY
Trading Symbol	unp
Entity common stock shares outstanding		813,795,240

Consolidated Statements Of Inco

Consolidated Statements Of Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating revenues:
Freight revenues	$ 18,601	$ 20,397	$ 22,560
Other revenues	1,340	1,416	1,428
Total operating revenues	19,941	21,813	23,988
Operating expenses:
Compensation and benefits	4,750	5,161	5,076
Purchased services and materials	2,258	2,421	2,558
Depreciation	2,038	2,012	1,904
Fuel	1,489	2,013	3,539
Equipment and other rents	1,137	1,230	1,234
Other	997	924	924
Total operating expenses	12,669	13,761	15,235
Operating income	7,272	8,052	8,753
Other income (Note 7)	192	226	151
Interest expense	(698)	(622)	(561)
Income before income taxes	6,766	7,656	8,343
Income taxes (Note 8)	(2,533)	(2,884)	(3,163)
Net income	$ 4,233	$ 4,772	$ 5,180
Share and Per Share (Note 9):
Earnings per share - basic	$ 5.09	$ 5.51	$ 5.77
Earnings per share - diluted	$ 5.07	$ 5.49	$ 5.75
Weighted average number of shares - basic	832.4	866.2	897.1
Weighted average number of shares - diluted	835.4	869.4	901.1
Dividends declared per share	$ 2.255	$ 2.20	$ 1.91

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Consolidated Statements of Comprehensive Income [Abstract]
Net income		$ 4,233	$ 4,772	$ 5,180
Other comprehensive income/(loss):
Defined benefit plans		(29)	58	(448)
Foreign currency translation		(48)	(43)	(12)
Total other comprehensive income/(loss)	[1]	(77)	15	(460)
Comprehensive income		$ 4,156	$ 4,787	$ 4,720
[1]	Net of deferred taxes of $49 million, ($8) million, and $291 million during 2016, 2015, and 2014, respectively.

Consolidated Statements Of Com4

Consolidated Statements Of Comprehensive Income (Parentheticals) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Consolidated Statements of Comprehensive Income [Abstract]
Deferred taxes activity other comprehensive income/(loss)	$ 49	$ (8)	$ 291

Consolidated Statements Of Fina

Consolidated Statements Of Financial Position - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 1,277	$ 1,391
Short-term investments (Note 14)	60
Accounts receivable, net (Note 11)	1,258	1,356
Materials and supplies	717	736
Other current assets	284	647
Total current assets	3,596	4,130
Investments	1,457	1,410
Net properties (Note 12)	50,389	48,866
Other assets	276	194
Total assets	55,718	54,600
Current liabilities:
Accounts payable and other current liabilities (Note 13)	2,882	2,612
Debt due within one year (Note 15)	758	594
Total current liabilities	3,640	3,206
Debt due after one year (Note 15)	14,249	13,607
Deferred income taxes (Note 8)	15,996	15,241
Other long-term liabilities	1,901	1,844
Commitments and contingencies (Notes 17 and 18)
Total liabilities	35,786	33,898
Common shareholders' equity:
Common shares, $2.50 par value, 1,400,000,000 authorized; 1,110,986,415 and 1,110,426,354 issued; 815,824,413 and 849,211,436 outstanding, respectively	2,777	2,776
Paid-in-surplus	4,421	4,417
Retained earnings	32,587	30,233
Treasury stock	(18,581)	(15,529)
Accumulated other comprehensive loss (Note 10)	(1,272)	(1,195)
Total common shareholders' equity	19,932	20,702
Total liabilities and common shareholders' equity	$ 55,718	$ 54,600

Consolidated Statements Of Fin6

Consolidated Statements Of Financial Position (Parentheticals) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Consolidated Statements Of Financial Position [Abstract]
Common shares, par value	$ 2.50	$ 2.50
Common shares authorized	1,400,000,000	1,400,000,000
Common shares issued	1,110,986,415	1,110,426,354
Common shares outstanding	815,824,413	849,211,436

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Operating Activities
Net income	$ 4,233	$ 4,772	$ 5,180
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	2,038	2,012	1,904
Deferred and other income taxes	831	765	895
Net gain on non-operating asset dispositions	(94)	(144)	(69)
Other operating activities, net	(228)	116	(216)
Changes in current assets and liabilities:
Accounts receivable, net	98	255	(197)
Materials and supplies	19	(24)	(59)
Other current assets	22	(47)	(35)
Accounts payable and other current liabilities	232	(276)	295
Income and other taxes	374	(85)	(313)
Cash provided by operating activities	7,525	7,344	7,385
Investing Activities
Capital investments	(3,505)	(4,650)	(4,346)
Purchases of short-term investments (Note 14)	(580)
Maturities of short-term investments (Note 14)	520
Proceeds from asset sales	129	251	138
Other investing activities, net	43	(77)	(41)
Cash used in investing activities	(3,393)	(4,476)	(4,249)
Financing Activities
Common share repurchases (Note 19)	(3,105)	(3,465)	(3,225)
Debt issued	1,983	3,328	2,588
Dividends paid	(1,879)	(2,344)	(1,632)
Debt repaid	(1,013)	(556)	(710)
Debt exchange	(191)
Other financing activities, net	(41)	(26)	(3)
Cash used in financing activities	(4,246)	(3,063)	(2,982)
Net change in cash and cash equivalents	(114)	(195)	154
Cash and cash equivalents at beginning of year	1,391	1,586	1,432
Cash and cash equivalents at end of year	1,277	1,391	1,586
Non-cash investing and financing activities:
Capital investments accrued but not yet paid	223	100	174
Capital lease financings		13
Cash dividends declared but not yet paid			438
Cash paid during the year for:
Income taxes, net of refunds	(1,347)	(2,156)	(2,492)
Interest, net of amounts capitalized	$ (652)	$ (592)	$ (554)

Consolidated Statements Of Chan

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, 2013	$ 2,774	$ 4,210	$ 23,901	$ (8,910)	$ (750)		$ 21,225
Common shares, beginning balance at Dec. 31, 2013	1,109,700,000			(197,700,000)
Net income			5,180				5,180
Other comp. income/(loss)					(460)		(460)	[2]
Conversion, stock option exercises, forfeitures, and other	$ 1	111		$ 71			183
Conversion, stock option exercises, forfeitures, and other (shares)	400,000			3,000,000
Share repurchases (Note 19)				$ (3,225)			(3,225)
Share repurchases (Note 19) (shares)				(32,000,000)
Cash dividends declared			(1,714)				(1,714)
Shareholders' equity, ending balance at Dec. 31, 2014	$ 2,775	4,321	27,367	$ (12,064)	(1,210)		21,189
Common shares, ending balance at Dec. 31, 2014	1,110,100,000			(226,700,000)
Net income			4,772				4,772
Other comp. income/(loss)					15		15	[2]
Conversion, stock option exercises, forfeitures, and other	$ 1	96					97
Conversion, stock option exercises, forfeitures, and other (shares)	300,000			800,000
Share repurchases (Note 19)				$ (3,465)			$ (3,465)
Share repurchases (Note 19) (shares)				(35,300,000)			(35,304,154)
Cash dividends declared			(1,906)				$ (1,906)
Shareholders' equity, ending balance at Dec. 31, 2015	$ 2,776	4,417	30,233	$ (15,529)	(1,195)		$ 20,702
Common shares, ending balance at Dec. 31, 2015	1,110,400,000			(261,200,000)			849,211,436
Net income			4,233				$ 4,233
Other comp. income/(loss)					(77)		(77)	[2]
Conversion, stock option exercises, forfeitures, and other	$ 1	4		$ 53			58
Conversion, stock option exercises, forfeitures, and other (shares)	600,000			1,100,000
Share repurchases (Note 19)				$ (3,105)			$ (3,105)
Share repurchases (Note 19) (shares)				(35,100,000)			(35,055,187)
Cash dividends declared			(1,879)				$ (1,879)
Shareholders' equity, ending balance at Dec. 31, 2016	$ 2,777	$ 4,421	$ 32,587	$ (18,581)	$ (1,272)		$ 19,932
Common shares, ending balance at Dec. 31, 2016	1,111,000,000			(295,200,000)			815,824,413
[1]	AOCI = Accumulated Other Comprehensive Income/(Loss) (Note 10)
[2]	Net of deferred taxes of $49 million, ($8) million, and $291 million during 2016, 2015, and 2014, respectively.

Consolidated Statements of Cha9

Consolidated Statements of Changes in Common Shareholders' Equity (Parentheticals) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Consolidated Statements Of Changes In Common Shareholders' Equity [Abstract]
Cash dividends declared per share	$ 2.255	$ 2.20	$ 1.91

Nature Of Operations

Nature Of Operations	12 Months Ended
	Dec. 31, 2016
Nature Of Operations [Abstract]
Nature of Operations	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. Nature of Operations  Operations and Segmentation – We are a Class I railroad operating in the U.S. Our network includes 32,070 route miles, linking Pacific Coast and Gulf Coast ports with the Midwest and Eastern U.S. gateways and providing several corridors to key Mexican gateways. We own 26,053 miles and operate on the remainder pursuant to trackage rights or leases. We serve the western two-thirds of the country and maintain coordinated schedules with other rail carriers for the handling of freight to and from the Atlantic Coast, the Pacific Coast, the Southeast, the Southwest, Canada, and Mexico. Export and import traffic is moved through Gulf Coast and Pacific Coast ports and across the Mexican and Canadian borders.  The Railroad, along with its subsidiaries and rail affiliates, is our one reportable operating segment. Although we provide and analyze revenue by commodity group, we treat the financial results of the Railroad as one segment due to the integrated nature of our rail network. The following table provides freight revenue by commodity group:      Millions 2016 2015 2014  Agricultural Products $ 3,625 $ 3,581 $ 3,777  Automotive 2,000 2,154 2,103  Chemicals 3,474 3,543 3,664  Coal 2,440 3,237 4,127  Industrial Products 3,348 3,808 4,400  Intermodal 3,714 4,074 4,489  Total freight revenues $ 18,601 $ 20,397 $ 22,560  Other revenues 1,340 1,416 1,428  Total operating revenues $ 19,941 $ 21,813 $ 23,988  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 $2.2 billion in 201 6 , $2. 2 billion in 201 5 , and $2. 3 billion in 201 4 .  Basis of Presentation – The Consolidated Financial Statements are presented in accordance with accounting principles generally accepted in the U.S. (GAAP) as codified in the Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC).

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Significant Accounting Policies [Abstract]
Significant Accounting Policies	2. Significant Accounting Policies  Principles of Consolidation – The Consolidated Financial Statements include the accounts of Union Pacific Corporation and all of its subsidiaries. Investments in affiliated companies (20% to 50% owned) are accounted for using the equity method of accounting. All intercompany transactions are eliminated. We currently have no less than majority-owned investments that require consolidation under variable interest entity requirements.  Cash and Cash Equivalents – Cash equivalents consist of investments with original maturities of three months or less.  Accounts Receivable – Accounts receivable includes receivables reduced by an allowance for doubtful accounts. The allowance is based upon historical losses, credit worthiness of customers, and current economic conditions. Receivables not expected to be collected in one year and the associated allowances are classified as other assets in our Consolidated Statements of Financial Position.  Investments – Investments represent our investments in affiliated companies (20% to 50% owned) that are accounted for under the equity method of accounting and investments in companies (less than 20% owned) accounted for under the cost method of accounting.  Materials and Supplies – Materials and supplies are carried at the lower of average cost or market.  Property and Depreciation – Properties and equipment are carried at cost and are depreciated on a straight-line basis over their estimated service lives, which are measured in years, except for rail in high-density traffic corridors (i.e., all rail lines except for those subject to abandonment, yard and switching tracks, and electronic yards), for which lives are measured in millions of gross tons per mile of track. We use the group method of depreciation in which all items with similar characteristics, use, and expected lives are grouped together in asset classes, and are depreciated using composite depreciation rates. The group method of depreciation treats each asset class as a pool of resources, not as singular items. We determine the estimated service lives of depreciable railroad assets by means of depreciation studies. Under the group method of depreciation, no gain or loss is recognized when depreciable property is retired or replaced in the ordinary course of business.  Impairment of Long-lived Assets – We review long-lived assets, including identifiable intangibles, for impairment when events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If impairment indicators are present and the estimated future undiscounted cash flows are less than the carrying value of the long-lived assets, the carrying value is reduced to the estimated fair value as measured by the discounted cash flows.  Revenue Recognition – We recognize freight revenues 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. Other revenues, which include revenues earned by our subsidiaries, revenues from our commuter rail operations, and accessorial revenue, are recognized as service is performed or contractual obligations are met. 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.  Translation of Foreign Currency – Our portion of the assets and liabilities related to foreign investments are translated into U.S. dollars at the exchange rates in effect at the balance sheet date. Revenue and expenses are translated at the average rates of exchange prevailing during the year. Unrealized gains or losses are reflected within common shareholders’ equity as accumulated other comprehensive income or loss.  Fair Value Measurements – We use a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. The level in the fair value hierarchy within which the fair value measurement in its entirety falls is determined based on the lowest level input that is significant to the fair value measurement in its entirety. These levels include:  Level 1: Quoted market prices in active markets for identical assets or liabilities. Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data. Level 3: Unobservable inputs that are not corroborated by market data.  We have applied fair value measurements to our short term investments, pension plan assets and short- and long-term debt.  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.  We measure and recognize compensation expense for all stock-based awards made to employees and directors, including stock options. Compensation expense is based on the calculated fair value of the awards as measured at the grant date and is expensed ratably over the service period of the awards (generally the vesting period). The fair value of retention awards is the closing stock price on the date of grant, while the fair value of stock options is determined by using the Black-Scholes option pricing model.  Earnings Per Share – Basic earnings per share are calculated on the weighted-average number of common shares outstanding during each period. Diluted earnings per share include shares issuable upon exercise of outstanding stock options and stock-based awards where the conversion of such instruments would be dilutive.  Income Taxes – We account for income taxes by recording taxes payable or refundable for the current year and deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in our financial statements or tax returns. These expected future tax consequences are measured based on current tax law; the effects of future tax legislation are not anticipated. Future tax legislation, such as a change in the corporate tax rate, could have a material impact on our financial condition, results of operations, or liquidity.  When appropriate, we record a valuation allowance against deferred tax assets to reflect that these tax assets may not be realized. In determining whether a valuation allowance is appropriate, we consider whether it is more likely than not that all or some portion of our deferred tax assets will not be realized, based on management’s judgments using available evidence for purposes of estimating whether future taxable income will be sufficient to realize a deferred tax asset.  We recognize tax benefits that are more likely than not to be sustained upon examination by tax authorities. The amount recognized is measured as the largest amount of benefit that is greater than 50 percent likely to be realized upon settlement. A liability for “unrecognized tax benefits” is recorded for any tax benefits claimed in our tax returns that do not meet these recognition and measurement standards.  Pension and Postretirement Benefits – We incur certain employment-related expenses associated with pensions and postretirement health benefits. In order to measure the expense associated with these benefits, we must make various assumptions including discount rates used to value certain liabilities, expected return on plan assets used to fund these expenses, compensation increases, employee turnover rates, anticipated mortality rates, and expected future health care costs. The assumptions used by us are based on our historical experience as well as current facts and circumstances. We use an actuarial analysis to measure the expense and liability associated with these benefits.  Personal Injury – The cost of injuries to employees and others on our property is charged to expense based on estimates of the ultimate cost and number of incidents each year. We use an actuarial analysis to measure the expense and liability. Our personal injury liability is not discounted to present value. Legal fees and incidental costs are expensed as incurred.  Asbestos – We estimate a liability for asserted and unasserted asbestos-related claims based on an assessment of the number and value of those claims. We use a statistical analysis to assist us in properly measuring our potential liability. Our liability for asbestos-related claims is not discounted to present value due to the uncertainty surrounding the timing of future payments. Legal fees and incidental costs are expensed as incurred.  Environmental – When environmental issues have been identified with respect to property currently or formerly owned, leased, or otherwise used in the conduct of our business, we perform, with the assistance of our consultants, environmental assessments on such property. We expense the cost of the assessments as incurred. We accrue the cost of remediation where our obligation is probable and such costs can be reasonably estimated. We do not discount our environmental liabilities when the timing of the anticipated cash payments is not fixed or readily determinable. Legal fees and incidental costs are expensed as incurred.  Use of Estimates – The preparation of our Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect certain reported assets and liabilities, and the disclosure of certain contingent assets and liabilities as of the date of the consolidated financial statements, as well as the reported amounts of revenue and expenses during the reporting period . Actual future results may differ from such estimates.

Accounting Pronouncements

Accounting Pronouncements	12 Months Ended
	Dec. 31, 2016
Accounting Pronouncements [Abstract]
Accounting Pronouncements	3. 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 standard is effective for annual reporting periods beginning after December 15, 2017 , and can be adopted either retrospectively or as a cumulative effect adjustment as of the date of adoption . ASU 2014-09 is not expected to have a material 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. ASU 2016-01 is not expected to have a material impact on our consolidated financial position, results of operations, or cash flows .  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 significant increase in the Company’s assets and liabilities.  In March 2016, the FASB issued Accounting Standards Update No. 2016-09 (ASU 2016-09) Compensation - Stock Compensation (Topic 718), which simplifies the accounting for income taxes related to stock-based compensation. We elected to early adopt ASU 2016-09 in the first quarter of 2016 with an effective date of January 1, 2016. As a result of the adoption, we recognized excess tax benefits in the Consolidated Statements of Income and the Consolidated Statements of Cash Flows of $ 28 million for the year ended December 31, 2016. Prior periods have not been adjusted .

Stock Split

Stock Split	12 Months Ended
	Dec. 31, 2016
Stock Split [Abstract]
Stock Split	4. Stock Split  On June 6, 2014 , we completed a two -for-one stock split, effected in the form of a 100% stock dividend. The stock split entitled all shareholders of record at the close of business on May 27, 2014 , to receive one additional share of our common stock, par value $2.50 per share, for each share of common stock held on that date. All references to common shares and per share amounts have been retroactively adjusted to reflect the stock split for all periods presented.

Stock Options And Other Stock P

Stock Options And Other Stock Plans	12 Months Ended
	Dec. 31, 2016
Stock Options And Other Stock Plans [Abstract]
Stock Options and Other Stock Plans	5. Stock Options and Other Stock Plans  There are no restricted shares outstanding under the 1992 Restricted Stock Plan for Non-Employee Directors of Union Pacific Corporation. We no longer grant awards of restricted shares under this plan.  In April 2000, the shareholders approved the Union Pacific Corporation 2000 Directors Plan (Directors Plan) whereby 2,200,000 shares of our common stock were reserved for issuance to our non-employee directors. Under the Directors Plan, each non-employee director, upon his or her initial election to the Board of Directors, receives a grant of 4,000 retention shares or retention stock units. Prior to December 31, 2007, each non-employee director received annually an option to purchase at fair value a number of shares of our common stock, not to exceed 20,000 shares during any calendar year, determined by dividing 60,000 by 1/3 of the fair market value of one share of our common stock on the date of such Board of Directors meeting, with the resulting quotient rounded up or down to the nearest 50 shares. In September 2007, the Board of Directors eliminated the annual payment of options for 2008 and all future years. As of December 31, 2016 , 40,000 restricted shares and 7,400 options were outstanding under the Directors Plan.  The Union Pacific Corporation 2004 Stock Incentive Plan (2004 Plan) was approved by shareholders in April 2004. The 2004 Plan reserved 84,000,000 shares of our common stock for issuance, plus any shares subject to awards made under previous plans that were outstanding on April 16, 2004, and became available for regrant pursuant to the terms of the 2004 Plan. Under the 2004 Plan, non-qualified options, stock appreciation rights, retention shares, stock units, and incentive bonus awards may be granted to eligible employees of the Corporation and its subsidiaries. Non-employee directors are not eligible for awards under the 2004 Plan. As of December 31, 2016 , 2,715,137 options and 726,657 retention shares and stock units were outstanding under the 2004 Plan. We no longer grant any stock options or other stock or unit awards under this plan. The Union Pacific Corporation 2013 Stock Incentive Plan (2013 Plan) was approved by shareholders in May 2013. The 2013 Plan reserved 78,000,000 shares of our common stock for issuance, plus any shares subject to awards made under previous plans as of February 28, 2013, that are subsequently cancelled, expired, forfeited or otherwise not issued under previous plans. Under the 2013 Plan, non-qualified options, incentive stock options, retention shares, stock units, and incentive bonus awards may be granted to eligible employees of the Corporation and its subsidiaries. Non-employee directors are not eligible for awards under the 2013 Plan. As of December 31, 2016 , 3,439,910 options and 3,207,689 retention shares and stock units were outstanding under the 2013 Plan.  Pursuant to the above plans 73,745,250; 76,548,520; and 77,786,772 shares of our common stock were authorized and available for grant at December 31, 2016 , 2015, and 2014, respectively.  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:      Millions 2016 2015 2014  Stock-based compensation, before tax:  Stock options $ 16 $ 17 $ 21  Retention awards 66 81 91  Total stock-based compensation, before tax $ 82 $ 98 $ 112  Excess tax benefits from equity compensation plans $ 28 $ 62 $ 118  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 2016 2015 2014  Risk-free interest rate 1.3% 1.3% 1.6%  Dividend yield 2.9% 1.8% 2.1%  Expected life (years) 5.1 5.1 5.2  Volatility 23.2% 23.4% 30.0%  Weighted-average grant-date fair value of options granted $ 11.36 $ 22.30 $ 20.18  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 2016 is presented below:      Options (thous.) Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value (millions)  Outstanding at January 1, 2016 5,571 $ 66.69 5.4 yrs. $ 114  Granted 1,672 75.52 N/A N/A  Exercised (978) 37.66 N/A N/A  Forfeited or expired (103) 100.16 N/A N/A  Outstanding at December 31, 2016 6,162 $ 73.13 5.9 yrs. $ 205  Vested or expected to vest at December 31, 2016 6,101 $ 73.05 5.9 yrs. $ 204  Options exercisable at December 31, 2016 3,639 $ 62.95 4.2 yrs. $ 154  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 December 31, 2016 , are subject to performance or market-based vesting conditions.  At December 31, 2016 , there was $18 million of unrecognized compensation expense related to nonvested stock options, which is expected to be recognized over a weighted-average period of 1.3 years. Additional information regarding stock option exercises appears in the table below:      Millions 2016 2015 2014  Intrinsic value of stock options exercised $ 52 $ 50 $ 194  Cash received from option exercises 39 27 54  Treasury shares repurchased for employee payroll taxes (15) (12) (24)  Tax benefit realized from option exercises 20 19 74  Aggregate grant-date fair value of stock options vested 19 19 17  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 2016 were as follows:      Shares (thous.) Weighted-Average Grant-Date Fair Value  Nonvested at January 1, 2016 2,900 $ 80.01  Granted 836 75.77  Vested (799) 57.70  Forfeited (148) 88.42  Nonvested at December 31, 2016 2,789 $ 84.68  Retention awards are granted at no cost to the employee or non-employee director and vest over periods lasting up to four years. At December 31, 2016 , there was $84 million of total unrecognized compensation expense related to nonvested retention awards, which is expected to be recognized over a weighted-average period of 1.6 years.  Performance Retention Awards – In February 2016, our Board of Directors approved performance stock unit grants. The basic terms of these performance stock units are identical to those granted in February 2014 and February 2015, except for different annual return on invested capital (ROIC) performance targets and the addition of relative operating income growth (OIG) as a modifier compared to the companies included in t he 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 certain levels of ROIC, and for the 2016 plan, 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 2016 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 2016 grant were as follows:      2016  Dividend per share per quarter $ 0.55  Risk-free interest rate at date of grant 0.9%  Changes in our performance retention awards during 2016 were as follows:      Shares (thous.) Weighted-Average Grant-Date Fair Value  Nonvested at January 1, 2016 1,255 $ 82.98  Granted 503 70.09  Vested (530) 62.57  Forfeited (83) 90.42  Nonvested at December 31, 2016 1,145 $ 86.23  At December 31, 2016 , there was $20 million of total unrecognized compensation expense related to nonvested performance retention awards, which is expected to be recognized over a weighted-average period of 1.2 years. This expense is subject to achievement of the performance measures established for the performance stock unit grants.

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2016
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.  Funded Status  We are required by GAAP to separately recognize the overfunded or underfunded status of our pension and OPEB plans as an asset or liability. The funded status represents the difference between the projected benefit obligation (PBO) and the fair value of the plan assets. Our non-qualified (supplemental) pension plan is unfunded by design. The PBO of the pension plans is the present value of benefits earned to date by plan participants, including the effect of assumed future compensation increases. The PBO of the OPEB plan is equal to the accumulated benefit obligation, as the present value of the OPEB liabilities is not affected by compensation increases. Plan assets are measured at fair value. We use a December 31 measurement date for plan assets and obligations for all our retirement plans.  Changes in our PBO and plan assets were as follows for the years ended December 31:      Funded Status Pension OPEB  Millions 2016 2015 2016 2015  Projected Benefit Obligation  Projected benefit obligation at beginning of year $ 3,958 $ 4,142 $ 329 $ 354  Service cost 84 106 1 3  Interest cost 143 163 11 13  Actuarial loss/(gain) 124 (267) 16 (18)  Gross benefits paid (199) (186) (23) (23)  Projected benefit obligation at end of year $ 4,110 $ 3,958 $ 334 $ 329  Plan Assets  Fair value of plan assets at beginning of year $ 3,544 $ 3,654 $ - $ -  Actual return/(loss) on plan assets 279 (43) - -  Voluntary funded pension plan contributions 100 100 - -  Non-qualified plan benefit contributions 24 19 23 23  Gross benefits paid (199) (186) (23) (23)  Fair value of plan assets at end of year $ 3,748 $ 3,544 $ - $ -  Funded status at end of year $ (362) $ (414) $ (334) $ (329)  Amounts recognized in the statement of financial position as of December 31, 2016, and 2015 consist of:      Pension OPEB  Millions 2016 2015 2016 2015  Noncurrent assets $ 67 $ 1 $ - $ -  Current liabilities (24) (22) (24) (23)  Noncurrent liabilities (405) (393) (310) (306)  Net amounts recognized at end of year $ (362) $ (414) $ (334) $ (329)  Pre-tax amounts recognized in accumulated other comprehensive income/(loss) as of December 31, 2016, and 2015 consist of:      2016 2015  Millions Pension OPEB Total Pension OPEB Total  Prior service (cost)/credit $ - $ (2) $ (2) $ - $ 7 $ 7  Net actuarial loss (1,681) (123) (1,804) (1,652) (117) (1,769)  Total $ (1,681) $ (125) $ (1,806) $ (1,652) $ (110) $ (1,762)  Pre-tax changes recognized in other comprehensive income/(loss) during 2016, 2015 and 2014 were as follows:      Pension OPEB  Millions 2016 2015 2014 2016 2015 2014  Net actuarial (loss)/gain $ (112) $ (31) $ (780) $ (16) $ 18 $ (33)  Amortization of:  Prior service cost/(credit) - - - (9) (10) (11)  Actuarial loss 83 106 71 10 13 10  Total $ (29) $ 75 $ (709) $ (15) $ 21 $ (34)  Amounts included in accumulated other comprehensive income/(loss) expected to be amortized into net periodic cost during 2017:      Millions Pension OPEB Total  Prior service credit $ - $ (1) $ (1)  Net actuarial loss (79) (10) (89)  Total $ (79) $ (11) $ (90)  Underfunded Accumulated Benefit Obligation – The accumulated benefit obligation (ABO) is the present value of benefits earned to date, assuming no future compensation growth. The underfunded accumulated benefit obligation represents the difference between the ABO and the fair value of plan assets. At December 31, 2016, and 2015 , the non-qualified (supplemental) plan ABO was $412 million and $388 million, respectively. The following table discloses only the PBO, ABO, and fair value of plan assets for pension plans where the accumulated benefit obligation is in excess of the fair value of the plan assets as of December 31 :      Underfunded Accumulated Benefit Obligation  Millions 2016 2015  Projected benefit obligation $ 428 $ 398  Accumulated benefit obligation $ 412 $ 388  Fair value of plan assets - -  Underfunded accumulated benefit obligation $ (412) $ (388)  The ABO for all defined benefit pension plans was $3.9 billion and $3.7 billion at December 31, 2016, and 2015 , respectively.  Assumptions – The weighted-average actuarial assumptions used to determine benefit obligations at December 31:      Pension OPEB  Percentages 2016 2015 2016 2015  Discount rate 4.20% 4.37% 4.00% 4.16%  Compensation increase 4.20% 4.10% N/A N/A  Health care cost trend rate (employees under 65) N/A N/A 6.31% 6.52%  Ultimate health care cost trend rate N/A N/A 4.50% 4.50%  Year ultimate trend rate reached N/A N/A 2038 2038  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 years ended December 31:      Pension OPEB  Millions 2016 2015 2014 2016 2015 2014  Net Periodic Benefit Cost:  Service cost $ 84 $ 106 $ 70 $ 1 $ 3 $ 2  Interest cost 143 163 158 11 13 14  Expected return on plan assets (267) (255) (230) - - -  Amortization of:  Prior service cost/(credit) - - - (9) (10) (11)  Actuarial loss 83 106 71 10 13 10  Net periodic benefit cost $ 43 $ 120 $ 69 $ 13 $ 19 $ 15  Assumptions – The weighted-average actuarial assumptions used to determine expense were as follows:      Pension OPEB  Percentages 2016 2015 2014 2016 2015 2014  Discount rate for benefit obligations 4.37% 3.94% 4.72% 4.13% 3.74% 4.47%  Discount rate for interest on benefit obligations 3.65% 3.94% 4.72% 3.34% 3.74% 4.47%  Discount rate for service cost 4.69% 3.94% 4.72% 4.59% 3.74% 4.47%  Discount rate for interest on service cost 4.55% 3.94% 4.72% 4.44% 3.74% 4.47%  Expected return on plan assets 7.50% 7.50% 7.50% N/A N/A N/A  Compensation increase 4.20% 4.00% 4.00% N/A N/A N/A  Health care cost trend rate (employees under 65) N/A N/A N/A 6.52% 6.34% 6.49%  Ultimate health care cost trend rate N/A N/A N/A 4.50% 4.50% 4.50%  Year ultimate trend reached N/A N/A N/A 2038 2028 2028  Beginning in 2016, we measure the service cost and interest cost components of our net periodic benefit cost by using individual spot discount rates matched with separate cash flows for each future year. The discount rates were based on a yield curve of high quality corporate bonds. The expected return on plan assets is based on our asset allocation mix and our historical return, taking into account current and expected market conditions. The actual return/(loss) on pension plan assets, net of fees, was approximately 8% in 2016, (1)% in 2015, and 6% in 2014.  Assumed health care cost trend rates have an effect on the expense and liabilities reported for health care plans. The assumed health care cost trend rate is based on historical rates and expected market conditions. The 2017 assumed health care cost trend rate for employees under 65 is 6.52% . It is assumed the rate will decrease gradually to an ultimate rate of 4.5% in 2038 and will remain at that level. A one-percentage point change in the assumed health care cost trend rates would have the following effects on OPEB:      Millions One % pt. Increase One % pt. Decrease  Effect on total service and interest cost components $ 1 $ (1)  Effect on accumulated benefit obligation 19 (16)  Cash Contributions  The following table details our cash contributions for the qualified pension plans and the benefit payments for the non-qualified (supplemental) pension and OPEB plans:      Pension  Millions Qualified Non-qualified OPEB  2016 $ 100 $ 24 $ 23  2015 100 19 23  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. All contributions made to the qualified pension plans in 2016 were voluntary and were made with cash generated from operations.  The non-qualified pension and OPEB plans are not funded and are not subject to any minimum regulatory funding requirements. Benefit payments for each year represent supplemental pension payments and claims paid for medical and life insurance. We anticipate our 2017 supplemental pension and OPEB payments will be made from cash generated from operations.  Benefit Payments  The following table details expected benefit payments for the years 2017 through 2026:      Millions Pension OPEB  2017 $ 199 $ 24  2018 201 24  2019 204 23  2020 206 22  2021 209 22  Years 2022 - 2026 1,094 98  Asset Allocation Strategy  Our pension plan asset allocation at December 31, 2016, and 2015 , and target allocation for 2017, are as follows:      Percentage of Plan Assets  Target December 31,  Allocation 2017 2016 2015  Equity securities 60% to 70% 68% 67%  Debt securities 20% to 30% 21 23  Real estate 2% to 8% 6 6  Commodities 4% to 6% 5 4  Total 100% 100%  The investment strategy for pension plan assets is to maintain a broadly diversified portfolio designed to achieve our target average long-term rate of return of 7.0% . We reduced our expected rate of return on plan assets to 7.0% in 2017 from 7.5% in 2016 to reflect our expected future returns on plan assets based on our current asset allocation strategy. While we believe we can achieve a long-term average rate of return of 7.0%, we cannot be certain that the portfolio will perform to our expectations. Assets are strategically allocated among equity, debt, and other investments in order to achieve a diversification level that reduces fluctuations in investment returns. Asset allocation target ranges for equity, debt, and other portfolios are evaluated at least every three years with the assistance of an independent consulting firm. Actual asset allocations are monitored monthly, and rebalancing actions are executed at least quarterly, if needed.  The pension plan investments are held in a Master Trust. The majority of pension plan assets are invested in equity securities because equity portfolios have historically provided higher returns than debt and other asset classes over extended time horizons and are expected to do so in the future. Correspondingly, equity investments also entail greater risks than other investments. Equity risks are balanced by investing a significant portion of the plans’ assets in high quality debt securities. The average credit rating of the debt portfolio exceeded A at both December 31, 2016 and December 31, 2015 . The debt portfolio is also broadly diversified and invested primarily in U.S. Treasury, mortgage, and corporate securities. The weighted-average maturity of the debt portfolio was 14 years and 12 years at December 31, 2016, and 2015 , respectively.  The investment of pension plan assets in securities issued by UPC is explicitly prohibited by the plan for both the equity and debt portfolios, other than through index fund holdings.  Fair Value Measurements  The pension plan assets are valued at fair value. The following is a description of the valuation methodologies used for the investments measured at fair value, including the general classification of such instruments pursuant to the valuation hierarchy.  Temporary Cash Investments – These investments consist of U.S. dollars and foreign currencies held in master trust accounts at The Northern Trust Company (the Trustee). Foreign currencies held are reported in terms of U.S. dollars based on currency exchange rates readily available in active markets. These temporary cash investments are classified as Level 1 investments.  Registered Investment Companies – Registered Investment Companies are entities primarily engaged in the business of investing in securities and are registered with the Securities and Exchange Commission. The Plan’s holdings of Registered Investment Companies include both public and private fund vehicles. The public vehicles are mutual funds (real estate) and exchange-traded funds (stocks), which are classified as Level 1 investments. The private vehicles (bonds) do not have published pricing and are valued using Net Asset Value (NAV).  Federal Government Securities – Federal Government Securities consist of bills, notes, bonds, and other fixed income securities issued directly by the U.S. Treasury or by government-sponsored enterprises. These assets are valued using a bid evaluation process with bid data provided by independent pricing sources. Federal Government Securities are classified as Level 2 investments.  Bonds and Debentures – Bonds and debentures consist of fixed income securities issued by U.S. and non-U.S. corporations as well as state and local governments. These assets are valued using a bid evaluation process with bid data provided by independent pricing sources. Corporate, state, and municipal bonds and debentures are classified as Level 2 investments.  Corporate Stock – This investment category consists of common and preferred stock issued by U.S. and non-U.S. corporations. Most common shares are traded actively on exchanges and price quotes for these shares are readily available. Common stock is classified as a Level 1 investment. Preferred shares included in this category are valued using a bid evaluation process with bid data provided by independent pricing sources. Preferred stock is classified as a Level 2 investment.  Venture Capital and Buyout Partnerships – This investment category is comprised of interests in limited partnerships that invest primarily in privately-held companies. Due to the private nature of the partnership investments, pricing inputs are not readily observable. Asset valuations are developed by the general partners that manage the partnerships. These valuations are based on the application of public market multiples to private company cash flows, market transactions that provide valuation information for comparable companies, and other methods. The fair value recorded by the Plan is calculated using each partnership’s NAV.  Real Estate Partnerships – Most of the Plan’s real estate investments are partnership interests. The Real Estate Partnership category also includes real estate investments held in similar structures such as private real estate investment trusts and limited liability companies. Valuations for the holdings in this category are not based on readily observable inputs and are primarily derived from property appraisals. The fair value recorded by the Plan is calculated using the NAV for each investment.  Collective Trust and Other Fund s – Collective trust and other funds are comprised of shares or units in commingled funds that are not publicly traded. The underlying assets in these funds (U.S. stock funds, non-U.S. stock funds, commodity funds, and short term investment funds) are publicly traded on exchanges and price quotes for the assets held by these funds are readily available. The fair value recorded by the Plan is calculated using NAV for each investment.  This category also includes investments in limited liability companies that invest in publicly-traded securities. The limited liability company investments are funds that invest in both long and short positions in convertible securities, stocks, commodities, and fixed income securities. The underlying securities held by the funds are traded actively on public exchanges and price quotes for these investments are readily available. The fair value recorded by the plan is calculated using the NAV for each investment.  As of December 31, 2016 , the pension plan assets measured at fair value on a recurring basis were as follows:       Quoted Prices Significant  in Active Other Significant  Markets for Observable Unobservable  Identical Inputs Inputs Inputs  Millions (Level 1) (Level 2) (Level 3) Total  Plan assets at fair value:  Temporary cash investments $ 27 $ - $ - $ 27  Registered investment companies [a] 17 - - 17  Federal government securities - 142 - 142  Bonds and debentures - 357 - 357  Corporate stock 1,059 8 - 1,067  Total plan assets at fair value $ 1,103 $ 507 $ - $ 1,610  Plan assets at NAV:  Registered investment companies [b] 280  Venture capital and buyout partnerships 283  Real estate partnerships 212  Collective trust and other funds 1,346  Total plan assets at NAV $ 2,121  Other assets [c] 17  Total plan assets $ 3,748  [a] Registered investment companies measured at fair value include stock and real estate investments. [b] Registered investment companies measured at NAV include bond investments. [c] Other assets include accrued receivables and pending broker settlements.  As of December 31, 2015 , the pension plan assets measured at fair value on a recurring basis were as follows:      Quoted Prices Significant  in Active Other Significant  Markets for Observable Unobservable  Identical Inputs Inputs Inputs  Millions (Level 1) (Level 2) (Level 3) Total  Plan assets at fair value:  Temporary cash investments $ 13 $ - $ - $ 13  Registered investment companies [a] 179 - - 179  Federal government securities - 125 - 125  Bonds and debentures - 383 - 383  Corporate stock 1,034 7 - 1,041  Total plan assets at fair value $ 1,226 $ 515 $ - $ 1,741  Plan assets at NAV:  Registered investment companies [b] 270  Venture capital and buyout partnerships 256  Real estate partnerships 199  Collective trust and other funds 1,075  Total plan assets at NAV $ 1,800  Other assets [c] 3  Total plan assets $ 3,544  [a] Registered investment companies measured at fair value include stock and real estate investments. [b] Registered investment companies measured at NAV include bond investments. [c] Other assets include accrued receivables and pending broker settlements.  For the years ended December 31, 2016 and 2015 , there were no significant transfers in or out of Levels 1, 2, or 3. Other Retirement Programs  401(k)/Thrift Plan – We provide a defined contribution plan (401(k)/thrift plan) to eligible non-union and union employees for whom we make matching contributions. We match 50 cents for each dollar contributed by employees up to the first six percent of compensation contributed. Our plan contributions were $19 million in 2016, $20 million in 2015, and $19 million in 2014.  Railroad Retirement System – All Railroad employees are covered by the Railroad Retirement System (the System). Contributions made to the System are expensed as incurred and amounted to approximately $671 million in 2016, $749 million in 2015, and $711 million in 2014.  Collective Bargaining Agreements – Under collective bargaining agreements, we participate in multi-employer benefit plans that provide certain postretirement health care and life insurance benefits for eligible union employees. Premiums paid under these plans are expensed as incurred and amounted to $50 million in 2016, $46 million in 2015, and $52 million in 2014.

Other Income

Other Income	12 Months Ended
	Dec. 31, 2016
Other Income [Abstract]
Other Income	7. Other Income  Other income included the following for the years ended December 31:      Millions 2016 2015 2014  Rental income $ 96 $ 96 $ 96  Net gain on non-operating asset dispositions [a] [b] 94 144 69  Interest income 11 5 4  Non-operating environmental costs and other [c] (9) (19) (18)  Total $ 192 $ 226 $ 151  [a] 2016 includes $ 17 million and $50 million related to a real estate sale in the first and second quarter, respectively. [b] 2015 includes $113 million related to a real estate sale. [c] 2014 includes $14 million related to the sale of a permanent easement.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Taxes [Abstract]
Income Taxes	8. Income Taxes  Components of income tax expense were as follows for the years ended December 31:      Millions 2016 2015 2014  Current tax expense:  Federal $ 1,518 $ 1,901 $ 2,019  State 176 210 239  Foreign 8 8 10  Total current tax expense 1,702 2,119 2,268  Deferred and other tax expense:  Federal 692 644 753  State 139 121 142  Total deferred and other tax expense 831 765 895  Total income tax expense $ 2,533 $ 2,884 $ 3,163  For the years ended December 31, reconciliations between statutory and effective tax rates are as follows:      Tax Rate Percentages 2016 2015 2014  Federal statutory tax rate 35.0 % 35.0 % 35.0 %  State statutory rates, net of federal benefits 3.1 3.1 3.1  Tax credits (0.5) (0.5) (0.4)  Other (0.2) 0.1 0.2  Effective tax rate 37.4 % 37.7 % 37.9 %  Deferred tax assets and liabilities are recorded for the expected future tax consequences of events that are reported in different periods for financial reporting and income tax purposes. The majority of our deferred tax assets relate to deductions that already have been claimed for financial reporting purposes but not for tax purposes. The majority of our deferred tax liabilities relate to differences between the tax bases and financial reporting amounts of our land and depreciable property, due to accelerated tax depreciation (including bonus depreciation), revaluation of assets in purchase accounting transactions, and differences in capitalization methods.  Deferred income tax (liabilities)/assets were comprised of the following at December 31:      Millions 2016 2015  Deferred income tax liabilities:  Property $ (16,687) $ (16,079)  Other (346) (352)  Total deferred income tax liabilities (17,033) (16,431)  Deferred income tax assets:  Accrued wages 75 76  Accrued casualty costs 231 237  Stock compensation 69 72  Debt and leases 14 149  Retiree benefits 222 204  Credits 145 156  Other 281 296  Total deferred income tax assets $ 1,037 $ 1,190  Net deferred income tax liability $ (15,996) $ (15,241)  When appropriate, we record a valuation allowance against deferred tax assets to reflect that these tax assets may not be realized. In determining whether a valuation allowance is appropriate, we consider whether it is more likely than not that all or some portion of our deferred tax assets will not be realized based on management’s judgments using available evidence for purposes of estimating whether future taxable income will be sufficient to realize a deferred tax asset. In 2016 and 2015, there were no valuation allowances.  Tax benefits are recognized only for tax positions that are more likely than not to be sustained upon examination by tax authorities. The amount recognized is measured as the largest amount of benefit that is greater than 50 percent likely to be realized upon settlement. Unrecognized tax benefits are tax benefits claimed in our tax returns that do not meet these recognition and measurement standards.  A reconciliation of changes in unrecognized tax benefits liabilities/(assets) from the beginning to the end of the reporting period is as follows:      Millions 2016 2015 2014  Unrecognized tax benefits at January 1 $ 94 $ 151 $ 59  Increases for positions taken in current year 31 38 92  Increases for positions taken in prior years 10 13 22  Decreases for positions taken in prior years (20) (87) (14)  Refunds from/(payments to) and settlements with taxing authorities 4 (13) (8)  Increases/(decreases) for interest and penalties 6 (5) 1  Lapse of statutes of limitations - (3) (1)  Unrecognized tax benefits at December 31 $ 125 $ 94 $ 151  We recognize interest and penalties as part of income tax expense. Total accrued liabilities for interest and penalties were $8 million and $2 million at December 31, 2016, and 2015 , respectively. Total interest and penalties recognized as part of income tax expense (benefit) were $5 million for 2016, $(3) million for 2015, and $9 million for 2014.  Internal Revenue Service (IRS) examinations have been completed and settled for all years prior to 2011, and the statute of limitations bars any additional tax assessments. In 2016, UPC amended its 2011 and 2012 income tax returns to claim deductions resulting from the resolution of IRS examinations for years prior to 2011. The IRS is currently reviewing the 2011 amended return.  In the third quarter of 2015, UPC and the IRS signed a closing agreement resolving all tax matters for tax years 2009-2010. The settlement had an immaterial effect on our income tax expense. In connection with the settlement, UPC paid $10 million in the fourth quarter of 2015.  In the fourth quarter of 2014, UPC and the IRS signed a closing agreement resolving all tax matters for tax years 2005-2008. The settlement had an immaterial effect on our income tax expense. In connection with the settlement, UPC paid $11 million in 2014.  Several state tax authorities are examining our state income tax returns for years 2006 through 2014.  We do not expect our unrecognized tax benefits to change significantly in the next 12 months.  The portion of our unrecognized tax benefits that relates to permanent changes in tax and interest would reduce our effective tax rate, if recognized. The remaining unrecognized tax benefits relate to tax positions for which only the timing of the benefit is uncertain. Recognition of the tax benefits with uncertain timing would reduce our effective tax rate only through a reduction of accrued interest and penalties. The unrecognized tax benefits that would reduce our effective tax rate are as follows:      Millions 2016 2015 2014  Unrecognized tax benefits that would reduce the effective tax rate $ 31 $ 31 $ 33  Unrecognized tax benefits that would not reduce the effective tax rate 94 63 118  Total unrecognized tax benefits $ 125 $ 94 $ 151 

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Earnings Per Share	9. Earnings Per Share  The following table provides a reconciliation between basic and diluted earnings per share for the years ended December 31:      Millions, Except Per Share Amounts 2016 2015 2014  Net income $ 4,233 $ 4,772 $ 5,180  Weighted-average number of shares outstanding:  Basic 832.4 866.2 897.1  Dilutive effect of stock options 1.5 1.5 2.1  Dilutive effect of retention shares and units 1.5 1.7 1.9  Diluted 835.4 869.4 901.1  Earnings per share – basic $ 5.09 $ 5.51 $ 5.77  Earnings per share – diluted $ 5.07 $ 5.49 $ 5.75  Common stock options totaling 2.0 million, 1.1 million, and 0. 4 million for 201 6 , 201 5 , and 201 4 , respectively, were excluded from the computation of diluted earnings per share because the exercise prices of these options exceeded the average market price of our common stock for the respective periods, and the effect of their inclusion would be anti-dilutive.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income/(Loss)	12 Months Ended
	Dec. 31, 2016
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) were as follows (net of tax):      Millions Defined benefit plans Foreign currency translation Total  Balance at January 1, 2016 $ (1,103) $ (92) $ (1,195)  Other comprehensive income/(loss) before reclassifications (3) (48) (51)  Amounts reclassified from accumulated other comprehensive income/(loss) [a] (26) - (26)  Net year-to-date other comprehensive income/(loss), net of taxes of $49 million (29) (48) (77)  Balance at December 31, 2016 $ (1,132) $ (140) $ (1,272)   Balance at January 1, 2015 $ (1,161) $ (49) $ (1,210)  Other comprehensive income/(loss) before reclassifications (4) (43) (47)  Amounts reclassified from accumulated other comprehensive income/(loss) [a] 62 - 62  Net year-to-date other comprehensive income/(loss), net of taxes of $(8) million 58 (43) 15  Balance at December 31, 2015 $ (1,103) $ (92) $ (1,195)  [a] The accumulated other comprehensive income/(loss) reclassification components are 1) prior service cost/(benefit) 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.

Accounts Receivable

Accounts Receivable	12 Months Ended
	Dec. 31, 2016
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 December 31, 2016, and 2015 , our accounts receivable were reduced by $5 million. Receivables not expected to be collected in one year and the associated allowances are classified as other assets in our Consolidated Statements of Financial Position. At December 31, 2016, and 2015 , receivables classified as other assets were reduced by allowances of $17 million and $1 1 million, respectively.  Receivables Securitization Facility – The Railroad maintains a $650 million, 3 -year receivables securitization facility (the Receivables Facility), which now matures in July 201 9 , after we completed a renewal in August 2016 with comparable terms. U nder 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 F acility was $0 and $400 million at December 31, 2016 , and December 31, 2015 , respectively . The Receivables F acility was supported by $1.0 billion and $0.9 billion of accounts receivable as collateral at December 31, 2016 , and December 31, 2015 , respectively, which, as a retained interest, is included in accounts receivable, net in our Consolidated Statements of Financial Position.  The outstanding amount the Railroad is allowed to maintain under the Receivables F acility, 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 F acility would not materially change.  The costs of the Receivables F acility 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 F acility are included in interest expense and were $7 million , $ 5 million and $ 4 million for 201 6 , 201 5 , and 201 4 , respectively.

Properties

Properties	12 Months Ended
	Dec. 31, 2016
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 December 31, 2016 Cost Depreciation Value Useful Life  Land $ 5,220 $ N/A $ 5,220 N/A  Road:  Rail and other track material 15,845 5,722 10,123 40  Ties 9,812 2,736 7,076 33  Ballast 5,242 1,430 3,812 34  Other roadway [a] 18,138 3,226 14,912 47  Total road 49,037 13,114 35,923 N/A  Equipment:  Locomotives 9,692 3,939 5,753 20  Freight cars 2,243 972 1,271 24  Work equipment and other 905 232 673 19  Total equipment 12,840 5,143 7,697 N/A  Technology and other 974 412 562 11  Construction in progress 987 - 987 N/A  Total $ 69,058 $ 18,669 $ 50,389 N/A      Millions, Except Estimated Useful Life Accumulated Net Book Estimated  As of December 31, 2015 Cost Depreciation Value Useful Life  Land $ 5,195 $ N/A $ 5,195 N/A  Road:  Rail and other track material 15,236 5,495 9,741 37  Ties 9,439 2,595 6,844 33  Ballast 5,024 1,350 3,674 34  Other roadway [a] 17,374 3,021 14,353 47  Total road 47,073 12,461 34,612 N/A  Equipment:  Locomotives 9,027 3,726 5,301 19  Freight cars 2,203 962 1,241 24  Work equipment and other 897 191 706 19  Total equipment 12,127 4,879 7,248 N/A  Technology and other 919 358 561 11  Construction in progress 1,250 - 1,250 N/A  Total $ 66,564 $ 17,698 $ 48,866 N/A  [a] Other roadway includes grading, bridges and tunnels, signals, buildings, and other road assets.  Property and Depreciation – Our railroad operations are highly capital intensive, and our large base of homogeneous, network-type assets turns over on a continuous basis. Each year we develop a capital program for the replacement of assets and for the acquisition or construction of assets that enable us to enhance our operations or provide new service offerings to customers. Assets purchased or constructed throughout the year are capitalized if they meet applicable minimum units of property criteria. Properties and equipment are carried at cost and are depreciated on a straight-line basis over their estimated service lives, which are measured in years, except for rail in high-density traffic corridors (i.e., all rail lines except for those subject to abandonment, yard and switching tracks, and electronic yards) for which lives are measured in millions of gross tons per mile of track. We use the group method of depreciation in which all items with similar characteristics, use, and expected lives are grouped together in asset classes, and are depreciated using composite depreciation rates. The group method of depreciation treats each asset class as a pool of resources, not as singular items. We currently have more than 60 depreciable asset classes, and we may increase or decrease the number of asset classes due to changes in technology, asset strategies, or other factors.  We determine the estimated service lives of depreciable railroad assets by means of depreciation studies. We perform depreciation studies at least every three years for equipment and every six years for track assets (i.e., rail and other track material, ties, and ballast) and other road property. Our depreciation studies take into account the following factors:  · Statistical analysis of historical patterns of use and retirements of each of our asset classes; · Evaluation of any expected changes in current operations and the outlook for continued use of the assets; · Evaluation of technological advances and changes to maintenance practices; and · Expected salvage to be received upon retirement.  For rail in high-density traffic corridors, we measure estimated service lives in millions of gross tons per mile of track. It has been our experience that the lives of rail in high-density traffic corridors are closely correlated to usage (i.e., the amount of weight carried over the rail). The service lives also vary based on rail weight, rail condition (e.g., new or secondhand), and rail type (e.g., straight or curve). Our depreciation studies for rail in high-density traffic corridors consider each of these factors in determining the estimated service lives. For rail in high-density traffic corridors, we calculate depreciation rates annually by dividing the number of gross ton-miles carried over the rail (i.e., the weight of loaded and empty freight cars, locomotives and maintenance of way equipment transported over the rail) by the estimated service lives of the rail measured in millions of gross tons per mile. For all other depreciable assets, we compute depreciation based on the estimated service lives of our assets as determined from the analysis of our depreciation studies. Changes in the estimated service lives of our assets and their related depreciation rates are implemented prospectively.  Under group depreciation, the historical cost (net of salvage) of depreciable property that is retired or replaced in the ordinary course of business is charged to accumulated depreciation and no gain or loss is recognized. The historical cost of certain track assets is estimated using (i) inflation indices published by the Bureau of Labor Statistics and (ii) the estimated useful lives of the assets as determined by our depreciation studies. The indices were selected because they closely correlate with the major costs of the properties comprising the applicable track asset classes. Because of the number of estimates inherent in the depreciation and retirement processes and because it is impossible to precisely estimate each of these variables until a group of property is completely retired, we continually monitor the estimated service lives of our assets and the accumulated depreciation associated with each asset class to ensure our depreciation rates are appropriate. In addition, we determine if the recorded amount of accumulated depreciation is deficient (or in excess) of the amount indicated by our depreciation studies. Any deficiency (or excess) is amortized as a component of depreciation expense over the remaining service lives of the applicable classes of assets.  For retirements of depreciable railroad properties that do not occur in the normal course of business, a gain or loss may be recognized if the retirement meets each of the following three conditions: (i) is unusual, (ii) is material in amount, and (iii) varies significantly from the retirement profile identified through our depreciation studies. A gain or loss is recognized in other income when we sell land or dispose of assets that are not part of our railroad operations.  When we purchase an asset, we capitalize all costs necessary to make the asset ready for its intended use. However, many of our assets are self-constructed. A large portion of our capital expenditures is for replacement of existing track assets and other road properties, which is typically performed by our employees, and for track line expansion and other capacity projects. Costs that are directly attributable to capital projects (including overhead costs) are capitalized. Direct costs that are capitalized as part of self-constructed assets include material, labor, and work equipment. Indirect costs are capitalized if they clearly relate to the construction of the asset.  Normal r epairs and maintenance are expensed as incurred, while costs incurred that extend the useful life of an asset, improve the safety of our operations or improve operating efficiency are capitalized. These costs are allocated using appropriate statistical bases. Total expense for repairs and maintenance incurred was $2.3 billion for 201 6 , $2. 5 billion for 201 5 , and $2. 4 billion for 201 4 .  Assets held under capital leases are recorded at the lower of the net present value of the minimum lease payments or the fair value of the leased asset at the inception of the lease. Amortization expense is computed using the straight-line method over the shorter of the estimated useful lives of the assets or the period of the related lease.

Accounts Payable And Other Curr

Accounts Payable And Other Current Liabilities	12 Months Ended
	Dec. 31, 2016
Accounts Payable And Other Current Liabilties [Abstract]
Accounts Payable And Other Current Liabilities	13. Accounts Payable and Other Current Liabilities      Dec. 31, Dec. 31,  Millions 2016 2015  Accounts payable $ 955 $ 743  Income and other taxes payable 472 434  Accrued wages and vacation 387 391  Interest payable 212 208  Accrued casualty costs 185 181  Equipment rents payable 101 105  Other 570 550  Total accounts payable and other current liabilities $ 2,882 $ 2,612 

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2016
Financial Instruments [Abstract]
Financial Instruments	14. Financial Instruments  Short-Term Investments – The Company’s short-term investments consist of time deposits and government agency securities. These investments are considered level 2 investments and are valued at amortized cost, which approximates fair value ( $60 million of time deposits as of December 31, 2016). 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 year ended December 31, 2016.  Fair Value of Financial Instruments – The fair value of our short- and long-term debt was estimated using a market value price model, which utilizes applicable U.S. Treasury rates along with current market quotes on comparable debt securities. All of the inputs used to determine the fair market value of the Corporation’s long-term debt are Level 2 inputs and obtained from an independent source. At December 31, 2016 , the fair value of total debt was $15.9 billion, approximately $0.9 billion more than the carrying value. At December 31, 2015 , the fair value of total debt was $15.2 billion, approximately $1.0 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 December 31, 2016, and 2015 , approximately $155 million 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	12 Months Ended
	Dec. 31, 2016
Debt [Abstract]
Debt	15. Debt  Total debt as of December 31, 2016, and 2015 , is summarized below:      Millions 2016 2015  Notes and debentures, 1.8% to 7.9% due through 2065 $ 13,547 $ 11,964  Capitalized leases, 3.1% to 8.4% due through 2028 1,105 1,268  Equipment obligations, 2.6% to 6.7% due through 2031 1,069 963  Term loans - floating rate, due in 2017 100 200  Mortgage bonds, 4.8% due through 2030 57 57  Medium-term notes, 9.3% to 10.0% due through 2020 23 23  Receivables Securitization (Note 11) - 400  Unamortized discount and deferred issuance costs (894) (674)  Total debt 15,007 14,201  Less: current portion (758) (594)  Total long-term debt $ 14,249 $ 13,607  Debt Maturities – The following table presents aggregate debt maturities as of December 31, 2016 , excluding market value adjustments:      Millions  2017 $ 763  2018 572  2019 645  2020 1,042  2021 673  Thereafter 12,206  Total principal 15,901  Unamortized discount and deferred issuance costs (894)  Total debt $ 15,007  Equipment Encumbrances – Equipment with a carrying value of approximately $2.3 billion and $2.6 billion at December 31, 2016, and 2015 , respectively, served as collateral for capital leases and other types of equipment obligations in accordance with the secured financing arrangements utilized to acquire such railroad equipment.  As a result of the merger of Missouri Pacific Railroad Company (MPRR) with and into UPRR on January 1, 1997, and pursuant to the underlying indentures for the MPRR mortgage bonds, UPRR must maintain the same value of assets after the merger in order to comply with the security requirements of the mortgage bonds. As of the merger date, the value of the MPRR assets that secured the mortgage bonds was approximately $6.0 billion. In accordance with the terms of the indentures, this collateral value must be maintained during the entire term of the mortgage bonds irrespective of the outstanding balance of such bonds.  Credit Facilities – At December 31, 2016 , we had $1.7 billion of credit available under the facility, which is designated for general corporate purposes and supports the issuance of commercial paper. We did not draw on the facility during 2016. 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 December 31, 2016 , the debt-to-net-worth coverage ratio allowed us to carry up to $39.9 billion of debt (as defined in the facility), and we had $15.1 billion of debt (as defined in the facility) outstanding at that date. Under our current capital 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.  During 2016, we did not issue or repay any commercial paper, and at December 31, 2016, and 2015 , we had no 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.  Dividend Restrictions – Our revolving credit facility includes a debt-to-net worth covenant (discussed in the Credit Facilities section above) that, under certain circumstances, restricts the payment of cash dividends to our shareholders. The amount of retained earnings available for dividends was $12.4 billion and $13.6 billion at December 31, 2016, and 2015 , respectively.  Shelf Registration Statement and Significant New Borrowings – On July 28, 2016, the Board of Directors renewed its authorization for the Company to issue up to $4.0 billion of debt securities under the Company’s current three -year shelf registration filed in February 2015, which had $0.9 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. At December 31, 2016, we had remaining authority to issue up to $3.55 billion of debt securities under our shelf registration.  During 2016, we issued the following unsecured, fixed-rate debt securities under our current shelf registration:       Date Description of Securities  March 1, 2016 $500 million of 2.750% Notes due March 1, 2026  $600 million of 4.050% Notes due March 1, 2046  $200 million of reopened 4.375% Notes due November 15, 2065  August 8, 2016 $150 million of reopened 2.750% Notes due March 1, 2026  $300 million of 3.350% Notes due August 15, 2046  We used the net proceeds from the offerings for general corporate purposes, including the repurchase of common stock pursuant to our share repurchase program. These debt securities include change-of-control provisions .  Equipment Trust – On May 9, 2016 , UPRR consummated a pass-through (P/T) financing, whereby a P/T trust was created, which issued $151 million of P/T trust certificates with a stated interest rate of 2.495% . The P/T trust certificates will mature on November 9, 2029 . The proceeds from the issuance of the P/T trust certificates were used to purchase equipment trust certificates to be issued by UPRR to finance the acquisition of 59 locomotives. The equipment trust certificates are secured by a lien on the locomotives. The $151 million is classified as debt due after one year in our Consolidated Statements of Financial Position.  Debt Exchange – On October 4, 2016 , we exchanged $1,006 million of various outstanding notes and debentures due between 2028 and 2044 (the Existing Notes) for $1,044 million of 3.799% notes (the New Notes) due October 1, 2051 , plus cash consideration of approximately $183 million in addition to $11 million for accrued and unpaid interest on the Existing Notes. In accordance with ASC 470-50-40, Debt-Modifications and Extinguishments-Derecognition , this transaction was accounted for as a debt exchange, as the exchanged debt instruments are not considered to be substantially different. The cash consideration was recorded as an adjustment to the carrying value of debt, and the balance of the unamortized discount and issue costs from the Existing Notes is being amortized as an adjustment of interest expense over the terms of the New Notes. No gain or loss was recognized as a result of the exchange. Costs related to the debt exchange that were payable to parties other than the debt holders totaled approximately $8 million and were included in interest expense during the year ended December 31, 2016.  The following table lists the outstanding notes and debentures that were exchanged:      Principal amount  Millions exchanged  7.125% Debentures due 2028 $ 2  6.625% Debentures due 2029 25  5.375% Debentures due 2033 15  6.250% Debentures due 2034 52  6.150% Debentures due 2037 2  5.780% Notes due 2040 4  4.750% Notes due 2041 175  4.750% Notes due 2043 204  4.821% Notes due 2044 373  4.850% Notes due 2044 154  Total $ 1,006  Receivables Securitization Facility – As of December 31, 2016, and 2015 , we recorded $0 and $400 million, respectively, of borrowings under our receivables securitization facility, as secured debt. (See further discussion of our receivables securitization facility in Note 11).

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2016
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 $2.2 billion as of December 31, 2016 .

Leases

Leases	12 Months Ended
	Dec. 31, 2016
Leases [Abstract]
Leases	17. Leases  We lease certain locomotives, freight cars, and other property. The Consolidated Statements of Financial Position as of December 31, 2016, and 2015 included $1,997 million, net of $ 1 , 121 million of accumulated depreciation, and $2,273 million, net of $1 , 189 million of accumulated depreciation, respectively, for properties held under capital leases. A charge to income resulting from the depreciation for assets held under capital leases is included within depreciation expense in our Consolidated Statements of Income. Future minimum lease payments for operating and capital leases with initial or remaining non-cancelable lease terms in excess of one year as of December 31, 2016 , were as follows:      Millions Operating Leases Capital Leases  2017 $ 461 $ 221  2018 390 193  2019 348 179  2020 285 187  2021 245 158  Later years 1,314 417  Total minimum lease payments $ 3,043 $ 1,355  Amount representing interest N/A (250)  Present value of minimum lease payments N/A $ 1,105  Approximately 96 % of capital lease payments relate to locomotives. Rent expense for operating leases with terms exceeding one month was $535 million in 201 6 , $5 90 million in 201 5 , and $ 593 million in 201 4 . When cash rental payments are not made on a straight-line basis, we recognize variable rental expense on a straight-line basis over the lease term. Contingent rentals and sub-rentals are not significant.

Commitments And Contingencies

Commitments And Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments And Contingencies [Abstract]
Commitments And Contingencies	18. Commitments and Contingencies  Asserted and Unasserted Claims – Various claims and lawsuits are pending against us and certain of our subsidiaries. We cannot fully determine the effect of all asserted and unasserted claims on our consolidated results of operations, financial condition, or liquidity. To the extent possible, we have recorded a liability where asserted and unasserted claims are considered probable and where such claims can be reasonably estimated. We do not expect that any known lawsuits, claims, environmental costs, commitments, contingent liabilities, or guarantees will have a material adverse effect on our consolidated results of operations, financial condition, or liquidity after taking into account liabilities and insurance recoveries previously recorded for these matters.  Personal Injury – The cost of personal injuries to employees and others related to our activities is charged to expense based on estimates of the ultimate cost and number of incidents each year. We use an actuarial analysis to measure the expense and liability, including unasserted claims. The Federal Employers’ Liability Act (FELA) governs compensation for work-related accidents. Under FELA, damages are assessed based on a finding of fault through litigation or out-of-court settlements. We offer a comprehensive variety of services and rehabilitation programs for employees who are injured at work.  Our personal injury liability is not discounted to present value due to the uncertainty surrounding the timing of future payments. Approximately 94% of the recorded liability is related to asserted claims and approximately 6% is related to unasserted claims at December 31, 2016 . 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 $290 million to $317 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 2016 2015 2014  Beginning balance $ 318 $ 335 $ 294  Current year accruals 75 89 96  Changes in estimates for prior years (29) (3) 9  Payments (74) (103) (64)  Ending balance at December 31 $ 290 $ 318 $ 335  Current portion, ending balance at December 31 $ 62 $ 63 $ 111  In conjunction with the liability update performed in 201 6 , we also reassessed our estimated insurance recoveries . We have recognized an asset for estimated insurance recoveries at December 31, 2016, and 2015 . Any changes to recorded insurance recoveries are included in the above table in the Changes in estimates for prior years category.  Asbestos – We are a defendant in a number of lawsuits in which current and former employees and other parties allege exposure to asbestos. We assess our potential liability using a statistical analysis of resolution costs for asbestos-related claims. This liability is updated annually and excludes future defense and processing costs. The liability for resolving both asserted and unasserted claims was based on the following assumptions:  · The ratio of future claims by alleged disease would be consistent with historical averages adjusted for inflation. · The number of claims filed against us will decline each year. · The average settlement values for asserted and unasserted claims will be equivalent to historical averages. · The percentage of claims dismissed in the future will be equivalent to historical averages.  Our liability for asbestos-related claims is not discounted to present value due to the uncertainty surrounding the timing of future payments. Approximately 20% of the recorded liability related to asserted claims and approximately 80% related to unasserted claims at December 31, 2016 . Because of the uncertainty surrounding the ultimate outcome of asbestos -related claims, it is reasonably possible that future costs to settle these claims may range from approximately $111 million to $118 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.  Our asbestos-related liability activity was as follows:      Millions 2016 2015 2014  Beginning balance $ 120 $ 126 $ 131  Accruals/(Credits) 12 - 1  Payments (21) (6) (6)  Ending balance at December 31 $ 111 $ 120 $ 126  Current portion, ending balance at December 31 $ 8 $ 6 $ 8  In conjunction with the liability update performed in 201 6 , we also reassessed our estimated insurance recoveries. We have recognized an asset for estimated insurance recoveries at December 31, 2016, and 2015 . The amounts recorded for asbestos-related liabilities and related insurance recoveries were based on currently known facts. However, future events, such as the number of new claims filed each year, average settlement costs, and insurance coverage issues, could cause the actual costs and insurance recoveries to be higher or lower than the projected amounts. Estimates also may vary in the future if strategies, activities, and outcomes of asbestos litigation materially change; federal and state laws governing asbestos litigation increase or decrease the probability or amount of compensation of claimants; and there are material changes with respect to payments made to claimants by other defendants.  Environmental Costs – We are subject to federal, state, and local environmental laws and regulations. We have identified 292 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 2016 2015 2014  Beginning balance $ 190 $ 182 $ 171  Accruals 84 61 56  Payments (62) (53) (45)  Ending balance at December 31 $ 212 $ 190 $ 182  Current portion, ending balance at December 31 $ 55 $ 52 $ 60  The environmental liability includes future costs for remediation and restoration of sites, as well as ongoing monitoring costs, but excludes any anticipated recoveries from third parties. Cost estimates are based on information available for each site, financial viability of other potentially responsible parties, and existing technology, laws, and regulations. The ultimate liability for remediation is difficult to determine because of the number of potentially responsible parties, site-specific cost sharing arrangements with other potentially responsible parties, the degree of contamination by various wastes, the scarcity and quality of volumetric data related to many of the sites, and the speculative nature of remediation costs. Estimates of liability may vary over time due to changes in federal, state, and local laws governing environmental remediation. Current obligations are not expected to have a material adverse effect on our consolidated results of operations, financial condition, or liquidity.  Insurance – The Company has a consolidated, wholly-owned captive insurance subsidiary (the captive), that provides insurance coverage for certain risks including 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 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 Consolidated Statements of Financial Position.  Guarantees – At December 31, 2016, and 2015 , we were contingently liable for $43 million and $53 million in guarantees, respectively. The fair value of these obligations as of both December 31, 2016, and 2015 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. Gain Contingency – UPRR and Santa Fe Pacific Pipelines (SFPP, a subsidiary of Kinder Morgan Energy Partners, L.P.) currently are engaged in a proceeding to resolve the fair market rent payable to UPRR commencing on January 1, 2004, for pipeline easements on UPRR rights-of-way ( Union Pacific Railroad Company vs. Santa Fe Pacific Pipelines, Inc., SFPP, L.P., Kinder Morgan Operating L.P. “D” Kinder Morgan G.P., Inc., et al., Superior Court of the State of California for the County of Los Angeles, filed July 28, 2004 ). In February 2007, a trial began to resolve this issue, and in May 2012, the trial judge rendered an opinion establishing the fair market rent and entering judgment for back rent, including prejudgment interest. SFPP appealed the judgment. On November 5, 2014, the Second District Circuit Court of Appeal in California issued an opinion holding that UPRR was not entitled to collect rent from SFPP for easements on the portions of the property acquired solely through federal government land grants issued during the 1800s. The Appellate Court also reversed the award of prejudgment interest and remanded the case to the trial court. A favorable final judgment may materially affect UPRR's results of operations in the period of any monetary recoveries. Due to the uncertainty regarding the amount and timing of any recovery or any subsequent proceedings, we consider this a gain contingency and have not recognized any amounts in the Consolidated Financial Statements as of December 31, 2016 .

Share Repurchase Program

Share Repurchase Program	12 Months Ended
	Dec. 31, 2016
Share Repurchase Program [Abstract]
Share Repurchase Program	19. Share Repurchase Program  Effective January 1, 2014, our Board of Directors authorized the repurchase of up to 120 million shares of our common stock by December 31, 2017 , replacing our previous repurchase program. As of December 31, 2016 , we repurchased a total of $19.1 billion of our common stock since the commencement of our repurchase programs in 2007. The table below represents shares repurchased under this repurchase program.      Number of Shares Purchased Average Price Paid  2016 2015 2016 2015  First quarter 9,315,807 6,881,455 $ 76.49 $ 117.28  Second quarter 7,026,100 7,975,100 85.66 104.62  Third quarter 9,088,613 13,800,700 93.63 89.65  Fourth quarter 9,624,667 6,646,899 97.60 88.19  Total 35,055,187 35,304,154 $ 88.57 $ 98.14  On November 17, 2016, our Board of Directors approved the early renewal of the share repurchase program, authorizing the repurchase of up to 120 million shares of our common stock by December 31, 2020. The new authorization was effective January 1, 2017, and replaces the previous authorization, which expired on Decem ber 31, 2016 .  Management's assessments of market conditions and other pertinent factors guide the timing and volume of all repurchases. Repurchased shares are recorded in treasury stock at cost, which includes any applicable commissions and fees.  From January 1, 2017, through February 2, 2017, we repurchased 2 . 75 million shares at an aggregate cost of approximately $ 291 million.

Related Parties

Related Parties	12 Months Ended
	Dec. 31, 2016
Related Parties [Abstract]
Related Parties	20. Related Parties  UPRR and other North American railroad companies jointly own TTX Company (TTX). UPRR has a 36.79% economic and voting interest in TTX while the other North American railroads own the remaining interest. In accordance with ASC 323 Investments - Equity Method and Joint Venture , UPRR applies the equity method of accounting to our investment in TTX.  TTX is a railcar pooling company that owns railcars and intermodal wells to serve North America’s railroads . TTX assists railroads in meet ing 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 h ad $877 million and $830 million recognized as inv estments related to TTX in our Consolidated Statements of Financial P osition as of December 31, 2016, and 2015 , respectively. TTX car hire expenses of $368 million in 2016, $376 million in 2015, and $350 million in 2014 are included in eq uipment and other rents in our Consolidated Statements of I ncome. In addition, UPRR had accounts payable to TTX of $61 million at both December 31, 2016, and December 31, 2015 .

Selected Quarterly Data (Unaudi

Selected Quarterly Data (Unaudited)	12 Months Ended
	Dec. 31, 2016
Selected Quarterly Data (Unaudited) [Abstract]
Selected Quarterly Data (Unaudited)	21. Selected Quarterly Data (Unaudited)      Millions, Except Per Share Amounts  2016 Mar. 31 Jun. 30 Sep. 30 Dec. 31  Operating revenues $ 4,829 $ 4,770 $ 5,174 $ 5,168  Operating income 1,687 1,660 1,960 1,965  Net income 979 979 1,131 1,144  Net income per share:  Basic 1.16 1.17 1.36 1.40  Diluted 1.16 1.17 1.36 1.39      Millions, Except Per Share Amounts  2015 Mar. 31 Jun. 30 Sep. 30 Dec. 31  Operating revenues $ 5,614 $ 5,429 $ 5,562 $ 5,208  Operating income 1,977 1,949 2,208 1,918  Net income 1,151 1,204 1,300 1,117  Net income per share:  Basic 1.31 1.38 1.51 1.31  Diluted 1.30 1.38 1.50 1.31  Per share net income for the four quarters combined may not equal the per share net income for the year due to rounding.

Schedule Of Valuation And Quali

Schedule Of Valuation And Qualifying Accounts	12 Months Ended
	Dec. 31, 2016
Schedule Of Valuation And Qualifying Accounts [Abstract]
Schedule Of Valuation And Qualifying Accounts	SCHEDULE II – VALUATION AND QUALIFYING ACCOUNTS Union Pacific Corporation and Subsidiary Companies      Millions, for the Years Ended December 31, 2016 2015 2014  Allowance for doubtful accounts:  Balance, beginning of period $ 16 $ 21 $ 23  Charges/(reduction) to expense 23 1 5  Net recoveries/(write-offs) (17) (6) (7)  Balance, end of period $ 22 $ 16 $ 21  Allowance for doubtful accounts are presented in the Consolidated Statements of Financial Position as follows:  Current $ 5 $ 5 $ 5  Long-term 17 11 16  Balance, end of period $ 22 $ 16 $ 21  Accrued casualty costs:  Balance, beginning of period $ 736 $ 757 $ 702  Charges to expense 202 227 256  Cash payments and other reductions (222) (248) (201)  Balance, end of period $ 716 $ 736 $ 757  Accrued casualty costs are presented in the Consolidated Statements of Financial Position as follows:  Current $ 185 $ 181 $ 249  Long-term 531 555 508  Balance, end of period $ 716 $ 736 $ 757 

Significant Accounting Polici32

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Significant Accounting Policies [Abstract]
Principles Of Consolidation	Principles of Consolidation – The Consolidated Financial Statements include the accounts of Union Pacific Corporation and all of its subsidiaries. Investments in affiliated companies (20% to 50% owned) are accounted for using the equity method of accounting. All intercompany transactions are eliminated. We currently have no less than majority-owned investments that require consolidation under variable interest entity requirements. 
Cash And Cash Equivalents	Cash and Cash Equivalents – Cash equivalents consist of investments with original maturities of three months or less.
Accounts Receivables	Accounts Receivable – Accounts receivable includes receivables reduced by an allowance for doubtful accounts. The allowance is based upon historical losses, credit worthiness of customers, and current economic conditions. Receivables not expected to be collected in one year and the associated allowances are classified as other assets in our Consolidated Statements of Financial Position.
Investments	Investments – Investments represent our investments in affiliated companies (20% to 50% owned) that are accounted for under the equity method of accounting and investments in companies (less than 20% owned) accounted for under the cost method of accounting. 
Materials and Supplies	Materials and Supplies – Materials and supplies are carried at the lower of average cost or market.
Property and Depreciation	Property and Depreciation – Properties and equipment are carried at cost and are depreciated on a straight-line basis over their estimated service lives, which are measured in years, except for rail in high-density traffic corridors (i.e., all rail lines except for those subject to abandonment, yard and switching tracks, and electronic yards), for which lives are measured in millions of gross tons per mile of track. We use the group method of depreciation in which all items with similar characteristics, use, and expected lives are grouped together in asset classes, and are depreciated using composite depreciation rates. The group method of depreciation treats each asset class as a pool of resources, not as singular items. We determine the estimated service lives of depreciable railroad assets by means of depreciation studies. Under the group method of depreciation, no gain or loss is recognized when depreciable property is retired or replaced in the ordinary course of business. 
Impairment of Long-lived Assets	Impairment of Long-lived Assets – We review long-lived assets, including identifiable intangibles, for impairment when events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If impairment indicators are present and the estimated future undiscounted cash flows are less than the carrying value of the long-lived assets, the carrying value is reduced to the estimated fair value as measured by the discounted cash flows. 
Revenue Recognition	Revenue Recognition – We recognize freight revenues 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. Other revenues, which include revenues earned by our subsidiaries, revenues from our commuter rail operations, and accessorial revenue, are recognized as service is performed or contractual obligations are met. 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.
Translation of Foreign Currency	Translation of Foreign Currency – Our portion of the assets and liabilities related to foreign investments are translated into U.S. dollars at the exchange rates in effect at the balance sheet date. Revenue and expenses are translated at the average rates of exchange prevailing during the year. Unrealized gains or losses are reflected within common shareholders’ equity as accumulated other comprehensive income or loss.
Fair Value Measurements	Fair Value Measurements – We use a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. The level in the fair value hierarchy within which the fair value measurement in its entirety falls is determined based on the lowest level input that is significant to the fair value measurement in its entirety. These levels include:  Level 1: Quoted market prices in active markets for identical assets or liabilities. Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data. Level 3: Unobservable inputs that are not corroborated by market data.  We have applied fair value measurements to our short term investments, pension plan assets and short- and long-term debt.
Stock-Based Compensation	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.  We measure and recognize compensation expense for all stock-based awards made to employees and directors, including stock options. Compensation expense is based on the calculated fair value of the awards as measured at the grant date and is expensed ratably over the service period of the awards (generally the vesting period). The fair value of retention awards is the closing stock price on the date of grant, while the fair value of stock options is determined by using the Black-Scholes option pricing model. 
Earnings Per Share	 Earnings Per Share – Basic earnings per share are calculated on the weighted-average number of common shares outstanding during each period. Diluted earnings per share include shares issuable upon exercise of outstanding stock options and stock-based awards where the conversion of such instruments would be dilutive.
Income Taxes	Income Taxes – We account for income taxes by recording taxes payable or refundable for the current year and deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in our financial statements or tax returns. These expected future tax consequences are measured based on current tax law; the effects of future tax legislation are not anticipated. Future tax legislation, such as a change in the corporate tax rate, could have a material impact on our financial condition, results of operations, or liquidity.  When appropriate, we record a valuation allowance against deferred tax assets to reflect that these tax assets may not be realized. In determining whether a valuation allowance is appropriate, we consider whether it is more likely than not that all or some portion of our deferred tax assets will not be realized, based on management’s judgments using available evidence for purposes of estimating whether future taxable income will be sufficient to realize a deferred tax asset.  We recognize tax benefits that are more likely than not to be sustained upon examination by tax authorities. The amount recognized is measured as the largest amount of benefit that is greater than 50 percent likely to be realized upon settlement. A liability for “unrecognized tax benefits” is recorded for any tax benefits claimed in our tax returns that do not meet these recognition and measurement standards. 
Pension And Postretirement Benefits	Pension and Postretirement Benefits – We incur certain employment-related expenses associated with pensions and postretirement health benefits. In order to measure the expense associated with these benefits, we must make various assumptions including discount rates used to value certain liabilities, expected return on plan assets used to fund these expenses, compensation increases, employee turnover rates, anticipated mortality rates, and expected future health care costs. The assumptions used by us are based on our historical experience as well as current facts and circumstances. We use an actuarial analysis to measure the expense and liability associated with these benefits.
Personal Injury	Personal Injury – The cost of injuries to employees and others on our property is charged to expense based on estimates of the ultimate cost and number of incidents each year. We use an actuarial analysis to measure the expense and liability. Our personal injury liability is not discounted to present value. Legal fees and incidental costs are expensed as incurred.
Asbestos	Asbestos – We estimate a liability for asserted and unasserted asbestos-related claims based on an assessment of the number and value of those claims. We use a statistical analysis to assist us in properly measuring our potential liability. Our liability for asbestos-related claims is not discounted to present value due to the uncertainty surrounding the timing of future payments. Legal fees and incidental costs are expensed as incurred.
Environmental	Environmental – When environmental issues have been identified with respect to property currently or formerly owned, leased, or otherwise used in the conduct of our business, we perform, with the assistance of our consultants, environmental assessments on such property. We expense the cost of the assessments as incurred. We accrue the cost of remediation where our obligation is probable and such costs can be reasonably estimated. We do not discount our environmental liabilities when the timing of the anticipated cash payments is not fixed or readily determinable. Legal fees and incidental costs are expensed as incurred.
Use Of Estimates	Use of Estimates – The preparation of our Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect certain reported assets and liabilities, and the disclosure of certain contingent assets and liabilities as of the date of the consolidated financial statements, as well as the reported amounts of revenue and expenses during the reporting period . Actual future results may differ from such estimates.

Nature Of Operations (Tables)

Nature Of Operations (Tables)	12 Months Ended
	Dec. 31, 2016
Nature Of Operations [Abstract]
Freight Revenue By Commodity Group	The following table provides freight revenue by commodity group:      Millions 2016 2015 2014  Agricultural Products $ 3,625 $ 3,581 $ 3,777  Automotive 2,000 2,154 2,103  Chemicals 3,474 3,543 3,664  Coal 2,440 3,237 4,127  Industrial Products 3,348 3,808 4,400  Intermodal 3,714 4,074 4,489  Total freight revenues $ 18,601 $ 20,397 $ 22,560  Other revenues 1,340 1,416 1,428  Total operating revenues $ 19,941 $ 21,813 $ 23,988 

Stock Options And Other Stock34

Stock Options And Other Stock Plans (Tables)	12 Months Ended
	Dec. 31, 2016
Stock Options And Other Stock Plans [Abstract]
Schedule Of Stock-Based Compensation	Information regarding stock-based compensation appears in the table below:      Millions 2016 2015 2014  Stock-based compensation, before tax:  Stock options $ 16 $ 17 $ 21  Retention awards 66 81 91  Total stock-based compensation, before tax $ 82 $ 98 $ 112  Excess tax benefits from equity compensation plans $ 28 $ 62 $ 118 
Schedule Of Stock Options Weighted Average Assumptions	The table below shows the annual weighted-average assumptions used for valuation purposes:      Weighted-Average Assumptions 2016 2015 2014  Risk-free interest rate 1.3% 1.3% 1.6%  Dividend yield 2.9% 1.8% 2.1%  Expected life (years) 5.1 5.1 5.2  Volatility 23.2% 23.4% 30.0%  Weighted-average grant-date fair value of options granted $ 11.36 $ 22.30 $ 20.18 
Summary Of Stock Options Activity	A summary of stock option activity during 2016 is presented below:      Options (thous.) Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value (millions)  Outstanding at January 1, 2016 5,571 $ 66.69 5.4 yrs. $ 114  Granted 1,672 75.52 N/A N/A  Exercised (978) 37.66 N/A N/A  Forfeited or expired (103) 100.16 N/A N/A  Outstanding at December 31, 2016 6,162 $ 73.13 5.9 yrs. $ 205  Vested or expected to vest at December 31, 2016 6,101 $ 73.05 5.9 yrs. $ 204  Options exercisable at December 31, 2016 3,639 $ 62.95 4.2 yrs. $ 154 
Schedule Of Stock Option Exercises	Additional information regarding stock option exercises appears in the table below:      Millions 2016 2015 2014  Intrinsic value of stock options exercised $ 52 $ 50 $ 194  Cash received from option exercises 39 27 54  Treasury shares repurchased for employee payroll taxes (15) (12) (24)  Tax benefit realized from option exercises 20 19 74  Aggregate grant-date fair value of stock options vested 19 19 17 
Schedule Of Retention Awards	Changes in our retention awards during 2016 were as follows:      Shares (thous.) Weighted-Average Grant-Date Fair Value  Nonvested at January 1, 2016 2,900 $ 80.01  Granted 836 75.77  Vested (799) 57.70  Forfeited (148) 88.42  Nonvested at December 31, 2016 2,789 $ 84.68 
Schedule Of Performance Retention Awards, Present Value Calculation Assumptions	The assumptions used to calculate the present value of estimated future dividends related to the February 2016 grant were as follows:      2016  Dividend per share per quarter $ 0.55  Risk-free interest rate at date of grant 0.9% 
Schedule Of Performance Retention Awards	Changes in our performance retention awards during 2016 were as follows:      Shares (thous.) Weighted-Average Grant-Date Fair Value  Nonvested at January 1, 2016 1,255 $ 82.98  Granted 503 70.09  Vested (530) 62.57  Forfeited (83) 90.42  Nonvested at December 31, 2016 1,145 $ 86.23 

Retirement Plans (Tables)

Retirement Plans (Tables)	12 Months Ended
	Dec. 31, 2016
Retirement Plans [Abstract]
Schedule Of Changes In Projected Benefit Obligation And Plan Assets	Changes in our PBO and plan assets were as follows for the years ended December 31:      Funded Status Pension OPEB  Millions 2016 2015 2016 2015  Projected Benefit Obligation  Projected benefit obligation at beginning of year $ 3,958 $ 4,142 $ 329 $ 354  Service cost 84 106 1 3  Interest cost 143 163 11 13  Actuarial loss/(gain) 124 (267) 16 (18)  Gross benefits paid (199) (186) (23) (23)  Projected benefit obligation at end of year $ 4,110 $ 3,958 $ 334 $ 329  Plan Assets  Fair value of plan assets at beginning of year $ 3,544 $ 3,654 $ - $ -  Actual return/(loss) on plan assets 279 (43) - -  Voluntary funded pension plan contributions 100 100 - -  Non-qualified plan benefit contributions 24 19 23 23  Gross benefits paid (199) (186) (23) (23)  Fair value of plan assets at end of year $ 3,748 $ 3,544 $ - $ -  Funded status at end of year $ (362) $ (414) $ (334) $ (329) 
Schedule Of Amounts Recognized In Statement Of Financial Position	Amounts recognized in the statement of financial position as of December 31, 2016, and 2015 consist of:      Pension OPEB  Millions 2016 2015 2016 2015  Noncurrent assets $ 67 $ 1 $ - $ -  Current liabilities (24) (22) (24) (23)  Noncurrent liabilities (405) (393) (310) (306)  Net amounts recognized at end of year $ (362) $ (414) $ (334) $ (329) 
Schedule Of Pre-Tax Amounts Recognized In Accumulated Other Comprehensive Income/(Loss)	Pre-tax amounts recognized in accumulated other comprehensive income/(loss) as of December 31, 2016, and 2015 consist of:      2016 2015  Millions Pension OPEB Total Pension OPEB Total  Prior service (cost)/credit $ - $ (2) $ (2) $ - $ 7 $ 7  Net actuarial loss (1,681) (123) (1,804) (1,652) (117) (1,769)  Total $ (1,681) $ (125) $ (1,806) $ (1,652) $ (110) $ (1,762) 
Schedule Of Other Pre-Tax Changes Recognized In Other Comprehensive Income	Pre-tax changes recognized in other comprehensive income/(loss) during 2016, 2015 and 2014 were as follows:      Pension OPEB  Millions 2016 2015 2014 2016 2015 2014  Net actuarial (loss)/gain $ (112) $ (31) $ (780) $ (16) $ 18 $ (33)  Amortization of:  Prior service cost/(credit) - - - (9) (10) (11)  Actuarial loss 83 106 71 10 13 10  Total $ (29) $ 75 $ (709) $ (15) $ 21 $ (34) 
Amounts Included In Accumulated Other Comprehensive Income Expected To Be Amortized Into Net Periodic Cost (Benefit)	Amounts included in accumulated other comprehensive income/(loss) expected to be amortized into net periodic cost during 2017:      Millions Pension OPEB Total  Prior service credit $ - $ (1) $ (1)  Net actuarial loss (79) (10) (89)  Total $ (79) $ (11) $ (90) 
Schedule Of Underfunded Accumulated Benefit Obligation	The following table discloses only the PBO, ABO, and fair value of plan assets for pension plans where the accumulated benefit obligation is in excess of the fair value of the plan assets as of December 31 :      Underfunded Accumulated Benefit Obligation  Millions 2016 2015  Projected benefit obligation $ 428 $ 398  Accumulated benefit obligation $ 412 $ 388  Fair value of plan assets - -  Underfunded accumulated benefit obligation $ (412) $ (388) 
Weighted-Average Actuarial Assumptions Used To Determine Benefit Obligations And Expense	The weighted-average actuarial assumptions used to determine benefit obligations at December 31:      Pension OPEB  Percentages 2016 2015 2016 2015  Discount rate 4.20% 4.37% 4.00% 4.16%  Compensation increase 4.20% 4.10% N/A N/A  Health care cost trend rate (employees under 65) N/A N/A 6.31% 6.52%  Ultimate health care cost trend rate N/A N/A 4.50% 4.50%  Year ultimate trend rate reached N/A N/A 2038 2038  The weighted-average actuarial assumptions used to determine expense were as follows:       Pension OPEB  Percentages 2016 2015 2014 2016 2015 2014  Discount rate for benefit obligations 4.37% 3.94% 4.72% 4.13% 3.74% 4.47%  Discount rate for interest on benefit obligations 3.65% 3.94% 4.72% 3.34% 3.74% 4.47%  Discount rate for service cost 4.69% 3.94% 4.72% 4.59% 3.74% 4.47%  Discount rate for interest on service cost 4.55% 3.94% 4.72% 4.44% 3.74% 4.47%  Expected return on plan assets 7.50% 7.50% 7.50% N/A N/A N/A  Compensation increase 4.20% 4.00% 4.00% N/A N/A N/A  Health care cost trend rate (employees under 65) N/A N/A N/A 6.52% 6.34% 6.49%  Ultimate health care cost trend rate N/A N/A N/A 4.50% 4.50% 4.50%  Year ultimate trend reached N/A N/A N/A 2038 2028 2028 
Net Periodic Pension And OPEB Cost/(Benefit)	The components of our net periodic pension and OPEB cost were as follows for the years ended December 31:      Pension OPEB  Millions 2016 2015 2014 2016 2015 2014  Net Periodic Benefit Cost:  Service cost $ 84 $ 106 $ 70 $ 1 $ 3 $ 2  Interest cost 143 163 158 11 13 14  Expected return on plan assets (267) (255) (230) - - -  Amortization of:  Prior service cost/(credit) - - - (9) (10) (11)  Actuarial loss 83 106 71 10 13 10  Net periodic benefit cost $ 43 $ 120 $ 69 $ 13 $ 19 $ 15 
OPEB Effects From One-Percentage Point Change Assumed Healthcare Cost Trend Rates	A one-percentage point change in the assumed health care cost trend rates would have the following effects on OPEB:      Millions One % pt. Increase One % pt. Decrease  Effect on total service and interest cost components $ 1 $ (1)  Effect on accumulated benefit obligation 19 (16) 
Cash Contributions For Qualified Pension Plan Benefit Payments For Non-Qualified OPEB Plans	The following table details our cash contributions for the qualified pension plans and the benefit payments for the non-qualified (supplemental) pension and OPEB plans:      Pension  Millions Qualified Non-qualified OPEB  2016 $ 100 $ 24 $ 23  2015 100 19 23 
Schedule Of Expected Benefit Payments	The following table details expected benefit payments for the years 2017 through 2026:      Millions Pension OPEB  2017 $ 199 $ 24  2018 201 24  2019 204 23  2020 206 22  2021 209 22  Years 2022 - 2026 1,094 98 
Schedule Of Pension Plan Asset Allocation	Our pension plan asset allocation at December 31, 2016, and 2015 , and target allocation for 2017, are as follows:      Percentage of Plan Assets  Target December 31,  Allocation 2017 2016 2015  Equity securities 60% to 70% 68% 67%  Debt securities 20% to 30% 21 23  Real estate 2% to 8% 6 6  Commodities 4% to 6% 5 4  Total 100% 100% 
Schedule Of Assets Measured At Fair Value On A Recurring Basis	As of December 31, 2016 , the pension plan assets measured at fair value on a recurring basis were as follows:       Quoted Prices Significant  in Active Other Significant  Markets for Observable Unobservable  Identical Inputs Inputs Inputs  Millions (Level 1) (Level 2) (Level 3) Total  Plan assets at fair value:  Temporary cash investments $ 27 $ - $ - $ 27  Registered investment companies [a] 17 - - 17  Federal government securities - 142 - 142  Bonds and debentures - 357 - 357  Corporate stock 1,059 8 - 1,067  Total plan assets at fair value $ 1,103 $ 507 $ - $ 1,610  Plan assets at NAV:  Registered investment companies [b] 280  Venture capital and buyout partnerships 283  Real estate partnerships 212  Collective trust and other funds 1,346  Total plan assets at NAV $ 2,121  Other assets [c] 17  Total plan assets $ 3,748  [a] Registered investment companies measured at fair value include stock and real estate investments. [b] Registered investment companies measured at NAV include bond investments. [c] Other assets include accrued receivables and pending broker settlements.  As of December 31, 2015 , the pension plan assets measured at fair value on a recurring basis were as follows:      Quoted Prices Significant  in Active Other Significant  Markets for Observable Unobservable  Identical Inputs Inputs Inputs  Millions (Level 1) (Level 2) (Level 3) Total  Plan assets at fair value:  Temporary cash investments $ 13 $ - $ - $ 13  Registered investment companies [a] 179 - - 179  Federal government securities - 125 - 125  Bonds and debentures - 383 - 383  Corporate stock 1,034 7 - 1,041  Total plan assets at fair value $ 1,226 $ 515 $ - $ 1,741  Plan assets at NAV:  Registered investment companies [b] 270  Venture capital and buyout partnerships 256  Real estate partnerships 199  Collective trust and other funds 1,075  Total plan assets at NAV $ 1,800  Other assets [c] 3  Total plan assets $ 3,544  [a] Registered investment companies measured at fair value include stock and real estate investments. [b] Registered investment companies measured at NAV include bond investments. [c] Other assets include accrued receivables and pending broker settlements.

Other Income (Tables)

Other Income (Tables)	12 Months Ended
	Dec. 31, 2016
Other Income [Abstract]
Other Income	Other income included the following for the years ended December 31:      Millions 2016 2015 2014  Rental income $ 96 $ 96 $ 96  Net gain on non-operating asset dispositions [a] [b] 94 144 69  Interest income 11 5 4  Non-operating environmental costs and other [c] (9) (19) (18)  Total $ 192 $ 226 $ 151  [a] 2016 includes $ 17 million and $50 million related to a real estate sale in the first and second quarter, respectively. [b] 2015 includes $113 million related to a real estate sale. [c] 2014 includes $14 million related to the sale of a permanent easement.

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Taxes [Abstract]
Schedule Of Components Of Income Tax Expense	Components of income tax expense were as follows for the years ended December 31:      Millions 2016 2015 2014  Current tax expense:  Federal $ 1,518 $ 1,901 $ 2,019  State 176 210 239  Foreign 8 8 10  Total current tax expense 1,702 2,119 2,268  Deferred and other tax expense:  Federal 692 644 753  State 139 121 142  Total deferred and other tax expense 831 765 895  Total income tax expense $ 2,533 $ 2,884 $ 3,163 
Reconciliations Between Statutory And Effective Tax Rates	For the years ended December 31, reconciliations between statutory and effective tax rates are as follows:      Tax Rate Percentages 2016 2015 2014  Federal statutory tax rate 35.0 % 35.0 % 35.0 %  State statutory rates, net of federal benefits 3.1 3.1 3.1  Tax credits (0.5) (0.5) (0.4)  Other (0.2) 0.1 0.2  Effective tax rate 37.4 % 37.7 % 37.9 % 
Schedule Of Deferred Income Tax Liabilities And Assets	Deferred income tax (liabilities)/assets were comprised of the following at December 31:      Millions 2016 2015  Deferred income tax liabilities:  Property $ (16,687) $ (16,079)  Other (346) (352)  Total deferred income tax liabilities (17,033) (16,431)  Deferred income tax assets:  Accrued wages 75 76  Accrued casualty costs 231 237  Stock compensation 69 72  Debt and leases 14 149  Retiree benefits 222 204  Credits 145 156  Other 281 296  Total deferred income tax assets $ 1,037 $ 1,190  Net deferred income tax liability $ (15,996) $ (15,241) 
Reconciliation Of Changes In Unrecognized Tax Benefits Liabilities/(Assets)	A reconciliation of changes in unrecognized tax benefits liabilities/(assets) from the beginning to the end of the reporting period is as follows:      Millions 2016 2015 2014  Unrecognized tax benefits at January 1 $ 94 $ 151 $ 59  Increases for positions taken in current year 31 38 92  Increases for positions taken in prior years 10 13 22  Decreases for positions taken in prior years (20) (87) (14)  Refunds from/(payments to) and settlements with taxing authorities 4 (13) (8)  Increases/(decreases) for interest and penalties 6 (5) 1  Lapse of statutes of limitations - (3) (1)  Unrecognized tax benefits at December 31 $ 125 $ 94 $ 151 
Unrecognized Tax Benefits That Would/Not Reduce The Effective Tax Rate	The unrecognized tax benefits that would reduce our effective tax rate are as follows:      Millions 2016 2015 2014  Unrecognized tax benefits that would reduce the effective tax rate $ 31 $ 31 $ 33  Unrecognized tax benefits that would not reduce the effective tax rate 94 63 118  Total unrecognized tax benefits $ 125 $ 94 $ 151 

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Reconciliation Between Earnings Per Share	The following table provides a reconciliation between basic and diluted earnings per share for the years ended December 31:      Millions, Except Per Share Amounts 2016 2015 2014  Net income $ 4,233 $ 4,772 $ 5,180  Weighted-average number of shares outstanding:  Basic 832.4 866.2 897.1  Dilutive effect of stock options 1.5 1.5 2.1  Dilutive effect of retention shares and units 1.5 1.7 1.9  Diluted 835.4 869.4 901.1  Earnings per share – basic $ 5.09 $ 5.51 $ 5.77  Earnings per share – diluted $ 5.07 $ 5.49 $ 5.75 

Accumulated Other Comprehensi39

Accumulated Other Comprehensive Income/(Loss) (Tables)	12 Months Ended
	Dec. 31, 2016
Accumulated Other Comprehensive Income/(Loss) [Abstract]
After-Tax Components Of Accumulated Other Comprehensive Loss	Reclassifications out of accumulated other comprehensive income/(loss) were as follows (net of tax):      Millions Defined benefit plans Foreign currency translation Total  Balance at January 1, 2016 $ (1,103) $ (92) $ (1,195)  Other comprehensive income/(loss) before reclassifications (3) (48) (51)  Amounts reclassified from accumulated other comprehensive income/(loss) [a] (26) - (26)  Net year-to-date other comprehensive income/(loss), net of taxes of $49 million (29) (48) (77)  Balance at December 31, 2016 $ (1,132) $ (140) $ (1,272)   Balance at January 1, 2015 $ (1,161) $ (49) $ (1,210)  Other comprehensive income/(loss) before reclassifications (4) (43) (47)  Amounts reclassified from accumulated other comprehensive income/(loss) [a] 62 - 62  Net year-to-date other comprehensive income/(loss), net of taxes of $(8) million 58 (43) 15  Balance at December 31, 2015 $ (1,103) $ (92) $ (1,195)  [a] The accumulated other comprehensive income/(loss) reclassification components are 1) prior service cost/(benefit) 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.

Properties (Tables)

Properties (Tables)	12 Months Ended
	Dec. 31, 2016
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 December 31, 2016 Cost Depreciation Value Useful Life  Land $ 5,220 $ N/A $ 5,220 N/A  Road:  Rail and other track material 15,845 5,722 10,123 40  Ties 9,812 2,736 7,076 33  Ballast 5,242 1,430 3,812 34  Other roadway [a] 18,138 3,226 14,912 47  Total road 49,037 13,114 35,923 N/A  Equipment:  Locomotives 9,692 3,939 5,753 20  Freight cars 2,243 972 1,271 24  Work equipment and other 905 232 673 19  Total equipment 12,840 5,143 7,697 N/A  Technology and other 974 412 562 11  Construction in progress 987 - 987 N/A  Total $ 69,058 $ 18,669 $ 50,389 N/A      Millions, Except Estimated Useful Life Accumulated Net Book Estimated  As of December 31, 2015 Cost Depreciation Value Useful Life  Land $ 5,195 $ N/A $ 5,195 N/A  Road:  Rail and other track material 15,236 5,495 9,741 37  Ties 9,439 2,595 6,844 33  Ballast 5,024 1,350 3,674 34  Other roadway [a] 17,374 3,021 14,353 47  Total road 47,073 12,461 34,612 N/A  Equipment:  Locomotives 9,027 3,726 5,301 19  Freight cars 2,203 962 1,241 24  Work equipment and other 897 191 706 19  Total equipment 12,127 4,879 7,248 N/A  Technology and other 919 358 561 11  Construction in progress 1,250 - 1,250 N/A  Total $ 66,564 $ 17,698 $ 48,866 N/A  [a] Other roadway includes grading, bridges and tunnels, signals, buildings, and other road assets.

Accounts Payable And Other Cu41

Accounts Payable And Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2016
Accounts Payable And Other Current Liabilties [Abstract]
Schedule Of Accounts Payable And Other Current Liabilities	   Dec. 31, Dec. 31,  Millions 2016 2015  Accounts payable $ 955 $ 743  Income and other taxes payable 472 434  Accrued wages and vacation 387 391  Interest payable 212 208  Accrued casualty costs 185 181  Equipment rents payable 101 105  Other 570 550  Total accounts payable and other current liabilities $ 2,882 $ 2,612 

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2016
Debt [Abstract]
Schedule Of Debt	Total debt as of December 31, 2016, and 2015 , is summarized below:      Millions 2016 2015  Notes and debentures, 1.8% to 7.9% due through 2065 $ 13,547 $ 11,964  Capitalized leases, 3.1% to 8.4% due through 2028 1,105 1,268  Equipment obligations, 2.6% to 6.7% due through 2031 1,069 963  Term loans - floating rate, due in 2017 100 200  Mortgage bonds, 4.8% due through 2030 57 57  Medium-term notes, 9.3% to 10.0% due through 2020 23 23  Receivables Securitization (Note 11) - 400  Unamortized discount and deferred issuance costs (894) (674)  Total debt 15,007 14,201  Less: current portion (758) (594)  Total long-term debt $ 14,249 $ 13,607 
Aggregate Debt Maturities	The following table presents aggregate debt maturities as of December 31, 2016 , excluding market value adjustments:      Millions  2017 $ 763  2018 572  2019 645  2020 1,042  2021 673  Thereafter 12,206  Total principal 15,901  Unamortized discount and deferred issuance costs (894)  Total debt $ 15,007 
Unsecured Fixed Rate Debt Securities Issued Under Current Shelf Registration	During 2016, we issued the following unsecured, fixed-rate debt securities under our current shelf registration:      Date Description of Securities  March 1, 2016 $500 million of 2.750% Notes due March 1, 2026  $600 million of 4.050% Notes due March 1, 2046  $200 million of reopened 4.375% Notes due November 15, 2065  August 8, 2016 $150 million of reopened 2.750% Notes due March 1, 2026  $300 million of 3.350% Notes due August 15, 2046 
Debt Exchange	The following table lists the outstanding notes and debentures that were exchanged:      Principal amount  Millions exchanged  7.125% Debentures due 2028 $ 2  6.625% Debentures due 2029 25  5.375% Debentures due 2033 15  6.250% Debentures due 2034 52  6.150% Debentures due 2037 2  5.780% Notes due 2040 4  4.750% Notes due 2041 175  4.750% Notes due 2043 204  4.821% Notes due 2044 373  4.850% Notes due 2044 154  Total $ 1,006 

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2016
Leases [Abstract]
Future Minimum Lease Payments For Operating And Capital Leases	Future minimum lease payments for operating and capital leases with initial or remaining non-cancelable lease terms in excess of one year as of December 31, 2016 , were as follows:      Millions Operating Leases Capital Leases  2017 $ 461 $ 221  2018 390 193  2019 348 179  2020 285 187  2021 245 158  Later years 1,314 417  Total minimum lease payments $ 3,043 $ 1,355  Amount representing interest N/A (250)  Present value of minimum lease payments N/A $ 1,105 

Commitments And Contingencies (

Commitments And Contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments And Contingencies [Abstract]
Commitments And Contingencies Activity	Our personal injury liability activity was as follows:      Millions 2016 2015 2014  Beginning balance $ 318 $ 335 $ 294  Current year accruals 75 89 96  Changes in estimates for prior years (29) (3) 9  Payments (74) (103) (64)  Ending balance at December 31 $ 290 $ 318 $ 335  Current portion, ending balance at December 31 $ 62 $ 63 $ 111  Our asbestos-related liability activity was as follows:      Millions 2016 2015 2014  Beginning balance $ 120 $ 126 $ 131  Accruals/(Credits) 12 - 1  Payments (21) (6) (6)  Ending balance at December 31 $ 111 $ 120 $ 126  Current portion, ending balance at December 31 $ 8 $ 6 $ 8  Our environmental liability activity was as follows:      Millions 2016 2015 2014  Beginning balance $ 190 $ 182 $ 171  Accruals 84 61 56  Payments (62) (53) (45)  Ending balance at December 31 $ 212 $ 190 $ 182  Current portion, ending balance at December 31 $ 55 $ 52 $ 60 

Share Repurchase Program (Table

Share Repurchase Program (Tables)	12 Months Ended
	Dec. 31, 2016
Share Repurchase Program [Abstract]
Share Repurchase Program	The table below represents shares repurchased under this repurchase program.      Number of Shares Purchased Average Price Paid  2016 2015 2016 2015  First quarter 9,315,807 6,881,455 $ 76.49 $ 117.28  Second quarter 7,026,100 7,975,100 85.66 104.62  Third quarter 9,088,613 13,800,700 93.63 89.65  Fourth quarter 9,624,667 6,646,899 97.60 88.19  Total 35,055,187 35,304,154 $ 88.57 $ 98.14 

Selected Quarterly Data (Unau46

Selected Quarterly Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2016
Selected Quarterly Data (Unaudited) [Abstract]
Selected Quarterly Data (Unaudited)	   Millions, Except Per Share Amounts  2016 Mar. 31 Jun. 30 Sep. 30 Dec. 31  Operating revenues $ 4,829 $ 4,770 $ 5,174 $ 5,168  Operating income 1,687 1,660 1,960 1,965  Net income 979 979 1,131 1,144  Net income per share:  Basic 1.16 1.17 1.36 1.40  Diluted 1.16 1.17 1.36 1.39      Millions, Except Per Share Amounts  2015 Mar. 31 Jun. 30 Sep. 30 Dec. 31  Operating revenues $ 5,614 $ 5,429 $ 5,562 $ 5,208  Operating income 1,977 1,949 2,208 1,918  Net income 1,151 1,204 1,300 1,117  Net income per share:  Basic 1.31 1.38 1.51 1.31  Diluted 1.30 1.38 1.50 1.31 

Nature Of Operations (Details)

Nature Of Operations (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016USD ($)mi	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2016USD ($)segmentmi	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Commodity Group Information [Line Items]
Freight revenues									$ 18,601	$ 20,397	$ 22,560
Other revenues									1,340	1,416	1,428
Total operating revenues	$ 5,168	$ 5,174	$ 4,770	$ 4,829	$ 5,208	$ 5,562	$ 5,429	$ 5,614	$ 19,941	21,813	23,988
Network route miles | mi	32,070								32,070
Route miles owned | mi	26,053								26,053
Reportable segments | segment									1
Agricultural Products [Member]
Commodity Group Information [Line Items]
Freight revenues									$ 3,625	3,581	3,777
Automotive [Member]
Commodity Group Information [Line Items]
Freight revenues									2,000	2,154	2,103
Chemicals [Member]
Commodity Group Information [Line Items]
Freight revenues									3,474	3,543	3,664
Coal [Member]
Commodity Group Information [Line Items]
Freight revenues									2,440	3,237	4,127
Industrial Products [Member]
Commodity Group Information [Line Items]
Freight revenues									3,348	3,808	4,400
Intermodal [Member]
Commodity Group Information [Line Items]
Freight revenues									3,714	4,074	4,489
Mexico [Member]
Commodity Group Information [Line Items]
Freight revenues									$ 2,200	$ 2,200	$ 2,300

Accounting Pronouncements (Deta

Accounting Pronouncements (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)
New Accounting Pronouncement, Early Adoption [Line Items]
Excess tax benefit from share-based compensation, operating activities	$ 28
ASU 2016-09 [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Excess tax benefit from share-based compensation, operating activities	$ 28

Stock Split (Details)

Stock Split (Details)	May 27, 2014$ / shares	Dec. 31, 2016$ / shares	Dec. 31, 2015$ / shares
Stock Split [Abstract]
Stock split effective date		Jun. 6, 2014
Stock split conversion ratio	2
Percent of dividend in stock	100.00%
Stock split record date		May 27, 2014
Common shares, par value	$ 2.50	$ 2.50	$ 2.50

Stock Options And Other Stock50

Stock Options And Other Stock Plans (Narrative) (Details) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Share-based Compensation Arrangements [Line Items]
Shares of common stock authorized and available	73,745,250	76,548,520	77,786,772
Union Pacific Corporation 1992 Restricted Stock Plan For Non-Employee Directors [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
Restricted shares outstanding	0
Union Pacific Corporation 2000 Directors Plan [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
Stock options, shares outstanding	7,400
Restricted shares outstanding	40,000
Common stock reserved for issuance	2,200,000
Initial grant of retention stock share/units description	Under the Directors Plan, each non-employee director, upon his or her initial election to the Board of Directors, receives a grant of 4,000 retention shares or retention stock units. Prior to December 31, 2007, each non-employee director received annually an option to purchase at fair value a number of shares of our common stock, not to exceed 20,000 shares during any calendar year, determined by dividing 60,000 by 1/3 of the fair market value of one share of our common stock on the date of such Board of Directors meeting, with the resulting quotient rounded up or down to the nearest 50 shares.
Union Pacific Corporation 2004 Stock Incentive Plan [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
Stock options, shares outstanding	2,715,137
Retention shares and stock units outstanding	726,657
Common stock reserved for issuance	84,000,000
Union Pacific Corporation 2013 Stock Incentive Plan [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
Stock options, shares outstanding	3,439,910
Retention shares and stock units outstanding	3,207,689
Common stock reserved for issuance	78,000,000

Stock Options And Other Stock51

Stock Options And Other Stock Plans (Stock Options, Retention Awards And Performance Retention Awards) (Narrative) (Details) $ / shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)$ / shares
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 | $ / shares	$ 0
Unrecognized compensation expense	$ 18
Expected weighted average period (in years) of nonvested stock options to be recognized	1 year 3 months 18 days
Retention Awards [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
Years until vest	4 years
Unrecognized compensation expense	$ 84
Expected weighted average period (in years) of nonvested stock options to be recognized	1 year 7 months 6 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
Continued employment requirement	Stock units awarded to selected employees under these grants are subject to continued employment for 37 months and the attainment of certain levels of ROIC, and for the 2016 plan, modified for the relative OIG.
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 2016 plan, the relative OIG modifier.
ROIC performance period	3 years
Unrecognized compensation expense	$ 20
Expected weighted average period (in years) of nonvested stock options to be recognized	1 year 2 months 12 days

Stock-based Compensation (Sched

Stock-based Compensation (Schedule Of Stock-Based Compensation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock-Based Compensation, Before Tax: [Abstract]
Stock options	$ 16	$ 17	$ 21
Retention awards	66	81	91
Total stock-based compensation, before tax	82	98	112
Excess tax benefits from equity compensation plans, financing activities		$ 62	$ 118
Excess tax benefits from equity compensation plans, operating activities	$ 28

Stock-based Compensation (Sch53

Stock-based Compensation (Schedule Of Stock Options Weighted Average Assumptions) (Details) - Stock Options [Member] - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assumptions For Stock Awards [Abstract]
Risk-free interest rate	1.30%	1.30%	1.60%
Dividend yield	2.90%	1.80%	2.10%
Expected life (years)	5 years 1 month 6 days	5 years 1 month 6 days	5 years 2 months 12 days
Volatility	23.20%	23.40%	30.00%
Weighted-average grant-date fair value of options granted	$ 11.36	$ 22.30	$ 20.18

Stock-based Compensation (Summa

Stock-based Compensation (Summary Of Stock Option Activities) (Details) - Stock Options [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Schedule of Share-based Compensation Arrangements [Line Items]
Stock options, shares outstanding at January 1, 2016	5,571
Stock options, shares granted	1,672
Stock options, shares exercised	(978)
Stock options, shares forfeited or expired	(103)
Stock options, shares outstanding at December 31, 2016	6,162	5,571
Stock options, shares vested or expected to vest at December 31, 2016	6,101
Stock options, shares exercisable at December 31, 2016	3,639
Stock options weighted-average exercise price, outstanding at January 1, 2016	$ 66.69
Stock options weighted-average exercise price, granted	75.52
Stock options weighted-average exercise price, exercised	37.66
Stock options weighted-average exercise price, forfeited or expired	100.16
Stock options weighted-average exercise price, outstanding at December 31, 2016	73.13	$ 66.69
Stock options weighted-average exercise price, vested or expected to vest at December 31, 2016	73.05
Stock options weighted-average exercise price, options exercisable at December 31, 2016	$ 62.95
Stock options weighted-average remaining contractual term in years, outstanding at January 1, 2016		5 years 4 months 24 days
Stock options weighted-average remaining contractual term in years, outstanding at December 31, 2016	5 years 10 months 24 days
Stock options weighted-average remaining contractual term in years, vested or expected to vest at December 31, 2016	5 years 10 months 24 days
Stock options weighted-average remaining contractual term in years, options exercisable at December 31, 2016	4 years 2 months 12 days
Stock options aggregate intrinsic value, outstanding at January 1, 2016	$ 114
Stock options aggregate intrinsic value, outstanding at December 31, 2016	205	$ 114
Stock options aggregate intrinsic value, vested or expected to vest at December 31, 2016	204
Stock options aggregate intrinsic value, options exercisable at December 31, 2016	$ 154

Stock-based Compensation (Sch55

Stock-based Compensation (Schedule Of Stock Option Exercises) (Details) - Stock Options [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock Option Aggregate Disclosures [Abstract]
Intrinsic value of stock options exercised	$ 52	$ 50	$ 194
Cash received from option exercises	39	27	54
Treasury shares repurchased for employee payroll taxes	(15)	(12)	(24)
Tax benefit realized from option exercises	20	19	74
Aggregate grant-date fair value of stock options vested	$ 19	$ 19	$ 17

Stock-based Compensation (Sch56

Stock-based Compensation (Schedule Of Retention Awards) (Details) - Retention Awards [Member] shares in Thousands	12 Months Ended
	Dec. 31, 2016$ / sharesshares
Schedule of Share-based Compensation Arrangements [Line Items]
Awards, shares nonvested at January 1, 2016 | shares	2,900
Awards, shares granted | shares	836
Awards, shares vested | shares	(799)
Awards, shares forfeited | shares	(148)
Awards, shares nonvested at December 31, 2016 | shares	2,789
Awards weighted-average grant-date fair value, nonvested at January 1, 2016 | $ / shares	$ 80.01
Awards weighted-average grant-date fair value, granted | $ / shares	75.77
Awards weighted-average grant-date fair value, vested | $ / shares	57.70
Awards weighted-average grant-date fair value, forfeited | $ / shares	88.42
Awards weighted-average grant-date fair value, nonvested at December 31, 2016 | $ / shares	$ 84.68

Stock-based Compensation (Perfo

Stock-based Compensation (Performance Retention Awards, Present Value Calculation Assumptions) (Details) - Performance Retention Awards [Member]	12 Months Ended
	Dec. 31, 2016$ / shares
Assumptions For Stock Awards [Abstract]
Dividend per share per quarter	$ 0.55
Risk-free interest rate at date of grant	0.90%

Stock-based Compensation (Sch58

Stock-based Compensation (Schedule Of Performance Retention Awards) (Details) - Performance Retention Awards [Member] shares in Thousands	12 Months Ended
	Dec. 31, 2016$ / sharesshares
Schedule of Share-based Compensation Arrangements [Line Items]
Awards, shares nonvested at January 1, 2016 | shares	1,255
Awards, shares granted | shares	503
Awards, shares vested | shares	(530)
Awards, shares forfeited | shares	(83)
Awards, shares nonvested at December 31, 2016 | shares	1,145
Awards weighted-average grant-date fair value, nonvested at January 1, 2016 | $ / shares	$ 82.98
Awards weighted-average grant-date fair value, granted | $ / shares	70.09
Awards weighted-average grant-date fair value, vested | $ / shares	62.57
Awards weighted-average grant-date fair value, forfeited | $ / shares	90.42
Awards weighted-average grant-date fair value, nonvested at December 31, 2016 | $ / shares	$ 86.23

Retirement Plans (Narrative) (D

Retirement Plans (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Retirement Plans [Line Items]
Pension & OPEB Descriptions		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.
Changes in fair value period		5 years
Significant transfers in or out of Levels 1, 2, or 3		$ 0	$ 0
Pension [Member]
Retirement Plans [Line Items]
Accumulated benefit obligation		412,000,000	388,000,000
Accumulated benefit obligation.		$ 3,900,000,000	$ 3,700,000,000
Actual return (loss) on pension plan assets, net of fees		8.00%	(1.00%)	6.00%
OPEB [Member]
Retirement Plans [Line Items]
Health care cost trend rate (employees under 65)		6.52%	6.34%	6.49%
Ultimate health care cost trend rate		4.50%	4.50%	4.50%
Year ultimate trend rate reached		2,038	2,028	2,028
OPEB [Member] | 2017 Forecast [Member]
Retirement Plans [Line Items]
Health care cost trend rate (employees under 65)	6.52%
Ultimate health care cost trend rate	4.50%
Year ultimate trend rate reached	2,038
Pension Non-qualified Plan [Member]
Retirement Plans [Line Items]
Accumulated benefit obligation		$ 412,000,000	$ 388,000,000

Retirement Plans (Other Retirem

Retirement Plans (Other Retirement Programs) (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
401(k)/Thrift Plan [Abstract]
401(k)/Thrift plan description	We provide a defined contribution plan (401(k)/thrift plan) to eligible non-union and union employees for whom we make matching contributions.
401(k)/Thrift plan contributions	$ 19	$ 20	$ 19
Railroad Retirement System [Abstract]
Railroad Retirement System description	All Railroad employees are covered by the Railroad Retirement System (the System).
Railroad Retirement System contributions	$ 671	749	711
Collective Bargaining Agreements [Member]
Collective Bargaining Agreements [Abstract]
Collective bargaining agreements description	Under collective bargaining agreements, we participate in multi-employer benefit plans that provide certain postretirement health care and life insurance benefits for eligible union employees.
Collective bargaining agreements premiums	$ 50	$ 46	$ 52

Retirement Plans (Schedule Of C

Retirement Plans (Schedule Of Changes In Projected Benefit Obligation And Plan Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension [Member]
Projected Benefit Obligation [Abstract]
Projected benefit obligation at beginning of year	$ 3,958	$ 4,142
Service cost	84	106	$ 70
Interest cost	143	163	158
Actuarial loss/(gain)	124	(267)
Gross benefits paid	(199)	(186)
Projected benefit obligation at end of year	4,110	3,958	4,142
Plan Assets [Abstract]
Fair value of plan assets at beginning of year	3,544	3,654
Actual return/(loss) on plan assets	279	(43)
Voluntary funded pension plan contributions	100	100
Non-qualified plan benefit contributions	24	19
Gross benefits paid	(199)	(186)
Fair value of plan assets at end of year	3,748	3,544	3,654
Defined Benefit Plan, Funded Status of Plan [Abstract]
Funded status at end of year	(362)	(414)
OPEB [Member]
Projected Benefit Obligation [Abstract]
Projected benefit obligation at beginning of year	329	354
Service cost	1	3	2
Interest cost	11	13	14
Actuarial loss/(gain)	16	(18)
Gross benefits paid	(23)	(23)
Projected benefit obligation at end of year	334	329	354
Plan Assets [Abstract]
Fair value of plan assets at beginning of year
Actual return/(loss) on plan assets
Voluntary funded pension plan contributions
Non-qualified plan benefit contributions - OPEB	23	23
Gross benefits paid	(23)	(23)
Fair value of plan assets at end of year
Defined Benefit Plan, Funded Status of Plan [Abstract]
Funded status at end of year	$ (334)	$ (329)

Retirement Plans (Schedule Of A

Retirement Plans (Schedule Of Amounts Recognized In Statement Of Financial Position) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Amounts recognized - noncurrent assets	$ 67	$ 1
Amounts recognized - current liabilities	(24)	(22)
Amounts recognized - noncurrent liabilities	(405)	(393)
Net amounts recognized at end of year	(362)	(414)
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Amounts recognized - noncurrent assets
Amounts recognized - current liabilities	(24)	(23)
Amounts recognized - noncurrent liabilities	(310)	(306)
Net amounts recognized at end of year	$ (334)	$ (329)

Retirement Plans (Schedule Of P

Retirement Plans (Schedule Of Pre-Tax Amounts Recognized In Accumulated Other Comprehensive Income/(Loss)) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Prior service (cost)/credit	$ (2)	$ 7
Net actuarial loss	(1,804)	(1,769)
Total pre-tax amounts recognized in accumulated other comprehensive income/(loss)	(1,806)	(1,762)
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service (cost)/credit
Net actuarial loss	(1,681)	(1,652)
Total pre-tax amounts recognized in accumulated other comprehensive income/(loss)	(1,681)	(1,652)
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service (cost)/credit	(2)	7
Net actuarial loss	(123)	(117)
Total pre-tax amounts recognized in accumulated other comprehensive income/(loss)	$ (125)	$ (110)

Retirement Plans (Schedule Of O

Retirement Plans (Schedule Of Other Pre-Tax Changes Recognized In Other Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial (loss)/gain - OCI	$ (112)	$ (31)	$ (780)
Amortization of prior service cost/(credit) - OCI
Amortization of actuarial loss - OCI	83	106	71
Total other pre-tax changes recognized in other comprehensive income	(29)	75	(709)
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial (loss)/gain - OCI	(16)	18	(33)
Amortization of prior service cost/(credit) - OCI	(9)	(10)	(11)
Amortization of actuarial loss - OCI	10	13	10
Total other pre-tax changes recognized in other comprehensive income	$ (15)	$ 21	$ (34)

Retirement Plans (Amounts Inclu

Retirement Plans (Amounts Included In Accumulated Other Comprehensive Income Expected To Be Amortized Into Net Periodic Cost (Benefit)) (Details) - 2017 Forecast [Member] $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Defined Benefit Plan Disclosure [Line Items]
Prior service credit - AOCI	$ (1)
Net actuarial loss - AOCI	(89)
Total amounts included in accumulated other comprehensive income expected to be amortized into net periodic cost (benefit)	(90)
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service credit - AOCI
Net actuarial loss - AOCI	(79)
Total amounts included in accumulated other comprehensive income expected to be amortized into net periodic cost (benefit)	(79)
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service credit - AOCI	(1)
Net actuarial loss - AOCI	(10)
Total amounts included in accumulated other comprehensive income expected to be amortized into net periodic cost (benefit)	$ (11)

Retirement Plans (Underfunded A

Retirement Plans (Underfunded Accumulated Benefit Obligation) (Details) - Pension [Member] - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Retirement Plans [Line Items]
Projected benefit obligation	$ 428	$ 398
Accumulated benefit obligation	412	388
Fair value of plan assets
Underfunded accumulated benefit obligation	$ (412)	$ (388)

Retirement Plans (Weighted-Aver

Retirement Plans (Weighted-Average Actuarial Assumptions Used To Determine Benefit Obligations) (Detail)	Dec. 31, 2016	Dec. 31, 2015
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate - benefit obligations	4.20%	4.37%
Compensation increase - benefit obligations	4.20%	4.10%
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate - benefit obligations	4.00%	4.16%
Health care cost trend rate (employees under 65) - benefit obligations	6.31%	6.52%
Ultimate health care cost trend rate - benefit obligations	4.50%	4.50%
Year ultimate trend reached - benefit obligations	2,038	2,038

Retirement Plans (Net Periodic

Retirement Plans (Net Periodic Pension And OPEB Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension [Member]
Net Periodic Pension And OPEB Cost [Abstract]
Service cost	$ 84	$ 106	$ 70
Interest cost	143	163	158
Expected return on plan assets	(267)	(255)	(230)
Amortization of prior service cost/(credit)
Amortization of actuarial loss	83	106	71
Net periodic pension/OPEB cost	43	120	69
OPEB [Member]
Net Periodic Pension And OPEB Cost [Abstract]
Service cost	1	3	2
Interest cost	11	13	14
Expected return on plan assets
Amortization of prior service cost/(credit)	(9)	(10)	(11)
Amortization of actuarial loss	10	13	10
Net periodic pension/OPEB cost	$ 13	$ 19	$ 15

Retirement Plans (Weighted-Av69

Retirement Plans (Weighted-Average Actuarial Assumptions Used To Determine Benefit Expense) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets - expense	7.50%
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate for benefit obligations	4.37%	3.94%	4.72%
Discount rate for interest on benefit obligations	3.65%	3.94%	4.72%
Discount rate for service cost	4.69%	3.94%	4.72%
Discount rate for interest on service cost	4.55%	3.94%	4.72%
Expected return on plan assets - expense	7.50%	7.50%	7.50%
Compensation increase - expense	4.20%	4.00%	4.00%
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate for benefit obligations	4.13%	3.74%	4.47%
Discount rate for interest on benefit obligations	3.34%	3.74%	4.47%
Discount rate for service cost	4.59%	3.74%	4.47%
Discount rate for interest on service cost	4.44%	3.74%	4.47%
Health care cost trend rate for next year (employees under 65) - expense	6.52%	6.34%	6.49%
Ultimate health care cost trend rate - expense	4.50%	4.50%	4.50%
Year ultimate trend rate reached - expense	2,038	2,028	2,028

Retirement Plans (OPEB Effects

Retirement Plans (OPEB Effects From One-Percentage Point Change Assumed Healthcare Cost Trend Rates) (Details) - OPEB [Member] $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)
Defined Benefit Plan Disclosure [Line Items]
Effect on total service and interest cost components - one % pt. increase	$ 1
Effect on total service and interest cost components - one % pt. decrease	(1)
Effect on accumulated benefit obligation - one % pt. increase	19
Effect on accumulated benefit obligation - one % pt. decrease	$ (16)

Retirement Plans (Cash Contribu

Retirement Plans (Cash Contributions For Qualified Pension Plan Benefit Payments For Non-Qualified OPEB Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash contributions to qualified pension plan
Cash contribution to non-qualified OPEB plan	23	23
Pension Qualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash contributions to qualified pension plan	100	100
Pension Non-qualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash contributions to non-qualified pension plan	$ 24	$ 19

Retirement Plans (Schedule Of E

Retirement Plans (Schedule Of Expected Benefit Payments) (Details) $ in Millions	Dec. 31, 2016USD ($)
Pension [Member]
Benefit Payments [Abstract]
2,017	$ 199
2,018	201
2,019	204
2,020	206
2,021	209
Years 2022 - 2026	1,094
OPEB [Member]
Benefit Payments [Abstract]
2,017	24
2,018	24
2,019	23
2,020	22
2,021	22
Years 2022 - 2026	$ 98

Retirement Plans (Schedule Of73

Retirement Plans (Schedule Of Pension Plan Asset Allocation) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Asset allocation	100.00%	100.00%
Target average long-term rate of return	7.00%
Average long-term rate of return target description	The investment strategy for pension plan assets is to maintain a broadly diversified portfolio designed to achieve our target average long-term rate of return of 7.0%.
Expected return on plan assets - expense	7.50%
Weighted-average maturity of Pension Plan debt portfolio	14 years	12 years
Prohibited investments description	The investment of pension plan assets in securities issued by UPC is explicitly prohibited by the plan for both the equity and debt portfolios, other than through index fund holdings.
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation 2017 range minimum	60.00%
Target allocation 2017 range maximum	70.00%
Asset allocation	68.00%	67.00%
Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation 2017 range minimum	20.00%
Target allocation 2017 range maximum	30.00%
Asset allocation	21.00%	23.00%
Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation 2017 range minimum	2.00%
Target allocation 2017 range maximum	8.00%
Asset allocation	6.00%	6.00%
Commodities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation 2017 range minimum	4.00%
Target allocation 2017 range maximum	6.00%
Asset allocation	5.00%	4.00%

Retirement Plans (Schedule Of74

Retirement Plans (Schedule Of Assets Measured At Fair Value On A Recurring Basis) (Details) - Pension [Member] - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 3,748	$ 3,544	$ 3,654
Temporary Cash Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		27	13
Registered Investment Companies [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	17	179
Federal Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		142	125
Bonds and Debentures [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		357	383
Corporate Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1,067	1,041
Total Plan Assets At Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1,610	1,741
Registered Investment Companies - NAV [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[2]	280	270
Venture Capital And Buyout Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		283	256
Real Estate Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		212	199
Collective Trust And Other Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1,346	1,075
Total Plan Assets at NAV [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		2,121	1,800
Other Assets - Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[3]	17	3
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | Temporary Cash Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		27	13
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | Registered Investment Companies [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	17	179
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | Federal Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | Bonds and Debentures [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | Corporate Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1,059	1,034
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | Total Plan Assets At Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1,103	1,226
Significant Other Observable Inputs (Level 2) [Member] | Temporary Cash Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Significant Other Observable Inputs (Level 2) [Member] | Registered Investment Companies [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]
Significant Other Observable Inputs (Level 2) [Member] | Federal Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		142	125
Significant Other Observable Inputs (Level 2) [Member] | Bonds and Debentures [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		357	383
Significant Other Observable Inputs (Level 2) [Member] | Corporate Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		8	7
Significant Other Observable Inputs (Level 2) [Member] | Total Plan Assets At Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		507	515
Significant Unobservable Inputs (Level 3) [Member] | Temporary Cash Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Significant Unobservable Inputs (Level 3) [Member] | Registered Investment Companies [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]
Significant Unobservable Inputs (Level 3) [Member] | Federal Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Significant Unobservable Inputs (Level 3) [Member] | Bonds and Debentures [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Significant Unobservable Inputs (Level 3) [Member] | Corporate Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Significant Unobservable Inputs (Level 3) [Member] | Total Plan Assets At Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
[1]	Registered investment companies measured at fair value include stock and real estate investments.
[2]	Registered investment companies measured at NAV include bond investments.
[3]	Other assets include accrued receivables and pending broker settlements.

Other Income (Details)

Other Income (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Other Income [Abstract]
Rental income			$ 96		$ 96		$ 96
Net gain on non-operating asset dispositions.			94	[1]	144	[2]	69
Interest income			11		5		4
Non-operating environmental costs and other			(9)		(19)		(18)	[3]
Total			$ 192		226		151
Real estate sale	$ 50	$ 17			$ 113
Permanent easement sale							$ 14
[1]	2016 includes $17 million and $50 million related to a real estate sale in the first and second quarter, respectively.
[2]	2015 includes $113 million related to a real estate sale.
[3]	2014 includes $14 million related to the sale of a permanent easement.

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Abstract]
Total accrued liabilities for interest and penalties	$ 2	$ 8	$ 2
Total interest and penalties recognized as part of income tax expense		$ 5		$ 9
Total interest and penalties recognized as part of income tax benefit			$ (3)
Taxes paid in connection to settlement	$ 10			$ 11

Income Taxes (Schedule Of Compo

Income Taxes (Schedule Of Components Of Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current Income Tax Expense [Abstract]
Current federal income tax expense	$ 1,518	$ 1,901	$ 2,019
Current state income tax expense	176	210	239
Current foreign income tax expense	8	8	10
Total current income tax expense	1,702	2,119	2,268
Deferred Income Tax Expense [Abstract]
Deferred federal income tax expense	692	644	753
Deferred state income tax expense	139	121	142
Total deferred income tax expense	831	765	895
Total income tax expense	$ 2,533	$ 2,884	$ 3,163

Income Taxes (Reconciliations B

Income Taxes (Reconciliations Between Statutory And Effective Tax Rates) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation Between Statutory And Effective Tax Rates [Abstract]
Federal statutory tax rate	35.00%	35.00%	35.00%
State statutory rates, net of federal benefits	3.10%	3.10%	3.10%
Tax credits	(0.50%)	(0.50%)	(0.40%)
Other tax rate adjustments	(0.20%)	0.10%	0.20%
Effective tax rate	37.40%	37.70%	37.90%

Income Taxes (Schedule Of Defer

Income Taxes (Schedule Of Deferred Income Tax Liabilities And Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Components Of Deferred Income Tax (Liabilities)/Assets [Abstract]
Deferred income tax liabilities - property	$ (16,687)	$ (16,079)
Deferred income tax liabilities - other	(346)	(352)
Total deferred income tax liabilities	(17,033)	(16,431)
Deferred income tax asset - accrued wages	75	76
Deferred income tax asset - accrued casualty costs	231	237
Deferred income tax asset - stock compensation	69	72
Deferred income tax asset - debt and leases	14	149
Deferred income tax asset - retiree benefits	222	204
Deferred income tax asset - credits	145	156
Deferred income tax asset - other	281	296
Total deferred income tax asset	1,037	1,190
Net deferred income tax liability	(15,996)	(15,241)
Income Tax Details [Abstract]
Deferred tax valuation allowance	$ 0	$ 0

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of Changes In Unrecognized Tax Benefits Liabilities/(Assets)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation Of Changes In Unrecognized Tax Benefits Liabilities/(Assets) [Abstract]
Unrecognized tax benefits at January 1	$ 94	$ 151	$ 59
Increases for positions taken in current year	31	38	92
Increases for positions taken in prior years	10	13	22
Decreases for positions taken in prior years	(20)	(87)	(14)
Refunds from and settlements with taxing authorities	4
Payments to and settlements with taxing authorities		(13)	(8)
Increases/(decreases) for interest and penalties	6	(5)	1
Lapse of statutes of limitations		(3)	(1)
Unrecognized tax benefits at December 31	$ 125	$ 94	$ 151

Income Taxes (Unrecognized Tax

Income Taxes (Unrecognized Tax Benefits That Would/Not Reduce The Effective Tax Rate) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Unrecognized Tax Benefits That Would Impact Effective Tax Rate [Abstract]
Unrecognized tax benefits that would reduce the effective tax rate	$ 31	$ 31	$ 33
Unrecognized tax benefits that would not reduce the effective tax rate	94	63	118
Total unrecognized tax benefits	$ 125	$ 94	$ 151	$ 59

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Net income	$ 1,144	$ 1,131	$ 979	$ 979	$ 1,117	$ 1,300	$ 1,204	$ 1,151	$ 4,233	$ 4,772	$ 5,180
Weighted-Average Number Of Shares Outstanding
Basic									832.4	866.2	897.1
Dilutive effect of stock options									1.5	1.5	2.1
Dilutive effect of retention shares and units									1.5	1.7	1.9
Diluted									835.4	869.4	901.1
Earnings per share – basic	$ 1.40	$ 1.36	$ 1.17	$ 1.16	$ 1.31	$ 1.51	$ 1.38	$ 1.31	$ 5.09	$ 5.51	$ 5.77
Earnings per share – diluted	$ 1.39	$ 1.36	$ 1.17	$ 1.16	$ 1.31	$ 1.50	$ 1.38	$ 1.30	$ 5.07	$ 5.49	$ 5.75
Stock options excluded as their inclusion would be anti-dilutive									2	1.1	0.4

Accumulated Other Comprehensi83

Accumulated Other Comprehensive Income/(Loss) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at January 1		$ (1,195)	$ (1,210)
Other comprehensive income/(loss) before reclassifications		(51)	(47)
Amounts reclassified from accumulated other comprehensive income/(loss)	[1]	(26)	62
Net year-to-date other comprehensive income/(loss), net of taxes	[2]	(77)	15	$ (460)
Balance at December 31		(1,272)	(1,195)	(1,210)
Deferred taxes activity other comprehensive income/(loss)		49	(8)	291
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at January 1		(1,103)	(1,161)
Other comprehensive income/(loss) before reclassifications		(3)	(4)
Amounts reclassified from accumulated other comprehensive income/(loss)	[1]	(26)	62
Net year-to-date other comprehensive income/(loss), net of taxes		(29)	58
Balance at December 31		(1,132)	(1,103)	(1,161)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at January 1		(92)	(49)
Other comprehensive income/(loss) before reclassifications		(48)	(43)
Amounts reclassified from accumulated other comprehensive income/(loss)	[1]
Net year-to-date other comprehensive income/(loss), net of taxes		(48)	(43)
Balance at December 31		$ (140)	$ (92)	$ (49)
[1]	The accumulated other comprehensive income/(loss) reclassification components are 1) prior service cost/(benefit) 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 $49 million, ($8) million, and $291 million during 2016, 2015, and 2014, respectively.

Accounts Receivable (Details)

Accounts Receivable (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounts Receivable Details [Abstract]
Allowance for doubtful accounts	$ 5	$ 5
Allowance for doubtful accounts - receivables not expected to be collected in one year	17	11
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 renewal date	2016-08
Receivables securitization facility duration	3 years
Value of the outstanding undivided interest held by investors under the receivables securitization facility	$ 0	400
Accounts receivable supporting the undivided interest held by investors	1,000	900
Cost of the receivables securitization facility - interest expense	$ 7	$ 5	$ 4

Properties (Details)

Properties (Details) $ in Millions		12 Months Ended
		Dec. 31, 2016USD ($)item	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Property, Plant and Equipment [Line Items]
Cost		$ 69,058	$ 66,564
Accumulated depreciation		18,669	17,698
Net book value		$ 50,389	48,866
Depreciable asset classes description		We currently have more than 60 depreciable asset classes, and we may increase or decrease the number of asset classes due to changes in technology, asset strategies, or other factors.
Total repairs and maintenance expense		$ 2,300	2,500	$ 2,400
Land [Member]
Property, Plant and Equipment [Line Items]
Cost		5,220	5,195
Accumulated depreciation
Net book value		5,220	5,195
Road: Rail and Other Track Material [Member]
Property, Plant and Equipment [Line Items]
Cost		15,845	15,236
Accumulated depreciation		5,722	5,495
Net book value		$ 10,123	$ 9,741
Estimated useful life		40 years	37 years
Road: Ties [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 9,812	$ 9,439
Accumulated depreciation		2,736	2,595
Net book value		$ 7,076	$ 6,844
Estimated useful life		33 years	33 years
Road: Ballast [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 5,242	$ 5,024
Accumulated depreciation		1,430	1,350
Net book value		$ 3,812	$ 3,674
Estimated useful life		34 years	34 years
Road: Other Roadway [Member]
Property, Plant and Equipment [Line Items]
Cost	[1]	$ 18,138	$ 17,374
Accumulated depreciation	[1]	3,226	3,021
Net book value	[1]	$ 14,912	$ 14,353
Estimated useful life	[1]	47 years	47 years
Total Road [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 49,037	$ 47,073
Accumulated depreciation		13,114	12,461
Net book value		$ 35,923	34,612
Term of Depreciation Studies		6 years
Equipment: Locomotives [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 9,692	9,027
Accumulated depreciation		3,939	3,726
Net book value		$ 5,753	$ 5,301
Estimated useful life		20 years	19 years
Equipment: Freight Cars [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 2,243	$ 2,203
Accumulated depreciation		972	962
Net book value		$ 1,271	$ 1,241
Estimated useful life		24 years	24 years
Equipment: Work Equipment and Other [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 905	$ 897
Accumulated depreciation		232	191
Net book value		$ 673	$ 706
Estimated useful life		19 years	19 years
Total Equipment [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 12,840	$ 12,127
Accumulated depreciation		5,143	4,879
Net book value		$ 7,697	7,248
Term of Depreciation Studies		3 years
Technology and Other [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 974	919
Accumulated depreciation		412	358
Net book value		$ 562	$ 561
Estimated useful life		11 years	11 years
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 987	$ 1,250
Accumulated depreciation
Net book value		$ 987	$ 1,250
Minimum [Member]
Property, Plant and Equipment [Line Items]
Number of depreciable asset classes | item		60
[1]	Other roadway includes grading, bridges and tunnels, signals, buildings, and other road assets.

Accounts Payable And Other Cu86

Accounts Payable And Other Current Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Accounts Payable And Other Current Liabilities [Abstract]
Accounts payable	$ 955	$ 743
Income and other taxes payable	472	434
Accrued wages and vacation	387	391
Interest payable	212	208
Accrued casualty costs	185	181
Equipment rents payable	101	105
Other	570	550
Total accounts payable and other current liabilities	$ 2,882	$ 2,612

Financial Instruments (Details)

Financial Instruments (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Short-term investments [Abstract]
Short-term investments	$ 60,000,000
Transfers out of level 2	0
Fair Value of Debt Instruments [Abstract]
Fair value of total debt	15,900,000,000	15,200,000,000
Fair value of total debt in excess of carrying value	900,000,000	1,000,000,000
Fixed rate debt securities containing call provisions	155,000,000	$ 155,000,000
Time Deposits [Member] | Significant Other Observable Inputs (Level 2) [Member]
Short-term investments [Abstract]
Short-term investments	$ 60,000,000

Debt (Equipment Encumbrances) (

Debt (Equipment Encumbrances) (Narrative) (Details) - USD ($) $ in Billions	Dec. 31, 2016	Dec. 31, 2015	Jan. 01, 1997
Debt [Abstract]
Carrying value of equipment serving as collateral for capital leases and other types of equipment obligations	$ 2.3	$ 2.6
Value of Missouri Pacific Railroad company assets that secured mortgage bonds			$ 6

Debt (Credit Facilities) (Narra

Debt (Credit Facilities) (Narrative) (Details) - Revolving Credit Facility [Member] - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Facility expiration date	May 25, 2019
Credit facility term	5 years
Revolving credit facility available credit	$ 1,700,000,000
Revolving credit facility withdrawals	0
Allowable debt per debt-to-net-worth coverage ratio (as defined in the facility)	39,900,000,000
Outstanding debt (as defined by facility)	15,100,000,000
Cross-default provision (as defined by facility)	125,000,000
Commercial paper issued	0
Commercial paper repaid	0
Commercial paper outstanding	$ 0	$ 0

Debt (Dividend Restrictions) (N

Debt (Dividend Restrictions) (Narrative) (Details) - USD ($) $ in Billions	Dec. 31, 2016	Dec. 31, 2015
Debt [Abstract]
Retained earnings available for dividends	$ 12.4	$ 13.6

Debt (Shelf Registration And Si

Debt (Shelf Registration And Significant New Borrowings) (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Jul. 28, 2016
Debt [Abstract]
Board of Directors authorized debt issuance		$ 4,000,000,000
Shelf registration duration	3 years
Board of Directors remaining debt issuance	$ 3,550,000,000	$ 900,000,000

Debt (Equipment Trust) (Narrati

Debt (Equipment Trust) (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)	May 09, 2016USD ($)item	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
Debt due after one year	$ 14,249		$ 13,607
Equipment obligations [Member] | 2.495% Pass-Through Trust Certificates Due 2029 [Member]
Debt Instrument [Line Items]
Issuance date	May 9, 2016
Note amount		$ 151
Interest rate on note		2.495%
Maturity date on new borrowing	Nov. 9, 2029
Total locomotives financed from proceeds | item		59
Debt due after one year	$ 151

Debt (Debt Exchange) (Narrative

Debt (Debt Exchange) (Narrative) (Details) - Notes and debentures [Member] - 3.799% Debt Due 2051 [Member] - USD ($)	Oct. 04, 2016	Dec. 31, 2016
Debt Conversion [Line Items]
Date of exchange		Oct. 4, 2016
Original debt	$ 1,006,000,000
New debt	$ 1,044,000,000
New rate	3.799%
Cash consideration	$ 183,000,000
Accrued and unpaid interest	11,000,000
New due date		Oct. 1, 2051
Gain (loss) recognized resulting from exhange	$ 0
Debt exchange fees		$ 8,000,000

Debt (Receivables Securitizatio

Debt (Receivables Securitization Facility) (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Debt	$ 15,901
Receivables Securitization (Note 11) [Member]
Debt Instrument [Line Items]
Debt	$ 0	$ 400

Debt (Schedule Of Debt) (Detail

Debt (Schedule Of Debt) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Debt	$ 15,901
Unamortized discount and deferred issuance costs	(894)	$ (674)
Total debt	15,007	14,201
Less: current portion	(758)	(594)
Total long-term debt	14,249	13,607
Notes and debentures [Member]
Debt Instrument [Line Items]
Debt	$ 13,547	11,964
Debt due through	Nov. 15, 2065
Notes and debentures [Member] | Minimum [Member]
Debt Instrument [Line Items]
Stated percentage rate	1.80%
Notes and debentures [Member] | Maximum [Member]
Debt Instrument [Line Items]
Stated percentage rate	7.90%
Capitalized leases [Member]
Debt Instrument [Line Items]
Debt	$ 1,105	1,268
Debt due through	Dec. 10, 2028
Capitalized leases [Member] | Minimum [Member]
Debt Instrument [Line Items]
Stated percentage rate	3.10%
Capitalized leases [Member] | Maximum [Member]
Debt Instrument [Line Items]
Stated percentage rate	8.40%
Equipment obligations [Member]
Debt Instrument [Line Items]
Debt	$ 1,069	963
Debt due through	Jan. 2, 2031
Equipment obligations [Member] | Minimum [Member]
Debt Instrument [Line Items]
Stated percentage rate	2.60%
Equipment obligations [Member] | Maximum [Member]
Debt Instrument [Line Items]
Stated percentage rate	6.70%
Term loans - floating rate [Member]
Debt Instrument [Line Items]
Debt	$ 100	200
Debt due through	Oct. 31, 2017
Mortgage bonds [Member]
Debt Instrument [Line Items]
Debt	$ 57	57
Stated percentage rate	4.80%
Debt due through	Jan. 1, 2030
Medium-term notes [Member]
Debt Instrument [Line Items]
Debt	$ 23	23
Debt due through	Apr. 15, 2020
Medium-term notes [Member] | Minimum [Member]
Debt Instrument [Line Items]
Stated percentage rate	9.30%
Medium-term notes [Member] | Maximum [Member]
Debt Instrument [Line Items]
Stated percentage rate	10.00%
Receivables Securitization (Note 11) [Member]
Debt Instrument [Line Items]
Debt	$ 0	$ 400

Debt (Aggregate Debt Maturities

Debt (Aggregate Debt Maturities) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Aggregate Debt Maturities Excluding Market Value Adjustments [Abstract]
Debt maturities - 2017	$ 763
Debt maturities - 2018	572
Debt maturities - 2019	645
Debt maturities - 2020	1,042
Debt maturities - 2021	673
Debt maturities - thereafter	12,206
Total principal	15,901
Unamortized discount and deferred issuance costs	(894)	$ (674)
Total debt	$ 15,007	$ 14,201

Debt (Unsecured Fixed Rate Debt

Debt (Unsecured Fixed Rate Debt Securities Issued Under Current Shelf Registration) (Details) - Unsecured Debt [Member] - USD ($)	12 Months Ended
	Dec. 31, 2016	Aug. 08, 2016	Mar. 01, 2016
2.750% Notes Due 2026 [Member]
Debt Instrument [Line Items]
Issuance date	Mar. 1, 2016
Note amount			$ 500,000,000
Interest rate on note			2.75%
Maturity date on new borrowing	Mar. 1, 2026
4.050% Notes Due 2046 [Member]
Debt Instrument [Line Items]
Issuance date	Mar. 1, 2016
Note amount			$ 600,000,000
Interest rate on note			4.05%
Maturity date on new borrowing	Mar. 1, 2046
4.375% Notes Due 2065 [Member]
Debt Instrument [Line Items]
Issuance date	Mar. 1, 2016
Note amount			$ 200,000,000
Interest rate on note			4.375%
Maturity date on new borrowing	Nov. 15, 2065
2.750% Reopened Notes Due 2026 [Member]
Debt Instrument [Line Items]
Issuance date	Aug. 8, 2016
Note amount		$ 150,000,000
Interest rate on note		2.75%
Maturity date on new borrowing	Mar. 1, 2026
3.350% Notes Due 2046 [Member]
Debt Instrument [Line Items]
Issuance date	Aug. 8, 2016
Note amount		$ 300,000,000
Interest rate on note		3.35%
Maturity date on new borrowing	Aug. 15, 2046

Debt (Schedule Of Debt Exchange

Debt (Schedule Of Debt Exchange) (Details) - 3.799% Debt Due 2051 [Member] - Notes and debentures [Member] - USD ($) $ in Millions	Oct. 04, 2016	Dec. 31, 2016
Debt Conversion [Line Items]
Original debt	$ 1,006
7.125% Debentures Due 2028 [Member]
Debt Conversion [Line Items]
Original debt	$ 2
Original rate	7.125%
Original due date, year		2,028
6.625% Debentures Due 2029 [Member]
Debt Conversion [Line Items]
Original debt	$ 25
Original rate	6.625%
Original due date, year		2,029
5.375% Debentures Due 2033 [Member]
Debt Conversion [Line Items]
Original debt	$ 15
Original rate	5.375%
Original due date, year		2,033
6.250% Debentures Due 2034 [Member]
Debt Conversion [Line Items]
Original debt	$ 52
Original rate	6.25%
Original due date, year		2,034
6.150% Debentures Due 2037 [Member]
Debt Conversion [Line Items]
Original debt	$ 2
Original rate	6.15%
Original due date, year		2,037
5.780% Notes Due 2040 [Member]
Debt Conversion [Line Items]
Original debt	$ 4
Original rate	5.78%
Original due date, year		2,040
4.750% Notes Due 2041 [Member]
Debt Conversion [Line Items]
Original debt	$ 175
Original rate	4.75%
Original due date, year		2,041
4.750% Notes Due 2043 [Member]
Debt Conversion [Line Items]
Original debt	$ 204
Original rate	4.75%
Original due date, year		2,043
4.821% Notes Due 2044 [Member]
Debt Conversion [Line Items]
Original debt	$ 373
Original rate	4.821%
Original due date, year		2,044
4.850% Notes Due 2044 [Member]
Debt Conversion [Line Items]
Original debt	$ 154
Original rate	4.85%
Original due date, year		2,044

Variable Interest Entities (Det

Variable Interest Entities (Details) $ in Millions	Dec. 31, 2016USD ($)
Future minimum lease payments	$ 3,043
Variable Interest Entity (VIEs) [Member]
Future minimum lease payments	$ 2,200

Leases (Narrative) (Details)

Leases (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Future Minimum Lease Payments For Capital Leases [Abstract]
Properties held under capital leases	$ 1,997	$ 2,273
Properties held under capital leases - accumulated depreciation	$ 1,121	1,189
Lease payments related to locomotives	96.00%
Future Minimum Lease Payments For Operating Leases [Abstract]
Rent expense for operating leases with terms exceeding one month	$ 535	$ 590	$ 593

Leases (Future Minimum Lease Pa

Leases (Future Minimum Lease Payments For Operating And Capital Leases) (Details) $ in Millions	Dec. 31, 2016USD ($)
Future Minimum Lease Payments For Capital Leases [Abstract]
Minimum capital lease payments - 2017	$ 221
Minimum capital lease payments - 2018	193
Minimum capital lease payments - 2019	179
Minimum capital lease payments - 2020	187
Minimum capital lease payments - 2021	158
Minimum capital lease payments - later years	417
Total minimum capital lease payments	1,355
Capital lease payments - amount representing interest	(250)
Capital lease payments - present value of minimum lease payments	1,105
Future Minimum Lease Payments For Operating Leases [Abstract]
Minimum operating lease payments - 2017	461
Minimum operating lease payments - 2018	390
Minimum operating lease payments - 2019	348
Minimum operating lease payments - 2020	285
Minimum operating lease payments - 2021	245
Minimum operating lease payments - later years	1,314
Total minimum operating lease payments	$ 3,043

Commitments And Contingencie102

Commitments And Contingencies (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)site	Dec. 31, 2015USD ($)
Commitments and Contingencies [Line Items]
Sites identified which we are or may be liable for remediation costs | site	292
Sites subject of actions taken by the U.S. government | site	33
Sites on the Superfund National Priorities List | site	21
Personal Injury [Member]
Commitments and Contingencies [Line Items]
Percent of liability recorded related to asserted claims	94.00%
Percent of liability recorded related to unasserted claims	6.00%
Personal Injury [Member] | Minimum [Member]
Commitments and Contingencies [Line Items]
Reasonably possible outcome of related claims	$ 290
Personal Injury [Member] | Maximum [Member]
Commitments and Contingencies [Line Items]
Reasonably possible outcome of related claims	$ 317
Asbestos [Member]
Commitments and Contingencies [Line Items]
Percent of liability recorded related to asserted claims	20.00%
Percent of liability recorded related to unasserted claims	80.00%
Asbestos [Member] | Minimum [Member]
Commitments and Contingencies [Line Items]
Reasonably possible outcome of related claims	$ 111
Asbestos [Member] | Maximum [Member]
Commitments and Contingencies [Line Items]
Reasonably possible outcome of related claims	118
Guarantees [Member]
Commitments and Contingencies [Line Items]
Maximum potential amount of guarantee payments	43	$ 53
Recorded liability for fair value of guarantees	$ 0	$ 0
Expiration year of final guarantee	The final guarantee expires in 2022.

Commitments And Contingencie103

Commitments And Contingencies (Commitments And Contingencies Activity) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Commitments and Contingencies [Line Items]
Current portion, ending balance at December 31	$ 185	$ 181
Environmental [Abstract]
Beginning balance.	190	182	$ 171
Accruals	84	61	56
Payments	(62)	(53)	(45)
Ending balance at December 31	212	190	182
Current portion, ending balance at December 31	55	52	60
Personal Injury [Member]
Commitments and Contingencies [Line Items]
Beginning balance	318	335	294
Current year accruals	75	89	96
Changes in estimates for prior years	(29)	(3)	9
Payments	(74)	(103)	(64)
Ending balance at December 31	290	318	335
Current portion, ending balance at December 31	62	63	111
Asbestos [Member]
Commitments and Contingencies [Line Items]
Beginning balance	120	126	131
Current year accruals	12		1
Payments	(21)	(6)	(6)
Ending balance at December 31	111	120	126
Current portion, ending balance at December 31	$ 8	$ 6	$ 8

Share Repurchase Program (Detai

Share Repurchase Program (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended								12 Months Ended			120 Months Ended
	Feb. 02, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Nov. 17, 2016	Jan. 01, 2014
Share Repurchase Program [Line Items]
BOD authorized														120,000,000	120,000,000
Stock repurchase program expiration date										Dec. 31, 2017
Aggregate cost										$ 3,105	$ 3,465	$ 3,225	$ 19,100
Shares repurchased		9,624,667	9,088,613	7,026,100	9,315,807	6,646,899	13,800,700	7,975,100	6,881,455	35,055,187	35,304,154
Average purchase price		$ 97.60	$ 93.63	$ 85.66	$ 76.49	$ 88.19	$ 89.65	$ 104.62	$ 117.28	$ 88.57	$ 98.14
Subsequent Event [Member]
Share Repurchase Program [Line Items]
Aggregate cost	$ 291
Shares repurchased	2,750,000

Related Parties (Details)

Related Parties (Details) - TTX Company [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Related Party Transaction [Line Items]
Equity method investment, ownership percentage	36.79%
Equity method investments	$ 877	$ 830
Related party transaction, expenses from transactions with related party	368	376	$ 350
Accounts payable, related parties, current	$ 61	$ 61

Selected Quarterly Data (Una106

Selected Quarterly Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Selected Quarterly Data (Unaudited) [Abstract]
Operating revenues	$ 5,168	$ 5,174	$ 4,770	$ 4,829	$ 5,208	$ 5,562	$ 5,429	$ 5,614	$ 19,941	$ 21,813	$ 23,988
Operating income	1,965	1,960	1,660	1,687	1,918	2,208	1,949	1,977	7,272	8,052	8,753
Net income	$ 1,144	$ 1,131	$ 979	$ 979	$ 1,117	$ 1,300	$ 1,204	$ 1,151	$ 4,233	$ 4,772	$ 5,180
Net income per share:
Earnings per share – basic	$ 1.40	$ 1.36	$ 1.17	$ 1.16	$ 1.31	$ 1.51	$ 1.38	$ 1.31	$ 5.09	$ 5.51	$ 5.77
Earnings per share – diluted	$ 1.39	$ 1.36	$ 1.17	$ 1.16	$ 1.31	$ 1.50	$ 1.38	$ 1.30	$ 5.07	$ 5.49	$ 5.75

Schedule Of Valuation And Qu107

Schedule Of Valuation And Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Presented in Consolidated Statements of Financial Position [Abstract]
Allowance for doubtful accounts - current	$ 5	$ 5
Allowance for doubtful accounts - long-term	17	11
Accrued casualty costs, current	185	181
Allowance For Doubtful Accounts [Member]
Schedule Of Valuation And Qualifying Accounts [Line Items]
Balance, beginning of period	16	21	$ 23
Charges/(reduction) to expense	23	1	5
Net recoveries/(write-offs), cash payments and other reductions	(17)	(6)	(7)
Balance, end of period	22	16	21
Presented in Consolidated Statements of Financial Position [Abstract]
Allowance for doubtful accounts - current	5	5	5
Allowance for doubtful accounts - long-term	17	11	16
Balance, end of period	22	16	21
Accrued Casualty Costs [Member]
Schedule Of Valuation And Qualifying Accounts [Line Items]
Balance, beginning of period	736	757	702
Charges/(reduction) to expense	202	227	256
Net recoveries/(write-offs), cash payments and other reductions	(222)	(248)	(201)
Balance, end of period	716	736	757
Presented in Consolidated Statements of Financial Position [Abstract]
Accrued casualty costs, current	185	181	249
Accrued casualty costs, long-term	531	555	508
Balance, end of period	$ 716	$ 736	$ 757