Union Pacific (UNP) 10-K 5 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2015	Jan. 29, 2016	Jun. 30, 2015
Document and Entity Information [Abstract]
Document type	10-K
Document period end date	Dec. 31, 2015
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			$ 82.7
Document fiscal year focus	2,015
Document fiscal period focus	FY
Trading Symbol	unp
Entity common stock shares outstanding		846,414,350

Consolidated Statements Of Inco

Consolidated Statements Of Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating revenues:
Freight revenues	$ 20,397	$ 22,560	$ 20,684
Other revenues	1,416	1,428	1,279
Total operating revenues	21,813	23,988	21,963
Operating expenses:
Compensation and benefits	5,161	5,076	4,807
Purchased services and materials	2,421	2,558	2,315
Fuel	2,013	3,539	3,534
Depreciation	2,012	1,904	1,777
Equipment and other rents	1,230	1,234	1,235
Other	924	924	849
Total operating expenses	13,761	15,235	14,517
Operating income	8,052	8,753	7,446
Other income (Note 7)	226	151	128
Interest expense	(622)	(561)	(526)
Income before income taxes	7,656	8,343	7,048
Income taxes (Note 8)	(2,884)	(3,163)	(2,660)
Net income	$ 4,772	$ 5,180	$ 4,388
Share and Per Share (Note 9):
Earnings per share - basic	$ 5.51	$ 5.77	$ 4.74
Earnings per share - diluted	$ 5.49	$ 5.75	$ 4.71
Weighted average number of shares - basic	866.2	897.1	926.5
Weighted average number of shares - diluted	869.4	901.1	931.5
Dividends declared per share	$ 2.20	$ 1.91	$ 1.48

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements of Comprehensive Income [Abstract]
Net income		$ 4,772	$ 5,180	$ 4,388
Other comprehensive income/(loss):
Defined benefit plans		58	(448)	436
Foreign currency translation		$ (43)	$ (12)	(1)
Derivatives				1
Total other comprehensive income/(loss)	[1]	$ 15	$ (460)	436
Comprehensive income		$ 4,787	$ 4,720	$ 4,824
[1]	Net of deferred taxes of ($8) million, $291 million, and ($264) million during 2015, 2014, and 2013, respectively.

Consolidated Statements Of Com4

Consolidated Statements Of Comprehensive Income (Parentheticals) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements of Comprehensive Income [Abstract]
Deferred taxes activity other comprehensive income/(loss)	$ (8)	$ 291	$ (264)

Consolidated Statements Of Fina

Consolidated Statements Of Financial Position - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 1,391	$ 1,586
Accounts receivable, net (Note 11)	1,356	1,611
Materials and supplies	736	712
Other current assets	647	492
Total current assets	4,130	4,401
Investments	1,410	1,390
Net properties (Note 12)	48,866	46,272
Other assets	194	309
Total assets	54,600	52,372
Current liabilities:
Accounts payable and other current liabilities (Note 13)	2,612	3,303
Debt due within one year (Note 15)	594	461
Total current liabilities	3,206	3,764
Debt due after one year (Note 15)	13,607	10,952
Deferred income taxes (Note 8)	15,241	14,403
Other long-term liabilities	$ 1,844	$ 2,064
Commitments and contingencies (Notes 17 and 18)
Total liabilities	$ 33,898	$ 31,183
Common shareholders' equity:
Common shares, $2.50 par value, 1,400,000,000 authorized; 1,110,426,354 and 1,110,100,423 issued; 849,211,436 and 883,366,476 outstanding, respectively	2,776	2,775
Paid-in-surplus	4,417	4,321
Retained earnings	30,233	27,367
Treasury stock	(15,529)	(12,064)
Accumulated other comprehensive loss (Note 10)	(1,195)	(1,210)
Total common shareholders' equity	20,702	21,189
Total liabilities and common shareholders' equity	$ 54,600	$ 52,372

Consolidated Statements Of Fin6

Consolidated Statements Of Financial Position (Parentheticals) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
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	1,110,426,354	1,110,100,423
Common shares outstanding	849,211,436	883,366,476

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)		Dec. 31, 2014USD ($)		Dec. 31, 2013USD ($)
Operating Activities
Net income	$ 4,772		$ 5,180		$ 4,388
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	2,012		1,904		1,777
Deferred and other income taxes	765		895		723
Net gain on non-operating asset dispositions	(144)		(69)		(32)
Other operating activities, net	116		(216)		(194)
Changes in current assets and liabilities:
Accounts receivable, net	255		(197)		(83)
Materials and supplies	(24)		(59)		7
Other current assets	(47)		(35)		1
Accounts payable and other current liabilities	(276)		295		40
Income and other taxes	(85)		(313)		196
Cash provided by operating activities	7,344		7,385		6,823
Investing Activities
Capital investments	(4,650)		(4,346)		(3,496)
Proceeds from asset sales	251		138		98
Other investing activities, net	(77)		(41)		(7)
Cash used in investing activities	(4,476)		(4,249)		(3,405)
Financing Activities
Common share repurchases (Note 19)	(3,465)		(3,225)		(2,218)
Debt issued	3,328		2,588		1,443
Dividends paid	(2,344)		(1,632)		(1,333)
Debt repaid	$ (556)		$ (710)		(640)
Debt exchange					(289)
Other financing activities, net	$ (26)		$ (3)		(12)
Cash used in financing activities	(3,063)		(2,982)		(3,049)
Net change in cash and cash equivalents	(195)		154		369
Cash and cash equivalents at beginning of year	1,586		1,432		1,063
Cash and cash equivalents at end of year	1,391		1,586		1,432
Non-cash investing and financing activities:
Capital investments accrued but not yet paid	100		$ 174		133
Capital lease financings	$ 13				39
Cash dividends declared but not yet paid (Note 13)		[1]	$ 438	[1]	356
Cash paid during the year for:
Income taxes, net of refunds	$ (2,156)		(2,492)		(1,656)
Interest, net of amounts capitalized	$ (592)		$ (554)		$ (528)
[1]	Beginning in 2015, the timing of the dividend declaration and payable dates was aligned to occur within the same quarter. The 2015 dividends paid amount includes the fourth quarter 2014 dividend of $438 million, which was paid on January 2, 2015, the first quarter 2015 dividend of $484 million, which was paid on March 30, 2015, the second quarter 2015 dividend of $479 million, which was paid on June 30, 2015, the third quarter 2015 dividend of $476 million, which was paid on September 30, 2015, as well as the fourth quarter 2015 dividend of $467 million, which was paid on December 30, 2015.

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, 2012	$ 2,773	$ 4,113	$ 20,884	$ (6,707)	$ (1,186)		$ 19,877
Common shares, beginning balance at Dec. 31, 2012	1,109,300,000			(170,300,000)
Net income			$ 4,388				4,388
Other comp. income/(loss)					$ 436		436	[2]
Conversion, stock option exercises, forfeitures, and other	$ 1	$ 97		$ 15			113
Conversion, stock option exercises, forfeitures, and other (shares)	400,000			1,600,000
Share repurchases (Note 19)				$ (2,218)			(2,218)
Share repurchases (Note 19) (shares)				(29,000,000)
Cash dividends declared			$ (1,371)				(1,371)
Shareholders' equity, ending balance at Dec. 31, 2013	$ 2,774	$ 4,210	23,901	$ (8,910)	$ (750)		21,225
Common shares, ending 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)			(32,043,400)
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)			883,366,476
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
[1]	AOCI = Accumulated Other Comprehensive Income/(Loss) (Note 10)
[2]	Net of deferred taxes of ($8) million, $291 million, and ($264) million during 2015, 2014, and 2013, respectively.

Consolidated Statements of Cha9

Consolidated Statements of Changes in Common Shareholders' Equity (Parentheticals) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements Of Changes In Common Shareholders' Equity [Abstract]
Cash dividends declared per share	$ 2.20	$ 1.91	$ 1.48

Nature Of Operations

Nature Of Operations	12 Months Ended
	Dec. 31, 2015
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 32,084 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 26,064 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 2015 2014 2013 Agricultural Products $ 3,581 $ 3,777 $ 3,276 Automotive 2,154 2,103 2,077 Chemicals 3,543 3,664 3,501 Coal 3,237 4,127 3,978 Industrial Products 3,808 4,400 3,822 Intermodal 4,074 4,489 4,030 Total freight revenues $ 20,397 $ 22,560 $ 20,684 Other revenues 1,416 1,428 1,279 Total operating revenues $ 21,813 $ 23,988 $ 21,963 Although our revenues are principally derived from customers domiciled in the U.S., the ultimate points of origination or destination for some products transported by us 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 2015, $2.3 billion in 2014, and $2.1 billion in 2013. Basis of Presentation – The Consolidated Financial Statements are presented in accordance with accounting principles generally accepted in the U.S. (GAAP) as codified in the Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC). Certain prior period amounts in the statement of cash flows and income tax footnote have been aggregated or disaggregated further to conform to the current period financial pre sentation .

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
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 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, 2015
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 April 2015, the FASB issued Accounting Standards Update No. 2015-03 (ASU 2015-03), Interest - Imputation of Interest (Subtopic 835-30) . ASU 2015-03 changes the presentation of debt issuance costs in the financial statements to present such costs as a direct deduction from the related debt liability rather than as an asset. Amortization of debt issuance costs will be reported as interest expense. This standard is effective for annual reporting periods beginning after December 15, 2015. We elected to early adopt ASU 2015-03 on December 31, 2015. As a result, the Company reclassified debt issuance costs from other assets to debt on the Consolidated Statements of Financial Position. ASU 2015-03 did not have a material impact on our consolidated financial position, and had no impact on our results of operations or cash flows . All prior period financial information presented herein has been adjusted to reflect the retrospective application of this ASU. In November 2015, the FASB issued Accounting Standards Update No. 2015-17 (ASU 2015-17), Balance Sheet Classification of Deferred Taxes (Subtopic 740-10) . ASU 2015-17 simplifies the presentation of deferred income taxes by eliminating the requirement for companies to present deferred tax liabilities and assets as current and non-current on the Consolidated Statements of Financial Position. Instead, companies will be required to classify all deferred tax assets and liabilities as non-current. This guidance is effective for annual and interim periods beginning after December 15, 2016 and early adoption is permitted. We elected to early adopt ASU 2015-17 on December 31, 2015. ASU 2015-17 did not have a material impact on our consolidated financial position, and had no impact on our results of operations or cash flows . All prior period financial information presented herein has been adjusted to reflect the retrospective application of this ASU. 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.

Stock Split

Stock Split	12 Months Ended
	Dec. 31, 2015
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, 2015
Stock Options And Other Stock Plans [Abstract]
Stock Options and Other Stock Plans	5. Stock Options and Other Stock Plans There are 7,140 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 share s. In September 2007, the Board of Directors eliminated the annual payment of options for 2008 and all future years. As of December 31, 2015, 36,000 restricted shares and 45,400 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, 2015, 3,652,954 options and 2,092,721 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, 2015, 1,873,014 options and 2,061,737 retention shares and stock units were outstanding under the 2013 Plan. Pursuant to the above plans 76,548,520; 77,786,772; and 79,574,896 shares of our common stock were authorized and available for grant at December 31, 2015, 2014, and 2013, 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 2015 2014 2013 Stock-based compensation, before tax: Stock options $ 17 $ 21 $ 19 Retention awards 81 91 79 Total stock-based compensation, before tax $ 98 $ 112 $ 98 Excess tax benefits from equity compensation plans $ 62 $ 118 $ 76 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 2015 2014 2013 Risk-free interest rate 1.3% 1.6% 0.8% Dividend yield 1.8% 2.1% 2.1% Expected life (years) 5.1 5.2 5.0 Volatility 23.4% 30.0% 36.2% Weighted-average grant-date fair value of options granted $ 22.30 $ 20.18 $ 17.49 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 2015 is presented below: Options (thous.) Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value (millions) Outstanding at January 1, 2015 5,387 $ 53.56 5.8 yrs. $ 353 Granted 934 122.85 N/A N/A Exercised (716) 40.10 N/A N/A Forfeited or expired (34) 89.24 N/A N/A Outstanding at December 31, 2015 5,571 $ 66.69 5.4 yrs. $ 114 Vested or expected to vest at December 31, 2015 5,532 $ 66.32 5.4 yrs. $ 114 Options exercisable at December 31, 2015 3,672 $ 49.00 4.1 yrs. $ 110 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, 2015, are subject to performance or market-based vesting conditions. At December 31, 2015, 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 1.0 year. Additional information regarding stock option exercises appears in the table below: Millions 2015 2014 2013 Intrinsic value of stock options exercised $ 50 $ 194 $ 112 Cash received from option exercises 27 54 51 Treasury shares repurchased for employee payroll taxes (12) (24) (21) Tax benefit realized from option exercises 19 74 43 Aggregate grant-date fair value of stock options vested 19 17 16 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 2015 were as follows: Shares (thous.) Weighted-Average Grant-Date Fair Value Nonvested at January 1, 2015 3,403 $ 64.39 Granted 521 122.79 Vested (934) 47.66 Forfeited (90) 72.87 Nonvested at December 31, 2015 2,900 $ 80.01 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, 2015, there was $88 million of total unrecognized compensation expense related to nonvested retention awards, which is expected to be recognized over a weighted-average period of 1.5 years. Performance Retention Awards – In February 2015, our Board of Directors approved performance stock unit grants. Other than different performance targets, the basic terms of these performance stock units are identical to those granted in February 2013 and February 2014, including using annual return on invested capital (ROIC) as the performance measure. 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. 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. 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. 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 2015 grant were as follows: 2015 Dividend per share per quarter $ 0.55 Risk-free interest rate at date of grant 0.8% Changes in our performance retention awards during 2015 were as follows: Shares (thous.) Weighted-Average Grant-Date Fair Value Nonvested at January 1, 2015 1,583 $ 65.33 Granted 339 117.42 Vested (580) 54.38 Forfeited (87) 86.66 Nonvested at December 31, 2015 1,255 $ 82.98 At December 31, 2015, there was $19 million of total unrecognized compensation expense related to nonvested performance retention awards, which is expected to be recognized over a weighted-average period of 0.7 years. This expense is subject to achievement of the ROIC levels established for the performance stock unit grants.

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2015
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 2015 2014 2015 2014 Projected Benefit Obligation Projected benefit obligation at beginning of year $ 4,142 $ 3,372 $ 354 $ 330 Service cost 106 70 3 2 Interest cost 163 158 13 14 Actuarial loss/(gain) (267) 735 (18) 33 Gross benefits paid (186) (193) (23) (25) Projected benefit obligation at end of year $ 3,958 $ 4,142 $ 329 $ 354 Plan Assets Fair value of plan assets at beginning of year $ 3,654 $ 3,429 $ - $ - Actual return on plan assets (43) 185 - - Voluntary funded pension plan contributions 100 200 - - Non-qualified plan benefit contributions 19 33 23 25 Gross benefits paid (186) (193) (23) (25) Fair value of plan assets at end of year $ 3,544 $ 3,654 $ - $ - Funded status at end of year $ (414) $ (488) $ (329) $ (354) Amounts recognized in the statement of financial position as of December 31, 2015 and 2014 consist of: Pension OPEB Millions 2015 2014 2015 2014 Noncurrent assets $ 1 $ 1 $ - $ - Current liabilities (22) (19) (23) (23) Noncurrent liabilities (393) (470) (306) (331) Net amounts recognized at end of year $ (414) $ (488) $ (329) $ (354) Pre-tax amounts recognized in accumulated other comprehensive income/(loss) as of December 31, 2015 and 2014 consist of: 2015 2014 Millions Pension OPEB Total Pension OPEB Total Prior service (cost)/credit $ - $ 7 $ 7 $ - $ 17 $ 17 Net actuarial loss (1,652) (117) (1,769) (1,727) (148) (1,875) Total $ (1,652) $ (110) $ (1,762) $ (1,727) $ (131) $ (1,858) Pre-tax changes recognized in other comprehensive income/(loss) during 2015, 2014 and 2013 were as follows: Pension OPEB Millions 2015 2014 2013 2015 2014 2013 Net actuarial (loss)/gain $ (31) $ (780) $ 561 $ 18 $ (33) $ 34 Amortization of: Prior service cost/(credit) - - - (10) (11) (16) Actuarial loss 106 71 106 13 10 15 Total $ 75 $ (709) $ 667 $ 21 $ (34) $ 33 Amounts included in accumulated other comprehensive income/(loss) expected to be amortized into net periodic cost during 2016: Millions Pension OPEB Total Prior service credit $ - $ 9 $ 9 Net actuarial loss (80) (10) (90) Total $ (80) $ (1) $ (81) 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, 2015 and 2014, the non-qualified (supplemental) plan ABO was $388 million and $379 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 2015 2014 Projected benefit obligation $ 398 $ 388 Accumulated benefit obligation $ 388 $ 379 Fair value of plan assets - - Underfunded accumulated benefit obligation $ (388) $ (379) The ABO for all defined benefit pension plans was $3.7 billion and $3.9 billion at December 31, 2015 and 2014, respectively. Assumptions – The weighted-average actuarial assumptions used to determine benefit obligations at December 31: Pension OPEB Percentages 2015 2014 2015 2014 Discount rate 4.37% 3.94% 4.16% 3.74% Compensation increase 4.10% 4.00% N/A N/A Health care cost trend rate (employees under 65) N/A N/A 6.52% 6.34% Ultimate health care cost trend rate N/A N/A 4.50% 4.50% Year ultimate trend rate reached N/A N/A 2038 2028 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/(benefit) were as follows for the years ended December 31: Pension OPEB Millions 2015 2014 2013 2015 2014 2013 Net Periodic Benefit Cost: Service cost $ 106 $ 70 $ 72 $ 3 $ 2 $ 3 Interest cost 163 158 134 13 14 12 Expected return on plan assets (255) (230) (202) - - - Amortization of: Prior service cost/(credit) - - - (10) (11) (16) Actuarial loss 106 71 106 13 10 15 Net periodic benefit cost/(benefit) $ 120 $ 69 $ 110 $ 19 $ 15 $ 14 Assumptions – The weighted-average actuarial assumptions used to determine expense were as follows: Pension OPEB Percentages 2015 2014 2013 2015 2014 2013 Discount rate 3.94% 4.72% 3.78% 3.74% 4.47% 3.48% Expected return on plan assets 7.50% 7.50% 7.50% N/A N/A N/A Compensation increase 4.00% 4.00% 3.43% N/A N/A N/A Health care cost trend rate (employees under 65) N/A N/A N/A 6.34% 6.49% 6.64% 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 2028 2028 2028 The discount rate was based on a yield curve of high quality corporate bonds with cash flows matching our plans’ expected benefit payments. 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 on pension plan assets, net of fees, was approximately (1)% in 2015, 6% in 2014, and 17% in 2013. 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 2016 assumed health care cost trend rate for employees under 65 is 6.34% . It is assumed the rate will decrease gradually to an ultimate rate of 4.5% in 2028 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 17 (14) 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 2014 $ 200 $ 33 $ 25 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 2015 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 2016 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 2016 through 2025: Millions Pension OPEB 2016 $ 191 $ 23 2017 194 23 2018 198 23 2019 202 23 2020 205 22 Years 2021 - 2025 1,077 102 Asset Allocation Strategy Our pension plan asset allocation at December 31, 2015 and 2014, and target allocation for 2016, are as follows: Percentage of Plan Assets Target December 31, Allocation 2016 2015 2014 Equity securities 60% to 70% 67% 68% Debt securities 20% to 30% 23 23 Real estate 2% to 8% 6 4 Commodities 4% to 6% 4 5 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 7.5% . While we believe we can achieve a long-term average rate of return of 7.5%, 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 as of December 31, 2015 and A+ as of December 31, 2014. 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 12 years at both December 31, 2015 and 2014. 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 real estate investments and bond investments registered with the Securities and Exchange Commission. The real estate investments are traded actively on public exchanges. The share prices for these investments are published at the close of each business day. The Plan’s holdings of real estate investments are classified as Level 1 investments. The bond investments are not traded publicly, but the underlying assets held in these funds are traded on active markets and the prices for these assets are readily observable. The Plan’s holdings in bond investments are classified as Level 2 investments. 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 net asset value (NAV), which is derived from the valuation method described here. The Plan’s holdings of limited partnership interests are classified as Level 3 investments. 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, which is derived from the valuation methods described here. The Plan’s interests in private real estate partnerships, investment trusts, and limited liability companies are classified as Level 3 investments. Collective Trust and Other Fund s – Collective trust 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 Plan’s holdings of common trust funds are classified as Level 2 investments. 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. Interests in the limited liability companies are classified as Level 2 investments. 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: Temporary cash investments $ 13 $ - $ - $ 13 Registered investment companies 179 270 - 449 Federal government securities - 125 - 125 Bonds & debentures - 383 - 383 Corporate stock 1,034 7 - 1,041 Venture capital and buyout partnerships - - 256 256 Real estate partnerships - - 199 199 Collective trust and other funds - 1,075 - 1,075 Total plan assets at fair value $ 1,226 $ 1,860 $ 455 3,541 Other assets [a] 3 Total plan assets $ 3,544 [a] Other assets include accrued receivables and pending broker settlements. As of December 31, 2014, 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: Temporary cash investments $ 22 $ - $ - $ 22 Registered investment companies 12 282 - 294 Federal government securities - 163 - 163 Bonds & debentures - 381 - 381 Corporate stock 1,076 15 - 1,091 Venture capital and buyout partnerships - - 234 234 Real estate partnerships - - 139 139 Collective trust and other funds - 1,340 - 1,340 Total plan assets at fair value $ 1,110 $ 2,181 $ 373 3,664 Other assets [a] (10) Total plan assets $ 3,654 [a] Other assets include accrued receivables and pending broker settlements. For the years ended December 31, 2015 and 2014 , there were no significant transfers in or out of Levels 1, 2, or 3. The following table presents a reconciliation of the beginning and ending balances of the fair value measurements using significant unobservable inputs (Level 3 investments) during 2015: Venture Capital and Buyout Real Estate Millions Partnerships Partnerships Total Beginning balance - January 1, 2015 $ 234 $ 139 $ 373 Realized gain 18 5 23 Unrealized gain 13 8 21 Purchases 54 74 128 Sales (63) (27) (90) Ending balance - December 31, 2015 $ 256 $ 199 $ 455 The following table presents a reconciliation of the beginning and ending balances of the fair value measurements using significant unobservable inputs (Level 3 investments) during 2014: Venture Capital and Buyout Real Estate Millions Partnerships Partnerships Total Beginning balance - January 1, 2014 $ 213 $ 139 $ 352 Realized gain 17 8 25 Unrealized gain 5 6 11 Purchases 54 19 73 Sales (55) (33) (88) Ending balance - December 31, 2014 $ 234 $ 139 $ 373 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 $20 million in 2015, $19 million in 2014, and $18 million in 2013. 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 $749 million in 2015, $711 million in 2014, and $670 million in 2013. 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 $46 million in 2015, $52 million in 2014, and $57 million in 2013.

Other Income

Other Income	12 Months Ended
	Dec. 31, 2015
Other Income [Abstract]
Other Income	7. Other Income Other income included the following for the years ended December 31: Millions 2015 2014 2013 Net gain on non-operating asset dispositions [a] $ 144 $ 69 $ 32 Rental income [b] 96 96 106 Interest income 5 4 4 Non-operating environmental costs and other [c] (19) (18) (14) Total $ 226 $ 151 $ 128 [a] 2015 includes $113 million related to a real estate sale. [b] 2013 includes $17 million related to a land lease contract settlement. [c] 2014 includes $14 million related to the sale of a permanent easement.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Taxes [Abstract]
Income Taxes	8. Income Taxes Components of income tax expense were as follows for the years ended December 31: Millions 2015 2014 2013 Current tax expense: Federal $ 1,901 $ 2,019 $ 1,727 State 210 239 199 Foreign 8 10 11 Total current tax expense 2,119 2,268 1,937 Deferred and other tax expense: Federal 644 753 605 State 121 142 118 Total deferred and other tax expense 765 895 723 Total income tax expense $ 2,884 $ 3,163 $ 2,660 For the years ended December 31, reconciliations between statutory and effective tax rates are as follows: Tax Rate Percentages 2015 2014 2013 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) (0.4) (0.2) Deferred tax adjustments - - (0.1) Other 0.1 0.2 (0.1) Effective tax rate 37.7 % 37.9 % 37.7 % 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 2015 2014 Deferred income tax liabilities: Property $ (16,079) $ (15,173) Other (352) (411) Total deferred income tax liabilities (16,431) (15,584) Deferred income tax assets: Accrued wages 76 74 Accrued casualty costs 237 228 Stock compensation 72 69 Debt and leases 149 86 Retiree benefits 204 392 Credits 156 164 Other 296 168 Total deferred income tax assets [a] $ 1,190 $ 1,181 Net deferred income tax liability $ (15,241) $ (14,403) [a] Prior to the adoption of Accounting Standard Update (ASU) 2015-17, deferred tax assets were required to be presented as current and non-current on the Consolidated Statement of Financial Position. In 2015, UP adopted ASU 2015-17 retrospectively. Current deferred income tax assets at December 31, 2014 of $277 million were reclassified from current to non-current for 2015 presentation. 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 2015 and 2014, 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 2015 2014 2013 Unrecognized tax benefits at January 1 $ 151 $ 59 $ 115 Increases for positions taken in current year 38 92 24 Increases for positions taken in prior years 13 22 15 Decreases for positions taken in prior years (87) (14) (35) Payments to and settlements with taxing authorities (13) (8) (58) Increases/(decreases) for interest and penalties (5) 1 - Lapse of statutes of limitations (3) (1) (2) Unrecognized tax benefits at December 31 $ 94 $ 151 $ 59 We recognize interest and penalties as part of income tax expense. Total accrued liabilities for interest and penalties were $2 million and $6 million at December 31, 2015 and 2014, respectively. Total interest and penalties recognized as part of income tax expense (benefit) were $(3) million for 2015, $9 million for 2014, and $7 million for 2013. 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. UPC is not currently under audit by the Internal Revenue Service. 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 2012. We do not expect our unrecognized tax benefits to change significantly in the next 12 months. At December 31, 2015, we had a net unrecognized tax benefit liability of $94 million. 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 2015 2014 2013 Unrecognized tax benefits that would reduce the effective tax rate $ 31 $ 33 $ 34 Unrecognized tax benefits that would not reduce the effective tax rate 63 118 25 Total unrecognized tax benefits $ 94 $ 151 $ 59

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2015
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 2015 2014 2013 Net income $ 4,772 $ 5,180 $ 4,388 Weighted-average number of shares outstanding: Basic 866.2 897.1 926.5 Dilutive effect of stock options 1.5 2.1 2.4 Dilutive effect of retention shares and units 1.7 1.9 2.6 Diluted 869.4 901.1 931.5 Earnings per share – basic $ 5.51 $ 5.77 $ 4.74 Earnings per share – diluted $ 5.49 $ 5.75 $ 4.71 Common stock options totaling 1.1 million, 0.4 million, and 0.5 million for 2015, 2014, and 2013, 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, 2015
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, 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) Balance at January 1, 2014 $ (713) $ (37) $ (750) Other comprehensive income/(loss) before reclassifications 10 (12) (2) Amounts reclassified from accumulated other comprehensive income/(loss) [a] (458) - (458) Net year-to-date other comprehensive income/(loss), net of taxes of $291 million (448) (12) (460) Balance at December 31, 2014 $ (1,161) $ (49) $ (1,210) [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, 2015
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, 2015, and 2014, 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, 2015, and 2014, receivables classified as other assets were reduced by allowances of $11 million and $16 million, respectively. Receivables Securitization Facility – The Railroad maintains a $650 million, 3 -year receivables securitization facility maturing in July 2017 under which it 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 facility was $400 million at both December 31, 2015, and December 31, 2014. The facility was supported by $0.9 billion and $1.2 billion of accounts receivable as collateral at December 31, 2015, and December 31, 2014, 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 facility, with a maximum of $650 million, may fluctuate based on the availability of eligible receivables and is directly affected by business volumes and credit risks, including receivables payment quality measures such as default and dilution ratios. If default or dilution ratios increase one percent, the allowable outstanding amount under the facility would not materially change. The costs of the receivables securitization facility include interest, which will vary based on prevailing benchmark and commercial paper rates, program fees paid to participating banks, commercial paper issuance costs, and fees of participating banks for unused commitment availability. The costs of the receivables securitization facility are included in interest expense and were $5 million, $4 million and $5 million for 2015, 2014, and 2013, respectively.

Properties

Properties	12 Months Ended
	Dec. 31, 2015
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, 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 Millions, Except Estimated Useful Life Accumulated Net Book Estimated As of December 31, 2014 Cost Depreciation Value Useful Life Land $ 5,194 $ N/A $ 5,194 N/A Road: Rail and other track material 14,588 5,241 9,347 33 Ties 9,102 2,450 6,652 33 Ballast 4,826 1,264 3,562 34 Other roadway [a] 16,476 2,852 13,624 47 Total road 44,992 11,807 33,185 N/A Equipment: Locomotives 8,276 3,694 4,582 20 Freight cars 2,116 968 1,148 25 Work equipment and other 684 153 531 18 Total equipment 11,076 4,815 6,261 N/A Technology and other 872 320 552 10 Construction in progress 1,080 - 1,080 N/A Total $ 63,214 $ 16,942 $ 46,272 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. General and administrative expenditures are expensed as incurred. Normal repairs and maintenance are also 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 $2.5 billion for 2015, $2.4 billion for 2014, and $2.3 billion for 2013. 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, 2015
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 2015 2014 Accounts payable $ 743 $ 877 Income and other taxes payable 434 412 Accrued wages and vacation 391 409 Interest payable 208 178 Accrued casualty costs 181 249 Equipment rents payable 105 100 Dividends payable [a] - 438 Other 550 640 Total accounts payable and other current liabilities $ 2,612 $ 3,303 [a] Beginning in 2015, the timing of the dividend declaration and payable dates was aligned to occur within the same quarter. The 2015 dividends paid amount includes the fourth quarter 2014 dividend of $438 million, which was paid on January 2, 2015, the first quarter 2015 dividend of $484 million, which was paid on March 30, 2015, the second quarter 2015 dividend of $479 million, which was paid on June 30, 2015, the third quarter 2015 dividend of $476 million, which was paid on September 30, 2015, as well as the fourth quarter 2015 dividend of $467 million, which was paid on December 30, 2015.

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2015
Financial Instruments [Abstract]
Financial Instruments	14. Financial Instruments Strategy and Risk – We may use derivative financial instruments in limited instances for other than trading purposes to assist in managing our overall exposure to fluctuations in interest rates and fuel prices. We are not a party to leveraged derivatives and, by policy, do not use derivative financial instruments for speculative purposes. Derivative financial instruments qualifying for hedge accounting must maintain a specified level of effectiveness between the hedging instrument and the item being hedged, both at inception and throughout the hedged period. We formally document the nature and relationships between the hedging instruments and hedged items at inception, as well as our risk-management objectives, strategies for undertaking the various hedge transactions, and method of assessing hedge effectiveness. Changes in the fair market value of derivative financial instruments that do not qualify for hedge accounting are charged to earnings. We may use swaps, collars, futures, and/or forward contracts to mitigate the risk of adverse movements in interest rates and fuel prices; however, the use of these derivative financial instruments may limit future benefits from favorable interest rate and fuel price movements. Market and Credit Risk – We address market risk related to derivative financial instruments by selecting instruments with value fluctuations that highly correlate with the underlying hedged item. We manage credit risk related to derivative financial instruments, which is minimal, by requiring high credit standards for counterparties and periodic settlements. At December 31, 2015, and 2014, we were not required to provide collateral, nor had we received collateral, relating to our hedging activities. Interest Rate Fair Value Hedges – We manage our overall exposure to fluctuations in interest rates by adjusting the proportion of fixed and floating rate debt instruments within our debt portfolio over a given period. We generally manage the mix of fixed and floating rate debt through the issuance of targeted amounts of each as debt matures or as we require incremental borrowings. We employ derivatives, primarily swaps, as one of the tools to obtain the targeted mix. In addition, we also obtain flexibility in managing interest costs and the interest rate mix within our debt portfolio by evaluating the issuance of and managing outstanding callable fixed-rate debt securities. Swaps allow us to convert debt from fixed rates to variable rates and thereby hedge the risk of changes in the debt’s fair value attributable to the changes in interest rates. We account for swaps as fair value hedges using the short-cut method; therefore, we do not record any ineffectiveness within our Consolidated Financial Statements. As of December 31, 2015, and 2014, we had no interest rate fair value hedges outstanding. Interest Rate Cash Flow Hedges – We report changes in the fair value of cash flow hedges in accumulated other comprehensive loss until the hedged item affects earnings. As of December 31, 2015, and 2014, we had no interest rate cash flow hedges outstanding. Earnings Impact – Our use of derivative financial instruments had no impact on pre-tax income for the years ended December 31, 2015, 2014, and 2013. 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, 2015, the fair value of total debt was $15.2 billion, approximately $1.0 billion more than the carrying value. At December 31, 2014, the fair value of total debt was $13.0 billion, approximately $1.5 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, 2015, and 2014, approximately $155 million and $163 million, respectively, of debt securities contained call provisions that allow us to retire the debt instruments prior to final maturity, with the payment of fixed call premiums, or in certain cases, at par. The fair value of our cash equivalents approximates their carrying value due to the short-term maturities of these instruments.

Debt

Debt	12 Months Ended
	Dec. 31, 2015
Debt [Abstract]
Debt	15. Debt Total debt as of December 31, 2015, and 2014, is summarized below: Millions 2015 2014 Notes and debentures, 1.8% to 7.9% due through 2065 $ 11,964 $ 9,266 Capitalized leases, 3.1% to 8.4% due through 2028 1,268 1,520 Equipment obligations, 2.8% to 6.7% due through 2031 963 597 Receivables Securitization (Note 11) 400 400 Term loans - floating rate, due in 2016 200 200 Mortgage bonds, 4.8% due through 2030 57 57 Medium-term notes, 9.3% to 10.0% due through 2020 23 23 Tax-exempt financings - floating rate, due in 2015 - 8 Unamortized discount and deferred issuance costs [a] (674) (658) Total debt 14,201 11,413 Less: current portion (594) (461) Total long-term debt $ 13,607 $ 10,952 [a] Includes deferred debt issuance costs of $89 million and $67 million as of December 31, 2015, and 2014, respectively, as a result of the retrospective adoption of Accounting Standard Update (ASU) 2015-03 on December 31, 2015. Prior to the ASU adoption, deferred debt issuance costs were presented in other assets. Debt Maturities – The following table presents aggregate debt maturities as of December 31, 2015, excluding market value adjustments: Millions 2016 $ 594 2017 1,052 2018 566 2019 637 2020 1,034 Thereafter 10,318 Total debt $ 14,201 Equipment Encumbrances – Equipment with a carrying value of approximately $2.6 billion and $2.8 billion at December 31, 2015, and 2014, 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, 2015, 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 2015. 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, 2015, the debt-to-net-worth coverage ratio allowed us to carry up to $41.4 billion of debt (as defined in the facility), and we had $14.3 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 2015, we did not issue or repay any commercial paper, and at December 31, 2015, and 2014, 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 $13.6 billion and $15.4 billion at December 31, 2015, and 2014, respectively. Shelf Registration Statement and Significant New Borrowings – We filed a new shelf registration statement with the SEC that became effective on February 9, 2015. The Board of Directors authorized the issuance of up to $4.0 billion of debt securities, replacing the $4.0 billion authorized under our shelf registration filed in February 2013, which was fully utilized after our January 2015 debt offering noted below. Under our current shelf registration, we may issue, from time to time, any combination of debt securities, preferred stock, common stock, or warrants for debt securities or preferred stock in one or more offerings. During 2015, we issued the following unsecured, fixed-rate debt securities under our shelf registrations: Date Description of Securities January 29, 2015 $250 million of 1.80% Notes due February 1, 2020 $450 million of 3.375% Notes due February 1, 2035 $450 million of 3.875% Notes due February 1, 2055 June 19, 2015 $400 million of 2.250% Notes due June 19, 2020 $300 million of 3.250% Notes due August 15, 2025 October 29, 2015 $200 million of reopened 3.250% Notes due August 15, 2025 $500 million of 4.050% Notes due November 15, 2045 $400 million of 4.375% Notes due November 15, 2065 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. At December 31, 2015, we had remaining authority to issue up to $2.2 billion of debt securities under our shelf registration. Equipment Trust – On May 12, 2015 , UPRR consummated a pass-through (P/T) financing, whereby a P/T trust was created, which issued $399 million of P/T trust certificates with a stated interest rate of 2.695% . The P/T trust certificates will mature on May 12, 2027 . 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 182 locomotives. The equipment trust certificates are secured by a lien on the locomotives. The $399 million is classified as debt due after one year in our Consolidated Statements of Financial Position. Debt Exchange – On August 21, 2013 , we exchanged $1,170 million of various outstanding notes and debentures due between 2016 and 2040 (the Existing Notes) for $439 million of 3.646% notes (the New 2024 Notes) due February 15, 2024 and $700 million of 4.821% notes (the New 2044 Notes) due February 1, 2044 , plus cash consideration of approximately $280 million in addition to $8 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 2024 Notes and the New 2044 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 $9 million and were included in interest expense during the year ended December 31, 2013. The following table lists the outstanding notes and debentures that were exchanged: Principal amount Millions exchanged The 2024 Offers 7.000% Debentures due 2016 $ 8 5.650% Notes due 2017 38 5.750% Notes due 2017 70 5.700% Notes due 2018 103 7.875% Notes due 2019 20 6.125% Notes due 2020 238 The 2044 Offers 7.125% Debentures due 2028 73 6.625% Debentures due 2029 177 6.250% Debentures due 2034 19 6.150% Debentures due 2037 138 5.780% Notes due 2040 286 Total $ 1,170 Receivables Securitization Facility – As of both December 31, 2015 and 2014, we recorded $400 million 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, 2015
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 $2.6 billion as of December 31, 2015.

Leases

Leases	12 Months Ended
	Dec. 31, 2015
Leases [Abstract]
Leases	17. Leases We lease certain locomotives, freight cars, and other property. The Consolidated Statements of Financial Position as of December 31, 2015 and 2014 included $2,273 million, net of $1,189 million of accumulated depreciation, and $2,454 million, net of $1,210 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, 2015, were as follows: Millions Operating Leases Capital Leases 2016 $ 491 $ 217 2017 446 220 2018 371 198 2019 339 184 2020 282 193 Later years 1,501 575 Total minimum lease payments $ 3,430 $ 1,587 Amount representing interest N/A (319) Present value of minimum lease payments N/A $ 1,268 Approximately 95% of capital lease payments relate to locomotives. Rent expense for operating leases with terms exceeding one month was $590 million in 2015, $593 million in 2014, and $618 million in 2013. 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, 2015
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, 2015. 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 $318 million to $345 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 2015 2014 2013 Beginning balance $ 335 $ 294 $ 334 Current year accruals 89 96 87 Changes in estimates for prior years (3) 9 (38) Payments (103) (64) (89) Ending balance at December 31 $ 318 $ 335 $ 294 Current portion, ending balance at December 31 $ 63 $ 111 $ 82 In conjunction with the liability update performed in 2015, we also reassessed our estimated insurance recoveries. We have recognized an asset for estimated insurance recoveries at December 31, 2015, and 2014. 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 22% of the recorded liability related to asserted claims and approximately 78% related to unasserted claims at December 31, 2015. 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 $120 million to $129 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 2015 2014 2013 Beginning balance $ 126 $ 131 $ 139 Accruals/(Credits) - 1 2 Payments (6) (6) (10) Ending balance at December 31 $ 120 $ 126 $ 131 Current portion, ending balance at December 31 $ 6 $ 8 $ 9 In conjunction with the liability update performed in 2015, we also reassessed our estimated insurance recoveries. We have recognized an asset for estimated insurance recoveries at December 31, 2015, and 2014. 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 290 sites at which we are or may be liable for remediation costs associated with alleged contamination or for violations of environmental requirements. This includes 31 sites that are the subject of actions taken by the U.S. government, 19 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 2015 2014 2013 Beginning balance $ 182 $ 171 $ 170 Accruals 61 56 58 Payments (53) (45) (57) Ending balance at December 31 $ 190 $ 182 $ 171 Current portion, ending balance at December 31 $ 52 $ 60 $ 53 The environmental liability includes future costs for remediation and restoration of sites, as well as ongoing monitoring costs, but excludes any anticipated recoveries from third parties. Cost estimates are based on information available for each site, financial viability of other potentially responsible parties, and existing technology, laws, and regulations. The ultimate liability for remediation is difficult to determine because of the number of potentially responsible parties, site-specific cost sharing arrangements with other potentially responsible parties, the degree of contamination by various wastes, the scarcity and quality of volumetric data related to many of the sites, and the speculative nature of remediation costs. Estimates of liability may vary over time due to changes in federal, state, and local laws governing environmental remediation. Current obligations are not expected to have a material adverse effect on our consolidated results of operations, financial condition, or liquidity. Insurance – The Company has a consolidated, wholly-owned captive insurance subsidiary (the captive), that provides insurance coverage for certain risks including FELA claims and property coverage which are subject to reinsurance. The captive entered into annual reinsurance treaty agreements that insure workers compensation, general liability, auto liability and FELA risk. The captive cedes a portion of its FELA exposure through the treaty and assumes a proportionate share of the entire risk. The captive receives direct premiums, which are netted against the Company’s premium costs in other expenses in the 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, 2015, and 2014, we were contingently liable for $53 million and $82 million in guarantees, respectively. We have recorded liabilities of $0 and $0.3 million for the fair value of these obligations as of December 31, 2015, and 2014, respectively. 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, 2015.

Share Repurchase Program

Share Repurchase Program	12 Months Ended
	Dec. 31, 2015
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, 2015, we repurchased a total of $16.0 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 2015 2014 2015 2014 First quarter 6,881,455 7,640,000 $ 117.28 $ 89.43 Second quarter 7,975,100 8,320,000 104.62 96.84 Third quarter 13,800,700 8,347,000 89.65 102.54 Fourth quarter 6,646,899 7,736,400 88.19 113.77 Total 35,304,154 32,043,400 $ 98.14 $ 100.65 Remaining number of shares that may be repurchased under current authority 52,652,446 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, 2016, through February 4 , 2016, we repurchas ed 3. 7 million sh ares at an aggregate cost of approximately $2 68 million.

Related Parties

Related Parties	12 Months Ended
	Dec. 31, 2015
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 had $830 million and $795 million recognized as investments related to TTX in our consolidated statements of financial position as of December 31, 2015 and 2014, respectively. TTX car hire expenses of $376 million in 2015, $350 million in 2014, and $326 million in 2013 are i ncluded in equipment and other rents in our consolidated statements of income . In addition, UPRR had accounts payable to TTX of $61 million and $53 million as of December 31, 2015 and 2014, respectively.

Selected Quarterly Data (Unaudi

Selected Quarterly Data (Unaudited)	12 Months Ended
	Dec. 31, 2015
Selected Quarterly Data (Unaudited) [Abstract]
Selected Quarterly Data (Unaudited)	21. Selected Quarterly Data (Unaudited) 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 Millions, Except Per Share Amounts 2014 Mar. 31 Jun. 30 Sep. 30 Dec. 31 Operating revenues $ 5,638 $ 6,015 $ 6,182 $ 6,153 Operating income 1,854 2,196 2,330 2,373 Net income 1,088 1,291 1,370 1,431 Net income per share: Basic 1.20 1.43 1.53 1.62 Diluted 1.19 1.43 1.53 1.61 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, 2015
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, 2015 2014 2013 Allowance for doubtful accounts: Balance, beginning of period $ 21 $ 23 $ 37 Charges/(reduction) to expense 1 5 (4) Net recoveries/(write-offs) (6) (7) (10) Balance, end of period $ 16 $ 21 $ 23 Allowance for doubtful accounts are presented in the Consolidated Statements of Financial Position as follows: Current $ 5 $ 5 $ 1 Long-term 11 16 22 Balance, end of period $ 16 $ 21 $ 23 Accrued casualty costs: Balance, beginning of period $ 757 $ 702 $ 734 Charges to expense 227 256 188 Cash payments and other reductions (248) (201) (220) Balance, end of period $ 736 $ 757 $ 702 Accrued casualty costs are presented in the Consolidated Statements of Financial Position as follows: Current $ 181 $ 249 $ 207 Long-term 555 508 495 Balance, end of period $ 736 $ 757 $ 702

Significant Accounting Polici32

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
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 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, 2015
Nature Of Operations [Abstract]
Freight Revenue By Commodity Group	The following table provides freight revenue by commodity group: Millions 2015 2014 2013 Agricultural Products $ 3,581 $ 3,777 $ 3,276 Automotive 2,154 2,103 2,077 Chemicals 3,543 3,664 3,501 Coal 3,237 4,127 3,978 Industrial Products 3,808 4,400 3,822 Intermodal 4,074 4,489 4,030 Total freight revenues $ 20,397 $ 22,560 $ 20,684 Other revenues 1,416 1,428 1,279 Total operating revenues $ 21,813 $ 23,988 $ 21,963

Stock Options And Other Stock34

Stock Options And Other Stock Plans (Tables)	12 Months Ended
	Dec. 31, 2015
Stock Options And Other Stock Plans [Abstract]
Schedule Of Stock-Based Compensation	Information regarding stock-based compensation appears in the table below: Millions 2015 2014 2013 Stock-based compensation, before tax: Stock options $ 17 $ 21 $ 19 Retention awards 81 91 79 Total stock-based compensation, before tax $ 98 $ 112 $ 98 Excess tax benefits from equity compensation plans $ 62 $ 118 $ 76
Schedule Of Stock Options Weighted Average Assumptions	The table below shows the annual weighted-average assumptions used for valuation purposes: Weighted-Average Assumptions 2015 2014 2013 Risk-free interest rate 1.3% 1.6% 0.8% Dividend yield 1.8% 2.1% 2.1% Expected life (years) 5.1 5.2 5.0 Volatility 23.4% 30.0% 36.2% Weighted-average grant-date fair value of options granted $ 22.30 $ 20.18 $ 17.49
Summary Of Stock Options Activity	A summary of stock option activity during 2015 is presented below: Options (thous.) Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value (millions) Outstanding at January 1, 2015 5,387 $ 53.56 5.8 yrs. $ 353 Granted 934 122.85 N/A N/A Exercised (716) 40.10 N/A N/A Forfeited or expired (34) 89.24 N/A N/A Outstanding at December 31, 2015 5,571 $ 66.69 5.4 yrs. $ 114 Vested or expected to vest at December 31, 2015 5,532 $ 66.32 5.4 yrs. $ 114 Options exercisable at December 31, 2015 3,672 $ 49.00 4.1 yrs. $ 110
Schedule Of Stock Option Exercises	Additional information regarding stock option exercises appears in the table below: Millions 2015 2014 2013 Intrinsic value of stock options exercised $ 50 $ 194 $ 112 Cash received from option exercises 27 54 51 Treasury shares repurchased for employee payroll taxes (12) (24) (21) Tax benefit realized from option exercises 19 74 43 Aggregate grant-date fair value of stock options vested 19 17 16
Schedule Of Retention Awards	Changes in our retention awards during 2015 were as follows: Shares (thous.) Weighted-Average Grant-Date Fair Value Nonvested at January 1, 2015 3,403 $ 64.39 Granted 521 122.79 Vested (934) 47.66 Forfeited (90) 72.87 Nonvested at December 31, 2015 2,900 $ 80.01
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 2015 grant were as follows: 2015 Dividend per share per quarter $ 0.55 Risk-free interest rate at date of grant 0.8%
Schedule Of Performance Retention Awards	Changes in our performance retention awards during 2015 were as follows: Shares (thous.) Weighted-Average Grant-Date Fair Value Nonvested at January 1, 2015 1,583 $ 65.33 Granted 339 117.42 Vested (580) 54.38 Forfeited (87) 86.66 Nonvested at December 31, 2015 1,255 $ 82.98

Retirement Plans (Tables)

Retirement Plans (Tables)	12 Months Ended
	Dec. 31, 2015
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 2015 2014 2015 2014 Projected Benefit Obligation Projected benefit obligation at beginning of year $ 4,142 $ 3,372 $ 354 $ 330 Service cost 106 70 3 2 Interest cost 163 158 13 14 Actuarial loss/(gain) (267) 735 (18) 33 Gross benefits paid (186) (193) (23) (25) Projected benefit obligation at end of year $ 3,958 $ 4,142 $ 329 $ 354 Plan Assets Fair value of plan assets at beginning of year $ 3,654 $ 3,429 $ - $ - Actual return on plan assets (43) 185 - - Voluntary funded pension plan contributions 100 200 - - Non-qualified plan benefit contributions 19 33 23 25 Gross benefits paid (186) (193) (23) (25) Fair value of plan assets at end of year $ 3,544 $ 3,654 $ - $ - Funded status at end of year $ (414) $ (488) $ (329) $ (354)
Schedule Of Amounts Recognized In Statement Of Financial Position	Amounts recognized in the statement of financial position as of December 31, 2015 and 2014 consist of: Pension OPEB Millions 2015 2014 2015 2014 Noncurrent assets $ 1 $ 1 $ - $ - Current liabilities (22) (19) (23) (23) Noncurrent liabilities (393) (470) (306) (331) Net amounts recognized at end of year $ (414) $ (488) $ (329) $ (354)
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, 2015 and 2014 consist of: 2015 2014 Millions Pension OPEB Total Pension OPEB Total Prior service (cost)/credit $ - $ 7 $ 7 $ - $ 17 $ 17 Net actuarial loss (1,652) (117) (1,769) (1,727) (148) (1,875) Total $ (1,652) $ (110) $ (1,762) $ (1,727) $ (131) $ (1,858)
Schedule Of Other Pre-Tax Changes Recognized In Other Comprehensive Income	Pre-tax changes recognized in other comprehensive income/(loss) during 2015, 2014 and 2013 were as follows: Pension OPEB Millions 2015 2014 2013 2015 2014 2013 Net actuarial (loss)/gain $ (31) $ (780) $ 561 $ 18 $ (33) $ 34 Amortization of: Prior service cost/(credit) - - - (10) (11) (16) Actuarial loss 106 71 106 13 10 15 Total $ 75 $ (709) $ 667 $ 21 $ (34) $ 33
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 2016: Millions Pension OPEB Total Prior service credit $ - $ 9 $ 9 Net actuarial loss (80) (10) (90) Total $ (80) $ (1) $ (81)
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 2015 2014 Projected benefit obligation $ 398 $ 388 Accumulated benefit obligation $ 388 $ 379 Fair value of plan assets - - Underfunded accumulated benefit obligation $ (388) $ (379)
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 2015 2014 2015 2014 Discount rate 4.37% 3.94% 4.16% 3.74% Compensation increase 4.10% 4.00% N/A N/A Health care cost trend rate (employees under 65) N/A N/A 6.52% 6.34% Ultimate health care cost trend rate N/A N/A 4.50% 4.50% Year ultimate trend rate reached N/A N/A 2038 2028 The weighted-average actuarial assumptions used to determine expense were as follows: Pension OPEB Percentages 2015 2014 2013 2015 2014 2013 Discount rate 3.94% 4.72% 3.78% 3.74% 4.47% 3.48% Expected return on plan assets 7.50% 7.50% 7.50% N/A N/A N/A Compensation increase 4.00% 4.00% 3.43% N/A N/A N/A Health care cost trend rate (employees under 65) N/A N/A N/A 6.34% 6.49% 6.64% 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 2028 2028 2028
Net Periodic Pension And OPEB Cost/(Benefit)	The components of our net periodic pension and OPEB cost/(benefit) were as follows for the years ended December 31: Pension OPEB Millions 2015 2014 2013 2015 2014 2013 Net Periodic Benefit Cost: Service cost $ 106 $ 70 $ 72 $ 3 $ 2 $ 3 Interest cost 163 158 134 13 14 12 Expected return on plan assets (255) (230) (202) - - - Amortization of: Prior service cost/(credit) - - - (10) (11) (16) Actuarial loss 106 71 106 13 10 15 Net periodic benefit cost/(benefit) $ 120 $ 69 $ 110 $ 19 $ 15 $ 14
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 17 (14)
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 2014 $ 200 $ 33 $ 25 2015 100 19 23
Schedule Of Expected Benefit Payments	The following table details expected benefit payments for the years 2016 through 2025: Millions Pension OPEB 2016 $ 191 $ 23 2017 194 23 2018 198 23 2019 202 23 2020 205 22 Years 2021 - 2025 1,077 102
Schedule Of Pension Plan Asset Allocation	Our pension plan asset allocation at December 31, 2015 and 2014, and target allocation for 2016, are as follows: Percentage of Plan Assets Target December 31, Allocation 2016 2015 2014 Equity securities 60% to 70% 67% 68% Debt securities 20% to 30% 23 23 Real estate 2% to 8% 6 4 Commodities 4% to 6% 4 5 Total 100% 100%
Schedule Of Assets Measured At Fair Value On A Recurring Basis	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: Temporary cash investments $ 13 $ - $ - $ 13 Registered investment companies 179 270 - 449 Federal government securities - 125 - 125 Bonds & debentures - 383 - 383 Corporate stock 1,034 7 - 1,041 Venture capital and buyout partnerships - - 256 256 Real estate partnerships - - 199 199 Collective trust and other funds - 1,075 - 1,075 Total plan assets at fair value $ 1,226 $ 1,860 $ 455 3,541 Other assets [a] 3 Total plan assets $ 3,544 [a] Other assets include accrued receivables and pending broker settlements. As of December 31, 2014, 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: Temporary cash investments $ 22 $ - $ - $ 22 Registered investment companies 12 282 - 294 Federal government securities - 163 - 163 Bonds & debentures - 381 - 381 Corporate stock 1,076 15 - 1,091 Venture capital and buyout partnerships - - 234 234 Real estate partnerships - - 139 139 Collective trust and other funds - 1,340 - 1,340 Total plan assets at fair value $ 1,110 $ 2,181 $ 373 3,664 Other assets [a] (10) Total plan assets $ 3,654 [a] Other assets include accrued receivables and pending broker settlements.
Reconciliation Of Beginning Ending Balances Of Fair Value Measurements Using Significant Unobservable Inputs (Level 3)	The following table presents a reconciliation of the beginning and ending balances of the fair value measurements using significant unobservable inputs (Level 3 investments) during 2015: Venture Capital and Buyout Real Estate Millions Partnerships Partnerships Total Beginning balance - January 1, 2015 $ 234 $ 139 $ 373 Realized gain 18 5 23 Unrealized gain 13 8 21 Purchases 54 74 128 Sales (63) (27) (90) Ending balance - December 31, 2015 $ 256 $ 199 $ 455 The following table presents a reconciliation of the beginning and ending balances of the fair value measurements using significant unobservable inputs (Level 3 investments) during 2014: Venture Capital and Buyout Real Estate Millions Partnerships Partnerships Total Beginning balance - January 1, 2014 $ 213 $ 139 $ 352 Realized gain 17 8 25 Unrealized gain 5 6 11 Purchases 54 19 73 Sales (55) (33) (88) Ending balance - December 31, 2014 $ 234 $ 139 $ 373

Other Income (Tables)

Other Income (Tables)	12 Months Ended
	Dec. 31, 2015
Other Income [Abstract]
Other Income	Other income included the following for the years ended December 31: Millions 2015 2014 2013 Net gain on non-operating asset dispositions [a] $ 144 $ 69 $ 32 Rental income [b] 96 96 106 Interest income 5 4 4 Non-operating environmental costs and other [c] (19) (18) (14) Total $ 226 $ 151 $ 128 [a] 2015 includes $113 million related to a real estate sale. [b] 2013 includes $17 million related to a land lease contract settlement. [c] 2014 includes $14 million related to the sale of a permanent easement.

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
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 2015 2014 2013 Current tax expense: Federal $ 1,901 $ 2,019 $ 1,727 State 210 239 199 Foreign 8 10 11 Total current tax expense 2,119 2,268 1,937 Deferred and other tax expense: Federal 644 753 605 State 121 142 118 Total deferred and other tax expense 765 895 723 Total income tax expense $ 2,884 $ 3,163 $ 2,660
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 2015 2014 2013 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) (0.4) (0.2) Deferred tax adjustments - - (0.1) Other 0.1 0.2 (0.1) Effective tax rate 37.7 % 37.9 % 37.7 %
Schedule Of Deferred Income Tax Liabilities And Assets	Deferred income tax (liabilities)/assets were comprised of the following at December 31: Millions 2015 2014 Deferred income tax liabilities: Property $ (16,079) $ (15,173) Other (352) (411) Total deferred income tax liabilities (16,431) (15,584) Deferred income tax assets: Accrued wages 76 74 Accrued casualty costs 237 228 Stock compensation 72 69 Debt and leases 149 86 Retiree benefits 204 392 Credits 156 164 Other 296 168 Total deferred income tax assets [a] $ 1,190 $ 1,181 Net deferred income tax liability $ (15,241) $ (14,403) [a] Prior to the adoption of Accounting Standard Update (ASU) 2015-17, deferred tax assets were required to be presented as current and non-current on the Consolidated Statement of Financial Position. In 2015, UP adopted ASU 2015-17 retrospectively. Current deferred income tax assets at December 31, 2014 of $277 million were reclassified from current to non-current for 2015 presentation.
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 2015 2014 2013 Unrecognized tax benefits at January 1 $ 151 $ 59 $ 115 Increases for positions taken in current year 38 92 24 Increases for positions taken in prior years 13 22 15 Decreases for positions taken in prior years (87) (14) (35) Payments to and settlements with taxing authorities (13) (8) (58) Increases/(decreases) for interest and penalties (5) 1 - Lapse of statutes of limitations (3) (1) (2) Unrecognized tax benefits at December 31 $ 94 $ 151 $ 59
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 2015 2014 2013 Unrecognized tax benefits that would reduce the effective tax rate $ 31 $ 33 $ 34 Unrecognized tax benefits that would not reduce the effective tax rate 63 118 25 Total unrecognized tax benefits $ 94 $ 151 $ 59

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2015
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 2015 2014 2013 Net income $ 4,772 $ 5,180 $ 4,388 Weighted-average number of shares outstanding: Basic 866.2 897.1 926.5 Dilutive effect of stock options 1.5 2.1 2.4 Dilutive effect of retention shares and units 1.7 1.9 2.6 Diluted 869.4 901.1 931.5 Earnings per share – basic $ 5.51 $ 5.77 $ 4.74 Earnings per share – diluted $ 5.49 $ 5.75 $ 4.71

Accumulated Other Comprehensi39

Accumulated Other Comprehensive Income/(Loss) (Tables)	12 Months Ended
	Dec. 31, 2015
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, 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) Balance at January 1, 2014 $ (713) $ (37) $ (750) Other comprehensive income/(loss) before reclassifications 10 (12) (2) Amounts reclassified from accumulated other comprehensive income/(loss) [a] (458) - (458) Net year-to-date other comprehensive income/(loss), net of taxes of $291 million (448) (12) (460) Balance at December 31, 2014 $ (1,161) $ (49) $ (1,210) [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, 2015
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, 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 Millions, Except Estimated Useful Life Accumulated Net Book Estimated As of December 31, 2014 Cost Depreciation Value Useful Life Land $ 5,194 $ N/A $ 5,194 N/A Road: Rail and other track material 14,588 5,241 9,347 33 Ties 9,102 2,450 6,652 33 Ballast 4,826 1,264 3,562 34 Other roadway [a] 16,476 2,852 13,624 47 Total road 44,992 11,807 33,185 N/A Equipment: Locomotives 8,276 3,694 4,582 20 Freight cars 2,116 968 1,148 25 Work equipment and other 684 153 531 18 Total equipment 11,076 4,815 6,261 N/A Technology and other 872 320 552 10 Construction in progress 1,080 - 1,080 N/A Total $ 63,214 $ 16,942 $ 46,272 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, 2015
Accounts Payable And Other Current Liabilties [Abstract]
Schedule Of Accounts Payable And Other Current Liabilities	Dec. 31, Dec. 31, Millions 2015 2014 Accounts payable $ 743 $ 877 Income and other taxes payable 434 412 Accrued wages and vacation 391 409 Interest payable 208 178 Accrued casualty costs 181 249 Equipment rents payable 105 100 Dividends payable [a] - 438 Other 550 640 Total accounts payable and other current liabilities $ 2,612 $ 3,303 [a] Beginning in 2015, the timing of the dividend declaration and payable dates was aligned to occur within the same quarter. The 2015 dividends paid amount includes the fourth quarter 2014 dividend of $438 million, which was paid on January 2, 2015, the first quarter 2015 dividend of $484 million, which was paid on March 30, 2015, the second quarter 2015 dividend of $479 million, which was paid on June 30, 2015, the third quarter 2015 dividend of $476 million, which was paid on September 30, 2015, as well as the fourth quarter 2015 dividend of $467 million, which was paid on December 30, 2015.

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2015
Debt [Abstract]
Schedule Of Debt	Total debt as of December 31, 2015, and 2014, is summarized below: Millions 2015 2014 Notes and debentures, 1.8% to 7.9% due through 2065 $ 11,964 $ 9,266 Capitalized leases, 3.1% to 8.4% due through 2028 1,268 1,520 Equipment obligations, 2.8% to 6.7% due through 2031 963 597 Receivables Securitization (Note 11) 400 400 Term loans - floating rate, due in 2016 200 200 Mortgage bonds, 4.8% due through 2030 57 57 Medium-term notes, 9.3% to 10.0% due through 2020 23 23 Tax-exempt financings - floating rate, due in 2015 - 8 Unamortized discount and deferred issuance costs [a] (674) (658) Total debt 14,201 11,413 Less: current portion (594) (461) Total long-term debt $ 13,607 $ 10,952 [a] Includes deferred debt issuance costs of $89 million and $67 million as of December 31, 2015, and 2014, respectively, as a result of the retrospective adoption of Accounting Standard Update (ASU) 2015-03 on December 31, 2015. Prior to the ASU adoption, deferred debt issuance costs were presented in other assets.
Aggregate Debt Maturities	The following table presents aggregate debt maturities as of December 31, 2015, excluding market value adjustments: Millions 2016 $ 594 2017 1,052 2018 566 2019 637 2020 1,034 Thereafter 10,318 Total debt $ 14,201
Unsecured Fixed Rate Debt Securities Issued Under Current Shelf Registration	During 2014, we issued the following unsecured, fixed-rate debt securities under our current shelf registration: Date Description of Securities January 29, 2015 $250 million of 1.80% Notes due February 1, 2020 $450 million of 3.375% Notes due February 1, 2035 $450 million of 3.875% Notes due February 1, 2055 June 19, 2015 $400 million of 2.250% Notes due June 19, 2020 $300 million of 3.250% Notes due August 15, 2025 October 29, 2015 $200 million of reopened 3.250% Notes due August 15, 2025 $500 million of 4.050% Notes due November 15, 2045 $400 million of 4.375% Notes due November 15, 2065
Schedule Of Debt Exchange	The following table lists the outstanding notes and debentures that were exchanged: Principal amount Millions exchanged The 2024 Offers 7.000% Debentures due 2016 $ 8 5.650% Notes due 2017 38 5.750% Notes due 2017 70 5.700% Notes due 2018 103 7.875% Notes due 2019 20 6.125% Notes due 2020 238 The 2044 Offers 7.125% Debentures due 2028 73 6.625% Debentures due 2029 177 6.250% Debentures due 2034 19 6.150% Debentures due 2037 138 5.780% Notes due 2040 286 Total $ 1,170

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015, were as follows: Millions Operating Leases Capital Leases 2016 $ 491 $ 217 2017 446 220 2018 371 198 2019 339 184 2020 282 193 Later years 1,501 575 Total minimum lease payments $ 3,430 $ 1,587 Amount representing interest N/A (319) Present value of minimum lease payments N/A $ 1,268

Commitments And Contingencies (

Commitments And Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies [Abstract]
Commitments And Contingencies Activity	Our personal injury liability activity was as follows: Millions 2015 2014 2013 Beginning balance $ 335 $ 294 $ 334 Current year accruals 89 96 87 Changes in estimates for prior years (3) 9 (38) Payments (103) (64) (89) Ending balance at December 31 $ 318 $ 335 $ 294 Current portion, ending balance at December 31 $ 63 $ 111 $ 82 Our asbestos-related liability activity was as follows: Millions 2015 2014 2013 Beginning balance $ 126 $ 131 $ 139 Accruals/(Credits) - 1 2 Payments (6) (6) (10) Ending balance at December 31 $ 120 $ 126 $ 131 Current portion, ending balance at December 31 $ 6 $ 8 $ 9 Our environmental liability activity was as follows: Millions 2015 2014 2013 Beginning balance $ 182 $ 171 $ 170 Accruals 61 56 58 Payments (53) (45) (57) Ending balance at December 31 $ 190 $ 182 $ 171 Current portion, ending balance at December 31 $ 52 $ 60 $ 53

Share Repurchase Program (Table

Share Repurchase Program (Tables)	12 Months Ended
	Dec. 31, 2015
Share Repurchase Program [Abstract]
Share Repurchase Program	The table below represents shares repurchased under this repurchase program. Number of Shares Purchased Average Price Paid 2015 2014 2015 2014 First quarter 6,881,455 7,640,000 $ 117.28 $ 89.43 Second quarter 7,975,100 8,320,000 104.62 96.84 Third quarter 13,800,700 8,347,000 89.65 102.54 Fourth quarter 6,646,899 7,736,400 88.19 113.77 Total 35,304,154 32,043,400 $ 98.14 $ 100.65 Remaining number of shares that may be repurchased under current authority 52,652,446

Selected Quarterly Data (Unau46

Selected Quarterly Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
Selected Quarterly Data (Unaudited) [Abstract]
Selected Quarterly Data (Unaudited)	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 Millions, Except Per Share Amounts 2014 Mar. 31 Jun. 30 Sep. 30 Dec. 31 Operating revenues $ 5,638 $ 6,015 $ 6,182 $ 6,153 Operating income 1,854 2,196 2,330 2,373 Net income 1,088 1,291 1,370 1,431 Net income per share: Basic 1.20 1.43 1.53 1.62 Diluted 1.19 1.43 1.53 1.61

Nature Of Operations (Details)

Nature Of Operations (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015USD ($)mi	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Sep. 30, 2014USD ($)	Jun. 30, 2014USD ($)	Mar. 31, 2014USD ($)	Dec. 31, 2015USD ($)segmentmi	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Commodity Group Information [Line Items]
Freight revenues									$ 20,397	$ 22,560	$ 20,684
Other revenues									1,416	1,428	1,279
Total operating revenues	$ 5,208	$ 5,562	$ 5,429	$ 5,614	$ 6,153	$ 6,182	$ 6,015	$ 5,638	$ 21,813	23,988	21,963
Network route miles | mi	32,084								32,084
Route miles owned | mi	26,064								26,064
Reportable segments | segment									1
Agricultural Products [Member]
Commodity Group Information [Line Items]
Freight revenues									$ 3,581	3,777	3,276
Automotive [Member]
Commodity Group Information [Line Items]
Freight revenues									2,154	2,103	2,077
Chemicals [Member]
Commodity Group Information [Line Items]
Freight revenues									3,543	3,664	3,501
Coal [Member]
Commodity Group Information [Line Items]
Freight revenues									3,237	4,127	3,978
Industrial Products [Member]
Commodity Group Information [Line Items]
Freight revenues									3,808	4,400	3,822
Intermodal [Member]
Commodity Group Information [Line Items]
Freight revenues									4,074	4,489	4,030
Mexico [Member]
Commodity Group Information [Line Items]
Freight revenues									$ 2,200	$ 2,300	$ 2,100

Stock Split (Details)

Stock Split (Details)	May. 27, 2014$ / shares	Dec. 31, 2015$ / shares	Dec. 31, 2014$ / 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 Stock49

Stock Options And Other Stock Plans (Narrative) (Details) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Share-based Compensation Arrangements [Line Items]
Shares of common stock authorized and available	76,548,520	77,786,772	79,574,896
Union Pacific Corporation 1992 Restricted Stock Plan For Non-Employee Directors [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
Restricted shares outstanding	7,140
Union Pacific Corporation 2000 Directors Plan [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
Stock options, shares outstanding	45,400
Restricted shares outstanding	36,000
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	3,652,954
Retention shares and stock units outstanding	2,092,721
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	1,873,014
Retention shares and stock units outstanding	2,061,737
Common stock reserved for issuance	78,000,000

Stock Options And Other Stock50

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, 2015USD ($)$ / 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
Retention Awards [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
Years until vest	4 years
Unrecognized compensation expense	$ 88
Expected weighted average period (in years) of nonvested stock options to be recognized	1 year 6 months
Performance Retention Awards [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
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.
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.
ROIC performance period	3 years
Unrecognized compensation expense	$ 19
Expected weighted average period (in years) of nonvested stock options to be recognized	8 months 12 days

Stock-based Compensation (Sched

Stock-based Compensation (Schedule Of Stock-Based Compensation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock-Based Compensation, Before Tax: [Abstract]
Stock options	$ 17	$ 21	$ 19
Retention awards	81	91	79
Total stock-based compensation, before tax	98	112	98
Excess tax benefits from equity compensation plans	$ 62	$ 118	$ 76

Stock-based Compensation (Sch52

Stock-based Compensation (Schedule Of Stock Options Weighted Average Assumptions) (Details) - Stock Options [Member] - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Assumptions For Stock Awards [Abstract]
Risk-free interest rate	1.30%	1.60%	0.80%
Dividend yield	1.80%	2.10%	2.10%
Expected life (years)	5 years 1 month 6 days	5 years 2 months 12 days	5 years
Volatility	23.40%	30.00%	36.20%
Weighted-average grant-date fair value of options granted	$ 22.30	$ 20.18	$ 17.49

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, 2015	Dec. 31, 2014
Schedule of Share-based Compensation Arrangements [Line Items]
Stock options, shares outstanding at January 1, 2015	5,387
Stock options, shares granted	934
Stock options, shares exercised	(716)
Stock options, shares forfeited or expired	(34)
Stock options, shares outstanding at December 31, 2015	5,571	5,387
Stock options, shares vested or expected to vest at December 31, 2015	5,532
Stock options, shares exercisable at December 31, 2015	3,672
Stock options weighted-average exercise price, outstanding at January 1, 2015	$ 53.56
Stock options weighted-average exercise price, granted	122.85
Stock options weighted-average exercise price, exercised	40.10
Stock options weighted-average exercise price, forfeited or expired	89.24
Stock options weighted-average exercise price, outstanding at December 31, 2015	66.69	$ 53.56
Stock options weighted-average exercise price, vested or expected to vest at December 31, 2015	66.32
Stock options weighted-average exercise price, options exercisable at December 31, 2015	$ 49
Stock options weighted-average remaining contractual term in years, outstanding at January 1, 2015		5 years 9 months 18 days
Stock options weighted-average remaining contractual term in years, outstanding at December 31, 2015	5 years 4 months 24 days
Stock options weighted-average remaining contractual term in years, vested or expected to vest at December 31, 2015	5 years 4 months 24 days
Stock options weighted-average remaining contractual term in years, options exercisable at December 31, 2015	4 years 1 month 6 days
Stock options aggregate intrinsic value, outstanding at January 1, 2015	$ 353
Stock options aggregate intrinsic value, outstanding at December 31, 2015	114	$ 353
Stock options aggregate intrinsic value, vested or expected to vest at December 31, 2015	114
Stock options aggregate intrinsic value, options exercisable at December 31, 2015	$ 110

Stock-based Compensation (Sch54

Stock-based Compensation (Schedule Of Stock Option Exercises) (Details) - Stock Options [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock Option Aggregate Disclosures [Abstract]
Intrinsic value of stock options exercised	$ 50	$ 194	$ 112
Cash received from option exercises	27	54	51
Treasury shares repurchased for employee payroll taxes	(12)	(24)	(21)
Tax benefit realized from option exercises	19	74	43
Aggregate grant-date fair value of stock options vested	$ 19	$ 17	$ 16

Stock-based Compensation (Sch55

Stock-based Compensation (Schedule Of Retention Awards) (Details) - Retention Awards [Member] shares in Thousands	12 Months Ended
	Dec. 31, 2015$ / sharesshares
Schedule of Share-based Compensation Arrangements [Line Items]
Awards, shares nonvested at January 1, 2015 | shares	3,403
Awards, shares granted | shares	521
Awards, shares vested | shares	(934)
Awards, shares forfeited | shares	(90)
Awards, shares nonvested at December 31, 2015 | shares	2,900
Awards weighted-average grant-date fair value, nonvested at January 1, 2015 | $ / shares	$ 64.39
Awards weighted-average grant-date fair value, granted | $ / shares	122.79
Awards weighted-average grant-date fair value, vested | $ / shares	47.66
Awards weighted-average grant-date fair value, forfeited | $ / shares	72.87
Awards weighted-average grant-date fair value, nonvested at December 31, 2015 | $ / shares	$ 80.01

Stock-based Compensation (Perfo

Stock-based Compensation (Performance Retention Awards, Present Value Calculation Assumptions) (Details) - Performance Retention Awards [Member]	12 Months Ended
	Dec. 31, 2015$ / shares
Assumptions For Stock Awards [Abstract]
Dividend per share per quarter	$ 0.55
Risk-free interest rate at date of grant	0.80%

Stock-based Compensation (Sch57

Stock-based Compensation (Schedule Of Performance Retention Awards) (Details) - Performance Retention Awards [Member] shares in Thousands	12 Months Ended
	Dec. 31, 2015$ / sharesshares
Schedule of Share-based Compensation Arrangements [Line Items]
Awards, shares nonvested at January 1, 2015 | shares	1,583
Awards, shares granted | shares	339
Awards, shares vested | shares	(580)
Awards, shares forfeited | shares	(87)
Awards, shares nonvested at December 31, 2015 | shares	1,255
Awards weighted-average grant-date fair value, nonvested at January 1, 2015 | $ / shares	$ 65.33
Awards weighted-average grant-date fair value, granted | $ / shares	117.42
Awards weighted-average grant-date fair value, vested | $ / shares	54.38
Awards weighted-average grant-date fair value, forfeited | $ / shares	86.66
Awards weighted-average grant-date fair value, nonvested at December 31, 2015 | $ / shares	$ 82.98

Retirement Plans (Narrative) (D

Retirement Plans (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
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		388,000,000	379,000,000
Accumulated benefit obligation.		$ 3,700,000,000	$ 3,900,000,000
Actual return (loss) on pension plan assets, net of fees		(1.00%)	6.00%	17.00%
OPEB [Member]
Retirement Plans [Line Items]
Health care cost trend rate (employees under 65)		6.34%	6.49%	6.64%
Ultimate health care cost trend rate		4.50%	4.50%	4.50%
Year ultimate trend rate reached		2,028	2,028	2,028
OPEB [Member] | 2016 Forecast [Member]
Retirement Plans [Line Items]
Health care cost trend rate (employees under 65)	6.34%
Ultimate health care cost trend rate	4.50%
Year ultimate trend rate reached	2,028
Pension Non-qualified Plan [Member]
Retirement Plans [Line Items]
Accumulated benefit obligation		$ 388,000,000	$ 379,000,000

Retirement Plans (Other Retirem

Retirement Plans (Other Retirement Programs) (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
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	$ 20	$ 19	$ 18
Railroad Retirement System [Abstract]
Railroad Retirement System description	All Railroad employees are covered by the Railroad Retirement System (the System).
Railroad Retirement System contributions	$ 749	711	670
Multiemployer Plans, Postretirement Benefit [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	$ 46	$ 52	$ 57

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, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension [Member]
Projected Benefit Obligation [Abstract]
Projected benefit obligation at beginning of year	$ 4,142	$ 3,372
Service cost	106	70	$ 72
Interest cost	163	158	134
Actuarial loss/(gain)	(267)	735
Gross benefits paid	(186)	(193)
Projected benefit obligation at end of year	3,958	4,142	3,372
Plan Assets [Abstract]
Fair value of plan assets at beginning of year	3,654	3,429
Actual return on plan assets	(43)	185
Voluntary funded pension plan contributions	100	200
Non-qualified plan benefit contributions	19	33
Gross benefits paid	(186)	(193)
Fair value of plan assets at end of year	3,544	3,654	3,429
Defined Benefit Plan, Funded Status of Plan [Abstract]
Funded status at end of year	(414)	(488)
OPEB [Member]
Projected Benefit Obligation [Abstract]
Projected benefit obligation at beginning of year	354	330
Service cost	3	2	3
Interest cost	13	14	12
Actuarial loss/(gain)	(18)	33
Gross benefits paid	(23)	(25)
Projected benefit obligation at end of year	$ 329	$ 354	$ 330
Plan Assets [Abstract]
Fair value of plan assets at beginning of year
Actual return on plan assets
Voluntary funded pension plan contributions
Non-qualified plan benefit contributions - OPEB	$ 23	$ 25
Gross benefits paid	$ (23)	$ (25)
Fair value of plan assets at end of year
Defined Benefit Plan, Funded Status of Plan [Abstract]
Funded status at end of year	$ (329)	$ (354)

Retirement Plans (Schedule Of A

Retirement Plans (Schedule Of Amounts Recognized In Statement Of Financial Position) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Amounts recognized - noncurrent assets	$ 1	$ 1
Amounts recognized - current liabilities	(22)	(19)
Amounts recognized - noncurrent liabilities	(393)	(470)
Net amounts recognized at end of year	$ (414)	$ (488)
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Amounts recognized - noncurrent assets
Amounts recognized - current liabilities	$ (23)	$ (23)
Amounts recognized - noncurrent liabilities	(306)	(331)
Net amounts recognized at end of year	$ (329)	$ (354)

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, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Prior service (cost)/credit	$ 7	$ 17
Net actuarial loss	(1,769)	(1,875)
Total pre-tax amounts recognized in accumulated other comprehensive income/(loss)	$ (1,762)	$ (1,858)
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service (cost)/credit
Net actuarial loss	$ (1,652)	$ (1,727)
Total pre-tax amounts recognized in accumulated other comprehensive income/(loss)	(1,652)	(1,727)
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service (cost)/credit	7	17
Net actuarial loss	(117)	(148)
Total pre-tax amounts recognized in accumulated other comprehensive income/(loss)	$ (110)	$ (131)

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, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial (loss)/gain - OCI	$ (31)	$ (780)	$ 561
Amortization of prior service cost/(credit) - OCI
Amortization of actuarial loss - OCI	$ 106	$ 71	$ 106
Total other pre-tax changes recognized in other comprehensive income	75	(709)	667
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial (loss)/gain - OCI	18	(33)	34
Amortization of prior service cost/(credit) - OCI	(10)	(11)	(16)
Amortization of actuarial loss - OCI	13	10	15
Total other pre-tax changes recognized in other comprehensive income	$ 21	$ (34)	$ 33

Retirement Plans (Amounts Inclu

Retirement Plans (Amounts Included In Accumulated Other Comprehensive Income Expected To Be Amortized Into Net Periodic Cost (Benefit)) (Details) - 2016 Forecast [Member] $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)
Defined Benefit Plan Disclosure [Line Items]
Prior service credit - AOCI	$ 9
Net actuarial loss - AOCI	(90)
Total amounts included in accumulated other comprehensive income expected to be amortized into net periodic cost (benefit)	$ (81)
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service credit - AOCI
Net actuarial loss - AOCI	$ (80)
Total amounts included in accumulated other comprehensive income expected to be amortized into net periodic cost (benefit)	(80)
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service credit - AOCI	9
Net actuarial loss - AOCI	(10)
Total amounts included in accumulated other comprehensive income expected to be amortized into net periodic cost (benefit)	$ (1)

Retirement Plans (Underfunded A

Retirement Plans (Underfunded Accumulated Benefit Obligation) (Details) - Pension [Member] - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Retirement Plans [Line Items]
Projected benefit obligation	$ 398	$ 388
Accumulated benefit obligation	$ 388	$ 379
Fair value of plan assets
Underfunded accumulated benefit obligation	$ (388)	$ (379)

Retirement Plans (Weighted-Aver

Retirement Plans (Weighted-Average Actuarial Assumptions Used To Determine Benefit Obligations) (Detail)	Dec. 31, 2015	Dec. 31, 2014
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate - benefit obligations	4.37%	3.94%
Compensation increase - benefit obligations	4.10%	4.00%
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate - benefit obligations	4.16%	3.74%
Health care cost trend rate (employees under 65) - benefit obligations	6.52%	6.34%
Ultimate health care cost trend rate - benefit obligations	4.50%	4.50%
Year ultimate trend reached - benefit obligations	2,038	2,028

Retirement Plans (Net Periodic

Retirement Plans (Net Periodic Pension And OPEB Cost/(Benefit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension [Member]
Net Periodic Pension And OPEB Cost/(Benefit) [Abstract]
Service cost	$ 106	$ 70	$ 72
Interest cost	163	158	134
Expected return on plan assets	$ (255)	$ (230)	$ (202)
Amortization of prior service credit
Amortization of actuarial loss	$ 106	$ 71	$ 106
Net periodic pension/OPEB cost	120	69	110
OPEB [Member]
Net Periodic Pension And OPEB Cost/(Benefit) [Abstract]
Service cost	3	2	3
Interest cost	$ 13	$ 14	$ 12
Expected return on plan assets
Amortization of prior service credit	$ (10)	$ (11)	$ (16)
Amortization of actuarial loss	13	10	15
Net periodic pension/OPEB cost	$ 19	$ 15	$ 14

Retirement Plans (Weighted-Av68

Retirement Plans (Weighted-Average Actuarial Assumptions Used To Determine Benefit Expense) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate - expense	3.94%	4.72%	3.78%
Expected return on plan assets - expense	7.50%	7.50%	7.50%
Compensation increase - expense	4.00%	4.00%	3.43%
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate - expense	3.74%	4.47%	3.48%
Health care cost trend rate for next year (employees under 65) - expense	6.34%	6.49%	6.64%
Ultimate health care cost trend rate - expense	4.50%	4.50%	4.50%
Year ultimate trend rate reached - expense	2,028	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, 2015USD ($)
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	17
Effect on accumulated benefit obligation - one % pt. decrease	$ (14)

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, 2015	Dec. 31, 2014
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash contributions to qualified pension plan
Cash contribution to non-qualified OPEB plan	$ 23	$ 25
Pension Qualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash contributions to qualified pension plan	100	200
Pension Non-qualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash contributions to non-qualified pension plan	$ 19	$ 33

Retirement Plans (Schedule Of E

Retirement Plans (Schedule Of Expected Benefit Payments) (Details) $ in Millions	Dec. 31, 2015USD ($)
Pension [Member]
Benefit Payments [Abstract]
2,016	$ 191
2,017	194
2,018	198
2,019	202
2,020	205
Years 2021 - 2025	1,077
OPEB [Member]
Benefit Payments [Abstract]
2,016	23
2,017	23
2,018	23
2,019	23
2,020	22
Years 2021 - 2025	$ 102

Retirement Plans (Schedule Of72

Retirement Plans (Schedule Of Pension Plan Asset Allocation) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Asset allocation	100.00%	100.00%
Target average long-term rate of return	7.50%
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 7.5%.
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.
Weighted-average maturity of Pension Plan debt portfolio	12 years	12 years
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation 2016 range minimum	60.00%
Target allocation 2016 range maximum	70.00%
Asset allocation	67.00%	68.00%
Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation 2016 range minimum	20.00%
Target allocation 2016 range maximum	30.00%
Asset allocation	23.00%	23.00%
Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation 2016 range minimum	2.00%
Target allocation 2016 range maximum	8.00%
Asset allocation	6.00%	4.00%
Commodities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation 2016 range minimum	4.00%
Target allocation 2016 range maximum	6.00%
Asset allocation	4.00%	5.00%

Retirement Plans (Schedule Of73

Retirement Plans (Schedule Of Assets Measured At Fair Value On A Recurring Basis) (Details) - Pension [Member] - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 3,544	$ 3,654	$ 3,429
Temporary Cash Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		13	22
Registered Investment Companies [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		449	294
Federal Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		125	163
Bonds & Debentures [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		383	381
Corporate Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1,041	1,091
Venture Capital And Buyout Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		256	234
Real Estate Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		199	139
Collective Trust And Other Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1,075	1,340
Other Assets - Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	3	(10)
Total Plan Assets At Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		3,541	3,664
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		13	22
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		$ 179	$ 12
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 & 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		$ 1,034	$ 1,076
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | Venture Capital And Buyout Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | Real Estate Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | Collective Trust And Other Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
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		$ 1,226	$ 1,110
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		$ 270	$ 282
Significant Other Observable Inputs (Level 2) [Member] | Federal Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		125	163
Significant Other Observable Inputs (Level 2) [Member] | Bonds & Debentures [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		383	381
Significant Other Observable Inputs (Level 2) [Member] | Corporate Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 7	$ 15
Significant Other Observable Inputs (Level 2) [Member] | Venture Capital And Buyout Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Significant Other Observable Inputs (Level 2) [Member] | Real Estate Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Significant Other Observable Inputs (Level 2) [Member] | Collective Trust And Other Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 1,075	$ 1,340
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		1,860	2,181
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 455	$ 373	352
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
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 & 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] | Venture Capital And Buyout Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 256	$ 234	213
Significant Unobservable Inputs (Level 3) [Member] | Real Estate Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 199	$ 139	$ 139
Significant Unobservable Inputs (Level 3) [Member] | Collective Trust And Other Funds [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		$ 455	$ 373
[1]	Other assets include accrued receivables and pending broker settlements.

Retirement Plans (Reconciliatio

Retirement Plans (Reconciliation Of Beginning Ending Balances Of Fair Value Measurements Using Significant Unobservable Inputs (Level 3)) (Details) - Pension [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	$ 3,654	$ 3,429
Fair value of plan assets at end of year	3,544	3,654
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	373	352
Realized gain/(loss)	23	25
Unrealized gain	21	11
Purchases	128	73
Sales	(90)	(88)
Fair value of plan assets at end of year	455	373
Venture Capital And Buyout Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	234
Fair value of plan assets at end of year	256	234
Venture Capital And Buyout Partnerships [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	234	213
Realized gain/(loss)	18	17
Unrealized gain	13	5
Purchases	54	54
Sales	(63)	(55)
Fair value of plan assets at end of year	256	234
Real Estate Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	139
Fair value of plan assets at end of year	199	139
Real Estate Partnerships [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	139	139
Realized gain/(loss)	5	8
Unrealized gain	8	6
Purchases	74	19
Sales	(27)	(33)
Fair value of plan assets at end of year	$ 199	$ 139

Other Income (Details)

Other Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Other Income [Abstract]
Net gain on non-operating asset dispositions.	$ 144	[1]	$ 69		$ 32
Rental income	96		96		106	[2]
Interest Income	5		4		4
Non-operating environmental costs and other	(19)		(18)	[3]	(14)
Total	226		151		128
Real estate sale	$ 113
Land lease contract settlement					$ 17
Permanent easement sale			$ 14
[1]	2015 includes $113 million related to a real estate sale.
[2]	2013 includes $17 million related to a land lease contract settlement.
[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, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes [Abstract]
Total accrued liabilities for interest and penalties	$ 2	$ 2	$ 6
Total interest and penalties recognized as part of income tax expense			9	$ 7
Total interest and penalties recognized as part of income tax benefit		(3)
Taxes paid in connection to settlement	10		11
Net unrecognized tax benefit liability	$ 94	$ 94	$ 151	$ 59	$ 115

Income Taxes (Schedule Of Compo

Income Taxes (Schedule Of Components Of Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current Income Tax Expense [Abstract]
Current federal income tax expense	$ 1,901	$ 2,019	$ 1,727
Current state income tax expense	210	239	199
Current foreign income tax expense	8	10	11
Total current income tax expense	2,119	2,268	1,937
Deferred Income Tax Expense [Abstract]
Deferred federal income tax expense	644	753	605
Deferred state income tax expense	121	142	118
Total deferred income tax expense	765	895	723
Total income tax expense	$ 2,884	$ 3,163	$ 2,660

Income Taxes (Reconciliations B

Income Taxes (Reconciliations Between Statutory And Effective Tax Rates) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
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%)	(0.40%)	(0.20%)
Deferred tax adjustments			(0.10%)
Other tax rate adjustments	0.10%	0.20%	(0.10%)
Effective tax rate	37.70%	37.90%	37.70%

Income Taxes (Schedule Of Defer

Income Taxes (Schedule Of Deferred Income Tax Liabilities And Assets) (Details) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Components Of Deferred Income Tax (Liabilities)/Assets [Abstract]
Deferred income tax liabilities - property		$ (16,079)	$ (15,173)
Deferred income tax liabilities - other		(352)	(411)
Total deferred income tax liabilities		(16,431)	(15,584)
Deferred income tax asset - accrued wages		76	74
Deferred income tax asset - accrued casualty costs		237	228
Deferred income tax asset - stock compensation		72	69
Deferred income tax asset - debt and leases		149	86
Deferred income tax asset - retiree benefits		204	392
Deferred income tax asset - credits		156	164
Deferred income tax asset - other		296	168
Total deferred income tax asset	[1]	1,190	1,181
Net deferred income tax liability		(15,241)	(14,403)
Current deferred income tax assets			277
Income Tax Details [Abstract]
Deferred tax valuation allowance		$ 0	$ 0
[1]	Prior to the adoption of Accounting Standard Update (ASU) 2015-17, deferred tax assets were required to be presented as current and non-current on the Consolidated Statement of Financial Position. In 2015, UP adopted ASU 2015-17 retrospectively. Current deferred income tax assets at December 31, 2014 of $277 million were reclassified from current to non-current for 2015 presentation.

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of Changes In Unrecognized Tax Benefits Liabilities/(Assets)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation Of Changes In Unrecognized Tax Benefits Liabilities/(Assets) [Abstract]
Unrecognized tax benefits at January 1	$ 151	$ 59	$ 115
Increases for positions taken in current year	38	92	24
Increases for positions taken in prior years	13	22	15
Decreases for positions taken in prior years	(87)	(14)	(35)
Payments to and settlements with taxing authorities	(13)	(8)	(58)
Increases/(decreases) for interest and penalties	(5)	1
Lapse of statutes of limitations	(3)	(1)	(2)
Unrecognized tax benefits at December 31	$ 94	$ 151	$ 59

Income Taxes (Unrecognized Tax

Income Taxes (Unrecognized Tax Benefits That Would/Not Reduce The Effective Tax Rate) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Unrecognized Tax Benefits That Would Impact Effective Tax Rate [Abstract]
Unrecognized tax benefits that would reduce the effective tax rate	$ 31	$ 33	$ 34
Unrecognized tax benefits that would not reduce the effective tax rate	63	118	25
Total unrecognized tax benefits	$ 94	$ 151	$ 59	$ 115

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, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Net income	$ 1,117	$ 1,300	$ 1,204	$ 1,151	$ 1,431	$ 1,370	$ 1,291	$ 1,088	$ 4,772	$ 5,180	$ 4,388
Weighted-Average Number Of Shares Outstanding
Basic									866.2	897.1	926.5
Dilutive effect of stock options									1.5	2.1	2.4
Dilutive effect of retention shares and units									1.7	1.9	2.6
Diluted									869.4	901.1	931.5
Earnings per share – basic	$ 1.31	$ 1.51	$ 1.38	$ 1.31	$ 1.62	$ 1.53	$ 1.43	$ 1.20	$ 5.51	$ 5.77	$ 4.74
Earnings per share – diluted	$ 1.31	$ 1.50	$ 1.38	$ 1.30	$ 1.61	$ 1.53	$ 1.43	$ 1.19	$ 5.49	$ 5.75	$ 4.71
Stock options excluded as their inclusion would be anti-dilutive									1.1	0.4	0.5

Accumulated Other Comprehensi83

Accumulated Other Comprehensive Income/(Loss) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at January 1		$ (1,210)	$ (750)
Other comprehensive income/(loss) before reclassifications		(47)	(2)
Amounts reclassified from accumulated other comprehensive income/(loss)	[1]	62	(458)
Net year-to-date other comprehensive income/(loss), net of taxes	[2]	15	(460)	$ 436
Balance at December 31		(1,195)	(1,210)	(750)
Deferred taxes activity other comprehensive income/(loss)		(8)	291	(264)
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at January 1		(1,161)	(713)
Other comprehensive income/(loss) before reclassifications		(4)	10
Amounts reclassified from accumulated other comprehensive income/(loss)	[1]	62	(458)
Net year-to-date other comprehensive income/(loss), net of taxes		58	(448)
Balance at December 31		(1,103)	(1,161)	(713)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at January 1		(49)	(37)
Other comprehensive income/(loss) before reclassifications		$ (43)	$ (12)
Amounts reclassified from accumulated other comprehensive income/(loss)	[1]
Net year-to-date other comprehensive income/(loss), net of taxes		$ (43)	$ (12)
Balance at December 31		$ (92)	$ (49)	$ (37)
[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 ($8) million, $291 million, and ($264) million during 2015, 2014, and 2013, respectively.

Accounts Receivable (Details)

Accounts Receivable (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounts Receivable Details [Abstract]
Allowance for doubtful accounts	$ 5	$ 5
Allowance for doubtful accounts - receivables not expected to be collected in one year	11	16
Receivables Securitization Facility [Abstract]
Total capacity to transfer undivided interests to investors under the receivables securitization facility	$ 650
Receivables securitization facility renewal date	2017-07
Receivables securitization facility duration	3 years
Value of the outstanding undivided interest held by investors under the receivables securitization facility	$ 400	400
Accounts receivable supporting the undivided interest held by investors	900	1,200
Cost of the receivables securitization facility - interest expense	$ 5	$ 4	$ 5

Properties (Details)

Properties (Details) $ in Millions		12 Months Ended
		Dec. 31, 2015USD ($)item	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Property, Plant and Equipment [Line Items]
Cost		$ 66,564	$ 63,214
Accumulated depreciation		17,698	16,942
Net book value		$ 48,866	46,272
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		$ 2,500	2,400	$ 2,300
Land [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 5,195	$ 5,194
Accumulated depreciation
Net book value		$ 5,195	$ 5,194
Road: Rail and Other Track Material [Member]
Property, Plant and Equipment [Line Items]
Cost		15,236	14,588
Accumulated depreciation		5,495	5,241
Net book value		$ 9,741	$ 9,347
Estimated useful life		37 years	33 years
Road: Ties [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 9,439	$ 9,102
Accumulated depreciation		2,595	2,450
Net book value		$ 6,844	$ 6,652
Estimated useful life		33 years	33 years
Road: Ballast [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 5,024	$ 4,826
Accumulated depreciation		1,350	1,264
Net book value		$ 3,674	$ 3,562
Estimated useful life		34 years	34 years
Road: Other Roadway [Member]
Property, Plant and Equipment [Line Items]
Cost	[1]	$ 17,374	$ 16,476
Accumulated depreciation	[1]	3,021	2,852
Net book value	[1]	$ 14,353	$ 13,624
Estimated useful life	[1]	47 years	47 years
Total Road [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 47,073	$ 44,992
Accumulated depreciation		12,461	11,807
Net book value		$ 34,612	33,185
Term of Depreciation Studies		6 years
Equipment: Locomotives [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 9,027	8,276
Accumulated depreciation		3,726	3,694
Net book value		$ 5,301	$ 4,582
Estimated useful life		19 years	20 years
Equipment: Freight Cars [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 2,203	$ 2,116
Accumulated depreciation		962	968
Net book value		$ 1,241	$ 1,148
Estimated useful life		24 years	25 years
Equipment: Work Equipment and Other [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 897	$ 684
Accumulated depreciation		191	153
Net book value		$ 706	$ 531
Estimated useful life		19 years	18 years
Total Equipment [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 12,127	$ 11,076
Accumulated depreciation		4,879	4,815
Net book value		$ 7,248	6,261
Term of Depreciation Studies		3 years
Technology and Other [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 919	872
Accumulated depreciation		358	320
Net book value		$ 561	$ 552
Estimated useful life		11 years	10 years
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Cost		$ 1,250	$ 1,080
Accumulated depreciation
Net book value		$ 1,250	$ 1,080
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. 30, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 30, 2015	Jan. 02, 2015	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Accounts Payable And Other Current Liabilities [Abstract]
Accounts payable						$ 743		$ 877
Income and other taxes payable						434		412
Accrued wages and vacation						391		409
Interest payable						208		178
Accrued casualty costs						181		249
Equipment rents payable						$ 105		100
Dividends payable							[1]	438	[1]	$ 356
Other						$ 550		640
Total accounts payable and other current liabilities						2,612		3,303
Dividends paid	$ 467	$ 476	$ 479	$ 484	$ 438	$ 2,344		$ 1,632		$ 1,333
[1]	Beginning in 2015, the timing of the dividend declaration and payable dates was aligned to occur within the same quarter. The 2015 dividends paid amount includes the fourth quarter 2014 dividend of $438 million, which was paid on January 2, 2015, the first quarter 2015 dividend of $484 million, which was paid on March 30, 2015, the second quarter 2015 dividend of $479 million, which was paid on June 30, 2015, the third quarter 2015 dividend of $476 million, which was paid on September 30, 2015, as well as the fourth quarter 2015 dividend of $467 million, which was paid on December 30, 2015.

Financial Instruments (Details)

Financial Instruments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Market and Credit Risk [Abstract]
Collateral for hedging activity	$ 0	$ 0
Interest Rate Derivatives [Abstract]
Interest rate fair value hedges outstanding	0	0
Interest Rate Cash Flow Hedges [Abstract]
Interest rate cash flow hedges outstanding	0	0
Earnings Impact [Abstract]
Increase in pre-tax income	0	0	$ 0
Fair Value of Debt Instruments [Abstract]
Fair value of total debt	15,200	13,000
Fair value of total debt in excess of carrying value	1,000	1,500
Fixed rate debt securities containing call provisions	$ 155	$ 163

Debt (Equipment Encumbrances) (

Debt (Equipment Encumbrances) (Narrative) (Details) - USD ($) $ in Billions	Dec. 31, 2015	Dec. 31, 2014	Jan. 01, 1997
Debt [Abstract]
Carrying value of equipment serving as collateral for capital leases and other types of equipment obligations	$ 2.6	$ 2.8
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, 2015	Dec. 31, 2014
Debt Instrument [Line Item]
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)	41,400,000,000
Outstanding debt (as defined by facility)	14,300,000,000
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, 2015	Dec. 31, 2014
Debt [Abstract]
Retained earnings available for dividends	$ 13.6	$ 15.4

Debt (Shelf Registration And Si

Debt (Shelf Registration And Significant New Borrowings) (Narrative) (Details) - USD ($)	Dec. 31, 2015	Feb. 09, 2015	Feb. 28, 2013
Debt [Abstract]
Board of Directors remaining debt issuance	$ 2,200,000,000
Board of Directors authorized debt issuance		$ 4,000,000,000	$ 4,000,000,000

Debt (Equipment Trust) (Narrati

Debt (Equipment Trust) (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)item	Dec. 31, 2014USD ($)
Debt Instrument [Line Item]
Debt due after one year	$ 13,607	$ 10,952
Equipment Obligations [Member] | 2.695% Notes Due 2027 [Member]
Debt Instrument [Line Item]
Issuance date	May 12, 2015
Note amount	$ 399
Interest rate on note	2.695%
Maturity date on new borrowing	May 12, 2027
Total locomotives financed from proceeds | item	182
Debt due after one year	$ 399

Debt (Debt Exchange) (Narrative

Debt (Debt Exchange) (Narrative) (Details) - USD ($)	Aug. 21, 2013	Dec. 31, 2015	Dec. 31, 2013
Debt Conversion [Line Items]
Original debt	$ 1,170,000,000
3.646% Debt Due 2024 [Member]
Debt Conversion [Line Items]
Date of exchange		Aug. 21, 2013
New debt	$ 439,000,000
New rate	3.646%
New due date		Feb. 15, 2024
4.821% Debt Due 2044 [Member]
Debt Conversion [Line Items]
Date of exchange		Aug. 21, 2013
New debt	$ 700,000,000
New rate	4.821%
New due date		Feb. 1, 2044
Notes And Debentures [Member]
Debt Conversion [Line Items]
Original debt	$ 1,170,000,000
Cash consideration	280,000,000
Accrued and unpaid interest	8,000,000
Gain (loss) recognized resulting from exhange	$ 0
Debt exchange fees			$ 9,000,000

Debt (Receivables Securitizatio

Debt (Receivables Securitization Facility) (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Receivables Securitization Facility [Member]
Debt Instrument [Line Item]
Debt	$ 400	$ 400

Debt (Schedule Of Debt) (Detail

Debt (Schedule Of Debt) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Item]
Unamortized discount and deferred issuance costs	[1]	$ (674)	$ (658)
Total debt		14,201	11,413
Less: current portion		(594)	(461)
Total long-term debt		13,607	10,952
Deferred debt issuance costs		89	67
Notes And Debentures [Member]
Debt Instrument [Line Item]
Debt		$ 11,964	9,266
Stated percentage rate range, minimum		1.80%
Stated percentage rate range, maximum		7.90%
Debt due through		Nov. 15, 2065
Capitalized Leases [Member]
Debt Instrument [Line Item]
Debt		$ 1,268	1,520
Stated percentage rate range, minimum		3.10%
Stated percentage rate range, maximum		8.40%
Debt due through		Dec. 10, 2028
Equipment Obligations [Member]
Debt Instrument [Line Item]
Debt		$ 963	597
Stated percentage rate range, minimum		2.80%
Stated percentage rate range, maximum		6.70%
Debt due through		Jan. 2, 2031
Receivables Securitization Facility [Member]
Debt Instrument [Line Item]
Debt		$ 400	400
Floating Rate Term Loan [Member]
Debt Instrument [Line Item]
Debt		$ 200	200
Debt due through		Oct. 31, 2016
Mortgage Bonds [Member]
Debt Instrument [Line Item]
Debt		$ 57	57
Stated percentage rate		4.80%
Debt due through		Jan. 1, 2030
Medium-Term Notes [Member]
Debt Instrument [Line Item]
Debt		$ 23	23
Stated percentage rate range, minimum		9.30%
Stated percentage rate range, maximum		10.00%
Debt due through		Apr. 15, 2020
Tax-Exempt Financings [Member]
Debt Instrument [Line Item]
Debt			$ 8
Debt due through		Dec. 1, 2015
[1]	Includes deferred debt issuance costs of $89 million and $67 million as of December 31, 2015, and 2014, respectively, as a result of the retrospective adoption of Accounting Standard Update (ASU) 2015-03 on December 31, 2015. Prior to the ASU adoption, deferred debt issuance costs were presented in other assets.

Debt (Aggregate Debt Maturities

Debt (Aggregate Debt Maturities) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Aggregate Debt Maturities Excluding Market Value Adjustments [Abstract]
Debt maturities - 2016	$ 594
Debt maturities - 2017	1,052
Debt maturities - 2018	566
Debt maturities - 2019	637
Debt maturities - 2020	1,034
Debt maturities - thereafter	10,318
Total debt	$ 14,201	$ 11,413

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, 2015	Oct. 29, 2015	Jun. 19, 2015	Jan. 29, 2015
1.80% Notes Due 2020 [Member]
Debt Instrument [Line Item]
Issuance date	Jan. 29, 2015
Note amount				$ 250,000,000
Interest rate on note				1.80%
Maturity date on new borrowing	Feb. 1, 2020
3.375% Notes Due 2035 [Member]
Debt Instrument [Line Item]
Issuance date	Jan. 29, 2015
Note amount				$ 450,000,000
Interest rate on note				3.375%
Maturity date on new borrowing	Feb. 1, 2035
3.875% Notes Due 2055 [Member]
Debt Instrument [Line Item]
Issuance date	Jan. 29, 2015
Note amount				$ 450,000,000
Interest rate on note				3.875%
Maturity date on new borrowing	Feb. 1, 2055
2.250% Notes Due 2020 [Member]
Debt Instrument [Line Item]
Issuance date	Jun. 19, 2015
Note amount			$ 400,000,000
Interest rate on note			2.25%
Maturity date on new borrowing	Jun. 19, 2020
3.250% Notes Due 2025 [Member]
Debt Instrument [Line Item]
Issuance date	Jun. 19, 2015
Note amount			$ 300,000,000
Interest rate on note			3.25%
Maturity date on new borrowing	Aug. 15, 2025
3.250% Reopened Notes Due 2025 [Member]
Debt Instrument [Line Item]
Issuance date	Oct. 29, 2015
Note amount		$ 200,000,000
Interest rate on note		3.25%
Maturity date on new borrowing	Aug. 15, 2025
4.050% Notes Due 2045 [Member]
Debt Instrument [Line Item]
Issuance date	Oct. 29, 2015
Note amount		$ 500,000,000
Interest rate on note		4.05%
Maturity date on new borrowing	Nov. 15, 2045
4.375% Notes Due 2065 [Member]
Debt Instrument [Line Item]
Issuance date	Oct. 29, 2015
Note amount		$ 400,000,000
Interest rate on note		4.375%
Maturity date on new borrowing	Nov. 15, 2065

Debt (Schedule Of Debt Exchange

Debt (Schedule Of Debt Exchange) (Details) - USD ($) $ in Millions	Aug. 21, 2013	Dec. 31, 2015
Debt Conversion [Line Items]
Original debt	$ 1,170
3.646% Debt Due 2024 [Member] | 7.000% Debentures Due 2016 [Member]
Debt Conversion [Line Items]
Original debt	$ 8
Original rate	7.00%
Original due date, year		2,016
3.646% Debt Due 2024 [Member] | 5.650% Notes Due 2017 [Member]
Debt Conversion [Line Items]
Original debt	$ 38
Original rate	5.65%
Original due date, year		2,017
3.646% Debt Due 2024 [Member] | 5.750% Notes Due 2017 [Member]
Debt Conversion [Line Items]
Original debt	$ 70
Original rate	5.75%
Original due date, year		2,017
3.646% Debt Due 2024 [Member] | 5.700% Notes Due 2018 [Member]
Debt Conversion [Line Items]
Original debt	$ 103
Original rate	5.70%
Original due date, year		2,018
3.646% Debt Due 2024 [Member] | 7.875% Notes Due 2019 [Member]
Debt Conversion [Line Items]
Original debt	$ 20
Original rate	7.875%
Original due date, year		2,019
3.646% Debt Due 2024 [Member] | 6.125% Notes Due 2020 [Member]
Debt Conversion [Line Items]
Original debt	$ 238
Original rate	6.125%
Original due date, year		2,020
4.821% Debt Due 2044 [Member] | 7.125% Debentures Due 2028 [Member]
Debt Conversion [Line Items]
Original debt	$ 73
Original rate	7.125%
Original due date, year		2,028
4.821% Debt Due 2044 [Member] | 6.625% Debentures Due 2029 [Member]
Debt Conversion [Line Items]
Original debt	$ 177
Original rate	6.625%
Original due date, year		2,029
4.821% Debt Due 2044 [Member] | 6.250% Debentures Due 2034 [Member]
Debt Conversion [Line Items]
Original debt	$ 19
Original rate	6.25%
Original due date, year		2,034
4.821% Debt Due 2044 [Member] | 6.150% Debentures Due 2037 [Member]
Debt Conversion [Line Items]
Original debt	$ 138
Original rate	6.15%
Original due date, year		2,037
4.821% Debt Due 2044 [Member] | 5.780% Notes Due 2040 [Member]
Debt Conversion [Line Items]
Original debt	$ 286
Original rate	5.78%
Original due date, year		2,040

Variable Interest Entities (Det

Variable Interest Entities (Details) $ in Millions	Dec. 31, 2015USD ($)
Future minimum lease payments	$ 3,430
Variable Interest Entity (VIEs) [Member]
Future minimum lease payments	$ 2,600

Leases (Narrative) (Details)

Leases (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Future Minimum Lease Payments For Capital Leases [Abstract]
Properties held under capital leases	$ 2,273	$ 2,454
Properties held under capital leases - accumulated depreciation	$ 1,189	1,210
Lease payments related to locomotives	95.00%
Future Minimum Lease Payments For Operating Leases [Abstract]
Rent expense for operating leases with terms exceeding one month	$ 590	$ 593	$ 618

Leases (Future Minimum Lease Pa

Leases (Future Minimum Lease Payments For Operating And Capital Leases) (Details) $ in Millions	Dec. 31, 2015USD ($)
Future Minimum Lease Payments For Capital Leases [Abstract]
Minimum capital lease payments - 2016	$ 217
Minimum capital lease payments - 2017	220
Minimum capital lease payments - 2018	198
Minimum capital lease payments - 2019	184
Minimum capital lease payments - 2020	193
Minimum capital lease payments - later years	575
Total minimum capital lease payments	1,587
Capital lease payments - amount representing interest	(319)
Capital lease payments - present value of minimum lease payments	1,268
Future Minimum Lease Payments For Operating Leases [Abstract]
Minimum operating lease payments - 2016	491
Minimum operating lease payments - 2017	446
Minimum operating lease payments - 2018	371
Minimum operating lease payments - 2019	339
Minimum operating lease payments - 2020	282
Minimum operating lease payments - later years	1,501
Total minimum operating lease payments	$ 3,430

Commitments And Contingencie102

Commitments And Contingencies (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)site	Dec. 31, 2014USD ($)
Commitments and Contingencies [Line Items]
Sites identified which we are or may be liable for remediation costs | site	290
Sites subject of actions taken by the U.S. government | site	31
Sites on the Superfund National Priorities List | site	19
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%
Reasonably possible outcome of related claims, range minimum	$ 318
Reasonably possible outcome of related claims, range maximum	$ 345
Asbestos [Member]
Commitments and Contingencies [Line Items]
Percent of liability recorded related to asserted claims	22.00%
Percent of liability recorded related to unasserted claims	78.00%
Reasonably possible outcome of related claims, range minimum	$ 120
Reasonably possible outcome of related claims, range maximum	129
Guarantees [Member]
Commitments and Contingencies [Line Items]
Maximum potential amount of guarantee payments	53	$ 82
Recorded liability for fair value of guarantees	$ 0	$ 0.3
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, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies [Line Items]
Current portion, ending balance at December 31	$ 181	$ 249
Environmental [Abstract]
Beginning balance.	182	171	$ 170
Accruals	61	56	58
Payments	(53)	(45)	(57)
Ending balance at December 31	190	182	171
Current portion, ending balance at December 31	52	60	53
Personal Injury [Member]
Commitments and Contingencies [Line Items]
Beginning balance	335	294	334
Current year accruals	89	96	87
Changes in estimates for prior years	(3)	9	(38)
Payments	(103)	(64)	(89)
Ending balance at December 31	318	335	294
Current portion, ending balance at December 31	63	111	82
Asbestos [Member]
Commitments and Contingencies [Line Items]
Beginning balance	$ 126	131	139
Current year accruals		1	2
Payments	$ (6)	(6)	(10)
Ending balance at December 31	120	126	131
Current portion, ending balance at December 31	$ 6	$ 8	$ 9

Share Repurchase Program (Detai

Share Repurchase Program (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended								12 Months Ended			108 Months Ended
	Feb. 04, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015	Jan. 01, 2014
Share Repurchase Program [Line Items]
BOD authorized														120,000,000
Stock repurchase program expiration date										Dec. 31, 2017
Aggregate cost										$ 3,465	$ 3,225	$ 2,218	$ 16,000
Shares repurchased		6,646,899	13,800,700	7,975,100	6,881,455	7,736,400	8,347,000	8,320,000	7,640,000	35,304,154	32,043,400
Average purchase price		$ 88.19	$ 89.65	$ 104.62	$ 117.28	$ 113.77	$ 102.54	$ 96.84	$ 89.43	$ 98.14	$ 100.65
Remaining number of shares that may be repurchased under current authority		52,652,446								52,652,446			52,652,446
Subsequent Event [Member]
Share Repurchase Program [Line Items]
Aggregate cost	$ 268
Shares repurchased	3,700,000

Related Parties (Details)

Related Parties (Details) - TTX Company [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Related Party Transaction [Line Items]
Equity Method Investment, Ownership Percentage	36.79%
Equity Method Investments	$ 830	$ 795
Related Party Transaction, Expenses from Transactions with Related Party	376	350	$ 326
Accounts Payable, Related Parties, Current	$ 61	$ 53

Selected Quarterly Data (Una106

Selected Quarterly Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Selected Quarterly Data (Unaudited) [Abstract]
Operating revenues	$ 5,208	$ 5,562	$ 5,429	$ 5,614	$ 6,153	$ 6,182	$ 6,015	$ 5,638	$ 21,813	$ 23,988	$ 21,963
Operating income	1,918	2,208	1,949	1,977	2,373	2,330	2,196	1,854	8,052	8,753	7,446
Net income	$ 1,117	$ 1,300	$ 1,204	$ 1,151	$ 1,431	$ 1,370	$ 1,291	$ 1,088	$ 4,772	$ 5,180	$ 4,388
Net income per share:
Earnings per share – basic	$ 1.31	$ 1.51	$ 1.38	$ 1.31	$ 1.62	$ 1.53	$ 1.43	$ 1.20	$ 5.51	$ 5.77	$ 4.74
Earnings per share – diluted	$ 1.31	$ 1.50	$ 1.38	$ 1.30	$ 1.61	$ 1.53	$ 1.43	$ 1.19	$ 5.49	$ 5.75	$ 4.71

Schedule Of Valuation And Qu107

Schedule Of Valuation And Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Presented in Consolidated Statements of Financial Position [Abstract]
Allowance for doubtful accounts - current	$ 5	$ 5
Allowance for doubtful accounts - long-term	11	16
Accrued casualty costs, current	181	249
Allowance For Doubtful Accounts [Member]
Schedule Of Valuation And Qualifying Accounts [Line Items]
Balance, beginning of period	21	23	$ 37
Reduction to expense		5	(4)
Charges to expense	1
Net recoveries/(write-offs), cash payments and other reductions	(6)	(7)	(10)
Balance, end of period	16	21	23
Presented in Consolidated Statements of Financial Position [Abstract]
Allowance for doubtful accounts - current	5	5	1
Allowance for doubtful accounts - long-term	11	16	22
Accrued Casualty Costs [Member]
Schedule Of Valuation And Qualifying Accounts [Line Items]
Balance, beginning of period	757	702	734
Charges to expense	227	256	188
Net recoveries/(write-offs), cash payments and other reductions	(248)	(201)	(220)
Balance, end of period	736	757	702
Presented in Consolidated Statements of Financial Position [Abstract]
Accrued casualty costs, current	181	249	207
Accrued casualty costs, long-term	$ 555	$ 508	$ 495