Union Pacific (UNP) 10-K 6 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 31, 2014	Jan. 30, 2015	Jun. 30, 2014
Document and Entity Information [Abstract]
Document type	10-K
Document period end date	31-Dec-14
Amendment flag	FALSE
Entity registrant name	UNION PACIFIC CORPORATION
Entity central index key	100885
Entity current reporting status	Yes
Entity voluntary filers	No
Current fiscal year end date	-19
Entity filer category	Large Accelerated Filer
Entity well known seasoned issuer	Yes
Entity common stock shares outstanding		881,284,029
Entity public float			$89.40
Document fiscal year focus	2014
Document fiscal period focus	FY

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating revenues [Abstract]
Freight revenues	$22,560	$20,684	$19,686
Other revenues	1,428	1,279	1,240
Total operating revenues	23,988	21,963	20,926
Operating expenses [Abstract]
Compensation and benefits	5,076	4,807	4,685
Fuel	3,539	3,534	3,608
Purchased services and materials	2,558	2,315	2,143
Depreciation	1,904	1,777	1,760
Equipment and other rents	1,234	1,235	1,197
Other	924	849	788
Total operating expenses	15,235	14,517	14,181
Operating income	8,753	7,446	6,745
Other income (Note 7)	151	128	108
Interest expense	-561	-526	-535
Income before income taxes	8,343	7,048	6,318
Income taxes (Note 8)	-3,163	-2,660	-2,375
Net income	$5,180	$4,388	$3,943
Share and Per Share (Note 9) [Abstract]
Earnings per share - basic	$5.77	$4.74	$4.17
Earnings per share - diluted	$5.75	$4.71	$4.14
Weighted average number of shares - basic	897.1	926.5	946.2
Weighted average number of shares - diluted	901.1	931.5	952.9
Dividends declared per share	$1.91	$1.48	$1.25

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$5,180		$4,388		$3,943
Other comprehensive income/(loss):
Defined benefit plans	-448		436		-145
Foreign currency translation	-12		-1		12
Derivatives	0		1		1
Total other comprehensive income/(loss)	-460	[1]	436	[1]	-132	[1]
Comprehensive income	$4,720		$4,824		$3,811
[1]	Net of deferred taxes of $291 million, ($264) million, and $82 million during 2014, 2013, and 2012, respectively.

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Parentheticals) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Consolidated Statements of Comprehensive Income (Parentheticals) [Abstract]
Deferred taxes activity other comprehensive income/(loss)	$291	($264)	$82

Consolidated_Statements_of_Fin

Consolidated Statements of Financial Position (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Current assets [Abstract]
Cash and cash equivalents	$1,586	$1,432
Accounts receivable, net (Note 11)	1,611	1,414
Materials and supplies	712	653
Current deferred income taxes (Note 8)	277	268
Other current assets	493	223
Total current assets	4,679	3,990
Investments	1,390	1,321
Net properties (Note 12)	46,272	43,749
Other assets	375	671
Total assets	52,716	49,731
Current liabilities [Abstract]
Accounts payable and other current liabilities (Note 13)	3,303	3,086
Debt due within one year (Note 15)	462	705
Total current liabilities	3,765	3,791
Debt due after one year (Note 15)	11,018	8,872
Deferred income taxes (Note 8)	14,680	14,163
Other long-term liabilities	2,064	1,680
Commitments and contingencies (Notes 17 and 18)
Total liabilities	31,527	28,506
Common shareholders' equity [Abstract]
Common shares, $2.50 par value, 1,400,000,000 authorized; 1,110,100,423 and 1,109,657,652 issued; 883,366,476 and 912,001,996 outstanding, respectively	2,775	2,774
Paid-in-surplus	4,321	4,210
Retained earnings	27,367	23,901
Treasury stock	-12,064	-8,910
Accumulated other comprehensive loss (Note 10)	-1,210	-750
Total common shareholders' equity	21,189	21,225
Total liabilities and common shareholders' equity	$52,716	$49,731

Consolidated_Statements_of_Fin1

Consolidated Statements of Financial Position (Parentheticals) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements of Financial Position (Parentheticals) [Abstract]
Common shares, par value	$2.50	$2.50
Common shares authorized	1,400,000,000
Common shares issued	1,110,100,423	1,109,657,652
Common shares outstanding	883,366,476	912,001,996

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Activities [Abstract]
Net income	$5,180	$4,388	$3,943
Adjustments to reconcile net income to cash provided by operating activities [Abstract]
Depreciation	1,904	1,777	1,760
Deferred income taxes and unrecognized tax benefits	895	723	887
Other operating activities, net	-285	-226	-160
Changes in current assets and liabilities [Abstract]
Accounts receivable, net	-197	-83	70
Materials and supplies	-59	7	-46
Other current assets	-270	74	-108
Accounts payable and other current liabilities	217	163	-185
Cash provided by operating activities	7,385	6,823	6,161
Investing Activities [Abstract]
Capital investments	-4,346	-3,496	-3,738
Proceeds from asset sales	138	98	80
Acquisition of equipment pending financing	0	0	-274
Proceeds from sale of assets financed	0	0	274
Other investing activities, net	-41	-7	25
Cash used in investing activities	-4,249	-3,405	-3,633
Financing Activities [Abstract]
Common share repurchases (Note 19)	-3,225	-2,218	-1,474
Debt issued	2,588	1,443	695
Dividends paid	-1,632	-1,333	-1,146
Debt repaid	-710	-640	-758
Debt exchange	0	-289	0
Other financing activities, net	-3	-12	1
Cash used in financing activities	-2,982	-3,049	-2,682
Net change in cash and cash equivalents	154	369	-154
Cash and cash equivalents at beginning of year	1,432	1,063	1,217
Cash and cash equivalents at end of year	1,586	1,432	1,063
Non-cash investing and financing activities [Abstract]
Cash dividends declared but not yet paid	438	356	318
Capital investments accrued but not yet paid	174	133	136
Capital lease financings	0	39	290
Cash paid during the year for: [Abstract]
Interest, net of amounts capitalized	-554	-528	-561
Income taxes, net of refunds	($2,492)	($1,656)	($1,552)

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Common Shareholders' Equity (USD $)		Total	Common Shares (Units) [Member]	Treasury Shares (Units) [Member]	Common Shares [Member]	Paid-in-Surplus [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income/(Loss) (Note 10) [Member]
In Millions, except Share data, unless otherwise specified		USD ($)			USD ($)	USD ($)	USD ($)	USD ($)	USD ($)
Shareholders' equity, beginning balance at Dec. 31, 2011		$18,578			$2,773	$4,031	$18,121	($5,293)	($1,054)
Common shares, beginning balance at Dec. 31, 2011			1,108,700,000	-148,900,000
Comprehensive income [Abstract]
Net income		3,943					3,943
Other comp. income/(loss)	[1]	-132							-132
Conversion, stock option exercises, forfeitures, and other		142				82		60
Conversion, stock option exercises, forfeitures, and other (shares)			600,000	4,200,000
Share repurchases (Note 19)		-1,474						-1,474
Share repurchases (Note 19) (shares)				-25,600,000
Cash dividends declared		-1,180					-1,180
Shareholders' equity, ending balance at Dec. 31, 2012		19,877			2,773	4,113	20,884	-6,707	-1,186
Common shares, ending balance at Dec. 31, 2012			1,109,300,000	-170,300,000
Comprehensive income [Abstract]
Net income		4,388					4,388
Other comp. income/(loss)	[1]	436							436
Conversion, stock option exercises, forfeitures, and other		113			1	97		15
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)		-29,077,638		-29,000,000
Cash dividends declared		-1,371					-1,371
Shareholders' equity, ending balance at Dec. 31, 2013		21,225			2,774	4,210	23,901	-8,910	-750
Common shares, ending balance at Dec. 31, 2013		912,001,996	1,109,700,000	-197,700,000
Comprehensive income [Abstract]
Net income		5,180					5,180
Other comp. income/(loss)	[1]	-460							-460
Conversion, stock option exercises, forfeitures, and other		183			1	111		71
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)		-32,043,400		-32,000,000
Cash dividends declared		-1,714					-1,714
Shareholders' equity, ending balance at Dec. 31, 2014		$21,189			$2,775	$4,321	$27,367	($12,064)	($1,210)
Common shares, ending balance at Dec. 31, 2014		883,366,476	1,110,100,000	-226,700,000
[1]	Net of deferred taxes of $291 million, ($264) million, and $82 million during 2014, 2013, and 2012, respectively.

Consolidated_Statements_of_Cha1

Consolidated Statements of Changes in Common Shareholders' Equity (Parentheticals) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash dividends [Abstract]
Cash dividends declared per share	$1.91	$1.48	$1.25

Nature_of_Operations

Nature of Operations	12 Months Ended
	Dec. 31, 2014
Nature of Operations [Abstract]
Nature Of Operations [Text Block]	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 31,974 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 26,012 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 review revenue by commodity group, we analyze the net 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		2014		2013		2012
	Agricultural Products	$	3,777	$	3,276	$	3,280
	Automotive		2,103		2,077		1,807
	Chemicals		3,664		3,501		3,238
	Coal		4,127		3,978		3,912
	Industrial Products		4,400		3,822		3,494
	Intermodal		4,489		4,030		3,955
	Total freight revenues	$	22,560	$	20,684	$	19,686
	Other revenues		1,428		1,279		1,240
	Total operating revenues	$	23,988	$	21,963	$	20,926
	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 revenues from our Mexico business which amounted to $2.3 billion in 2014, $2.1 billion in 2013, and $1.9 billion in 2012.
	Basis of Presentation – The Consolidated Financial Statements are presented in accordance with accounting principles generally accepted in the U.S. (GAAP) as codified in the Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC).

Significant_Accounting_Policie

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Significant Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	2. Significant Accounting Policies
	Principles of Consolidation – The Consolidated Financial Statements include the accounts of Union Pacific Corporation and all of its subsidiaries. Investments in affiliated companies (20% to 50% owned) are accounted for using the equity method of accounting. All intercompany transactions are eliminated. We currently have no less than majority-owned investments that require consolidation under variable interest entity requirements.
	Cash 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 – Our Consolidated Financial Statements include estimates and assumptions regarding certain assets, liabilities, revenue, and expenses and the disclosure of certain contingent assets and liabilities. Actual future results may differ from such estimates.

Accounting_Pronouncements

Accounting Pronouncements	12 Months Ended
	Dec. 31, 2014
Accounting Pronouncements [Abstract]
Accounting Pronouncements [Text Block]	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, 2016. ASU 2014-09 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, 2014
Stock Split [Abstract]
Stock Spilt [Text Block]	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_

Stock Options and Other Stock Plans	12 Months Ended
	Dec. 31, 2014
Stock Options and Other Stock Plans [Abstract]
Stock Options and Other Stock Plans [Text Block]	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 shares. In September 2007, the Board of Directors eliminated the annual payment of options for 2008 and all future years. As of December 31, 2014, 36,000 restricted shares and 78,000 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, 2014, 4,338,691 options and 3,677,642 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, 2014, 969,822 options and 1,307,905 retention shares and stock units were outstanding under the 2013 Plan.
	Pursuant to the above plans 77,786,772; 79,574,896; and 64,337,040 shares of our common stock were authorized and available for grant at December 31, 2014, 2013, and 2012, 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	2014		2013		2012
	Stock-based compensation, before tax:
	Stock options	$	21	$	19	$	18
	Retention awards		91		79		75
	Total stock-based compensation, before tax	$	112	$	98	$	93
	Excess tax benefits from equity compensation plans	$	118	$	76	$	100
	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		2014		2013		2012
	Risk-free interest rate		1.60%		0.80%		0.80%
	Dividend yield		2.10%		2.10%		2.10%
	Expected life (years)		5.2		5		5.3
	Volatility		30.00%		36.20%		36.80%
	Weighted-average grant-date fair value of options granted	$	20.18	$	17.49	$	15.65
	The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant; the 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 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 2014 is presented below:
		Options (thous.)	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value (millions)
	Outstanding at January 1, 2014	7,443	$	40.07	5.8 yrs.	$	327
	Granted	989		87.56	N/A		N/A
	Exercised	-2,961		30.59	N/A		N/A
	Forfeited or expired	-84		68.48	N/A		N/A
	Outstanding at December 31, 2014	5,387	$	53.56	5.8 yrs.	$	353
	Vested or expected to vest	5,325	$	53.3	5.8 yrs.	$	351
	at December 31, 2014
	Options exercisable at December 31, 2014	3,350	$	40.69	4.4 yrs.	$	263
	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, 2014, are subject to performance or market-based vesting conditions.
	At December 31, 2014, there was $15 million of unrecognized compensation expense related to nonvested stock options, which is expected to be recognized over a weighted-average period of 1 year. Additional information regarding stock option exercises appears in the table below:
	Millions	2014		2013		2012
	Intrinsic value of stock options exercised	$	194	$	112	$	244
	Cash received from option exercises		54		51		84
	Treasury shares repurchased for employee payroll taxes		-24		-21		-30
	Tax benefit realized from option exercises		74		43		93
	Aggregate grant-date fair value of stock options vested		17		16		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 2014 were as follows:
		Shares (thous.)	Weighted-Average Grant-Date Fair Value
	Nonvested at January 1, 2014	3,712	$	49.02
	Granted	871		88.14
	Vested	-1,080		31.33
	Forfeited	-100		57.82
	Nonvested at December 31, 2014	3,403	$	64.39
	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, 2014, there was $87 million of total unrecognized compensation expense related to nonvested retention awards, which is expected to be recognized over a weighted-average period of 1.6 years.
	Performance Retention Awards – In February 2014, 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 2012 and February 2013, 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 2014 grant were as follows:
		2014
	Dividend per share per quarter	$	0.455
	Risk-free interest rate at date of grant		0.70%
	Changes in our performance retention awards during 2014 were as follows:
		Shares (thous.)	Weighted-Average Grant-Date Fair Value
	Nonvested at January 1, 2014	1,888	$	53.7
	Granted	456		83.06
	Vested	-661		44.94
	Forfeited	-100		61.36
	Nonvested at December 31, 2014	1,583	$	65.33
	At December 31, 2014, there was $36 million of total unrecognized compensation expense related to nonvested performance retention awards, which is expected to be recognized over a weighted-average period of 1 year. 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, 2014
Retirement Plans [Abstract]
Retirement Plans [Text Block]	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	2014		2013			2014		2013
	Projected Benefit Obligation
	Projected benefit obligation at beginning of year	$	3,372	$	3,591		$	330	$	372
	Service cost		70		72			2		3
	Interest cost		158		134			14		12
	Actuarial loss/(gain)		735		-257			33		-34
	Gross benefits paid		-193		-168			-25		-23
	Projected benefit obligation at end of year	$	4,142	$	3,372		$	354	$	330
	Plan Assets
	Fair value of plan assets at beginning of year	$	3,429	$	2,875		$	-	$	-
	Actual return on plan assets		185		506			-		-
	Voluntary funded pension plan contributions		200		200			-		-
	Non-qualified plan benefit contributions		33		16			25		23
	Gross benefits paid		-193		-168			-25		-23
	Fair value of plan assets at end of year	$	3,654	$	3,429		$	-	$	-
	Funded status at end of year	$	-488	$	57		$	-354	$	-330
	Amounts recognized in the statement of financial position as of December 31, 2014 and 2013 consist of:
		Pension					OPEB
	Millions	2014		2013			2014		2013
	Noncurrent assets	$	1	$	364		$	-	$	-
	Current liabilities		-19		-16			-23		-25
	Noncurrent liabilities		-470		-291			-331		-305
	Net amounts recognized at end of year	$	-488	$	57		$	-354	$	-330
	The change in the funded status and accumulated other comprehensive income/(loss) is primarily a result of implementing a new set of mortality tables issued by the Society of Actuaries in October 2014 and lower discount rates.
	Pre-tax amounts recognized in accumulated other comprehensive income/(loss) as of December 31, 2014 and 2013 consist of:
		2014								2013
	Millions	Pension		OPEB		Total			Pension		OPEB		Total
	Prior service (cost)/credit	$	-	$	17	$	17		$	-	$	28	$	28
	Net actuarial loss		-1,727		-148		-1,875			-1,018		-125		-1,143
	Total	$	-1,727	$	-131	$	-1,858		$	-1,018	$	-97	$	-1,115
	Pre-tax changes recognized in other comprehensive income/(loss) during 2014, 2013 and 2012 were as follows:
		Pension								OPEB
	Millions	2014		2013		2012			2014		2013		2012
	Net actuarial (loss)/gain	$	-780	$	561	$	-265		$	-33	$	34	$	-42
	Amortization of:
	Prior service cost/(credit)		-		-		1			-11		-16		-18
	Actuarial loss		71		106		83			10		15		13
	Total	$	-709	$	667	$	-181		$	-34	$	33	$	-47
	Amounts included in accumulated other comprehensive income/(loss) expected to be amortized into net periodic cost during 2015:
	Millions	Pension		OPEB		Total
	Prior service credit	$	-	$	10	$	10
	Net actuarial loss		-103		-13		-116
	Total	$	-103	$	-3	$	-106
	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, 2014 and 2013, the non-qualified (supplemental) plan ABO was $379 million and $302 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	2014		2013
	Projected benefit obligation	$	388	$	308
	Accumulated benefit obligation	$	379	$	302
	Fair value of plan assets		-		-
	Underfunded accumulated benefit obligation	$	-379	$	-302
	The ABO for all defined benefit pension plans was $3.9 billion and $3.2 billion at December 31, 2014 and 2013, respectively.
	Assumptions – The weighted-average actuarial assumptions used to determine benefit obligations at December 31:
		Pension		OPEB
	Percentages	2014	2013	2014	2013
	Discount rate	3.94%	4.72%	3.74%	4.47%
	Compensation increase	4.00%	4.00%	N/A	N/A
Health care cost trend rate (employees under 65)	N/A	N/A	6.34%	6.49%
Ultimate health care cost trend rate	N/A	N/A	4.50%	4.50%
Year ultimate trend rate reached	N/A	N/A	2028	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	2014		2013		2012		2014		2013		2012
Net Periodic Benefit Cost:
Service cost	$	70	$	72	$	54	$	2	$	3	$	3
Interest cost		158		134		141		14		12		15
Expected return on plan assets		-230		-202		-190		-		-		-
Amortization of:
Prior service cost/(credit)		-		-		1		-11		-16		-18
Actuarial loss		71		106		83		10		15		13
Net periodic benefit cost/(benefit)	$	69	$	110	$	89	$	15	$	14	$	13
Assumptions – The weighted-average actuarial assumptions used to determine expense were as follows:
	Pension			OPEB
Percentages	2014	2013	2012	2014	2013	2012
Discount rate	4.72%	3.78%	4.54%	4.47%	3.48%	4.36%
Expected return on plan assets	7.50%	7.50%	7.50%	N/A	N/A	N/A
Compensation increase	4.00%	3.43%	3.69%	N/A	N/A	N/A
Health care cost trend rate (employees under 65)	N/A	N/A	N/A	6.49%	6.64%	6.91%
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 6% in 2014, 17% in 2013, and 13% in 2012.
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 2015 assumed health care cost trend rate for employees under 65 is 6.49%. 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		19		-16
Cash Contributions
The following table details our cash contributions for the qualified pension plans and the benefit payments for the non-qualified (supplemental) pension and OPEB plans:
		Pension
Millions		Qualified		Non-qualified		OPEB
2013		$	200	$	16	$	23
2014			200		33		25
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 2014 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 2015 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 2015 through 2024:
Millions	Pension		OPEB
2015	$	180	$	23
2016		186		23
2017		191		23
2018		196		23
2019		201		23
Years 2020 - 2024		1,069		107
Asset Allocation Strategy
Our pension plan asset allocation at December 31, 2014 and 2013, and target allocation for 2015, are as follows:
	Target Allocation 2015		Percentage of Plan Assets December 31,
			2014	2013
Equity securities	60% to 70%		68%	70%
Debt securities	20% to 30%		23	21
Real estate	2% to 8%		4	4
Commodities	4% to 6%		5	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, 2014 and 2013. 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, 2014 and 2013.
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 U.S. 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, local, and non-U.S. 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 the net asset value (NAV) per share, 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 interests in partnerships or other commingled funds. 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 per share, which is derived from the valuation method described here. The Plan's interests in real estate partnerships and other commingled funds are classified as Level 3 investments.
Common Trust and Other Funds – Common 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. 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 convertible securities, commodities, and other assets. 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 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, 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
Common 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.
As of December 31, 2013, 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	$	16		$	-		$	-		$	16
Registered investment companies		11			253			-			264
Federal government securities		-			126			-			126
Bonds & debentures		-			310			-			310
Corporate stock		983			16			-			999
Venture capital and buyout partnerships		-			-			213			213
Real estate partnerships		-			-			139			139
Common trust and other funds		-			1,357			-			1,357
Total plan assets at fair value	$	1,010		$	2,062		$	352			3,424
Other assets [a]											5
Total plan assets										$	3,429
[a] Other assets include accrued receivables and pending broker settlements.
For the years ended December 31, 2014 and 2013, 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 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
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 2013:
	Venture Capital
	and Buyout			Real Estate
Millions	Partnerships			Partnerships			Total
Beginning balance - January 1, 2013	$	179		$	143		$	322
Realized gain		7			8			15
Unrealized gain		24			3			27
Purchases		43			23			66
Sales		-40			-38			-78
Ending balance - December 31, 2013	$	213		$	139		$	352
Other Retirement Programs
401(k)/Thrift Plan – We provide a defined contribution plan (401(k)/thrift plan) to eligible non-union and union employees for whom we make matching contributions. We match 50 cents for each dollar contributed by employees up to the first six percent of compensation contributed. Our plan contributions were $19 million in 2014, $18 million in 2013, and $15 million in 2012.
Railroad Retirement System – All Railroad employees are covered by the Railroad Retirement System (the System). Contributions made to the System are expensed as incurred and amounted to approximately $711 million in 2014, $670 million in 2013, and $644 million in 2012.
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 $52 million in 2014, $57 million in 2013, and $62 million in 2012.

Other_Income

Other Income	12 Months Ended
	Dec. 31, 2014
Other Income [Abstract]
Other Income [Text Block]	7. Other Income
	Other income included the following for the years ended December 31:
	Millions	2014 [a]		2013 [b]		2012
	Rental income	$	96	$	106	$	83
	Net gain on non-operating asset dispositions		69		32		29
	Interest income		4		4		3
	Non-operating environmental costs and other		-18		-14		-7
	Total	$	151	$	128	$	108
	[a] Non-operating environmental costs and other includes $14 million related to the sale of a permanent easement.
	[b] Rental income includes $17 million related to a land lease contract settlement.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax [Abstract]
Income Taxes [Text Block]	8. Income Taxes
	Components of income tax expense were as follows for the years ended December 31:
	Millions	2014		2013		2012
	Current tax expense:
	Federal	$	2,029	$	1,738	$	1,335
	State		239		199		153
	Total current tax expense		2,268		1,937		1,488
	Deferred tax expense:
	Federal		667		659		760
	State		136		119		120
	Total deferred tax expense		803		778		880
	Unrecognized tax benefits:
	Federal		86		-54		5
	State		6		-1		2
	Total unrecognized tax benefits expense/(benefits)		92		-55		7
	Total income tax expense	$	3,163	$	2,660	$	2,375
	For the years ended December 31, reconciliations between statutory and effective tax rates are as follows:
	Tax Rate Percentages	2014		2013		2012
	Federal statutory tax rate	35	%	35	%	35	%
	State statutory rates, net of federal benefits	3.1		3.1		3.1
	Deferred tax adjustments	-		-0.1		-0.1
	Tax credits	-0.4		-0.2		-0.5
	Other	0.2		-0.1		0.1
	Effective tax rate	37.9	%	37.7	%	37.6	%
	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	2014		2013
	Deferred income tax liabilities:
	Property	$	-15,173	$	-14,448
	Other		-411		-260
	Total deferred income tax liabilities		-15,584		-14,708
	Deferred income tax assets:
	Accrued wages		74		71
	Accrued casualty costs		228		223
	Accrued stock compensation		69		66
	Debt and leases		86		41
	Retiree benefits		392		100
	Credits		164		182
	Other		168		130
	Total deferred income tax assets	$	1,181	$	813
	Net deferred income tax liability	$	-14,403	$	-13,895
	Current portion of deferred taxes	$	277	$	268
	Non-current portion of deferred taxes		-14,680		-14,163
	Net deferred income tax liability	$	-14,403	$	-13,895
	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 2014 and 2013, 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	2014		2013		2012
	Unrecognized tax benefits at January 1	$	59	$	115	$	107
	Increases for positions taken in current year		92		24		29
	Increases for positions taken in prior years		21		15		4
	Decreases for positions taken in prior years		-14		-30		-19
	Payments to and settlements with taxing authorities		-7		-63		-
	Increases/(decreases) for interest and penalties		1		-		-4
	Lapse of statutes of limitations		-1		-2		-2
	Unrecognized tax benefits at December 31	$	151	$	59	$	115
	We recognize interest and penalties as part of income tax expense. Total accrued liabilities for interest and penalties were $6 million at both December 31, 2014 and 2013. Total interest and penalties recognized as part of income tax expense (benefit) were $9 million for 2014, $7 million for 2013, and $(4) million for 2012.
	Internal Revenue Service (IRS) examinations have been completed and settled for all years prior to 2009, and the statute of limitations bars any additional tax assessments. The IRS has completed their examinations and issued notices of deficiency for tax years 2009 through 2010. We disagree with many of their proposed adjustments, and we are at IRS Appeals for those years. Additionally, several state tax authorities are examining our state income tax returns for years 2006 through 2010.
	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.
	In 2012, UPC and the IRS signed a closing agreement resolving all tax matters for tax years 1999-2004. The settlement had an immaterial effect on our income tax expense. In connection with the settlement, we received refunds of $8 million in 2013.
	We do not expect our unrecognized tax benefits to change significantly in the next 12 months. At December 31, 2014, we had a net unrecognized tax benefit liability of $151 million. Of that amount, $6 million is classified as a current liability in the Consolidated Statement of Financial Position.
	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	2014		2013		2012
	Unrecognized tax benefits that would reduce the effective tax rate	$	33	$	34	$	41
Unrecognized tax benefits that would not reduce the effective tax rate		118		25		74
Total unrecognized tax benefits	$	151	$	59	$	115

Earnings_Per_Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	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	2014		2013		2012
	Net income	$	5,180	$	4,388	$	3,943
	Weighted-average number of shares outstanding:
	Basic		897.1		926.5		946.2
	Dilutive effect of stock options		2.1		2.4		3.6
	Dilutive effect of retention shares and units		1.9		2.6		3.1
	Diluted		901.1		931.5		952.9
	Earnings per share – basic	$	5.77	$	4.74	$	4.17
	Earnings per share – diluted	$	5.75	$	4.71	$	4.14
	Common stock options totaling 0.4 million, 0.5 million, and 1.1 million for 2014, 2013, and 2012, 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_Comprehensiv

Accumulated Other Comprehensive Income/(Loss)	12 Months Ended
	Dec. 31, 2014
Accumulated Other Comprehensive Income/(Loss) [Abstract]
Accumulated Other Comprehensive Income/(Loss) [Text Block]	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		Derivatives			Total
	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
	Balance at January 1, 2013		$	-1,149	$	-36	$	-1	$	-1,186
	Other comprehensive income/(loss) before reclassifications			-1		-1		1		-1
	Amounts reclassified from accumulated other comprehensive income/(loss) [a]			437		-		-		437
	Net year-to-date other comprehensive income/(loss), net of taxes of ($264) million			436		-1		1		436
	Balance at December 31, 2013		$	-713	$	-37	$	-	$	-750
	[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, 2014
Accounts Receivable [Abstract]
Accounts Receivable [Text Block]	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 December 31, 2014, and 2013, our accounts receivable were reduced by $5 million and $1 million, respectively. Receivables not expected to be collected in one year and the associated allowances are classified as other assets in our Consolidated Statements of Financial Position. At December 31, 2014, and 2013, receivables classified as other assets were reduced by allowances of $16 million and $22 million, respectively.
	Receivables Securitization Facility – On July 29, 2014, we completed the renewal of our receivables securitization facility. The new $650 million, 3-year facility replaces the prior $600 million, 364-day facility. Under the facility, the Railroad sells most of its eligible third-party receivables to Union Pacific Receivables, Inc. (UPRI), a 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 and $0 at December 31, 2014, and December 31, 2013, respectively. The facility was supported by $1.2 billion and $1.1 billion of accounts receivable as collateral at December 31, 2014, and December 31, 2013, 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 issuing costs, and fees of participating banks for unused commitment availability. The costs of the receivables securitization facility are included in interest expense and were $4 million, $5 million and $3 million for 2014, 2013, and 2012, respectively.

Properties

Properties	12 Months Ended
	Dec. 31, 2014
Properties [Abstract]
Properties Disclosure [Text Block]	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, 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.
	Millions, Except Estimated Useful Life				Accumulated		Net Book		Estimated
	As of December 31, 2013		Cost		Depreciation		Value		Useful Life
	Land		$	5,120	$	N/A	$	5,120	N/A
	Road:
	Rail and other track material			13,861		4,970		8,891	35
	Ties			8,785		2,310		6,475	33
	Ballast			4,621		1,171		3,450	34
	Other roadway [a]			15,596		2,726		12,870	48
	Total road			42,863		11,177		31,686	N/A
	Equipment:
	Locomotives			7,518		3,481		4,037	20
	Freight cars			2,085		1,000		1,085	25
	Work equipment and other			561		119		442	18
	Total equipment			10,164		4,600		5,564	N/A
	Technology and other			711		286		425	10
	Construction in progress			954		-		954	N/A
	Total		$	59,812	$	16,063	$	43,749	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 $2.4 billion for 2014, $2.3 billion for 2013, and $2.1 billion for 2012.
	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_Cur

Accounts Payable and Other Current Liabilities	12 Months Ended
	Dec. 31, 2014
Accounts Payable and Other Current Liabilties [Abstract]
Accounts Payable and Other Current Liabilities [Text Block]	13. Accounts Payable and Other Current Liabilities
		Dec. 31,		Dec. 31,
	Millions	2014		2013
	Accounts payable	$	877	$	803
	Dividends payable		438		356
	Income and other taxes payable		412		491
	Accrued wages and vacation		409		385
	Accrued casualty costs		249		207
	Interest payable		178		169
	Equipment rents payable		100		96
	Other		640		579
	Total accounts payable and other current liabilities	$	3,303	$	3,086

Financial_Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2014
Financial Instruments[Abstract]
Financial Instruments [Text Block]	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, 2014, and 2013, 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, 2014, and 2013, 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. At December 31, 2014, and 2013, we had reductions of $0 and $1 million, respectively, recorded as an accumulated other comprehensive loss. As of December 31, 2014, and 2013, 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, 2014, 2013, and 2012.
	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, 2014, the fair value of total debt was $13.0 billion, approximately $1.5 billion more than the carrying value. At December 31, 2013, the fair value of total debt was $10.2 billion, approximately $0.6 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 both December 31, 2014, and 2013, approximately $163 million of debt securities contained call provisions that allow us to retire the debt instruments prior to final maturity, with the payment of fixed call premiums, or in certain cases, at par. The fair value of our cash equivalents approximates their carrying value due to the short-term maturities of these instruments.

Debt

Debt	12 Months Ended
	Dec. 31, 2014
Debt [Abstract]
Debt [Text Block]	15. Debt
	Total debt as of December 31, 2014, and 2013, is summarized below:
	Millions		2014		2013
	Notes and debentures, 2.3% to 7.9% due through 2054		$	9,266	$	8,068
	Capitalized leases, 3.1% to 8.4% due through 2028			1,520		1,702
	Equipment obligations, 3.2% to 6.7% due through 2031			597		110
	Receivables Securitization (Note 11)			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		32
	Tax-exempt financings - floating rate, due in 2015			8		12
	Unamortized discount			-591		-604
	Total debt			11,480		9,577
	Less: current portion			-462		-705
	Total long-term debt		$	11,018	$	8,872
	Debt Maturities – The following table presents aggregate debt maturities as of December 31, 2014, excluding market value adjustments:
	Millions
	2015	$	462
	2016		606
	2017		1,065
	2018		578
	2019		652
	Thereafter		8,117
	Total debt	$	11,480
	Equipment Encumbrances – Equipment with a carrying value of approximately $2.8 billion and $2.9 billion at December 31, 2014, and 2013, 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 – During the second quarter of 2014, we replaced our $1.8 billion revolving credit facility, which was scheduled to expire in May 2015, with a new $1.7 billion facility that expires in May 2019 (the facility). The facility is based on substantially similar terms as those in the previous credit facility. On December 31, 2014, 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 either facility at any time during 2014. 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 requires that the Corporation maintain a debt-to-net-worth coverage ratio as a condition to making a borrowing. At December 31, 2014, and December 31, 2013 (and at all times during the year), we were in compliance with this covenant. 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, 2014, the debt-to-net-worth coverage ratio allowed us to carry up to $42.4 billion of debt (as defined in the facility), and we had $11.6 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 2014, we did not issue or repay any commercial paper, and at December 31, 2014, and 2013, 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 $15.4 billion and $16.3 billion at December 31, 2014, and 2013, respectively.
	Shelf Registration Statement and Significant New Borrowings – 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. We have no immediate plans to issue equity securities; however, we will continue to explore opportunities to replace existing debt or access capital through issuances of debt securities under our shelf registration, and, therefore, we may issue additional debt securities at any time.
	During 2014, we issued the following unsecured, fixed-rate debt securities under our current shelf registration:
	Date	Description of Securities
	10-Jan-14	$300 million of 2.25% Notes due February 15, 2019
		$400 million of 3.75% Notes due March 15, 2024
		$300 million of 4.85% Notes due June 15, 2044
	12-Aug-14	$350 million of 3.25% Notes due January 15, 2025
		$350 million of 4.15% Notes due January 15, 2045
	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, 2014, we had remaining authority to issue up to $1.15 billion of debt securities under our shelf registration.
	Subsequent Event - In 2015, we issued the following unsecured, fixed-rate debt securities under our current shelf registration:
	Date	Description of Securities
	29-Jan-15	$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
	Proceeds from this offering are for general corporate purposes, including the repurchase of common stock pursuant to our share repurchase program. These debt securities include change-of-control provisions. This offering exhausted our current authority to issue debt securities under our existing shelf registration.
	On February 5, 2015, the Board of Directors approved proceeding with a new shelf registration statement and authorized the issuance of up to $4.0 billion of debt securities.
	Equipment Trust – On May 20, 2014, UPRR consummated a pass-through (P/T) financing, whereby a P/T trust was created, which issued $500 million of P/T trust certificates with a stated interest rate of 3.227%. The P/T trust certificates will mature on May 14, 2026. The proceeds from the issuance of the P/T trust certificates (net of $3 million in transaction fees) were used to purchase equipment trust certificates to be issued by UPRR to finance the acquisition of 245 locomotives. The equipment trust certificates are secured by a lien on the locomotives.
	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 three months ended September 30, 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
Debt Redemption – On May 14, 2013, we redeemed all $40 million of our outstanding 5.65% Port of Corpus Christi Authority Revenue Refunding Bonds due December 1, 2022. The redemption resulted in an early extinguishment charge of $1 million in the second quarter of 2013.
Receivables Securitization Facility – As of December 31, 2014 and 2013, we recorded $400 million and $0 of borrowings under our receivables securitization facility, respectively, 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, 2014
Variable Interest Entities [Abstract]
Variable Interest Entities [Text Block]	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 $3.0 billion as of December 31, 2014.

Leases

Leases	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Leases [Text Block]	17. Leases
	We lease certain locomotives, freight cars, and other property. The Consolidated Statements of Financial Position as of December 31, 2014 and 2013 included $2,454 million, net of $1,210 million of accumulated depreciation, and $2,486 million, net of $1,092 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, 2014, were as follows:
	Millions	Operating Leases		Capital Leases
	2015	$	508	$	253
	2016		484		249
	2017		429		246
	2018		356		224
	2019		323		210
	Later years		1,625		745
	Total minimum lease payments	$	3,725	$	1,927
	Amount representing interest		N/A		-407
	Present value of minimum lease payments		N/A	$	1,520
	Approximately 95% of capital lease payments relate to locomotives. Rent expense for operating leases with terms exceeding one month was $593 million in 2014, $618 million in 2013, and $631 million in 2012. 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, 2014
Commitments And Contingencies [Abstract]
Commitments and Contingencies [Text Block]	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; however, to the extent possible, where asserted and unasserted claims are considered probable and where such claims can be reasonably estimated, we have recorded a liability. 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 93% of the recorded liability is related to asserted claims and approximately 7% is related to unasserted claims at December 31, 2014. 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 $335 million to $368 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	2014		2013		2012
	Beginning balance	$	294	$	334	$	368
	Current year accruals		96		87		121
	Changes in estimates for prior years		9		-38		-58
	Payments		-64		-89		-97
	Ending balance at December 31	$	335	$	294	$	334
	Current portion, ending balance at December 31	$	111	$	82	$	95
	In conjunction with the liability update performed in 2014, we also reassessed our estimated insurance recoveries. We have recognized an asset for estimated insurance recoveries at December 31, 2014, and 2013.
	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 21% of the recorded liability related to asserted claims and approximately 79% related to unasserted claims at December 31, 2014. 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 $126 million to $135 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	2014		2013		2012
	Beginning balance	$	131	$	139	$	147
	Accruals/(Credits)		1		2		-2
	Payments		-6		-10		-6
	Ending balance at December 31	$	126	$	131	$	139
	Current portion, ending balance at December 31	$	8	$	9	$	8
	In conjunction with the liability update performed in 2014, we also reassessed our estimated insurance recoveries. We have recognized an asset for estimated insurance recoveries at December 31, 2014, and 2013. 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 270 sites at which we are or may be liable for remediation costs associated with alleged contamination or for violations of environmental requirements. This includes 29 sites that are the subject of actions taken by the U.S. government, 16 of which are currently on the Superfund National Priorities List. Certain federal legislation imposes joint and several liability for the remediation of identified sites; consequently, our ultimate environmental liability may include costs relating to activities of other parties, in addition to costs relating to our own activities at each site.
	When we identify an environmental issue with respect to property owned, leased, or otherwise used in our business, we perform, with assistance of our consultants, environmental assessments on the property. We expense the cost of the assessments as incurred. We accrue the cost of remediation where our obligation is probable and such costs can be reasonably estimated. Our environmental liability is not discounted to present value due to the uncertainty surrounding the timing of future payments.
	Our environmental liability activity was as follows:
	Millions	2014		2013		2012
	Beginning balance	$	171	$	170	$	172
	Accruals		56		58		48
	Payments		-45		-57		-50
	Ending balance at December 31	$	182	$	171	$	170
	Current portion, ending balance at December 31	$	60	$	53	$	50
	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, 2014, and 2013, we were contingently liable for $82 million and $299 million in guarantees. We have recorded liabilities of $0.3 million and $1 million for the fair value of these obligations as of December 31, 2014, and 2013, respectively. We entered into these contingent guarantees in the normal course of business, and they include guaranteed obligations related to our equipment financings and 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 – Our maximum potential exposure under indemnification arrangements, including certain tax indemnifications, can range from a specified dollar amount to an unlimited amount, depending on the nature of the transactions and the agreements. Due to uncertainty as to whether claims will be made or how they will be resolved, we cannot reasonably determine the probability of an adverse claim or reasonably estimate any adverse liability or the total maximum exposure under these indemnification arrangements. We do not have any reason to believe that we will be required to make any material payments under these indemnity provisions.
	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 do not reflect any amounts in the Consolidated Financial Statements as of December 31, 2014.

Share_Repurchase_Program

Share Repurchase Program	12 Months Ended
	Dec. 31, 2014
Share Repurchase Program [Abstract]
Share Repurchase Program [Text Block]	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, 2014, we repurchased a total of $12.6 billion of our common stock since the commencement of our repurchase programs in 2007. The table below represents shares repurchased in 2013 under our previous repurchase program, and shares repurchased in 2014 under the new program.
		Number of Shares Purchased		Average Price Paid
		2014	2013		2014		2013
	First quarter	7,640,000	5,762,800	$	89.43	$	68.29
	Second quarter	8,320,000	6,122,940		96.84		75.71
	Third quarter	8,347,000	7,333,788		102.54		78.39
	Fourth quarter	7,736,400	9,858,110		113.77		79.68
	Total	32,043,400	29,077,638	$	100.65	$	76.26
	Remaining number of shares that may be repurchased under current authority						87,956,600
	Management's assessments of market conditions and other pertinent facts guide the timing and volume of all repurchases. We expect to fund any share repurchases under this program through cash generated from operations, the sale or lease of various operating and non-operating properties, debt issuances, and cash on hand. Repurchased shares are recorded in treasury stock at cost, which includes any applicable commissions and fees.
	From January 1, 2015, through February 6, 2015, we repurchased 2.8 million shares at an aggregate cost of approximately $327 million.

Selected_Quarterly_Data_Unaudi

Selected Quarterly Data (Unaudited)	12 Months Ended
	Dec. 31, 2014
Selected Quarterly Data (Unaudited) [Abstract]
Selected Quarterly Data (Unaudited) [Text Block]	20. Selected Quarterly Data (Unaudited)
	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		1.2		1.43		1.53		1.62
	Diluted		1.19		1.43		1.53		1.61
	Millions, Except Per Share Amounts
	2013	Mar. 31		Jun. 30		Sep. 30		Dec. 31
	Operating revenues	$	5,290	$	5,470	$	5,573	$	5,630
	Operating income		1,633		1,878		1,962		1,973
	Net income		957		1,106		1,151		1,174
	Net income per share:
	Basic		1.02		1.19		1.25		1.28
	Diluted		1.02		1.18		1.24		1.27
	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_Qual

Schedule Of Valuation And Qualifying Accounts	12 Months Ended
	Dec. 31, 2014
Schedule Of Valuation And Qualifying Accounts [Abstract]
Schedule Of Valuation And Qualifying Accounts [Text Block]	SCHEDULE II – VALUATION AND QUALIFYING ACCOUNTS
	Union Pacific Corporation and Subsidiary Companies
	Millions, for the Years Ended December 31,	2014		2013		2012
	Allowance for doubtful accounts:
	Balance, beginning of period	$	23	$	37	$	50
	Charges/(reduction) to expense		5		-4		-1
	Net recoveries/(write-offs)		-7		-10		-12
	Balance, end of period	$	21	$	23	$	37
	Allowance for doubtful accounts are presented in the Consolidated Statements of Financial Position as follows:
	Current	$	5	$	1	$	4
	Long-term		16		22		33
	Balance, end of period	$	21	$	23	$	37
	Accrued casualty costs:
	Balance, beginning of period	$	702	$	734	$	778
	Charges to expense		256		188		190
	Cash payments and other reductions		-201		-220		-234
	Balance, end of period	$	757	$	702	$	734
	Accrued casualty costs are presented in the Consolidated Statements of Financial Position as follows:
	Current	$	249	$	207	$	213
	Long-term		508		495		521
	Balance, end of period	$	757	$	702	$	734

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Significant Accounting Policies [Abstract]
Principles of Consolidation Policy [Text Block]	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 Policy [Text Block]	Cash and Cash Equivalents – Cash equivalents consist of investments with original maturities of three months or less.
Accounts Receivables Policy [Text Block]	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 Policy [Text Block]	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 Policy [Text Block]	Materials and Supplies – Materials and supplies are carried at the lower of average cost or market.
Property and Depreciation Policy [Text Block]	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 Policy [Text Block]	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 Policy [Text Block]	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 Policy [Text Block]	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 Policy [Text Block]	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 Policy [Text Block]	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 Policy [Text Block]	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 Policy [Text Block]	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 Policy [Text Block]	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 Policy [Text Block]	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 Policy [Text Block]	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 Policy [Text Block]	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 Policy [Text Block]	Use of Estimates – Our Consolidated Financial Statements include estimates and assumptions regarding certain assets, liabilities, revenue, and expenses and the disclosure of certain contingent assets and liabilities. Actual future results may differ from such estimates.

Nature_of_Operations_Tables

Nature of Operations (Tables)	12 Months Ended
	Dec. 31, 2014
Nature of Operations [Abstract]
Freight Revenue By Commodity Group [Table Text Block]	The following table provides freight revenue by commodity group:
	Millions		2014		2013		2012
	Agricultural Products	$	3,777	$	3,276	$	3,280
	Automotive		2,103		2,077		1,807
	Chemicals		3,664		3,501		3,238
	Coal		4,127		3,978		3,912
	Industrial Products		4,400		3,822		3,494
	Intermodal		4,489		4,030		3,955
	Total freight revenues	$	22,560	$	20,684	$	19,686
	Other revenues		1,428		1,279		1,240
	Total operating revenues	$	23,988	$	21,963	$	20,926

Stock_Options_and_Other_Stock_1

Stock Options and Other Stock Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Stock Options and Other Stock Plans [Abstract]
Stock-Based Compensation [Table Text Block]	Information regarding stock-based compensation appears in the table below:
	Millions	2014		2013		2012
	Stock-based compensation, before tax:
	Stock options	$	21	$	19	$	18
	Retention awards		91		79		75
	Total stock-based compensation, before tax	$	112	$	98	$	93
	Excess tax benefits from equity compensation plans	$	118	$	76	$	100
Stock Options Weight Average Assumptions [Table Text Block]	The table below shows the annual weighted-average assumptions used for valuation purposes:
	Weighted-Average Assumptions		2014		2013		2012
	Risk-free interest rate		1.60%		0.80%		0.80%
	Dividend yield		2.10%		2.10%		2.10%
	Expected life (years)		5.2		5		5.3
	Volatility		30.00%		36.20%		36.80%
	Weighted-average grant-date fair value of options granted	$	20.18	$	17.49	$	15.65
Stock Options Activity [Table Text Block]	A summary of stock option activity during 2014 is presented below:
		Options (thous.)	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value (millions)
	Outstanding at January 1, 2014	7,443	$	40.07	5.8 yrs.	$	327
	Granted	989		87.56	N/A		N/A
	Exercised	-2,961		30.59	N/A		N/A
	Forfeited or expired	-84		68.48	N/A		N/A
	Outstanding at December 31, 2014	5,387	$	53.56	5.8 yrs.	$	353
	Vested or expected to vest	5,325	$	53.3	5.8 yrs.	$	351
	at December 31, 2014
	Options exercisable at December 31, 2014	3,350	$	40.69	4.4 yrs.	$	263
Stock Option Exercises [Table Text Block]	Additional information regarding stock option exercises appears in the table below:
	Millions	2014		2013		2012
	Intrinsic value of stock options exercised	$	194	$	112	$	244
	Cash received from option exercises		54		51		84
	Treasury shares repurchased for employee payroll taxes		-24		-21		-30
	Tax benefit realized from option exercises		74		43		93
	Aggregate grant-date fair value of stock options vested		17		16		16
Retention Awards Activity [Table Text Block]	Changes in our retention awards during 2014 were as follows:
		Shares (thous.)	Weighted-Average Grant-Date Fair Value
	Nonvested at January 1, 2014	3,712	$	49.02
	Granted	871		88.14
	Vested	-1,080		31.33
	Forfeited	-100		57.82
	Nonvested at December 31, 2014	3,403	$	64.39
Performance Retention Awards Present Value Calculation Assumptions [Table Text Block]	The assumptions used to calculate the present value of estimated future dividends related to the February 2014 grant were as follows:
		2014
	Dividend per share per quarter	$	0.455
	Risk-free interest rate at date of grant		0.70%
Performance Based Units Activity [Table Text Block]	Changes in our performance retention awards during 2014 were as follows:
		Shares (thous.)	Weighted-Average Grant-Date Fair Value
	Nonvested at January 1, 2014	1,888	$	53.7
	Granted	456		83.06
	Vested	-661		44.94
	Forfeited	-100		61.36
	Nonvested at December 31, 2014	1,583	$	65.33

Retirement_Plans_Tables

Retirement Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Retirement Plans [Abstract]
Changes In Projected Benefit Obligation And Plan Assets [Table Text Block]	Changes in our PBO and plan assets were as follows for the years ended December 31:
	Funded Status	Pension					OPEB
	Millions	2014		2013			2014		2013
	Projected Benefit Obligation
	Projected benefit obligation at beginning of year	$	3,372	$	3,591		$	330	$	372
	Service cost		70		72			2		3
	Interest cost		158		134			14		12
	Actuarial loss/(gain)		735		-257			33		-34
	Gross benefits paid		-193		-168			-25		-23
	Projected benefit obligation at end of year	$	4,142	$	3,372		$	354	$	330
	Plan Assets
	Fair value of plan assets at beginning of year	$	3,429	$	2,875		$	-	$	-
	Actual return on plan assets		185		506			-		-
	Voluntary funded pension plan contributions		200		200			-		-
	Non-qualified plan benefit contributions		33		16			25		23
	Gross benefits paid		-193		-168			-25		-23
	Fair value of plan assets at end of year	$	3,654	$	3,429		$	-	$	-
	Funded status at end of year	$	-488	$	57		$	-354	$	-330
Amounts Recognized In Statement Of Financial Position [Table Text Block]	Amounts recognized in the statement of financial position as of December 31, 2014 and 2013 consist of:
		Pension					OPEB
	Millions	2014		2013			2014		2013
	Noncurrent assets	$	1	$	364		$	-	$	-
	Current liabilities		-19		-16			-23		-25
	Noncurrent liabilities		-470		-291			-331		-305
	Net amounts recognized at end of year	$	-488	$	57		$	-354	$	-330
Pre-Tax Amounts Recognized In Accumulated Other Comprehensive Income/(Loss) [Table Text Block]	The change in the funded status and accumulated other comprehensive income/(loss) is primarily a result of implementing a new set of mortality tables issued by the Society of Actuaries in October 2014 and lower discount rates.
	Pre-tax amounts recognized in accumulated other comprehensive income/(loss) as of December 31, 2014 and 2013 consist of:
		2014								2013
	Millions	Pension		OPEB		Total			Pension		OPEB		Total
	Prior service (cost)/credit	$	-	$	17	$	17		$	-	$	28	$	28
	Net actuarial loss		-1,727		-148		-1,875			-1,018		-125		-1,143
	Total	$	-1,727	$	-131	$	-1,858		$	-1,018	$	-97	$	-1,115
Other Pre-Tax Changes Recognized In Other Comprehensive Income [Table Text Block]	Pre-tax changes recognized in other comprehensive income/(loss) during 2014, 2013 and 2012 were as follows:
		Pension								OPEB
	Millions	2014		2013		2012			2014		2013		2012
	Net actuarial (loss)/gain	$	-780	$	561	$	-265		$	-33	$	34	$	-42
	Amortization of:
	Prior service cost/(credit)		-		-		1			-11		-16		-18
	Actuarial loss		71		106		83			10		15		13
	Total	$	-709	$	667	$	-181		$	-34	$	33	$	-47
Amounts Included In Accumulated Other Comprehensive Income Expected To Be Amortized Into Net Periodic Cost (Benefit) [Table Text Block]	Amounts included in accumulated other comprehensive income/(loss) expected to be amortized into net periodic cost during 2015:
	Millions	Pension		OPEB		Total
	Prior service credit	$	-	$	10	$	10
	Net actuarial loss		-103		-13		-116
	Total	$	-103	$	-3	$	-106
Underfunded Accumulated Benefit Obligation [Table Text Block]	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	2014		2013
	Projected benefit obligation	$	388	$	308
	Accumulated benefit obligation	$	379	$	302
	Fair value of plan assets		-		-
	Underfunded accumulated benefit obligation	$	-379	$	-302
Weighted-Average Actuarial Assumptions Used To Determine Benefit Obligations And Expense [Table Text Block]	The weighted-average actuarial assumptions used to determine benefit obligations at December 31:
		Pension		OPEB
	Percentages	2014	2013	2014	2013
	Discount rate	3.94%	4.72%	3.74%	4.47%
	Compensation increase	4.00%	4.00%	N/A	N/A
	Health care cost trend rate (employees under 65)	N/A	N/A	6.34%	6.49%
	Ultimate health care cost trend rate	N/A	N/A	4.50%	4.50%
	Year ultimate trend rate reached	N/A	N/A	2028	2028
	The weighted-average actuarial assumptions used to determine expense were as follows:
		Pension			OPEB
	Percentages	2014	2013	2012	2014	2013	2012
	Discount rate	4.72%	3.78%	4.54%	4.47%	3.48%	4.36%
	Expected return on plan assets	7.50%	7.50%	7.50%	N/A	N/A	N/A
	Compensation increase	4.00%	3.43%	3.69%	N/A	N/A	N/A
	Health care cost trend rate (employees under 65)	N/A	N/A	N/A	6.49%	6.64%	6.91%
	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) [Table Text Block]	The components of our net periodic pension and OPEB cost/(benefit) were as follows for the years ended December 31:
		Pension							OPEB
	Millions	2014		2013		2012		2014		2013		2012
	Net Periodic Benefit Cost:
	Service cost	$	70	$	72	$	54	$	2	$	3	$	3
	Interest cost		158		134		141		14		12		15
	Expected return on plan assets		-230		-202		-190		-		-		-
	Amortization of:
	Prior service cost/(credit)		-		-		1		-11		-16		-18
	Actuarial loss		71		106		83		10		15		13
	Net periodic benefit cost/(benefit)	$	69	$	110	$	89	$	15	$	14	$	13
OPEB Effects From One-Percentage Point Change Assumed Healthcare Cost Trend Rates [Table Text Block]	A one-percentage point change in the assumed health care cost trend rates would have the following effects on OPEB:
	Millions	One % pt. Increase		One % pt. Decrease
	Effect on total service and interest cost components	$	1	$	-1
	Effect on accumulated benefit obligation		19		-16
Cash Contributions For Qualified Pension Plan Benefit Payments For Non-Qualified OPEB Plans [Table Text Block]	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
	2013		$	200	$	16	$	23
	2014			200		33		25
Expected Benefit Payments For Years 2012 Through 2022 [Table Text Block]	The following table details expected benefit payments for the years 2015 through 2024:
	Millions	Pension		OPEB
	2015	$	180	$	23
	2016		186		23
	2017		191		23
	2018		196		23
	2019		201		23
	Years 2020 - 2024		1,069		107
Pension Plan Asset Allocation And Fair Value Measured Recurring Basis [Table Text Block]	Our pension plan asset allocation at December 31, 2014 and 2013, and target allocation for 2015, are as follows:
		Target Allocation 2015		Percentage of Plan Assets December 31,
				2014	2013
	Equity securities	60% to 70%		68%	70%
	Debt securities	20% to 30%		23	21
	Real estate	2% to 8%		4	4
	Commodities	4% to 6%		5	5
	Total			100%	100%
	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
	Common 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.
	As of December 31, 2013, 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	$	16		$	-		$	-		$	16
	Registered investment companies		11			253			-			264
	Federal government securities		-			126			-			126
	Bonds & debentures		-			310			-			310
	Corporate stock		983			16			-			999
	Venture capital and buyout partnerships		-			-			213			213
	Real estate partnerships		-			-			139			139
	Common trust and other funds		-			1,357			-			1,357
	Total plan assets at fair value	$	1,010		$	2,062		$	352			3,424
	Other assets [a]											5
	Total plan assets										$	3,429
	[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) [Table Text Block]	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
	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 2013:
		Venture Capital
		and Buyout			Real Estate
	Millions	Partnerships			Partnerships			Total
	Beginning balance - January 1, 2013	$	179		$	143		$	322
	Realized gain		7			8			15
	Unrealized gain		24			3			27
	Purchases		43			23			66
	Sales		-40			-38			-78
	Ending balance - December 31, 2013	$	213		$	139		$	352

Other_Income_Tables

Other Income (Tables)	12 Months Ended
	Dec. 31, 2014
Other Income [Abstract]
Other Income [Table Text Block]	Other income included the following for the years ended December 31:
	Millions	2014 [a]		2013 [b]		2012
	Rental income	$	96	$	106	$	83
	Net gain on non-operating asset dispositions		69		32		29
	Interest income		4		4		3
	Non-operating environmental costs and other		-18		-14		-7
	Total	$	151	$	128	$	108
	[a] Non-operating environmental costs and other includes $14 million related to the sale of a permanent easement.
	[b] Rental income includes $17 million related to a land lease contract settlement.

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax [Abstract]
Components Of Income Tax Expense/(Benefit) [Table Text Block]	Components of income tax expense were as follows for the years ended December 31:
	Millions	2014		2013		2012
	Current tax expense:
	Federal	$	2,029	$	1,738	$	1,335
	State		239		199		153
	Total current tax expense		2,268		1,937		1,488
	Deferred tax expense:
	Federal		667		659		760
	State		136		119		120
	Total deferred tax expense		803		778		880
	Unrecognized tax benefits:
	Federal		86		-54		5
	State		6		-1		2
	Total unrecognized tax benefits expense/(benefits)		92		-55		7
	Total income tax expense	$	3,163	$	2,660	$	2,375
Reconciliations Between Statutory And Effective Tax Rates [Table Text Block]	For the years ended December 31, reconciliations between statutory and effective tax rates are as follows:
	Tax Rate Percentages	2014		2013		2012
	Federal statutory tax rate	35	%	35	%	35	%
	State statutory rates, net of federal benefits	3.1		3.1		3.1
	Deferred tax adjustments	-		-0.1		-0.1
	Tax credits	-0.4		-0.2		-0.5
	Other	0.2		-0.1		0.1
	Effective tax rate	37.9	%	37.7	%	37.6	%
Deferred Income Tax Liabilities/(Assets) [Table Text Block]	Deferred income tax (liabilities)/assets were comprised of the following at December 31:
	Millions	2014		2013
	Deferred income tax liabilities:
	Property	$	-15,173	$	-14,448
	Other		-411		-260
	Total deferred income tax liabilities		-15,584		-14,708
	Deferred income tax assets:
	Accrued wages		74		71
	Accrued casualty costs		228		223
	Accrued stock compensation		69		66
	Debt and leases		86		41
	Retiree benefits		392		100
	Credits		164		182
	Other		168		130
	Total deferred income tax assets	$	1,181	$	813
	Net deferred income tax liability	$	-14,403	$	-13,895
	Current portion of deferred taxes	$	277	$	268
	Non-current portion of deferred taxes		-14,680		-14,163
	Net deferred income tax liability	$	-14,403	$	-13,895
Reconciliation Of Changes In Unrecognized Tax Benefits Liabilities/(Assets) [Table Text Block]	A reconciliation of changes in unrecognized tax benefits liabilities/(assets) from the beginning to the end of the reporting period is as follows:
	Millions	2014		2013		2012
	Unrecognized tax benefits at January 1	$	59	$	115	$	107
	Increases for positions taken in current year		92		24		29
	Increases for positions taken in prior years		21		15		4
	Decreases for positions taken in prior years		-14		-30		-19
	Payments to and settlements with taxing authorities		-7		-63		-
	Increases/(decreases) for interest and penalties		1		-		-4
	Lapse of statutes of limitations		-1		-2		-2
	Unrecognized tax benefits at December 31	$	151	$	59	$	115
Schedule Of Unrecognized Tax Benefits That Would Reduce Effective Tax Rate [Table Text Block]	The unrecognized tax benefits that would reduce our effective tax rate are as follows:
	Millions	2014		2013		2012
	Unrecognized tax benefits that would reduce the effective tax rate	$	33	$	34	$	41
	Unrecognized tax benefits that would not reduce the effective tax rate		118		25		74
	Total unrecognized tax benefits	$	151	$	59	$	115

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings Per Share [Table Text Block]	The following table provides a reconciliation between basic and diluted earnings per share for the years ended December 31:
	Millions, Except Per Share Amounts	2014		2013		2012
	Net income	$	5,180	$	4,388	$	3,943
	Weighted-average number of shares outstanding:
	Basic		897.1		926.5		946.2
	Dilutive effect of stock options		2.1		2.4		3.6
	Dilutive effect of retention shares and units		1.9		2.6		3.1
	Diluted		901.1		931.5		952.9
	Earnings per share – basic	$	5.77	$	4.74	$	4.17
	Earnings per share – diluted	$	5.75	$	4.71	$	4.14

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income/(Loss) (Tables)	12 Months Ended
	Dec. 31, 2014
Accumulated Other Comprehensive Income/(Loss) [Abstract]
After-Tax Components Of Accumulated Other Comprehensive Loss [Table Text Block]	Reclassifications out of accumulated other comprehensive income/(loss) were as follows (net of tax):
	Millions			Defined benefit plans	Foreign currency translation		Derivatives			Total
	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
	Balance at January 1, 2013		$	-1,149	$	-36	$	-1	$	-1,186
	Other comprehensive income/(loss) before reclassifications			-1		-1		1		-1
	Amounts reclassified from accumulated other comprehensive income/(loss) [a]			437		-		-		437
	Net year-to-date other comprehensive income/(loss), net of taxes of ($264) million			436		-1		1		436
	Balance at December 31, 2013		$	-713	$	-37	$	-	$	-750
	[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, 2014
Properties [Abstract]
Properties [Table Text Block]	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, 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.
	Millions, Except Estimated Useful Life				Accumulated		Net Book		Estimated
	As of December 31, 2013		Cost		Depreciation		Value		Useful Life
	Land		$	5,120	$	N/A	$	5,120	N/A
	Road:
	Rail and other track material			13,861		4,970		8,891	35
	Ties			8,785		2,310		6,475	33
	Ballast			4,621		1,171		3,450	34
	Other roadway [a]			15,596		2,726		12,870	48
	Total road			42,863		11,177		31,686	N/A
	Equipment:
	Locomotives			7,518		3,481		4,037	20
	Freight cars			2,085		1,000		1,085	25
	Work equipment and other			561		119		442	18
	Total equipment			10,164		4,600		5,564	N/A
	Technology and other			711		286		425	10
	Construction in progress			954		-		954	N/A
	Total		$	59,812	$	16,063	$	43,749	N/A
	[a]	Other roadway includes grading, bridges and tunnels, signals, buildings, and other road assets.

Recovered_Sheet1

Accounts Payable And Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2014
Accounts Payable and Other Current Liabilties [Abstract]
Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]	Accounts Payable and Other Current Liabilities
		Dec. 31,		Dec. 31,
	Millions	2014		2013
	Accounts payable	$	877	$	803
	Dividends payable		438		356
	Income and other taxes payable		412		491
	Accrued wages and vacation		409		385
	Accrued casualty costs		249		207
	Interest payable		178		169
	Equipment rents payable		100		96
	Other		640		579
	Total accounts payable and other current liabilities	$	3,303	$	3,086

Debt_Tables

Debt (Tables)	12 Months Ended
	Dec. 31, 2014
Debt [Abstract]
Total debt, net of interest rate swaps designated as fair value hedges [Table Text Block]	Total debt as of December 31, 2014, and 2013, is summarized below:
	Millions		2014		2013
	Notes and debentures, 2.3% to 7.9% due through 2054		$	9,266	$	8,068
	Capitalized leases, 3.1% to 8.4% due through 2028			1,520		1,702
	Equipment obligations, 3.2% to 6.7% due through 2031			597		110
	Receivables Securitization (Note 11)			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		32
	Tax-exempt financings - floating rate, due in 2015			8		12
	Unamortized discount			-591		-604
	Total debt			11,480		9,577
	Less: current portion			-462		-705
	Total long-term debt		$	11,018	$	8,872
Aggregate debt maturities [Table Text Block]	The following table presents aggregate debt maturities as of December 31, 2014, excluding market value adjustments:
	Millions
	2015	$	462
	2016		606
	2017		1,065
	2018		578
	2019		652
	Thereafter		8,117
	Total debt	$	11,480
Unsecured Fixed Rate Debt Securities Issued Under Current Shelf Registration [Table Text Block]	During 2014, we issued the following unsecured, fixed-rate debt securities under our current shelf registration:
	Date	Description of Securities
	10-Jan-14	$300 million of 2.25% Notes due February 15, 2019
		$400 million of 3.75% Notes due March 15, 2024
		$300 million of 4.85% Notes due June 15, 2044
	12-Aug-14	$350 million of 3.25% Notes due January 15, 2025
		$350 million of 4.15% Notes due January 15, 2045
	Subsequent Event - In 2015, we issued the following unsecured, fixed-rate debt securities under our current shelf registration:
	Date	Description of Securities
	29-Jan-15	$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
Debt Exchange [Table Text Block]	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, 2014
Leases [Abstract]
Future Minimum Lease Payments For Operating And Capital Leases [Table Text Block]	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, 2014, were as follows:
	Millions	Operating Leases		Capital Leases
	2015	$	508	$	253
	2016		484		249
	2017		429		246
	2018		356		224
	2019		323		210
	Later years		1,625		745
	Total minimum lease payments	$	3,725	$	1,927
	Amount representing interest		N/A		-407
	Present value of minimum lease payments		N/A	$	1,520

Commitments_And_Contingencies_

Commitments And Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments And Contingencies Tables [Abstract]
Commitments And Contingencies Activity [Table Text Block]	Our personal injury liability activity was as follows:
	Millions	2014		2013		2012
	Beginning balance	$	294	$	334	$	368
	Current year accruals		96		87		121
	Changes in estimates for prior years		9		-38		-58
	Payments		-64		-89		-97
	Ending balance at December 31	$	335	$	294	$	334
	Current portion, ending balance at December 31	$	111	$	82	$	95
	Our asbestos-related liability activity was as follows:
	Millions	2014		2013		2012
	Beginning balance	$	131	$	139	$	147
	Accruals/(Credits)		1		2		-2
	Payments		-6		-10		-6
	Ending balance at December 31	$	126	$	131	$	139
	Current portion, ending balance at December 31	$	8	$	9	$	8
	Our environmental liability activity was as follows:
	Millions	2014		2013		2012
	Beginning balance	$	171	$	170	$	172
	Accruals		56		58		48
	Payments		-45		-57		-50
	Ending balance at December 31	$	182	$	171	$	170
	Current portion, ending balance at December 31	$	60	$	53	$	50

Share_Repurchase_Program_Table

Share Repurchase Program (Tables)	12 Months Ended
	Dec. 31, 2014
Share Repurchase Program Tables [Abstract]
Share Repurchase Program [Table Text Block]	The table below represents shares repurchased in 2013 under our previous repurchase program, and shares repurchased in 2014 under the new program.
		Number of Shares Purchased		Average Price Paid
		2014	2013		2014		2013
	First quarter	7,640,000	5,762,800	$	89.43	$	68.29
	Second quarter	8,320,000	6,122,940		96.84		75.71
	Third quarter	8,347,000	7,333,788		102.54		78.39
	Fourth quarter	7,736,400	9,858,110		113.77		79.68
	Total	32,043,400	29,077,638	$	100.65	$	76.26
	Remaining number of shares that may be repurchased under current authority						87,956,600

Selected_Quarterly_Data_Unaudi1

Selected Quarterly Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Selected Quarterly Data (Unaudited) [Abstract]
Selected Quarterly Data (Unaudited) [Table Text Block]	20. Selected Quarterly Data (Unaudited)
	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		1.2		1.43		1.53		1.62
	Diluted		1.19		1.43		1.53		1.61
	Millions, Except Per Share Amounts
	2013	Mar. 31		Jun. 30		Sep. 30		Dec. 31
	Operating revenues	$	5,290	$	5,470	$	5,573	$	5,630
	Operating income		1,633		1,878		1,962		1,973
	Net income		957		1,106		1,151		1,174
	Net income per share:
	Basic		1.02		1.19		1.25		1.28
	Diluted		1.02		1.18		1.24		1.27

Schedule_Of_Valuation_And_Qual1

Schedule Of Valuation And Qualifying Accounts (Tables)	12 Months Ended
	Dec. 31, 2014
Schedule Of Valuation And Qualifying Accounts [Abstract]
Schedule Of Valuation And Qualifying Accounts [Text Block]	SCHEDULE II – VALUATION AND QUALIFYING ACCOUNTS
	Union Pacific Corporation and Subsidiary Companies
	Millions, for the Years Ended December 31,	2014		2013		2012
	Allowance for doubtful accounts:
	Balance, beginning of period	$	23	$	37	$	50
	Charges/(reduction) to expense		5		-4		-1
	Net recoveries/(write-offs)		-7		-10		-12
	Balance, end of period	$	21	$	23	$	37
	Allowance for doubtful accounts are presented in the Consolidated Statements of Financial Position as follows:
	Current	$	5	$	1	$	4
	Long-term		16		22		33
	Balance, end of period	$	21	$	23	$	37
	Accrued casualty costs:
	Balance, beginning of period	$	702	$	734	$	778
	Charges to expense		256		188		190
	Cash payments and other reductions		-201		-220		-234
	Balance, end of period	$	757	$	702	$	734
	Accrued casualty costs are presented in the Consolidated Statements of Financial Position as follows:
	Current	$	249	$	207	$	213
	Long-term		508		495		521
	Balance, end of period	$	757	$	702	$	734

Nature_Of_Operations_Details

Nature Of Operations (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Network route miles	31,974								31,974
Route miles owned	26,012								26,012
Commodity Group Information [Line Items]
Freight revenues									$22,560,000,000	$20,684,000,000	$19,686,000,000
Other revenues									1,428,000,000	1,279,000,000	1,240,000,000
Total operating revenues	6,153,000,000	6,182,000,000	6,015,000,000	5,638,000,000	5,630,000,000	5,573,000,000	5,470,000,000	5,290,000,000	23,988,000,000	21,963,000,000	20,926,000,000
Freight revenues - Mexico									2,300,000,000	2,100,000,000	1,900,000,000
Agricultural Products [Member]
Commodity Group Information [Line Items]
Freight revenues									3,777,000,000	3,276,000,000	3,280,000,000
Automotive [Member]
Commodity Group Information [Line Items]
Freight revenues									2,103,000,000	2,077,000,000	1,807,000,000
Chemicals [Member]
Commodity Group Information [Line Items]
Freight revenues									3,664,000,000	3,501,000,000	3,238,000,000
Coal [Member]
Commodity Group Information [Line Items]
Freight revenues									4,127,000,000	3,978,000,000	3,912,000,000
Industrial Products [Member]
Commodity Group Information [Line Items]
Freight revenues									4,400,000,000	3,822,000,000	3,494,000,000
Intermodal [Member]
Commodity Group Information [Line Items]
Freight revenues									$4,489,000,000	$4,030,000,000	$3,955,000,000

Stock_Split_Details

Stock Split (Details) (USD $)	0 Months Ended	12 Months Ended
	27-May-14	Dec. 31, 2014	Dec. 31, 2013
Stock Split [Abstract]
Stock split effective date		6-Jun-14
Stock split conversion ratio	2
Percent of dividend in stock	100.00%
Stock split record date		27-May-14
Common shares, par value	$2.50	$2.50	$2.50

Stock_Options_and_Other_Stock_2

Stock Options and Other Stock Plans (Details 1)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock Options And Other Stock Plans Details [Abstract]
Shares of common stock authorized and available	77,786,772	79,574,896	64,337,040
Union Pacific Corporation 1992 Restricted Stock Plan For Non-Employee Directors [Member]
Stock Options And Other Stock Plans Details [Abstract]
Restricted shares outstanding	7,140
Union Pacific Corporation 2000 Directors Plan [Member]
Stock Options And Other Stock Plans Details [Abstract]
Stock options, shares outstanding	78,000
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]
Stock Options And Other Stock Plans Details [Abstract]
Stock options, shares outstanding	4,338,691
Retention shares and stock units	3,677,642
Common stock reserved for issuance	84,000,000
Union Pacific Corporation 2013 Stock Incentive Plan [Member]
Stock Options And Other Stock Plans Details [Abstract]
Stock options, shares outstanding	969,822
Retention shares and stock units	1,307,905
Common stock reserved for issuance	78,000,000

Stock_Options_and_Other_Stock_3

Stock Options and Other Stock Plans (Details 2) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014
Stock Options [Member]
Stock Option Activity [Abstract]
Stock options, shares outstanding at January 1, 2014	7,443,000
Stock options, shares granted	989,000
Stock options, shares exercised	-2,961,000
Stock options, shares forfeited or expired	-84,000
Stock options, shares outstanding at December 31, 2014	5,387,000
Stock options, shares vested or expected to vest at December 31, 2014	5,325,000
Stock options, share options exercisable at December 31, 2014	3,350,000
Stock options weighted-average exercise price, outstanding at January 1, 2014	$40.07
Stock options weighted-average exercise price, granted	$87.56
Stock options weighted-average exercise price, exercised	$30.59
Stock options weighted-average exercise price, forfeited or expired	$68.48
Stock options weighted-average exercise price, outstanding at December 31, 2014	$53.56
Stock options weighted-average exercise price, vested or expected to vest at December 31, 2014	$53.30
Stock options weighted-average exercise price, options exercisable at December 31, 2014	$40.69
Stock options weighted-average remaining contractual term in years, outstanding at January 1, 2014	5 years 10 months
Stock options weighted-average remaining contractual term in years, outstanding at December 31, 2014	5 years 10 months
Stock options weighted-average remaining contractual term in years, vested or expected to vest at December 31, 2014	5 years 10 months
Stock options weighted-average remaining contractual term in years, options exercisable at December 31, 2014	4 years 5 months
Stock options aggregate intrinsic value, outstanding at January 1, 2014	$327
Stock options aggregate intrinsic value, outstanding at December 31, 2014	353
Stock options aggregate intrinsic value, vested or expected to vest at December 31, 2014	351
Stock options aggregate intrinsic value, options exercisable at December 31, 2014	263
Contractual Term	Stock options are granted at the closing price on the date of grant, have ten-year contractual terms
Stock options, years until vest	3 years
Stock options, subject to performance or market-based vesting conditions	None
Unrecognized Compensation Expense [Abstract]
Unrecognized compensation expense	15
Expected weighted average period (in years) of nonvested stock options to be recognized	1 year
Retention Awards [Member]
Awards Activity [Abstract]
Awards, shares nonvested at January 1, 2014	3,712,000
Awards, shares granted	871,000
Awards, shares vested	-1,080,000
Awards, shares forfeited	-100,000
Awards, shares nonvested at December 31, 2014	3,403,000
Awards weighted-average grant-date fair value, nonvested at January 1, 2014	$49.02
Awards weighted-average grant-date fair value, granted	$88.14
Awards weighted-average grant-date fair value, vested	$31.33
Awards weighted-average grant-date fair value, forfeited	$57.82
Awards weighted-average grant-date fair value, nonvested at December 31, 2014	$64.39
Unrecognized Compensation Expense [Abstract]
Unrecognized compensation expense	87
Expected weighted average period (in years) of nonvested stock options to be recognized	1 year 7 months
Performance Retention Awards [Member]
Awards Activity [Abstract]
Awards, shares nonvested at January 1, 2014	1,888,000
Awards, shares granted	456,000
Awards, shares vested	-661,000
Awards, shares forfeited	-100,000
Awards, shares nonvested at December 31, 2014	1,583,000
Awards weighted-average grant-date fair value, nonvested at January 1, 2014	$53.70
Awards weighted-average grant-date fair value, granted	$83.06
Awards weighted-average grant-date fair value, vested	$44.94
Awards weighted-average grant-date fair value, forfeited	$61.36
Awards weighted-average grant-date fair value, nonvested at December 31, 2014	$65.33
Unrecognized Compensation Expense [Abstract]
Unrecognized compensation expense	$36
Expected weighted average period (in years) of nonvested stock options to be recognized	1 year

Stock_Options_and_Other_Stock_4

Stock Options and Other Stock Plans (Details 3) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock-Based Compensation, Before Tax: [Abstract]
Stock options	$21	$19	$18
Retention awards	91	79	75
Total stock-based compensation, before tax	112	98	93
Excess tax benefits from equity compensation plans	$118	$76	$100

Stock_Options_and_Other_Stock_5

Stock Options and Other Stock Plans (Details 4) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock Options [Member]
Assumptions For Stock Awards [Abstract]
Risk-free interest rate	1.60%	0.80%	0.80%
Dividend yield	2.10%	2.10%	2.10%
Expected life (years)	5 years 2 months	5 years	5 years 4 months
Volatility	30.00%	36.20%	36.80%
Weighted-average grant-date fair value of options granted	$20.18	$17.49	$15.65
Performance Retention Awards [Member]
Assumptions For Stock Awards [Abstract]
Dividend per share per quarter	$0.46
Risk-free interest rate	0.70%
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.

Stock_Options_and_Other_Stock_6

Stock Options and Other Stock Plans (Details 5) (Stock Options [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock Options [Member]
Stock Option Aggregate Disclosures [Abstract]
Intrinsic value of stock options exercised	$194	$112	$244
Cash received from option exercises	54	51	84
Treasury shares repurchased for employee payroll taxes	-24	-21	-30
Tax benefit realized from option exercises	74	43	93
Aggregate grant-date fair value of stock options vested	$17	$16	$16

Retirement_Plans_Details_1

Retirement Plans (Details 1) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pre-Tax Amounts Recognized in Accumulated Other Comprehensive Income/(Loss) [Abstract]
Prior service (cost)/credit		$17	$28
Net actuarial loss		-1,875	-1,143
Total pre-tax amounts recognized in accumulated other comprehensive income/(loss)		-1,858	-1,115
Total 2015 Forecast [Member]
Amounts Included In Accumulated Other Comprehensive Income/(Loss) Expected To Be Amortized Into Net Periodic Cost [Abstract]
Prior service credit - AOCI	10
Net actuarial loss - AOCI	-116
Total amounts included in accumulated other comprehensive income expected to be amortized into net periodic cost (benefit)	-106
Pension [Member]
Net Periodic Pension And OPEB Cost/(Benefit) [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.
Projected Benefit Obligation [Abstract]
Projected benefit obligation at beginning of year		3,372	3,591
Service cost		70	72	54
Interest cost		158	134	141
Actuarial loss/(gain)		735	-257
Gross benefits paid		-193	-168
Projected benefit obligation at end of year		4,142	3,372	3,591
Plan Assets [Abstract]
Fair value of plan assets at beginning of year		3,429	2,875
Actual return on plan assets		185	506
Voluntary funded pension plan contributions		200	200
Non-qualified plan benefit contributions		33	16
Gross benefits paid		-193	-168
Fair value of plan assets at end of year		3,654	3,429	2,875
Defined Benefit Plan, Funded Status of Plan [Abstract]
Funded status at end of year		-488	57
Amounts Recognized in the Statement of Financial Position [Abstract]
Amounts recognized - noncurrent assets		1	364
Amounts recognized - current liabilities		-19	-16
Amounts recognized - noncurrent liabilities		-470	-291
Net amounts recognized at end of year		-488	57
Pre-Tax Amounts Recognized in Accumulated Other Comprehensive Income/(Loss) [Abstract]
Prior service (cost)/credit		0	0
Net actuarial loss		-1,727	-1,018
Total pre-tax amounts recognized in accumulated other comprehensive income/(loss)		-1,727	-1,018
Other Pre-Tax Changes Recognized In Other Comprehensive Income/(Loss) [Abstract]
Net actuarial (loss)/gain - OCI		-780	561	-265
Amortization of prior service cost/(credit) - OCI		0	0	1
Amortization of actuarial loss - OCI		71	106	83
Total other pre-tax changes recognized in other comprehensive income		-709	667	-181
Pension [Member] | Total 2015 Forecast [Member]
Amounts Included In Accumulated Other Comprehensive Income/(Loss) Expected To Be Amortized Into Net Periodic Cost [Abstract]
Prior service credit - AOCI	0
Net actuarial loss - AOCI	-103
Total amounts included in accumulated other comprehensive income expected to be amortized into net periodic cost (benefit)	-103
OPEB [Member]
Net Periodic Pension And OPEB Cost/(Benefit) [Line Items]
Pension & OPEB Descriptions		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.
Projected Benefit Obligation [Abstract]
Projected benefit obligation at beginning of year		330	372
Service cost		2	3	3
Interest cost		14	12	15
Actuarial loss/(gain)		33	-34
Gross benefits paid		-25	-23
Projected benefit obligation at end of year		354	330	372
Plan Assets [Abstract]
Fair value of plan assets at beginning of year		0	0
Actual return on plan assets		0	0
Non-qualified plan benefit contributions - OPEB		25	23
Gross benefits paid		-25	-23
Fair value of plan assets at end of year		0	0	0
Defined Benefit Plan, Funded Status of Plan [Abstract]
Funded status at end of year		-354	-330
Amounts Recognized in the Statement of Financial Position [Abstract]
Amounts recognized - noncurrent assets		0	0
Amounts recognized - current liabilities		-23	-25
Amounts recognized - noncurrent liabilities		-331	-305
Net amounts recognized at end of year		-354	-330
Pre-Tax Amounts Recognized in Accumulated Other Comprehensive Income/(Loss) [Abstract]
Prior service (cost)/credit		17	28
Net actuarial loss		-148	-125
Total pre-tax amounts recognized in accumulated other comprehensive income/(loss)		-131	-97
Other Pre-Tax Changes Recognized In Other Comprehensive Income/(Loss) [Abstract]
Net actuarial (loss)/gain - OCI		-33	34	-42
Amortization of prior service cost/(credit) - OCI		-11	-16	-18
Amortization of actuarial loss - OCI		10	15	13
Total other pre-tax changes recognized in other comprehensive income		-34	33	-47
OPEB [Member] | Total 2015 Forecast [Member]
Amounts Included In Accumulated Other Comprehensive Income/(Loss) Expected To Be Amortized Into Net Periodic Cost [Abstract]
Prior service credit - AOCI	10
Net actuarial loss - AOCI	-13
Total amounts included in accumulated other comprehensive income expected to be amortized into net periodic cost (benefit)	($3)

Retirement_Plans_Details_2

Retirement Plans (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Non-qualified Plan [Member]
Underfunded Accumulated Benefit Obligation [Abstract]
Accumulated benefit obligation	379,000,000	302,000,000
Pension [Member]
Underfunded Accumulated Benefit Obligation [Abstract]
Projected benefit obligation	388,000,000	308,000,000
Accumulated benefit obligation	379,000,000	302,000,000
Fair value of plan assets	0	0
Underfunded accumulated benefit obligation	-379,000,000	-302,000,000
Accumulated Benefit Obligation [Abstract]
Accumulated benefit obligation	3,900,000,000	3,200,000,000
Weighted-Average Actuarial Assumptions Used To Determine Benefit Obligations [Abstract]
Discount rate - benefit obligations	3.94%	4.72%
Compensation increase - benefit obligations	4.00%	4.00%
OPEB [Member]
Weighted-Average Actuarial Assumptions Used To Determine Benefit Obligations [Abstract]
Discount rate - benefit obligations	3.74%	4.47%
Health care cost trend rate (employees under 65)	6.34%	6.49%
Ultimate health care cost trend rate	4.50%	4.50%	4.50%
Year ultimate trend rate reached	2028	2028	2028

Retirement_Plans_Details_3

Retirement Plans (Details 3) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2015
Pension [Member]
Net Periodic Pension And OPEB Cost/(Benefit) Abstract
Service cost	$70	$72	$54
Interest cost	158	134	141
Expected return on plan assets	-230	-202	-190
Amortization of prior service cost/(credit)	0	0	1
Amortization of actuarial loss	71	106	83
Net periodic benefit cost / (benefit)	69	110	89
Weighted-Average Actuarial Assumptions Used To Determine Benefit Expense [Abstract]
Discount rate - expense	4.72%	3.78%	4.54%
Expected return on plan assets - expense	7.50%	7.50%	7.50%
Compensation increase - expense	4.00%	3.43%	3.69%
Actual return (loss) on pension plan assets, net of fees	6.00%	17.00%	13.00%
OPEB [Member]
Net Periodic Pension And OPEB Cost/(Benefit) Abstract
Service cost	2	3	3
Interest cost	14	12	15
Expected return on plan assets	0	0	0
Amortization of prior service cost/(credit)	-11	-16	-18
Amortization of actuarial loss	10	15	13
Net periodic benefit cost / (benefit)	15	14	13
Weighted-Average Actuarial Assumptions Used To Determine Benefit Expense [Abstract]
Discount rate - expense	4.47%	3.48%	4.36%
Health care cost trend rate (employees under 65)	6.49%	6.64%	6.91%
Ultimate health care cost trend rate	4.50%	4.50%	4.50%
Year ultimate trend reached	2028	2028	2028
Effects On OPEB Of A One-Percentage Point Change In The Assumed Health Care Cost Trend Rates [Abstract]
Effect on total service and interest cost components - one % pt. increase	1
Effect on total service and interest cost components - one % pt. decrease	-1
Effect on accumulated benefit obligation - one % pt. increase	19
Effect on accumulated benefit obligation - one % pt. decrease	($16)
OPEB [Member] | 2015 Forecast [Member]
Weighted-Average Actuarial Assumptions Used To Determine Benefit Expense [Abstract]
Health care cost trend rate (employees under 65)				6.49%
Ultimate health care cost trend rate				4.50%
Year ultimate trend reached				2028

Retirement_Plans_Details_4

Retirement Plans (Details 4) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
OPEB [Member]
Cash Contributions [Abstract]
Cash contribution to non-qualified OPEB plan	$25	$23
Pension Qualified Plan [Member]
Cash Contributions [Abstract]
Cash contributions to qualified pension plan	200	200
Pension Non-qualified Plan [Member]
Cash Contributions [Abstract]
Cash contributions to non-qualified pension plan	$33	$16

Retirement_Plans_Details_5

Retirement Plans (Details 5) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Pension [Member]
Benefit Payments [Abstract]
Expected benefit payments - 2015	$180
Expected benefit payments - 2016	186
Expected benefit payments - 2017	191
Expected benefit payments - 2018	196
Expected benefit payments - 2019	201
Expected benefit payments - 2020 - 2024	1,069
OPEB [Member]
Benefit Payments [Abstract]
Expected benefit payments - 2015	23
Expected benefit payments - 2016	23
Expected benefit payments - 2017	23
Expected benefit payments - 2018	23
Expected benefit payments - 2019	23
Expected benefit payments - 2020 - 2024	$107

Retirement_Plans_Details_6

Retirement Plans (Details 6)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Information About Plan Assets [Abstract]
Asset allocation	100.00%	100.00%
Average long-term rate of return target description	The investment strategy for pension plan assets is to maintain a broadly diversified portfolio designed to achieve our target average long-term rate of return of 7.5%.
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]
Target Allocation [Abstract]
Target allocation 2015 range minimum	60.00%
Target allocation 2015 range maximum	70.00%
Defined Benefit Plan Information About Plan Assets [Abstract]
Asset allocation	68.00%	70.00%
Debt Securities [Member]
Target Allocation [Abstract]
Target allocation 2015 range minimum	20.00%
Target allocation 2015 range maximum	30.00%
Defined Benefit Plan Information About Plan Assets [Abstract]
Asset allocation	23.00%	21.00%
Real Estate [Member]
Target Allocation [Abstract]
Target allocation 2015 range minimum	2.00%
Target allocation 2015 range maximum	8.00%
Defined Benefit Plan Information About Plan Assets [Abstract]
Asset allocation	4.00%	4.00%
Commodities [Member]
Target Allocation [Abstract]
Target allocation 2015 range minimum	4.00%
Target allocation 2015 range maximum	6.00%
Defined Benefit Plan Information About Plan Assets [Abstract]
Asset allocation	5.00%	5.00%

Retirement_Plans_Details_7

Retirement Plans (Details 7) (Pension [Member], USD $)	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Retirement Plans [Line Items]
Fair value of plan assets	$3,654		$3,429		$2,875
Temporary Cash Investments [Member]
Retirement Plans [Line Items]
Fair value of plan assets	22		16
Registered Investment Companies [Member]
Retirement Plans [Line Items]
Fair value of plan assets	294		264
U.S. Government Securities [Member]
Retirement Plans [Line Items]
Fair value of plan assets	163		126
Corporate Bonds & Debentures [Member]
Retirement Plans [Line Items]
Fair value of plan assets	381		310
Corporate Stock [Member]
Retirement Plans [Line Items]
Fair value of plan assets	1,091		999
Venture Capital And Buyout Partnerships [Member]
Retirement Plans [Line Items]
Fair value of plan assets	234		213
Real Estate Partnerships [Member]
Retirement Plans [Line Items]
Fair value of plan assets	139		139
Common Trust And Other Funds [Member]
Retirement Plans [Line Items]
Fair value of plan assets	1,340		1,357
Other Assets - Pension Plan [Member]
Retirement Plans [Line Items]
Fair value of plan assets	-10	[1]	5	[1]
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member]
Retirement Plans [Line Items]
Fair value of plan assets	1,110		1,010
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | Temporary Cash Investments [Member]
Retirement Plans [Line Items]
Fair value of plan assets	22		16
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | Registered Investment Companies [Member]
Retirement Plans [Line Items]
Fair value of plan assets	12		11
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | U.S. Government Securities [Member]
Retirement Plans [Line Items]
Fair value of plan assets	0		0
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | Corporate Bonds & Debentures [Member]
Retirement Plans [Line Items]
Fair value of plan assets	0		0
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | Corporate Stock [Member]
Retirement Plans [Line Items]
Fair value of plan assets	1,076		983
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | Venture Capital And Buyout Partnerships [Member]
Retirement Plans [Line Items]
Fair value of plan assets	0		0
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | Real Estate Partnerships [Member]
Retirement Plans [Line Items]
Fair value of plan assets	0		0
Quoted Prices in Active Markets for Identical Inputs (Level 1) [Member] | Common Trust And Other Funds [Member]
Retirement Plans [Line Items]
Fair value of plan assets	0		0
Significant Other Observable Inputs (Level 2) [Member]
Retirement Plans [Line Items]
Fair value of plan assets	2,181		2,062
Significant Other Observable Inputs (Level 2) [Member] | Temporary Cash Investments [Member]
Retirement Plans [Line Items]
Fair value of plan assets	0		0
Significant Other Observable Inputs (Level 2) [Member] | Registered Investment Companies [Member]
Retirement Plans [Line Items]
Fair value of plan assets	282		253
Significant Other Observable Inputs (Level 2) [Member] | U.S. Government Securities [Member]
Retirement Plans [Line Items]
Fair value of plan assets	163		126
Significant Other Observable Inputs (Level 2) [Member] | Corporate Bonds & Debentures [Member]
Retirement Plans [Line Items]
Fair value of plan assets	381		310
Significant Other Observable Inputs (Level 2) [Member] | Corporate Stock [Member]
Retirement Plans [Line Items]
Fair value of plan assets	15		16
Significant Other Observable Inputs (Level 2) [Member] | Venture Capital And Buyout Partnerships [Member]
Retirement Plans [Line Items]
Fair value of plan assets	0		0
Significant Other Observable Inputs (Level 2) [Member] | Real Estate Partnerships [Member]
Retirement Plans [Line Items]
Fair value of plan assets	0		0
Significant Other Observable Inputs (Level 2) [Member] | Common Trust And Other Funds [Member]
Retirement Plans [Line Items]
Fair value of plan assets	1,340		1,357
Significant Unobservable Inputs (Level 3) [Member]
Retirement Plans [Line Items]
Fair value of plan assets	373		352		322
Significant Unobservable Inputs (Level 3) [Member] | Temporary Cash Investments [Member]
Retirement Plans [Line Items]
Fair value of plan assets	0		0
Significant Unobservable Inputs (Level 3) [Member] | Registered Investment Companies [Member]
Retirement Plans [Line Items]
Fair value of plan assets	0		0
Significant Unobservable Inputs (Level 3) [Member] | U.S. Government Securities [Member]
Retirement Plans [Line Items]
Fair value of plan assets	0		0
Significant Unobservable Inputs (Level 3) [Member] | Corporate Bonds & Debentures [Member]
Retirement Plans [Line Items]
Fair value of plan assets	0		0
Significant Unobservable Inputs (Level 3) [Member] | Corporate Stock [Member]
Retirement Plans [Line Items]
Fair value of plan assets	0		0
Significant Unobservable Inputs (Level 3) [Member] | Venture Capital And Buyout Partnerships [Member]
Retirement Plans [Line Items]
Fair value of plan assets	234		213		179
Significant Unobservable Inputs (Level 3) [Member] | Real Estate Partnerships [Member]
Retirement Plans [Line Items]
Fair value of plan assets	139		139		143
Significant Unobservable Inputs (Level 3) [Member] | Common Trust And Other Funds [Member]
Retirement Plans [Line Items]
Fair value of plan assets	$0		$0
[1]	Other assets include accrued receivables and pending broker settlements.

Retirement_Plans_Details_8

Retirement Plans (Details 8) (Pension [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Level 3 Rollforward [Line Items]
Fair value of plan assets at beginning of year			$2,875
Fair value of plan assets at end of year	3,654	3,429	2,875
Significant Unobservable Inputs (Level 3) [Member]
Level 3 Rollforward [Line Items]
Fair value of plan assets at beginning of year	352	322
Realized gain/(loss)	25	15
Unrealized gain	11	27
Purchases	73	66
Sales	-88	-78
Fair value of plan assets at end of year	373	352
Venture Capital And Buyout Partnerships [Member]
Level 3 Rollforward [Line Items]
Fair value of plan assets at end of year	234	213
Venture Capital And Buyout Partnerships [Member] | Significant Unobservable Inputs (Level 3) [Member]
Level 3 Rollforward [Line Items]
Fair value of plan assets at beginning of year	213	179
Realized gain/(loss)	17	7
Unrealized gain	5	24
Purchases	54	43
Sales	-55	-40
Fair value of plan assets at end of year	234	213
Real Estate Partnerships And Funds [Member]
Level 3 Rollforward [Line Items]
Fair value of plan assets at end of year	139	139
Real Estate Partnerships And Funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Level 3 Rollforward [Line Items]
Fair value of plan assets at beginning of year	139	143
Realized gain/(loss)	8	8
Unrealized gain	6	3
Purchases	19	23
Sales	-33	-38
Fair value of plan assets at end of year	$139	$139

Retirement_Plans_Details_9

Retirement Plans (Details 9) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
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. We match 50 cents for each dollar contributed by employees up to the first six percent of compensation contributed.
401(k)/Thrift plan contributions	$19	$18	$15
Railroad Retirement System [Abstract]
Railroad Retirement System description	All Railroad employees are covered by the Railroad Retirement System (the System).
Railroad Retirement System contributions	711	670	644
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	$52	$57	$62

Other_Income_Details

Other Income (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Other Income Details [Abstract]
Rental income	$96		$106	[1]	$83
Net gain on non-operating asset dispositions	69		32		29
Interest Income	4		4		3
Non-operating environmental costs and other	-18	[2]	-14		-7
Total	151		128		108
Land lease contract settlement			17
Permanent easement sale	$14
[1]	Rental income includes $17 million related to a land lease contract settlement.
[2]	Non-operating environmental costs and other includes $14 million related to the sale of a permanent easement.

Income_Taxes_Details_1

Income Taxes (Details 1) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current Income Tax Expense [Abstract]
Current federal income tax expense	$2,029	$1,738	$1,335
Current state income tax expense	239	199	153
Total current income tax expense	2,268	1,937	1,488
Deferred Income Tax Expense [Abstract]
Deferred federal income tax expense	667	659	760
Deferred state income tax expense	136	119	120
Total deferred income tax expense	803	778	880
Unrecognized Tax Benefits [Abstract]
Unrecognized federal tax benefits expense / (benefits)	86	-54	5
Unrecognized state tax benefits expense / (benefits)	6	-1	2
Unrecognized tax benefits expense / (benefits)	92	-55	7
Total income tax expense	$3,163	$2,660	$2,375

Income_Taxes_Details_2

Income Taxes (Details 2)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
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%
Deferred tax adjustments	0.00%	-0.10%	-0.10%
Tax credits	-0.40%	-0.20%	-0.50%
Other tax rate adjustments	0.20%	-0.10%	0.10%
Effective tax rate	37.90%	37.70%	37.60%

Income_Taxes_Details_3

Income Taxes (Details 3) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Components Of Deferred Income Tax (Liabilities)/Assets [Abstract]
Deferred income tax liabilities - property	($15,173)	($14,448)
Deferred income tax liabilities - other	-411	-260
Total deferred income tax liabilities	-15,584	-14,708
Deferred income tax asset - accrued wages	74	71
Deferred income tax asset - accrued casualty costs	228	223
Deferred income tax asset - accrued stock compensation	69	66
Deferred income tax asset - debt and leases	86	41
Deferred income tax asset - retiree benefits	392	100
Deferred income tax asset - credits	164	182
Deferred income tax asset - other	168	130
Total deferred income tax asset	1,181	813
Net deferred income tax liability	-14,403	-13,895
Current portion of deferred taxes	277	268
Non-current portion of deferred taxes	-14,680	-14,163
Income Tax Details [Abstract]
Deferred tax valuation allowance	$0	$0

Income_Taxes_Details_4

Income Taxes (Details 4) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current Unrecognized Tax Benefits [Abstract]
Current liability for unrecognized tax benefits	$6
Reconciliation Of Changes In Unrecognized Tax Benefits Liabilities/(Assets) [Abstract]
Unrecognized tax benefits at January 1	59	115	107
Increases for positions taken in current year	92	24	29
Increases for positions taken in prior years	21	15	4
Decreases for positions taken in prior years	-14	-30	-19
Payments to and settlements with taxing authorities	-7	-63	0
Increases/(decreases) for interest and penalties	1	0	-4
Lapse of statutes of limitations	-1	-2	-2
Unrecognized tax benefits at December 31	$151	$59	$115

Income_Taxes_Details_5

Income Taxes (Details 5) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Interest And Penalties - Income Tax Expense [Abstract]
Total accrued liabilities for interest and penalties	$6	$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			-4
Tax refund in connection to settlement		8
Taxes paid in connection to settlement	$11

Income_Taxes_Details_6

Income Taxes (Details 6) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Unrecognized Tax Benefits That Would Impact Effective Tax Rate [Abstract]
Unrecognized tax benefits that would reduce the effective tax rate	$33	$34	$41
Unrecognized tax benefits that would not reduce the effective tax rate	118	25	74
Total unrecognized tax benefits	$151	$59	$115	$107

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share Details [Abstract]
Net income	$1,431	$1,370	$1,291	$1,088	$1,174	$1,151	$1,106	$957	$5,180	$4,388	$3,943
Weighted-Average Number Of Shares Outstanding [Abstract]
Basic									897.1	926.5	946.2
Dilutive effect of stock options									2.1	2.4	3.6
Dilutive effect of retention shares and units									1.9	2.6	3.1
Diluted									901.1	931.5	952.9
Earnings per share - basic	$1.62	$1.53	$1.43	$1.20	$1.28	$1.25	$1.19	$1.02	$5.77	$4.74	$4.17
Earnings per share - diluted	$1.61	$1.53	$1.43	$1.19	$1.27	$1.24	$1.18	$1.02	$5.75	$4.71	$4.14
Stock options excluded as their inclusion would be antidilutive									0.4	0.5	1.1

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income/(Loss) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at January 1	($750)		($1,186)
Other comprehensive income/(loss) before reclassifications	-2		-1
Amounts reclassified from accumulated other comprehensive income/(loss)	-458	[1]	437	[1]
Net to-date other comprehensive income/(loss), net of taxes	-460	[2]	436	[2]	-132	[2]
Balance at December 31	-1,210		-750		-1,186
Deferred taxes activity other comprehensive income/(loss)	291		-264		82
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at January 1	-713		-1,149
Other comprehensive income/(loss) before reclassifications	10		-1
Amounts reclassified from accumulated other comprehensive income/(loss)	-458	[1]	437	[1]
Net to-date other comprehensive income/(loss), net of taxes	-448		436
Balance at December 31	-1,161		-713
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at January 1	-37		-36
Other comprehensive income/(loss) before reclassifications	-12		-1
Amounts reclassified from accumulated other comprehensive income/(loss)	0		0
Net to-date other comprehensive income/(loss), net of taxes	-12		-1
Balance at December 31	-49		-37
Derivatives [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at January 1	0		-1
Other comprehensive income/(loss) before reclassifications	0		1
Amounts reclassified from accumulated other comprehensive income/(loss)	0		0
Net to-date other comprehensive income/(loss), net of taxes	0		1
Balance at December 31	$0		$0
[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 5 Retirement Plans for additional details.
[2]	Net of deferred taxes of $291 million, ($264) million, and $82 million during 2014, 2013, and 2012, respectively.

Accounts_Receivable_Details

Accounts Receivable (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounts Receivable Details [Abstract]
Allowance for doubtful accounts	$5,000,000	$1,000,000
Allowance for doubtful accounts - receivables not expected to be collected in one year	16,000,000	22,000,000
Receivables Securitization Facility [Abstract]
Total capacity to transfer undivided interests to investors under the receivables securitization facility	650,000,000	600,000,000
Receivables securitization facility renewal date	29-Jul-14
Receivables securitization facility duration	3 years	1 year
Value of the outstanding undivided interest held by investors under the receivables securitization facility	400,000,000	0
Accounts receivable supporting the undivided interest held by investors	1,200,000,000	1,100,000,000
Cost of the receivables securitization facility - interest expense	$4,000,000	$5,000,000	$3,000,000

Properties_Details

Properties (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Cost	$63,214,000,000		$59,812,000,000
Accumulated depreciation	16,942,000,000		16,063,000,000
Net book value	46,272,000,000		43,749,000,000
Properties - Additional Disclosures [Abstract]
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	2,400,000,000		2,300,000,000		2,100,000,000
Land [Member]
Property, Plant and Equipment [Line Items]
Cost	5,194,000,000		5,120,000,000
Net book value	5,194,000,000		5,120,000,000
Road: Rail and Other Track Material [Member]
Property, Plant and Equipment [Line Items]
Cost	14,588,000,000		13,861,000,000
Accumulated depreciation	5,241,000,000		4,970,000,000
Net book value	9,347,000,000		8,891,000,000
Estimated useful life	33 years		35 years
Road: Ties [Member]
Property, Plant and Equipment [Line Items]
Cost	9,102,000,000		8,785,000,000
Accumulated depreciation	2,450,000,000		2,310,000,000
Net book value	6,652,000,000		6,475,000,000
Estimated useful life	33 years		33 years
Road: Ballast [Member]
Property, Plant and Equipment [Line Items]
Cost	4,826,000,000		4,621,000,000
Accumulated depreciation	1,264,000,000		1,171,000,000
Net book value	3,562,000,000		3,450,000,000
Estimated useful life	34 years		34 years
Road: Other Roadway [Member]
Property, Plant and Equipment [Line Items]
Cost	16,476,000,000	[1]	15,596,000,000	[1]
Accumulated depreciation	2,852,000,000	[1]	2,726,000,000	[1]
Net book value	13,624,000,000	[1]	12,870,000,000	[1]
Estimated useful life	47 years	[1]	48 years	[1]
Total Road [Member]
Property, Plant and Equipment [Line Items]
Cost	44,992,000,000		42,863,000,000
Accumulated depreciation	11,807,000,000		11,177,000,000
Net book value	33,185,000,000		31,686,000,000
Equipment: Locomotives [Member]
Property, Plant and Equipment [Line Items]
Cost	8,276,000,000		7,518,000,000
Accumulated depreciation	3,694,000,000		3,481,000,000
Net book value	4,582,000,000		4,037,000,000
Estimated useful life	20 years		20 years
Equipment: Freight Cars [Member]
Property, Plant and Equipment [Line Items]
Cost	2,116,000,000		2,085,000,000
Accumulated depreciation	968,000,000		1,000,000,000
Net book value	1,148,000,000		1,085,000,000
Estimated useful life	25 years		25 years
Equipment: Work Equipment and Other [Member]
Property, Plant and Equipment [Line Items]
Cost	684,000,000		561,000,000
Accumulated depreciation	153,000,000		119,000,000
Net book value	531,000,000		442,000,000
Estimated useful life	18 years		18 years
Total Equipment [Member]
Property, Plant and Equipment [Line Items]
Cost	11,076,000,000		10,164,000,000
Accumulated depreciation	4,815,000,000		4,600,000,000
Net book value	6,261,000,000		5,564,000,000
Technology and Other [Member]
Property, Plant and Equipment [Line Items]
Cost	872,000,000		711,000,000
Accumulated depreciation	320,000,000		286,000,000
Net book value	552,000,000		425,000,000
Estimated useful life	10 years		10 years
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Cost	1,080,000,000		954,000,000
Accumulated depreciation	0		0
Net book value	$1,080,000,000		$954,000,000
[1]	Other roadway includes grading, bridges and tunnels, signals, buildings, and other road assets.

Accounts_Payable_And_Other_Cur1

Accounts Payable And Other Current Liabilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Accounts Payable and Other Current Liabilities Details [Abstract]
Accounts payable	$877	$803
Dividends payable	438	356	318
Income and other taxes payable	412	491
Accrued wages and vacation	409	385
Accrued casualty costs	249	207
Interest payable	178	169
Equipment rents payable	100	96
Other current liabilities	640	579
Total accounts payable and other current liabilities	$3,303	$3,086

Financial_Instruments_Details

Financial Instruments (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Impact [Abstract]
Increase in pre-tax income	$0	$0	$0
Fair Value of Debt Instruments [Abstract]
Fair value of total debt	13,000,000,000	10,200,000,000
Fair value of total debt in excess of carrying value	1,500,000,000	600,000,000
Fixed rate debt securities containing call provisions	163,000,000	163,000,000
Interest Rate Cash Flow Hedges [Abstract]
Change in fair value of cash flow hedges as reported in accumulated other comprehensive loss	0	1,000,000
Interest rate cash flow hedges outstanding	0	0
Interest Rate Derivatives [Abstract]
Interest rate fair value hedges outstanding	0	0
Market and Credit Risk [Abstract]
Collateral for hedging activity	$0	$0

Debt_Details_1

Debt (Details 1) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Item]
Total debt	$11,480	$9,577
Current portion of debt	-462	-705
Total long-term debt	11,018	8,872
Notes And Debentures [Member]
Debt Instrument [Line Item]
Total debt	9,266	8,068
Stated percentage rate range, minimum	2.30%
Stated percentage rate range, maximum	7.90%
Debt due through	1-Jan-54
Capitalized Leases [Member]
Debt Instrument [Line Item]
Total debt	1,520	1,702
Stated percentage rate range, minimum	3.10%
Stated percentage rate range, maximum	8.40%
Debt due through	10-Dec-28
Equipment Obligations [Member]
Debt Instrument [Line Item]
Total debt	597	110
Stated percentage rate range, minimum	3.20%
Stated percentage rate range, maximum	6.70%
Debt due through	2-Jan-31
Receivables Securitization Facility [Member]
Debt Instrument [Line Item]
Total debt	400	0
Floating Rate Term Loan [Member]
Debt Instrument [Line Item]
Total debt	200	200
Debt due through	31-Oct-16
Mortgage Bonds [Member]
Debt Instrument [Line Item]
Total debt	57	57
Stated percentage rate range, minimum	4.80%
Stated percentage rate range, maximum	4.80%
Debt due through	1-Jan-30
Medium-Term Notes [Member]
Debt Instrument [Line Item]
Total debt	23	32
Stated percentage rate range, minimum	9.30%
Stated percentage rate range, maximum	10.00%
Debt due through	15-Apr-20
Tax-Exempt Financings [Member]
Debt Instrument [Line Item]
Total debt	8	12
Debt due through	1-Dec-15
Unamortized Discount [Member]
Debt Instrument [Line Item]
Total debt	($591)	($604)

Debt_Details_2

Debt (Details 2) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Aggregate Debt Maturities Excluding Market Value Adjustments [Abstract]
Debt maturities - 2015	$462
Debt maturities - 2016	606
Debt maturities - 2017	1,065
Debt maturities - 2018	578
Debt maturities - 2019	652
Debt maturities - thereafter	8,117
Total debt	$11,480	$9,577

Debt_Details_3

Debt (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013	Jan. 01, 1997
Credit Facilities [Abstract]
Line of credit facility replaced		$1,800,000,000
Revolving credit facility available credit	1,700,000,000
Revolving credit facility withdrawals	0
Compliance with covenant	At December 31, 2014, and December 31, 2013 (and at all times during the year), we were in compliance with this covenant.
Allowable debt per debt-to-net-worth coverage ratio (as defined in the facility)	42,400,000,000
Outstanding debt (as defined by facility)	11,600,000,000
Cross-default provision (as defined by facility)	125,000,000
Facility expiration date	25-May-19
Commercial paper outstanding	0	0
Commercial paper issued	0
Commercial paper repaid	0
Dividend Restrictions [Abstract]
Retained earnings available for dividends	15,400,000,000		16,300,000,000
Mortgaged Properties [Abstract]
Carrying value of equipment serving as collateral for capital leases and other types of equipment obligations	2,800,000,000		2,900,000,000
Value of Missouri Pacific Railroad company assets that secured mortgage bonds				$6,000,000,000

Debt_Details_4

Debt (Details 4) (USD $)	0 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Aug. 21, 2013	Dec. 31, 2014
Debt Conversion [Line Items]
Original debt	$1,170
Debt exchange fees	9
Cash consideration	280
Accrued and unpaid interest	8
3.646% Debt Due 2024 [Member]
Debt Conversion [Line Items]
New debt	439
New rate	3.65%
New due date		15-Feb-24
Date of exchange		21-Aug-13
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		2016
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		2017
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		2017
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		2018
3.646% Debt Due 2024 [Member] | 7.875% Notes Due 2019 [Member]
Debt Conversion [Line Items]
Original debt	20
Original rate	7.88%
Original due date, year		2019
3.646% Debt Due 2024 [Member] | 6.125% Notes Due 2020 [Member]
Debt Conversion [Line Items]
Original debt	238
Original rate	6.13%
Original due date, year		2020
4.821% Debt Due 2044 [Member]
Debt Conversion [Line Items]
New debt	700
New rate	4.82%
New due date		1-Feb-44
Date of exchange		21-Aug-13
4.821% Debt Due 2044 [Member] | 7.125% Debentures Due 2028 [Member]
Debt Conversion [Line Items]
Original debt	73
Original rate	7.13%
Original due date, year		2028
4.821% Debt Due 2044 [Member] | 6.625% Debentures Due 2029 [Member]
Debt Conversion [Line Items]
Original debt	177
Original rate	6.63%
Original due date, year		2029
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		2034
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		2037
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		2040

Debt_Details_5

Debt (Details 5) (USD $)	12 Months Ended	0 Months Ended
	Dec. 31, 2014	20-May-14	Dec. 31, 2013	Jan. 10, 2014	Aug. 12, 2014	Feb. 05, 2015	Jan. 29, 2015
Receivables Securitization Facility Debt [Abstract]
Secured debt under receivables securitization facility	400,000,000		$0
Unsecured Debt [Member]
Shelf Registration Statement and Significant New Borrowings [Abstract]
Board of Directors remaining debt issuance	1,150,000,000
Unsecured Debt [Member] | 2.25% Notes Due 2019 [Member]
Shelf Registration Statement and Significant New Borrowings [Abstract]
Issuance date	10-Jan-14
Note amount				300,000,000
Maturity date on new borrowing	15-Feb-19
Interest rate on note				2.25%
Unsecured Debt [Member] | 3.75% Notes Due 2024 [Member]
Shelf Registration Statement and Significant New Borrowings [Abstract]
Issuance date	10-Jan-14
Note amount				400,000,000
Maturity date on new borrowing	15-Mar-24
Interest rate on note				3.75%
Unsecured Debt [Member] | 4.85% Notes Due 2044 [Member]
Shelf Registration Statement and Significant New Borrowings [Abstract]
Issuance date	10-Jan-14
Note amount				300,000,000
Maturity date on new borrowing	15-Jun-44
Interest rate on note				4.85%
Unsecured Debt [Member] | 3.25% Notes Due 2025 [Member]
Shelf Registration Statement and Significant New Borrowings [Abstract]
Issuance date	12-Aug-14
Note amount					350,000,000
Maturity date on new borrowing	15-Jan-25
Interest rate on note					3.25%
Unsecured Debt [Member] | 4.15% Notes Due 2045 [Member]
Shelf Registration Statement and Significant New Borrowings [Abstract]
Issuance date	12-Aug-14
Note amount					350,000,000
Maturity date on new borrowing	15-Jan-45
Interest rate on note					4.15%
Pass-Through Trust Certificate [Member] | 3.227% Certificates Due 2026 [Member]
Shelf Registration Statement and Significant New Borrowings [Abstract]
Issuance date	20-May-14
Note amount		500,000,000
Maturity date on new borrowing	14-May-26
Interest rate on note		3.23%
Total locomotives financed from proceeds		245
Debt issuance costs		3,000,000
Subsequent Event [Member]
Shelf Registration Statement and Significant New Borrowings [Abstract]
Board of Directors authorized debt issuance						4,000,000,000
Subsequent Event [Member] | Unsecured Debt [Member] | 1.80% Notes Due 2020 [Member]
Shelf Registration Statement and Significant New Borrowings [Abstract]
Issuance date	29-Jan-15
Note amount							250,000,000
Maturity date on new borrowing	1-Feb-20
Interest rate on note							1.80%
Subsequent Event [Member] | Unsecured Debt [Member] | 3.375% Notes Due 2035 [Member]
Shelf Registration Statement and Significant New Borrowings [Abstract]
Issuance date	29-Jan-15
Note amount							450,000,000
Maturity date on new borrowing	1-Feb-35
Interest rate on note							3.38%
Subsequent Event [Member] | Unsecured Debt [Member] | 3.875% Notes Due 2055 [Member]
Shelf Registration Statement and Significant New Borrowings [Abstract]
Issuance date	29-Jan-15
Note amount							$450,000,000
Maturity date on new borrowing	1-Feb-55
Interest rate on note							3.88%

Debt_Details_6

Debt (Details 6) (Bonds [Member], 5.65% Notes Due 2022 [Member], USD $)	0 Months Ended	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	14-May-13	Jun. 30, 2013	Dec. 31, 2014
Bonds [Member] | 5.65% Notes Due 2022 [Member]
Extinguishment of Debt [Line Items]
Debt redemption	$40
Interest rate on note	5.65%
Due date of debt			1-Dec-22
Early extinguishment of debt		($1)

Variable_Interest_Entities_Det

Variable Interest Entities (Details) (USD $)	Dec. 31, 2014
In Billions, unless otherwise specified
Variable Interest Entities Details [Abstract]
Future minimum lease payments	$3

Leases_Details

Leases (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Future Minimum Lease Payments For Capital Leases [Abstract]
Minimum capital lease payments - 2015	$253
Minimum capital lease payments - 2016	249
Minimum capital lease payments - 2017	246
Minimum capital lease payments - 2018	224
Minimum capital lease payments - 2019	210
Minimum capital lease payments - later years	745
Total minimum capital lease payments	1,927
Capital lease payments - amount representing interest	-407
Capital lease payments - present value of minimum lease payments	1,520
Properties held under capital leases	2,454	2,486
Properties held under capital leases - accumulated depreciation	1,210	1,092
Lease payments related to locomotives	95.00%
Future Minimum Lease Payments For Operating Leases [Abstract]
Minimum operating lease payments - 2015	508
Minimum operating lease payments - 2016	484
Minimum operating lease payments - 2017	429
Minimum operating lease payments - 2018	356
Minimum operating lease payments - 2019	323
Minimum operating lease payments - later years	1,625
Total minimum operating lease payments	3,725
Rent expense for operating leases with terms exceeding one month	$593	$618	$631

Commitments_And_Contingencies_1

Commitments And Contingencies (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Liability Activity [Abstract]
Commitments and contingencies, current portion, ending balance at December 31	$249	$207
Environmental [Abstract]
Beginning balance at January 1	171	170	172
Accruals	56	58	48
Payments	-45	-57	-50
Ending balance at December 31	182	171	170
Current portion, ending balance at December 31	60	53	50
Sites identified which we are or may be liable for remediation costs	270
Sites subject of actions taken by the U.S. government	29
Sites on the Superfund National Priorities List	16
Personal Injury [Member]
Liability Activity [Abstract]
Commitments and contingencies, beginning balance	294	334	368
Accruals/(credits)	96	87	121
Changes in estimates for prior years	9	-38	-58
Payments	-64	-89	-97
Commitments and contingencies, ending balance at December 31	335	294	334
Commitments and contingencies, current portion, ending balance at December 31	111	82	95
Reasonably possible outcome of related claims, range minimum	335
Reasonably possible outcome of related claims, range maximum	368
Asserted And Unasserted Claims [Abstract]
Percent of liability recorded related to asserted claims	93.00%
Percent of liability recorded related to unasserted claims	7.00%
Asbestos Issue [Member]
Liability Activity [Abstract]
Commitments and contingencies, beginning balance	131	139	147
Accruals/(credits)	1	2	-2
Payments	-6	-10	-6
Commitments and contingencies, ending balance at December 31	126	131	139
Commitments and contingencies, current portion, ending balance at December 31	8	9	8
Reasonably possible outcome of related claims, range minimum	126
Reasonably possible outcome of related claims, range maximum	135
Asserted And Unasserted Claims [Abstract]
Percent of liability recorded related to asserted claims	21.00%
Percent of liability recorded related to unasserted claims	79.00%
Guarantees [Member]
Guarantees [Abstract]
Maximum potential amount of guarantee payments	82	299
Recorded liability for fair value of guarantees	$0.30	$1
Expiration year of final guarantee	The final guarantee expires in 2022.

Share_Repurchase_Program_Detai

Share Repurchase Program (Details) (USD $)	1 Months Ended	3 Months Ended								12 Months Ended
	Feb. 06, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 01, 2014
Shares Repurchased [Abstract]
BOD authorized													120,000,000
Stock repurchase program expiration date										31-Dec-17
Share repurchases (Note 19) (shares)	2,800,000	7,736,400	8,347,000	8,320,000	7,640,000	9,858,110	7,333,788	6,122,940	5,762,800	32,043,400	29,077,638
Average purchase price		$113.77	$102.54	$96.84	$89.43	$79.68	$78.39	$75.71	$68.29	$100.65	$76.26
Remaining number of shares yet to be repurchased		87,956,600								87,956,600
Aggregate cost	$327,000,000									$3,225,000,000	$2,218,000,000	$1,474,000,000
Stock repurchased since inception										$12,600,000,000

Selected_Quarterly_Data_Unaudi2

Selected Quarterly Data (Unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Selected Quarterly Data (Unaudited) [Abstract]
Operating revenues	$6,153	$6,182	$6,015	$5,638	$5,630	$5,573	$5,470	$5,290	$23,988	$21,963	$20,926
Operating income	2,373	2,330	2,196	1,854	1,973	1,962	1,878	1,633	8,753	7,446	6,745
Net income	$1,431	$1,370	$1,291	$1,088	$1,174	$1,151	$1,106	$957	$5,180	$4,388	$3,943
Net Income Per Share [Abstract]
Earnings per share - basic	$1.62	$1.53	$1.43	$1.20	$1.28	$1.25	$1.19	$1.02	$5.77	$4.74	$4.17
Earnings per share - diluted	$1.61	$1.53	$1.43	$1.19	$1.27	$1.24	$1.18	$1.02	$5.75	$4.71	$4.14

Schedule_Of_Valuation_And_Qual2

Schedule Of Valuation And Qualifying Accounts (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Presented in Consolidated Statements of Financial Position [Abstract]
Allowance for doubtful accounts - current	$5	$1
Allowance for doubtful accounts - long-term	16	22
Accrued casualty costs, current	249	207
Allowance For Doubtful Accounts [Member]
Schedule Of Valuation And Qualifying Accounts [Line Items]
Balance, beginning of period	23	37	50
Reduction to expense		-4	-1
Charges to expense	5
Net write-offs / cash payments and other reductions	-7	-10	-12
Balance, end of period	21	23	37
Presented in Consolidated Statements of Financial Position [Abstract]
Allowance for doubtful accounts - current	5	1	4
Allowance for doubtful accounts - long-term	16	22	33
Accrued Casualty Costs [Member]
Schedule Of Valuation And Qualifying Accounts [Line Items]
Balance, beginning of period	702	734	778
Charges to expense	256	188	190
Net write-offs / cash payments and other reductions	-201	-220	-234
Balance, end of period	757	702	734
Presented in Consolidated Statements of Financial Position [Abstract]
Accrued casualty costs, current	249	207	213
Accrued casualty costs, long-term	$508	$495	$521