CSX (CSX) 10-K11 Feb 152014 FY Annual reportFinancial data

Company Profile

Document_And_Entity_Informatio

Document And Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 26, 2014	Jan. 23, 2015	Jun. 27, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	CSX CORP
Entity Central Index Key	277948
Current Fiscal Year End Date	-14
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$31
Entity Common Stock, Shares Outstanding		990,564,824
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	26-Dec-14

CONSOLIDATED_INCOME_STATEMENTS

CONSOLIDATED INCOME STATEMENTS (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Income Statement [Abstract]
Revenue	$12,669	$12,026	$11,763
Expense
Labor and Fringe	3,377	3,138	3,020
Materials, Supplies and Other	2,484	2,275	2,156
Fuel	1,616	1,656	1,672
Depreciation	1,151	1,104	1,059
Equipment and Other Rents	428	380	392
Total Expense	9,056	8,553	8,299
Operating Income	3,613	3,473	3,464
Interest Expense	-545	-562	-566
Other (Expense) Income - Net	-24	11	73
Earnings Before Income Taxes	3,044	2,922	2,971
Income Tax Expense	-1,117	-1,058	-1,108
Net Earnings	$1,927	$1,864	$1,863
Net Earnings Per Share, Basic
Earnings Per Share, Basic (dollars per share)	$1.93	$1.83	$1.80
Net Earnings Per Common Share, Assuming Dilution
Earnings Per Share, Assuming Dilution (dollars per share)	$1.92	$1.83	$1.79
Average Common Shares Outstanding, Basic (shares)	1,001	1,019	1,038
Average Common Shares Outstanding, Assuming Dilution (shares)	1,002	1,019	1,040
Common Stock Dividends (dollars per share)	$0.63	$0.59	$0.54

CONSOLIDATED_COMPREHENSIVE_INC

CONSOLIDATED COMPREHENSIVE INCOME STATEMENTS (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Sep. 26, 2014	Jun. 27, 2014	Mar. 28, 2014	Dec. 27, 2013	Sep. 27, 2013	Jun. 28, 2013	Mar. 29, 2013	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Net Earnings	$491	$509	$529	$398	$426	$455	$521	$462	$1,927	$1,864	$1,863
Other Comprehensive (Loss) Income, Net of Tax									-143	413	-61
Comprehensive Earnings									1,784	2,277	1,802
Pension and Other Post-Employment Benefits
Other Comprehensive (Loss) Income, Net of Tax									-149	389	-52
Other
Other Comprehensive (Loss) Income, Net of Tax									$6	$24	($9)

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
Current Assets:
Cash and Cash Equivalents	$669	$592	$784	$783
Short-term Investments	292	487
Accounts Receivable - Net	1,129	1,052
Materials and Supplies	273	252
Deferred Income Taxes	141	155
Other Current Assets	68	64
Total Current Assets	2,572	2,602
Noncurrent Assets
Properties	39,343	37,184
Accumulated Depreciation	-10,759	-9,893
Properties - Net	28,584	27,291
Other Long-term Assets	541	591
Total Assets	33,053	31,782
Current Liabilities:
Accounts Payable	845	957
Labor and Fringe Benefits Payable	613	587
Casualty, Environmental and Other Reserves	142	151
Current Maturities of Long-term Debt	228	533
Income and Other Taxes Payable	163	91
Other Current Liabilities	116	105
Total Current Liabilities	2,107	2,424
Noncurrent Liabilities
Casualty, Environmental and Other Reserves	276	300
Long-term Debt	9,514	9,022
Deferred Income Taxes	8,858	8,662
Other Long-term Liabilities	1,122	870
Total Liabilities	21,877	21,278
Shareholders' Equity:
Common Stock, $1 Par Value	992	1,009
Other Capital	92	61
Retained Earnings	10,734	9,936
Accumulated Other Comprehensive Loss	-666	-523	-936	-875
Noncontrolling Minority Interest	24	21
Total Shareholders' Equity	11,176	10,504	9,136	8,598
Total Liabilities and Shareholders' Equity	33,053	31,782
Investments in Conrail
Noncurrent Assets
Investment in Affiliates and Joint Ventures	779	752
Affiliates and Other Companies
Noncurrent Assets
Investment in Affiliates and Joint Ventures	$577	$546

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 26, 2014	Dec. 27, 2013
Statement of Financial Position [Abstract]
Common stock par value (dollars per share)	$1	$1

CONSOLIDATED_CASH_FLOW_STATEME

CONSOLIDATED CASH FLOW STATEMENTS (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
OPERATING ACTIVITIES
Net Earnings	$1,927	$1,864	$1,863
Adjustments to Reconcile Net Earnings to Net Cash
Depreciation	1,151	1,104	1,059
Deferred Income Taxes	298	300	592
Contributions to Qualified Pension Plans	0	0	-275
Gain on Property Dispositions	-11	-70	-166
Other Operating Activities	14	-35	-64
Changes in Operating Assets and Liabilities:
Accounts Receivable	-119	-6	61
Other Current Assets	-26	36	-32
Accounts Payable	1	28	-4
Income and Other Taxes Payable	74	-67	-14
Other Current Liabilities	34	113	-74
Net Cash Provided by Operating Activities	3,343	3,267	2,946
INVESTING ACTIVITIES
Property Additions	-2,449	-2,313	-2,341
Purchase of Short-term Investments	-1,433	-1,256	-633
Proceeds from Sales of Short-term Investments	1,674	1,401	581
Proceeds from Property Dispositions	62	53	186
Other Investing Activities	-37	-112	-70
Net Cash Used in Investing Activities	-2,183	-2,227	-2,277
FINANCING ACTIVITIES
Long-term Debt Issued	1,000	500	1,100
Long-term Debt Repaid	-933	-780	-508
Dividends Paid	-629	-600	-558
Stock Options Exercised	0	9	14
Shares Repurchased	-517	-353	-734
Other Financing Activities	-4	-8	18
Net Cash Used in Financing Activities	-1,083	-1,232	-668
Net (Decrease) Increase in Cash and Cash Equivalents	77	-192	1
CASH AND CASH EQUIVALENTS
Cash and Cash Equivalents at Beginning of Period	592	784	783
Cash and Cash Equivalents at End of Period	669	592	784
SUPPLEMENTAL CASH FLOW INFORMATION
Interest Paid - Net of Amounts Capitalized	575	595	592
Income Taxes Paid	$741	$824	$506

CONSOLIDATED_STATEMENTS_OF_CHA

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS EQUITY (USD $)	Total	Common Shares Outstanding	Common Stock and Other Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)		Non-controlling Interest
In Millions, except Share data in Thousands, unless otherwise specified	USD ($)	Common Shares Outstanding	USD ($)	USD ($)	USD ($)		USD ($)
Shareholders' Equity, beginning balance at Dec. 30, 2011	$8,598		$1,055	$8,405	($875)	[1]	$13
Common Shares Outstanding, beginning balance at Dec. 30, 2011		1,049,157
Accumulated other comprehensive loss, tax					496
Comprehensive Earnings:
Net Earnings	1,863			1,863
Other Comprehensive (Loss) Income	-61				-61	[1]
Comprehensive Earnings	1,802
Common stock dividends	-558			-558			0
Share Repurchases (shares)	-34,000	-34,088
Share Repurchases	-734		-34	-700
Bond Conversions (shares)		155
Bond Conversions	1		1
Stock Option Exercises and Other (shares)		5,261
Stock Option Exercises and Other	27		26	0			1
Shareholders' Equity, ending balance at Dec. 28, 2012	9,136		1,048	9,010	-936	[1]	14
Common Shares Outstanding, ending balance at Dec. 28, 2012		1,020,485
Accumulated other comprehensive loss, tax					266
Comprehensive Earnings:
Net Earnings	1,864			1,864
Other Comprehensive (Loss) Income	413				413	[1]
Comprehensive Earnings	2,277
Common stock dividends	-600			-600			0
Share Repurchases (shares)	-14,000	-13,791
Share Repurchases	-353		-14	-339
Bond Conversions (shares)		1
Bond Conversions	0		0
Stock Option Exercises and Other (shares)		2,165
Stock Option Exercises and Other	44		36	1			7
Shareholders' Equity, ending balance at Dec. 27, 2013	10,504		1,070	9,936	-523	[1]	21
Common Shares Outstanding, ending balance at Dec. 27, 2013		1,008,860
Accumulated other comprehensive loss, tax					354
Comprehensive Earnings:
Net Earnings	1,927			1,927
Other Comprehensive (Loss) Income	-143				-143	[1]
Comprehensive Earnings	1,784
Common stock dividends	-629			-629			0
Share Repurchases (shares)	-17,000	-17,010
Share Repurchases	-517		-17	-500
Bond Conversions (shares)		134
Bond Conversions	1		1
Other (shares)		-393
Other	33		30	0			3
Shareholders' Equity, ending balance at Dec. 26, 2014	$11,176		$1,084	$10,734	($666)	[1]	$24
Common Shares Outstanding, ending balance at Dec. 26, 2014		991,591

[1]	Accumulated Other Comprehensive Loss year-end balances shown above are net of tax. The associated taxes were $496 million, $266 million and $354 million for 2012, 2013 and 2014, respectively. For additional information see Note 14, Other Comprehensive Income.

CONSOLIDATED_STATEMENTS_OF_CHA1

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS EQUITY (Parenthetical) (USD $)	12 Months Ended
	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Common Stock Dividends (dollars per share)	$0.63	$0.59	$0.54

Nature_of_Operations_and_Signi

Nature of Operations and Significant Accounting Policies	12 Months Ended
	Dec. 26, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations and Significant Accounting Policies	Nature of Operations and Significant Accounting Policies

	Business
	CSX Corporation (“CSX”), and together with its subsidiaries (the “Company”), based in Jacksonville, Florida, is one of the nation's leading transportation companies. The Company provides rail-based transportation services including traditional rail service and the transport of intermodal containers and trailers.

	The Company’s annual average number of employees was approximately 32,000 in 2014, which includes approximately 26,000 union employees. Most of the Company’s employees provide or support transportation services.

	CSX Transportation, Inc.
	CSX’s principal operating subsidiary, CSX Transportation, Inc. (“CSXT”), provides an important link to the transportation supply chain through its approximately 21,000 route mile rail network, which serves major population centers in 23 states east of the Mississippi River, the District of Columbia and the Canadian provinces of Ontario and Quebec. It has access to over 70 ocean, river and lake port terminals along the Atlantic and Gulf Coasts, the Mississippi River, the Great Lakes and the St. Lawrence Seaway. The Company’s intermodal business, also part of CSXT, links customers to railroads via trucks and terminals. CSXT also serves thousands of production and distribution facilities through track connections to approximately 240 short-line and regional railroads.

	Lines of Business
	During 2014, the Company services generated $12.7 billion of revenue and served three primary lines of business:


	•	The merchandise business shipped over 2.9 million carloads and generated approximately 60% of revenue and 42% of volume in 2014. The Company’s merchandise business is the most diverse market and transports aggregates (which include crushed stone, sand and gravel), metal, phosphate, fertilizer, food, consumer (manufactured goods and appliances), agricultural, automotive, paper and chemical products.

	•	The coal business shipped nearly 1.3 million carloads and accounted for 22% of revenue and 18% of volume in 2014. The Company transports domestic coal, coke and iron ore to electricity-generating power plants, steel manufacturers and industrial plants as well as export coal to deep-water port facilities. Almost half of export coal and nearly all of the domestic coal that the Company transports is used for generating electricity.

	•	The intermodal business accounted for approximately 14% of revenue and 40% of volume in 2014. The intermodal line of business combines the superior economics of rail transportation with the short-haul flexibility of trucks and offers a competitive cost advantage over long-haul trucking. Through a network of more than 50 terminals, the intermodal business serves all major markets east of the Mississippi and transports mainly manufactured consumer goods in containers, providing customers with truck-like service for longer shipments.

	Other revenue accounted for approximately 4% of the Company’s total revenue in 2014. This revenue category includes revenue from regional subsidiary railroads, demurrage, revenue for customer volume commitments not met, switching and other incidental charges. Revenue from regional railroads includes shipments by railroads that the Company does not directly operate. Demurrage represents charges assessed when freight cars are held beyond a specified period of time. Switching revenue is primarily generated when CSXT switches cars for a customer or another railroad.
	NOTE 1. Nature of Operations and Significant Accounting Policies, continued

	Other Entities
	In addition to CSXT, the Company’s subsidiaries include CSX Intermodal Terminals, Inc. (“CSX Intermodal Terminals”), Total Distribution Services, Inc. (“TDSI”), Transflo Terminal Services, Inc. (“Transflo”), CSX Technology, Inc. (“CSX Technology”) and other subsidiaries. CSX Intermodal Terminals owns and operates a system of intermodal terminals, predominantly in the eastern United States and also performs drayage services (the pickup and delivery of intermodal shipments) for certain CSXT customers and trucking dispatch operations. TDSI serves the automotive industry with distribution centers and storage locations. Transflo connects non-rail served customers to the many benefits of rail by transferring products from rail to trucks. Today, the biggest Transflo markets are chemicals and agriculture, which includes shipments of plastics and ethanol. CSX Technology and other subsidiaries provide support services for the Company.

	CSX’s other holdings include CSX Real Property, Inc., a subsidiary responsible for the Company’s real estate sales, leasing, acquisition and management and development activities. These activities are classified in other income - net because they are not considered to be operating activities by the Company. Results of these activities fluctuate with the timing of non-operating real estate transactions.

	Basis of Presentation
	In the opinion of management, the accompanying consolidated financial statements contain all normal, recurring adjustments necessary to fairly present the financial position of CSX and its subsidiaries at December 26, 2014 and December 27, 2013, and the consolidated statements of income, comprehensive income, cash flows and changes in shareholders’ equity for fiscal years 2014, 2013 and 2012. In addition, management has evaluated and disclosed all material events occurring subsequent to the date of the financial statements up to the date this annual report is filed on Form 10-K.

	Fiscal Year
	CSX follows a 52/53 week fiscal reporting calendar. This fiscal calendar allows every quarter to consistently end on a Friday and typically, to be of equal duration (13 weeks), resulting in a 52 week fiscal year. To maintain this type of reporting calendar every fifth or sixth year (depending on the Gregorian calendar and when leap year falls), an extra week will be included in the fourth quarter (a 14-week fiscal quarter) and, therefore, that full fiscal year will have 53 weeks. The next 53 week fiscal year will be 2016, which will end on December 30, 2016.

	Fiscal years 2014, 2013 and 2012 each consisted of 52 weeks ending on December 26, 2014, December 27, 2013 and December 28, 2012, respectively. Except as otherwise specified, references to full year indicate CSX’s fiscal periods ended on these dates.

	Principles of Consolidation
	The consolidated financial statements include results of operations of CSX and subsidiaries over which CSX has majority ownership or financial control. All significant intercompany accounts and transactions have been eliminated. Most investments in companies that were not majority-owned were carried at cost (if less than 20% owned and the Company has no significant influence) or were accounted for under the equity method (if the Company has significant influence but does not control). These investments are reported within Investment in Conrail or Affiliates and Other Investments on the consolidated balance sheets.


	NOTE 1. Nature of Operations and Significant Accounting Policies, continued

	Cash and Cash Equivalents
	On a daily basis, cash in excess of current operating requirements is invested in various highly liquid investments having a typical maturity date of three months or less at the date of acquisition. These investments were carried at cost, which approximated market value, and were classified as cash equivalents.

	Investments
	Investments in instruments with original maturities greater than three months but will mature in less than one year were classified as short-term investments. Investments with maturities greater than one year were classified within other long-term assets.

	Allowance for Doubtful Accounts
	The Company maintains an allowance for doubtful accounts on uncollectible amounts related to freight receivables, government reimbursement receivables, claims for damages and other various receivables. The allowance is based upon the credit worthiness of customers, historical experience, the age of the receivable and current market and economic conditions. Uncollectible amounts are charged against the allowance account. Allowance for doubtful accounts of $41 million and $33 million is included in the consolidated balance sheets as of December 2014 and December 2013, respectively.

	Materials and Supplies
	Materials and supplies in the consolidated balance sheets are carried at average costs and consist primarily of fuel and parts used in the repair and maintenance of CSXT’s freight car and locomotive fleets, equipment and track structure.

	Goodwill
	Goodwill represents purchase price in excess of fair value and is related to affiliates of CSXT, primarily P&L Transportation, Inc. Goodwill of $63 million and $64 million is recorded in other long-term assets in the consolidated balance sheets as of December 2014 and 2013, respectively.

	Revenue and Expense Recognition
	The Company recognizes freight revenue using Free-On-Board Origin pursuant to the Revenue Recognition Topic in the ASC. Accounting guidance in this topic provides for the allocation of revenue between reporting periods based on relative transit time in each reporting period. Expenses are recognized as incurred.

	The certain key estimates included in the recognition and measurement of revenue and related accounts receivable under the policies described above are as follows:

	•	revenue associated with shipments in transit is recognized ratably over transit time and is based on average cycle times to move commodities and products from their origin to their final destination or interchange;

•	adjustments to revenue for billing corrections, billing discounts and bad debts or to accounts receivable for allowances for doubtful accounts;

•	adjustments to revenue for overcharge claims filed by customers, which are based on historical cash paid to customers for rate overcharges as a percentage of total billing;

NOTE 1. Nature of Operations and Significant Accounting Policies, continued


•	incentive-based refunds to customers, which are primarily based on customers achieving certain volume thresholds and are recorded as a reduction to revenue on the basis of management’s best estimate of the projected liability (this estimate is based on historical activity, current volume levels and a forecast of future volume);
The Company regularly updates the estimates described above based on historical experience and current conditions. All other revenue, such as demurrage, switching and other incidental charges are recorded upon completion of the service.

New Accounting Pronouncements
In May 2014, the FASB issued an Accounting Standards Update, Revenue from Contracts with Customers, which supersedes previous revenue recognition guidance. The new standard requires that a company recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration the company expects to receive in exchange for those goods or services. Companies will need to use more judgment and estimates than under the guidance currently in effect, including estimating the amount of variable revenue to recognize over each identified performance obligation. Additional disclosures will be required to help users of financial statements understand the nature, amount and timing of revenue and cash flows arising from contracts. The new standard will become effective for CSX beginning with the first quarter 2017 and can be adopted either retrospectively to each prior reporting period presented or as a cumulative effect adjustment as of the date of adoption. The Company is currently evaluating the impact of adopting this new guidance on the consolidated financial statements.

In February 2013, the FASB issued an Accounting Standards Update to the Comprehensive Income Topic in the Accounting Standards Codifications ("ASC"). This update requires separate presentation of the components that are reclassified out of accumulated other comprehensive income either on the face of the financial statements or in the notes to the financial statements. This update also requires companies to disclose the income statement line items impacted by any significant reclassifications, such as the amortization of pension and other post-employment benefits adjustments. These items are required for both interim and annual reporting for public companies and became effective for CSX beginning with the first quarter 2013 Form 10-Q filing.

Use of Estimates
The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires that management make estimates in reporting the amounts of certain assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amount of certain revenues and expenses during the reporting period. Actual results may differ from those estimates. Critical accounting estimates using management judgment are made for the following areas:

•	casualty, environmental and legal reserves (see Note 5, Casualty, Environmental and Other Reserves);

•	pension and post-retirement medical plan accounting (see Note 8, Employee Benefit Plans);

•	depreciation policies for assets under the group-life method (see Note 6, Properties); and

•	income taxes (see Note 11, Income Taxes).

NOTE 1. Nature of Operations and Significant Accounting Policies, continued

Other Items
Share Repurchases
In April 2013, the Company announced a new $1 billion share repurchase program, which is expected to be completed by April 2015. Management's assessment of market conditions and other factors guides the timing and volume of repurchases. Future share repurchases are expected to be funded by cash on hand, cash generated from operations and debt issuances. During 2014 and 2013, CSX repurchased $517 million, or 17 million shares, and $353 million or 14 million shares, respectively, of common stock under this program. Additionally, the Company repurchased a total of $734 million, or 34 million shares in 2012 under a previous share repurchase program. In accordance with the Equity Topic in the ASC, the excess of repurchase price over par value is recorded in retained earnings. Generally, retained earnings is only impacted by net earnings and dividends.

Workforce Reduction Plan
In November 2014, the Company announced a workforce reduction plan to streamline the organization. The initiative reduced management workforce by approximately 300 positions through a voluntary separation program with enhanced benefits as well as a subsequent involuntary severance over the fourth quarter of 2014 and the first quarter of 2015. The Company recorded an initial charge of $39 million related to this program. The total estimated cost of the program is expected to be approximately $45 million. The majority of separation benefits will be paid from CSX’s qualified pension plans, with the remainder being paid from general corporate funds.

Earnings_Per_Share

Earnings Per Share	12 Months Ended
	Dec. 26, 2014
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share

	The following table sets forth the computation of basic earnings per share and earnings per share, assuming dilution:


		Fiscal Years
		2014			2013		2012
	Numerator (Dollars in Millions):
	Net Earnings	$	1,927		$	1,864	$	1,863

	Dividend Equivalents on Restricted Stock	(1		)	—		—

	Net Earnings, Attributable to Common Shareholders	$	1,926		$	1,864	$	1,863


	Denominator (Units in Millions):
	Average Common Shares Outstanding	1,001			1,019		1,038

	Other Potentially Dilutive Common Shares	1			—		2

	Average Common Shares Outstanding, Assuming Dilution	1,002			1,019		1,040


	Net Earnings Per Share, Basic	$	1.93		$	1.83	$	1.8

	Net Earnings Per Share, Assuming Dilution	$	1.92		$	1.83	$	1.79


	Basic earnings per share is based on the weighted-average number of shares of common stock outstanding. Earnings per share, assuming dilution, is based on the weighted-average number of shares of common stock equivalents outstanding adjusted for the effects of common stock that may be issued as a result of the following types of potentially dilutive instruments:
	NOTE 2. Earnings Per Share, continued


	•	equity awards, which include long-term incentive awards; and

	•	in prior periods, employee stock options (all stock options expired in May 2013).

	The Earnings Per Share Topic in the ASC requires CSX to include additional shares in the computation of earnings per share, assuming dilution. The additional shares included in diluted earnings per share represent the number of shares that would be issued if all of the above potentially dilutive instruments were converted into CSX common stock.

Shareholders_Equity

Shareholders' Equity	12 Months Ended
	Dec. 26, 2014
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Shareholders’ Equity

	Common and preferred stock consists of the following:




	Common Stock, $1 Par Value	Dec-14
		(Units in Millions)
	Common Shares Authorized	1,800

	Common Shares Issued and Outstanding	992


	Preferred Stock
	Preferred Shares Authorized	25

	Preferred Shares Issued and Outstanding	—


	Holders of common stock are entitled to one vote on all matters requiring a vote for each share held. Preferred stock is senior to common stock with respect to dividends and upon liquidation of CSX.

Stock_Plans_and_ShareBased_Com

Stock Plans and Share-Based Compensation	12 Months Ended
	Dec. 26, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Plans and Share-Based Compensation	Stock Plans and Share-Based Compensation

	Under CSX's share-based compensation plans, awards primarily consist of performance grants, restricted stock awards, restricted stock units and stock grants for directors. Awards granted under the various programs are determined and approved by the Compensation Committee of the Board of Directors or, in certain circumstances, by the Chief Executive Officer for awards to management employees other than senior executives. The Board of Directors approves awards granted to the Company’s non-management directors upon recommendation of the Governance Committee.

	The Compensation-Stock Compensation Topic in the ASC requires the cash flows resulting from income tax deductions in excess of compensation costs to be classified as financing cash flows. This requirement resulted in reduced net operating cash flows and increased net financing cash flows of approximately $3 million, $13 million and $37 million for fiscal years 2014, 2013 and 2012, respectively.

	The Compensation-Stock Compensation Topic also requires the disclosure of total compensation costs for share-based payment arrangements and the related tax benefits recognized in income. Share-based compensation expense is measured at the fair market value of the Company’s stock on the grant date and is recognized on a straight-line basis over the service period of the respective award. Total pre-tax expense associated with share-based compensation and its related income tax benefit is as follows:

	NOTE 4. Stock Plans and Share-Based Compensation, continued


		Fiscal Years
	(Dollars in Millions)	2014				2013				2012
	Share-Based Compensation Expense	$	33			$	14			$	14

	Income Tax Benefit	13				6				5


	Restricted Stock Grants

	Restricted stock grants consist of units and awards. Restricted stock units are granted as part of the Company's long-term incentive plan, with each unit being equivalent to one share of CSX stock and vest over three years. Restricted stock awards generally vest over an employment period of up to five years. The following table provides information about outstanding restricted stock units and awards combined. As of December 2014, unrecognized compensation expense for these awards and units was approximately $16 million, which will be expensed over a weighted-average remaining period of 2 years.



		Fiscal Years
		2014			2013			2012
	Restricted Stock Units and Awards Outstanding (Thousands)(a)	1,383			1,462			1,353

	Weighted-Average Fair Value at Grant Date	$	25.03		$	23.89		$	21.38

	Restricted Stock Units and Awards Expense (Millions)(a)	11			10			9

	Unvested Restricted Stock Units and Awards Outstanding (Thousands)	601			705			629

	Weighted-Average Fair Value of Unvested Units and Awards Outstanding	$	26.4		$	24.17		$	22.48


	(a) Time-based restricted stock units were granted to certain employees under the respective Long-term Incentive Plans in the amount of 371,000, 524,000, and 433,000 in 2014, 2013 and 2012, respectively, as described below. These units vest over three years, therefore only a partial amount of expense was recognized in 2014, 2013, and 2012, respectively.

	Long-term Incentive Plans

	The CSX Long-term Incentive Plans (“LTIP”) were adopted under the 2010 CSX Stock and Incentive Award Plan. The objective of these long-term incentive plans is to motivate and reward certain employees for achieving and exceeding certain financial and strategic initiatives. Grants were made in performance units, with each unit being equivalent to one share of CSX common stock, and payouts will be made in CSX common stock. The payout range for participants will be between 0% and 200% of the target awards depending on Company performance against predetermined goals for each three-year cycle. In May of 2012, 2013 and 2014, target performance units were granted to certain employees under three separate LTIP plans covering three-year cycles: the 2012-2014 (“2014 LTIP”), 2013-2015 (“2015 LTIP”) and 2014-2016 (“2016 LTIP”) plans (collectively, the “Plans”).

	The key financial target for the 2014 LTIP plan is based solely on operating ratio (operating expense divided by operating revenue) and excludes certain non-recurring items as disclosed in the Company's financial statements. The 2014 LTIP plan provides that payouts for certain executive officers are subject to downward adjustment by up to 30% based upon Company performance against certain CSX strategic initiatives. The 2014 LTIP plan ended on December 26, 2014, and CSX did not issue any shares in January 2015 as applicable performance targets for the three preceding fiscal years were not met.

	NOTE 4. Stock Plans and Share-Based Compensation, continued

	The key financial targets for the 2015 and 2016 LTIP plans will be based on the achievement of goals related to both operating ratio and return on assets (tax-adjusted operating income divided by net property) excluding non-recurring items as disclosed in the Company's financial statements. The three-year average operating ratio and return on assets over the performance period will each comprise 50% of the payout and are measured independently of the other. The 2015 and 2016 LTIP plans state that payouts for certain executive officers are subject to downward adjustment by up to 30% based upon total shareholder return relative to specified comparable groups.

	Total expense incurred due to long-term incentive plans was $19 million, $2 million and $3 million for fiscal years 2014, 2013 and 2012, respectively.


		LTIP Plan (Plan Ended In)
		2014				2015				2016
	Number of target units outstanding (Thousands)(a)	1,338				1,330				1,119

	Weighted-average fair value at grant date (a)	$	22.23			$	25.5			$	28.03

	Payout Range	0% - 200%				0% - 200%				0% - 200%

	(a) Number of target units granted and weighted-average fair value calculations above include the value of both initial grants and subsequent, smaller grants issued at different prices based on grant date fair value to new or promoted employees not previously included.

	Restricted Stock Units

As part of the 2014, 2015 and 2016 LTIP plans, 433 thousand, 524 thousand and 371 thousand restricted stock units, respectively, were granted. The restricted stock units vest three years after the date of grant. Participants receive cash dividend equivalents on the unvested shares during the restriction period. These awards are time-based and are not based upon CSX’s attainment of operational targets. The restricted stock units and expenses are included in the information as shown within the Restricted Stock Grants section above.

As of December 2014, there was $39 million of total unrecognized compensation cost related to these plans that is expected to be recognized over a weighted-average period of approximately 2 years. The activity related to each of the outstanding long-term incentive plans is summarized as follows:


	LTIP Plan (Plan Ended In)								Weighted-Average Fair Value at Grant Date
(Units Outstanding, in Thousands)	2014			2015			2016
Unvested at December 28, 2012	1,237			—			—		$	21.98

Granted in 2013	85			1,354			—		25.26

Forfeited in 2013	(4	)		(75	)		—		(25.19		)

Unvested at December 27, 2013	1,318			1,279			—		23.7



Granted in 2014	20			52			1,144		28.13

Forfeited in 2014	—			(1	)		(25	)	(28.07		)

Cancelled due to performance conditions(a)	(1,338	)		—			—		(22.23		)

Vested at December 26, 2014	—			—			—		—

Unvested at December 26, 2014	—			1,330			1,119		$	26.66

(a) The minimum financial target was not met in 2014. As a result, there was no performance unit payout for the LTIP ended December 26, 2014.
NOTE 4. Stock Plans and Share-Based Compensation, continued

Stock Awards for Directors

CSX’s non-management directors receive an annual retainer of $75,000 to be paid quarterly in cash, unless the director chooses to receive the retainer in the form of CSX common stock. Additionally, non-management directors receive an annual grant of common stock in the amount of approximately $150,000, with the number of shares to be granted based on the average closing price of CSX stock in the months of November, December and January. The following table provides information about shares issued to directors.


	Fiscal Years
	2014				2013				2012
Shares Issued to Directors (Thousands)	79				105				102

Expense (Millions)	$	2			$	2			$	2

Weighted Average Grant Date Stock Price	$	28.01			$	23.12			$	21.92


The directors may elect to defer receipt of their fees, in accordance with Internal Revenue Code ("IRC") Section 409A. Deferred cash amounts were credited to an account and invested in a choice of eight investment selections, including a CSX common stock equivalent fund. Distributions are made in accordance with elections made by the directors, consistent with the terms of the Directors' Deferred Compensation Plan.

Casualty_Environmental_and_Oth

Casualty, Environmental and Other Reserves	12 Months Ended
Casualty, Environmental and Other Reserves	Dec. 26, 2014
Casualty, Environmental and Other Reserves [Abstract]
Casualty, Environmental and Other Reserves	Casualty, Environmental and Other Reserves

	Activity related to casualty, environmental and other reserves is as follows:


		Casualty				Environmental			Other
	(Dollars in Millions)	Reserves				Reserves			Reserves			Total
	30-Dec-11	$	372			$	83		$	64		$	519
	30-Dec-11	$	372			$	83		$	64		$	519
	Charged to Expense	51				35			36			122
	Charged to Expense	51				35			36			122
	Payments	(98		)		(30		)	(36		)	(164		)
	28-Dec-12	325				88			64			477
	28-Dec-12	325				88			64			477
	Charged to Expense	54				48			38			140
	Charged to Expense	54				48			38			140
	Payments	(99		)		(36		)	(31		)	(166		)
	27-Dec-13	280				100			71			451
	27-Dec-13	280				100			71			451
	Charged to Expense (a)	89				57			30			176
	Charged to Expense (a)	89				57			30			176
	Payments	(104		)		(63		)	(42		)	(209		)
	26-Dec-14	$	265			$	94		$	59		$	418
	26-Dec-14	$	265			$	94		$	59		$	418

	(a)	Increase in expense in 2014 is primarily due to the resolution of personal injury claims for prior years.


	NOTE 5. Casualty, Environmental and Other Reserves, continued

	These reserves are considered critical accounting estimates due to the need for significant management judgment. They are provided for in the consolidated balance sheets as follows:


		Dec-14										Dec-13
	(Dollars in Millions)	Current				Long-term			Total			Current			Long-term		Total
	Casualty:
	Personal Injury	$	68			$	123		$	191		$	59		$	148	$	207
	Personal Injury	$	68			$	123		$	191		$	59		$	148	$	207
	Occupational	3				15			18			3			20		23
	Occupational	3				15			18			3			20		23
	Asbestos	5				51			56			10			40		50
	Asbestos	5				51			56			10			40		50
	Total Casualty	76				189			265			72			208		280
	Total Casualty	76				189			265			72			208		280
	Environmental	48				46			94			59			41		100
	Environmental	48				46			94			59			41		100
	Other	18				41			59			20			51		71
	Other	18				41			59			20			51		71
	Total	$	142			$	276		$	418		$	151		$	300	$	451
	Total	$	142			$	276		$	418		$	151		$	300	$	451

	These liabilities are accrued when estimable and probable in accordance with the Contingencies Topic in the ASC. Actual settlements and claims received could differ and final outcome of these matters cannot be predicted with certainty. Considering the legal defenses currently available, the liabilities that have been recorded and other factors, it is the opinion of management that none of these items individually, when finally resolved, will have a material effect on the Company's financial condition, results of operations or liquidity. Should a number of these items occur in the same period, however, they could have a material effect on the Company's financial condition, results of operations or liquidity in that particular period.

	Casualty
	Casualty reserves of $265 million for 2014 represent accruals for personal injury, occupational injury and asbestos claims. The Company's self-insured retention amount for these claims is $50 million per occurrence. Currently, no individual claim is expected to exceed the self-insured retention amount. In accordance with the Contingencies Topic in the ASC, to the extent the value of an individual claim exceeds the self-insured retention amount, the Company would present the liability on a gross basis with a corresponding receivable for insurance recoveries. These reserves fluctuate based upon the timing of payments as well as changes in independent third-party estimates, which are reviewed by management. Actual results may vary from estimates due to the number, type and severity of the injury, costs of medical treatments and uncertainties in litigation. Most of the Company's casualty claims relate to CSXT unless otherwise noted below. Defense and processing costs, which historically have been insignificant and are anticipated to be insignificant in the future, are not included in the recorded liabilities. During 2014, 2013 and 2012, there were no significant changes in estimate recorded to adjust casualty reserves.

	Personal Injury
	Personal injury reserves represent liabilities for employee work-related and third-party injuries. Work-related injuries for CSXT employees are primarily subject to FELA. In addition to FELA liabilities, employees of other CSX subsidiaries are covered by various state workers’ compensation laws, the Federal Longshore and Harbor Workers’ Compensation Program or the Maritime Jones Act.

	CSXT retains an independent actuary to assist management in assessing the value of personal injury claims. An analysis is performed by the actuary quarterly and is reviewed by management. The methodology used by the actuary includes a development factor to reflect growth or reduction in the value of these personal injury claims. It is based largely on CSXT's historical claims and settlement experience.
	NOTE 5. Casualty, Environmental and Other Reserves, continued

	Occupational & Asbestos
	Occupational claims arise from allegations of exposures to certain materials in the workplace, such as solvents, soaps, chemicals (collectively referred to as “irritants”) and diesel fuels (like exhaust fumes) or allegations of chronic physical injuries resulting from work conditions, such as repetitive stress injuries, carpal tunnel syndrome and hearing loss.

The Company is also party to a number of asbestos claims by employees alleging exposure to asbestos in the workplace. The heaviest possible exposure for employees resulted from work conducted in and around steam locomotive engines that were largely phased out beginning around the 1950s. Other types of exposures, however, including exposure from locomotive component parts and building materials, continued until these exposures were substantially eliminated by 1985. Additionally, the Company has retained liability for asbestos claims filed against its previously owned international container shipping business. Diseases associated with asbestos typically have long latency periods (amount of time between exposure to asbestos and the onset of the disease) which can range from ten to 40 years after exposure.

Occupational claims, excluding asbestos, are analyzed on a quarterly basis by an independent actuary in order to determine the number of unasserted, or incurred but not reported (“IBNR”), claims. The actuary’s analyses are reviewed by management. With the exception of carpal tunnel, management has determined that seven years is the most probable time period in which these unasserted occupational claim filings and claim values can be estimated. Carpal tunnel claims use a three-year period to estimate the reserve due to the shorter latency period for these types of injuries.

Asbestos claims are analyzed by an independent specialist in order to determine the number of unasserted, or IBNR, claims. Since exposure to asbestos has been substantially eliminated, management reviews asserted asbestos claims quarterly and the review by the specialist is completed annually. In 2014, management reviewed this assumption and determined that it was appropriate to extend the forecast period from seven years to ten years. Based on a review of historical settlement trends, management concluded that ten years is the most probable time period in which unasserted asbestos claim filings and claim values can be estimated. The Company does not believe there is sufficient data to justify a projection period longer than ten years at this time. The change in the forecast period resulted in an immaterial increase in the asbestos reserves during 2014.

The actuary and specialist analyze CSXT’s historical claim filings, settlement amounts, and dismissal rates to determine future anticipated claim filing rates and average settlement values for occupational and asbestos claims reserves. The potentially exposed population is estimated by using CSXT’s employment records and industry data. From this analysis, the actuary and specialist provide estimates of the IBNR claims liabilities.

NOTE 5. Casualty, Environmental and Other Reserves, continued

Undiscounted liabilities recorded related to occupational and asbestos claims were as follows:


	December				December
(Dollars in Millions)	2014				2013
Occupational:
Incurred but not reported claims	$	12			$	15
Incurred but not reported claims	$	12			$	15
Asserted claims	6				8
Asserted claims	6				8
Total liability	$	18			$	23
Total liability	$	18			$	23

Asbestos:
Incurred but not reported claims	$	45			$	35
Incurred but not reported claims	$	45			$	35
Asserted claims	11				15
Asserted claims	11				15
Total liability	$	56			$	50
Total liability	$	56			$	50

A summary of occupational and asbestos claims activity is as follows:


	Fiscal Years
	2014			2013
Asserted Claims
Open Claims - Beginning of Year	392			523
Open Claims - Beginning of Year	392			523
New Claims Filed	136			165
New Claims Filed	136			165
Claims Settled	(128	)		(146	)
Claims Dismissed	(130	)		(150	)
Open Claims - End of Year	270			392
Open Claims - End of Year	270			392

Environmental
Environmental reserves were $94 million for 2014. The Company is a party to various proceedings related to environmental issues, including administrative and judicial proceedings involving private parties and regulatory agencies. The Company has been identified as a potentially responsible party at approximately 250 environmentally impaired sites. Many of these are, or may be, subject to remedial action under the federal Comprehensive Environmental Response, Compensation and Liability Act of 1980, also known as the Superfund Law, or similar state statutes. Most of these proceedings arose from environmental conditions on properties used for ongoing or discontinued railroad operations. A number of these proceedings, however, are based on allegations that the Company, or its predecessors, sent hazardous substances to facilities owned or operated by others for treatment, recycling or disposal. In addition, some of the Company’s land holdings were leased to others for commercial or industrial uses that may have resulted in releases of hazardous substances or other regulated materials onto the property and could give rise to proceedings against the Company.

In any such proceedings, the Company is subject to environmental clean-up and enforcement actions under the Superfund Law, as well as similar state laws that may impose joint and several liability for clean-up and enforcement costs on current and former owners and operators of a site without regard to fault or the legality of the original conduct. These costs could be substantial.

NOTE 5. Casualty, Environmental and Other Reserves, continued

In accordance with the Asset Retirement and Environmental Obligations Topic in the ASC, the Company reviews its role with respect to each site identified at least quarterly, giving consideration to a number of factors such as:

•	type of clean-up required;

•	nature of the Company’s alleged connection to the location (e.g., generator of waste sent to the site or owner or operator of the site);

•	extent of the Company’s alleged connection (e.g., volume of waste sent to the location and other relevant factors); and

•	number, connection and financial viability of other named and unnamed potentially responsible parties at the location.

Based on the review process, the Company has recorded amounts to cover contingent anticipated future environmental remediation costs with respect to each site to the extent such costs are estimable and probable. The recorded liabilities for estimated future environmental costs are undiscounted. The liability includes future costs for remediation and restoration of sites as well as any significant ongoing monitoring costs, but excludes any anticipated insurance recoveries. Payments related to these liabilities are expected to be made over the next several years. Environmental remediation costs are included in materials, supplies and other on the consolidated income statement.

Currently, the Company does not possess sufficient information to reasonably estimate the amounts of additional liabilities, if any, on some sites until completion of future environmental studies. In addition, conditions that are currently unknown could, at any given location, result in additional exposure, the amount and materiality of which cannot presently be reasonably estimated. Based upon information currently available, however, the Company believes its environmental reserves accurately reflect the cost of remedial actions currently required.

Other
Other reserves of $59 million for 2014 include liabilities for various claims, such as property, automobile and general liability. Also included in other reserves are longshoremen disability claims related to a previously owned international shipping business (these claims are in runoff) as well as claims for current port employees.

Properties

Properties	12 Months Ended
	Dec. 26, 2014
Property, Plant and Equipment [Abstract]
Properties	Properties

	A detail of the Company’s net properties are as follows:



	(Dollars in Millions)							Accumulated				Net Book				Annual Depreciation		Depreciation		Estimated Useful
	Dec-14				Cost			Depreciation				Value				Rate		Method		Life
	Road
			Rail and Other Track Material		$	6,771		$	(1,400	)		$	5,371			2.50%		Group Life

			Ties		4,807			(1,060		)		3,747				3.70%		Group Life

			Grading		2,460			(481		)		1,979				1.40%		Group Life

			Ballast		2,693			(679		)		2,014				2.70%		Group Life

			Bridges, Trestles, and Culverts		2,119			(278		)		1,841				1.60%		Group Life

			Signals and Interlockers		2,103			(356		)		1,747				4.00%		Group Life

			Buildings		1,102			(377		)		725				2.50%		Group Life

			Other		4,070			(1,517		)		2,553				4.20%		Group Life

	Total Road				26,125			(6,148		)		19,977								8-90 Years

	Equipment

			Locomotive		5,036			(2,325		)		2,711				3.60%		Group Life

			Freight Cars		3,244			(1,169		)		2,075				3.20%		Group Life

			Work Equipment and Other		1,828			(1,032		)		796				7.10%		Group Life

	Total Equipment				10,108			(4,526		)		5,582								3-38 Years

	Land				1,875			—				1,875				N/A		N/A		N/A

	Construction In Progress				1,196			—				1,196				N/A		N/A		N/A

	Other				39			(85		)		(46		)		N/A		Straight Line		4-30 Years

	Total Properties				$	39,343		$	(10,759	)		$	28,584



	NOTE 6. Properties, continued



	(Dollars in Millions)							Accumulated				Net Book				Annual Depreciation		Depreciation		Estimated Useful
	Dec-13				Cost			Depreciation				Value				Rate		Method		Life
	Road
			Rail and Other Track Material		$	6,452		$	(1,270	)		$	5,182			2.90%		Group Life

			Ties		4,534			(947		)		3,587				4.00%		Group Life

			Grading		2,425			(448		)		1,977				1.50%		Group Life

			Ballast		2,612			(645		)		1,967				2.80%		Group Life

			Bridges, Trestles, and Culverts		2,008			(250		)		1,758				1.60%		Group Life

		Signals and Interlockers		1,922			(291		)		1,631				3.40%		Group Life

		Buildings		1,011			(355		)		656				2.50%		Group Life

		Other		3,654			(1,386		)		2,268				4.70%		Group Life

Total Road				24,618			(5,592		)		19,026								6-80 Years

Equipment
		Locomotive		4,987			(2,176		)		2,811				3.60%		Group Life

		Freight Cars		3,111			(1,135		)		1,976				3.10%		Group Life

		Work Equipment and Other		1,666			(914		)		752				7.10%		Group Life

Total Equipment				9,764			(4,225		)		5,539								5-38 Years

Land				1,842			—				1,842				N/A		N/A		N/A

Construction In Progress				854			—				854				N/A		N/A		N/A

Other				106			(76		)		30				N/A		Straight Line		4-30 Years

Total Properties				$	37,184		$	(9,893	)		$	27,291


Railroad Assets
The Company depreciates its rail assets, including main-line track, locomotives and freight cars, using the group-life method of accounting. Assets depreciated under the group-life method of accounting comprise 85% of total fixed assets of $39 billion on a gross basis as of December 2014. All other depreciable assets of the Company are depreciated on a straight-line basis. The group-life method aggregates assets with similar lives and characteristics into groups and depreciates each of these groups as a whole. When using the group-life method, an underlying assumption is that each group of assets, as a whole, is used and depreciated to the end of its recoverable life.

The Company currently utilizes more than 130 different depreciable asset categories to account for depreciation expense for the railroad assets that are depreciated under the group-life method of accounting. Examples of depreciable asset categories include 18 different categories for crossties due to the different combinations of density classifications and asset types. By utilizing various depreciable categories, the Company can more accurately account for the use of its assets. All assets of the Company are depreciated on a time or life basis.

The Company believes the group-life method of depreciation closely approximates the straight-line method of depreciation. Additionally, due to the nature of most of its assets (e.g. track is one contiguous, connected asset) the Company believes that this is the most effective way to properly depreciate its assets.

NOTE 6. Properties, continued

Under the group-life method of accounting, the service lives and salvage values for each group of assets are determined by completing periodic depreciation studies and applying management’s assumptions regarding the service lives of its properties. A depreciation study (also referred to as a life study) is the periodic review of asset service lives, salvage values, accumulated depreciation, and other related factors for group assets conducted by a third-party specialist, analyzed by the Company’s management and approved by the Surface Transportation Board (“STB”), the regulatory board that has broad jurisdiction over railroad practices. The STB requires depreciation studies be performed for equipment assets every three years and for road (e.g. bridges and signals) and track (e.g. rail, ties and ballast) assets every six years. The Company believes the frequency currently required by the STB provides adequate review of asset service lives and that a more frequent review would not result in a material change due to the long-lived nature of most of the assets.

The results of the depreciation study process determine the service lives for each asset group under the group-life method. Road assets, including main-line track, have estimated service lives ranging from eight years for system roadway machinery to 90 years for grading (construction of protection for the roadway, tracks and embankments). Equipment assets, including locomotives and freight cars, have estimated service lives ranging from three years for technology assets to 38 years for work equipment. Changes in asset service lives due to the results of the depreciation studies are applied on a prospective basis and could significantly impact future periods’ depreciation expense, and thus, the Company's results of operations.

There are several factors taken into account during the depreciation study and they include:

•	statistical analysis of historical life and salvage data for each group of property;

•	statistical analysis of historical retirements for each group of property;

•	evaluation of current operations;

•	evaluation of technological advances and maintenance schedules;

•	previous assessment of the condition of the assets and outlook for their continued use;

•	expected net salvage to be received upon retirement; and

•	comparison of assets to the same asset groups with other companies.

For retirements or disposals of depreciable rail assets that occur in the ordinary course of business, the asset cost (net of salvage value or sales proceeds) is charged to accumulated depreciation and no gain or loss is recognized. As individual assets within a specific group are retired or disposed of, resulting gains and losses are recorded in accumulated depreciation. As part of the depreciation study, an assessment of the recorded amount of accumulated depreciation is made to determine if it is deficient (or in excess) of the appropriate amount indicated by the study. Any such deficiency (or excess), including any deferred gains or losses, is amortized as a component of depreciation expense over the remaining service life of the asset group until the next required depreciation study. Since the overall assumption with the group-life method of accounting is that the assets within the group on average have the same service life and characteristics, it is therefore concluded that the deferred gains and losses offset over time.
NOTE 6. Properties, continued

Since the rail network is one contiguous, connected network it is impractical to maintain specific identification records for these assets. For road assets (such as rail and track related items), CSX utilizes a first-in, first-out approach to asset retirements. The historical cost of these replaced assets is estimated using inflation indices published by the Bureau of Labor Statistics applied to the replacement value based on the age of the retired asset. The indices are used because they closely correlate with the major cost of the materials comprising the applicable road assets.

Equipment assets (such as locomotives and freight cars) are specifically identified at retirement. When an equipment asset is retired that has been depreciated using the group-life method, the cost is reduced from the cost base and recorded in accumulated depreciation.

In the event that large groups of assets are removed from service as a result of unusual acts or sales, resulting gains and losses are recognized immediately. These acts are not considered to be in the normal course of business and are therefore recognized when incurred. Examples of such acts would be the major destruction of assets due to significant storm damage (e.g. major hurricanes), the sale of a rail line segment or the disposal of an entire class of assets (e.g. disposal of all refrigerated freight cars). There were no abnormal operating gains in 2014. Abnormal operating gains of $65 million in 2013 and $104 million in 2012 were related to the disposition of operating rail corridors. Included in these gains were $43 million and $94 million in 2013 and 2012, respectively, from the 2011 sale of an operating rail corridor to the state of Florida. In 2013, a gain was recognized for a non-monetary exchange of easements and rail assets, and in 2012, a gain was recognized for a sale of operating rail corridor to the Commonwealth of Massachusetts.

Recent experience with depreciation studies has resulted in depreciation rate changes, which did not materially affect the Company’s annual depreciation expense of $1.2 billion, $1.1 billion and $1.1 billion for 2014, 2013 and 2012, respectively. In general, changes in depreciation rates result from updated average asset service lives as determined during depreciation studies. In 2014, the Company completed a depreciation study for its road and track assets. In 2012, the Company completed a depreciation study for its equipment assets and a technical update (an update to the prior depreciation study) for its road and track assets.

Non-Railroad Assets, Capital Leases and Land
The majority of non-railroad property is depreciated using the straight-line method on a per asset basis. The depreciable lives of this property are periodically reviewed by the Company and any changes are applied on a prospective basis. Amortization expense recorded under capital leases is included in depreciation expense on the consolidated income statements. For retirements or disposals of non-railroad depreciable assets and all dispositions of land, the resulting gains or losses are recognized in earnings at the time of disposal. During 2012, the Company recognized a gain of $57 million related to the sale of non-operating property, which is recognized in other income in the consolidated statements of income. These gains and losses were not material for any other period presented.

Impairment Review
Properties and other long-lived assets are reviewed for impairment whenever events or business conditions indicate the carrying amount of such assets may not be fully recoverable. Initial assessments of recoverability are based on estimates of undiscounted future net cash flows associated with an asset or a group of assets in accordance with the Property, Plant, and Equipment Topic in the ASC. Where impairment is indicated, the assets are evaluated and their carrying amount is reduced to fair value based on discounted net cash flows or other estimates of fair value.

NOTE 6. Properties, continued

Capital Expenditures
The Company’s capital spending includes purchased or self-constructed assets and property additions that substantially extend the service life or increase the utility of those assets. Indirect costs that can be specifically traced to capital projects are also capitalized. The Company is committed to maintaining and improving its existing infrastructure and expanding its network for long-term growth. Rail operations are capital intensive and CSX accounts for these costs in accordance with GAAP and the Company’s capitalization policy. All properties are stated at historical cost less an allowance for accumulated depreciation.

The Company’s largest category of capital spending is the replacement of track assets and the acquisition or construction of new assets that enable CSX to enhance its operations or provide new capacity offerings to its customers. These construction projects are typically completed by CSXT employees. Costs for track asset replacement and capacity projects that are capitalized include:

•	labor costs, because many of the assets are self-constructed;

•	costs to purchase or construct new track or to prepare ground for the laying of track;

•	welding (rail, field and plant) which are processes used to connect segments of rail;

•	new ballast, which is gravel and crushed stone that holds track in line;

•	fuels and lubricants associated with tie, rail and surfacing work which is the process of raising track to a designated elevation over an extended distance;

•	cross, switch and bridge ties which are the braces that support the rails on a track;

•	gauging which is the process of standardizing the distance between rails;

•	handling costs associated with installing ties or ballast; and

•	other track materials.

The primary cost in self-constructed track replacement work is labor. CSXT engineering employees directly charge their labor to the track replacement project (the capitalized depreciable property). These employees concurrently perform deconstruction and installation of track material. Because of this concurrent process, CSX must estimate the amount of labor that is related to deconstruction versus installation. Through analysis of CSXT’s track replacement process, CSX determined that approximately 20% of labor costs associated with track material installation is related to the deconstruction of old track and 80% is associated with the installation of new track.

Capital spending related to locomotives and freight cars comprises the second largest category of the Company’s capital assets. This category includes purchase costs of locomotives and freight cars as well as certain equipment leases that are considered to be capital leases in accordance with the Leases Topic in the ASC. In addition, costs to modify or rebuild these assets are capitalized if the spending incurred extends the asset’s service life or improves utilization. Improvement projects must meet specified dollar thresholds to be capitalized and are reviewed by management to determine proper accounting treatment. Routine repairs and maintenance costs, for all asset categories, are expensed as incurred.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 26, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies

	Lease Commitments
	The Company has various lease agreements with other parties with terms up to 30 years. Non-cancelable, long-term leases may include provisions for maintenance, options to purchase, and options to extend the terms. The Company uses the straight-line method to recognize rent expense associated with operating leases that include escalations over their terms. These amounts are shown in the table below.



		Fiscal Years
	(Dollars in Millions)	2014			2013				2012
	Rent Expense on Operating Leases	$	61		$	60			$	73


	At December 2014, minimum rentals on land, buildings, track and equipment under operating leases are disclosed in the table below. Also, payments to Conrail for leases on shared rail infrastructure are included in these amounts. (See Note 12, Related Party Transactions).


	(Dollars in Millions)	Operating			Sublease				Net Lease
	Years	Leases			Income				Commitments
	2015	$	78		$	(3	)		$	75

	2016	71			(2		)		69

	2017	62			(2		)		60

	2018	54			(2		)		52

	2019	45			(2		)		43

	Thereafter	210			(11		)		199

	Total	$	520		$	(22	)		$	498


	Purchase Commitments
	CSXT has a commitment under a long-term maintenance program that currently covers 42% of CSXT’s fleet of locomotives. The agreement is based on the maintenance cycle for each locomotive. Under CSXT’s current obligations, the agreement will expire no earlier than 2031. The costs expected to be incurred throughout the duration of the agreement fluctuate as locomotives are placed into or removed from service, or as required maintenance schedules are revised. The table below includes both active and inactive locomotives covered under this agreement.

	The following table summarizes the number of locomotives covered and CSXT’s payments under the long-term maintenance program.


		Fiscal Years
	(Dollars in Millions)	2014			2013				2012

	Amounts Paid	$	247		$	287			$	287

	Number of Locomotives	1,886			1,886				1,899


	Annual payments related to the locomotive purchase obligations, including amounts that would be payable under the long-term maintenance program, are estimated in the table below. The amount of the ultimate purchase commitment depends upon the model of locomotive acquired and the timing of delivery.
	NOTE 7. Commitments and Contingencies, continued

	Additionally, the Company has various other commitments to purchase technology, communications, railcar maintenance and other services from various suppliers. Total annual payments under all of these purchase commitments are also estimated in the table below.


	(Dollars in Millions)	Locomotive & Maintenance Payments			Other				Total
					Commitments
	2015	$	727		$	236			$	963

	2016	474			22				496

	2017	177			13				190

	2018	169			12				181

	2019	159			11				170

Thereafter	1,203			69				1,272

Total	$	2,909		$	363			$	3,272


Insurance
The Company maintains numerous insurance programs with substantial limits for property damage (which includes business interruption) and third-party liability. A certain amount of risk is retained by the Company on each of the property and liability programs. The Company has a $25 million retention per occurrence for the non-catastrophic property program (such as a derailment) and a $50 million retention per occurrence for the liability and catastrophic property programs (such as hurricanes and floods). While the Company believes its insurance coverage is adequate, future claims could exceed existing insurance coverage or insurance may not continue to be available at commercially reasonable rates.

Legal
The Company is involved in litigation incidental to its business and is a party to a number of legal actions and claims, various governmental proceedings and private civil lawsuits, including, but not limited to, those related to fuel surcharge practices, environmental and hazardous material exposure matters, FELA claims by employees, other personal injury or property claims and disputes and complaints involving certain transportation rates and charges. Some of the legal proceedings include claims for compensatory as well as punitive damages and others are, or are purported to be, class actions. While the final outcome of these matters cannot be predicted with certainty, considering, among other things, the legal defenses available and liabilities that have been recorded along with applicable insurance, it is currently the opinion of CSX management that none of these pending items will have a material adverse effect on the Company's financial condition, results of operations or liquidity. An unexpected adverse resolution of one or more of these items, however, could have a material adverse effect on the Company's financial condition, results of operations or liquidity in that particular period.
The Company is able to estimate a range of possible loss for certain legal proceedings for which a loss is reasonably possible in excess of reserves established. The Company has estimated this range to be $4 million to $13 million in aggregate at December 26, 2014. This estimated aggregate range is based upon currently available information and is subject to significant judgment and a variety of assumptions. Accordingly, the Company's estimate will change from time to time, and actual losses may vary significantly from the current estimate.
NOTE 7. Commitments and Contingencies, continued

Fuel Surcharge Antitrust Litigation
In May 2007, class action lawsuits were filed against CSXT and three other U.S.-based Class I railroads alleging that the defendants' fuel surcharge practices relating to contract and unregulated traffic resulted from an illegal conspiracy in violation of antitrust laws. In November 2007, the class action lawsuits were consolidated in federal court in the District of Columbia, where they are now pending. The suit seeks treble damages allegedly sustained by purported class members as well as attorneys' fees and other relief. Plaintiffs are expected to allege damages at least equal to the fuel surcharges at issue.

In June 2012, the District Court certified the case as a class action. The decision was not a ruling on the merits of plaintiffs' claims, but rather a decision to allow the plaintiffs to seek to prove the case as a class. The defendant railroads petitioned the U.S. Court of Appeals for the D.C. Circuit for permission to appeal the District Court's class certification decision. In August 2013, the D.C. Circuit issued a decision vacating the class certification decision and remanded the case to the District Court to reconsider its class certification decision. In October 2013, the District Court held a case management conference to determine the scope and schedule of the remand proceedings, which are underway. The District Court has delayed proceedings on the merits of the case pending the outcome of the class certification remand proceedings.

CSXT believes that its fuel surcharge practices were arrived at and applied lawfully and that the case is without merit. Accordingly, the Company intends to defend itself vigorously. However, penalties for violating antitrust laws can be severe, and an unexpected adverse decision on the merits could have a material adverse effect on the Company's financial condition, results of operations or liquidity in that particular period or for the full year.

Environmental
CSXT has indemnified Pharmacia LLC (formerly known as Monsanto Company) for certain liabilities associated with real estate located in Kearny, New Jersey along the Lower Passaic River (the “Property”). The Property, which was formerly owned by Pharmacia, is now owned by CSXT. The indemnification and defense duties arise with respect to several matters. CSXT, on behalf of Pharmacia, is conducting a Remedial Investigation and Feasibility Study of the 17-mile Lower Passaic River Study Area with approximately 60 other parties pursuant to an Administrative Settlement Agreement and Order on Consent with the U.S. Environmental Protection Agency ("EPA"). The EPA, using its Comprehensive Environmental Response, Compensation, and Liability Act ("CERCLA") authority, seeks cleanup and removal costs and other damages associated with the presence of hazardous substances in the Lower Passaic River. In April 2014, the EPA announced its proposed plan to remediate the lower eight miles of the Lower Passaic River. The proposed plan, based on a Focused Feasibility Study, informs the public of EPA’s preferred remedial alternative. EPA’s proposed plan solicited public comments, which were due in August 2014. After review of comments, EPA is expected to issue its final cleanup plan in 2015. CSXT is also defending and indemnifying Pharmacia in a cooperative natural resource damages assessment process related to the Property. Based on currently available information, the Company does not believe any remediation costs potentially allocable to CSXT would be material to the Company's financial condition, results of operations or liquidity.

Employee_Benefit_Plans

Employee Benefit Plans	12 Months Ended
Employee Benefit Plans	Dec. 26, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Employee Benefit Plans	Employee Benefit Plans

	The Company sponsors defined benefit pension plans principally for salaried, management personnel. For employees hired prior to January 1, 2003, the plans provide eligible employees with retirement benefits based predominantly on years of service and compensation rates near retirement. For employees hired in 2003 or thereafter, benefits are determined based on a cash balance formula, which provides benefits by utilizing interest and pay credits based upon age, service and compensation.
	NOTE 8. Employee Benefit Plans, continued

	In addition to these plans, the Company sponsors a post-retirement medical plan and a life insurance plan that provide benefits to full-time, salaried, management employees, hired prior to January 1, 2003, upon their retirement if certain eligibility requirements are met. Medicare-eligible retirees are covered by a health reimbursement arrangement, which is an employer-funded account that can be used for reimbursement of eligible medical expenses. Non-Medicare eligible retirees are covered by a self-insured program partially funded by participating retirees. The life insurance plan is non-contributory.

	The Company engages independent actuaries to compute the amounts of liabilities and expenses relating to these plans subject to the assumptions that the Company selects. In order to perform this valuation, the actuaries are provided with the details of the population covered at the beginning of the year, summarized in the table below, and projects that population forward to the end of the year. These amounts are reviewed by management.



		Summary of Participants as of
		January 1, 2014
		Pension Plans			Post-retirement Medical Plan
	Active Employees	5,136			2,031
	Active Employees	5,136			2,031
	Retirees and Beneficiaries	11,699			12,148
	Retirees and Beneficiaries	11,699			12,148
	Other(a)	5,444			87
	Other(a)	5,444			87
	Total	22,279			14,266
	Total	22,279			14,266
	(a) For pension plans, the other category consists mostly of terminated but vested former employees. For post-retirement plans, the other category consists of employees on long-term disability that have not yet retired.

	The benefit obligation for these plans represents the liability of the Company for current and retired employees and is affected primarily by the following:

	•	service cost (benefits attributed to employee service during the period);

	•	interest cost (interest on the liability due to the passage of time);

	•	actuarial gains/losses (experience during the year different from that assumed and changes in plan assumptions); and

	•	benefits paid to participants.

	Cash Flows
	Plan assets are amounts that have been segregated and restricted to provide qualified pension plan benefits and include amounts contributed by the Company and amounts earned from invested contributions, net of benefits paid. Qualified pension plan obligations are funded in accordance with regulatory requirements and with an objective of meeting minimum funding requirements necessary to avoid restrictions on flexibility of plan operation and benefit payments. The Company funds the cost of the post-retirement medical and life insurance benefits as well as nonqualified pension benefits on a pay-as-you go basis. During 2012, the Company made a contribution of $275 million to its qualified pension plans, of which $25 million was the required minimum contribution. No contributions were made during 2013 and 2014. No significant contributions to the Company's qualified pension plans are expected in 2015.

	NOTE 8. Employee Benefit Plans, continued

	Future expected benefit payments are as follows:


		Expected Cash Flows
	(Dollars in Millions)	Pension Benefits				Post-retirement Benefits
	2015	$	207			$	37
	2015	$	207			$	37
	2016	188				34
	2016	188				34
	2017	188				33
	2017	188				33
	2018	185				30
	2018	185				30
	2019	186				28
	2019	186				28
	2020-2024	931				114
	2020-2024	931				114
	Total	$	1,885			$	276
	Total	$	1,885			$	276

	Plan Assets
	The CSX Investment Committee (the “Investment Committee”), whose members were selected by the Chief Financial Officer and approved by the Chief Executive Officer, is responsible for oversight and investment of plan assets. The Investment Committee utilizes an investment asset allocation strategy that is monitored on an ongoing basis and that is updated periodically in consideration of plan or employee changes, or changing market conditions. These studies provide an extensive modeling of asset investment return in conjunction with projected plan liabilities and seek to evaluate how to maximize return within the constraints of acceptable risk. The current asset allocation targets 70% equity investments and 30% fixed income investments and cash. Within equity, a further target is currently established for 42% of total plan assets in domestic equity and 28% in international equity. Allocations are evaluated for levels within 3% of targeted allocations and are adjusted quarterly as necessary. The distribution of pension plan assets as of the measurement date is shown in the table below, and these assets are netted against the pension liabilities on the balance sheet.



	Dec-14							Dec-13
					Percent of							Percent of
(Dollars in Millions)	Amount				Total Assets			Amount				Total Assets
Equity	$	1,715			68	%		$	1,619			65	%
Equity	$	1,715			68	%		$	1,619			65	%
Fixed Income	740				30			795				32
Fixed Income	740				30			795				32
Cash and Cash Equivalents	49				2			86				3
Cash and Cash Equivalents	49				2			86				3
Total	$	2,504			100	%		$	2,500			100	%
Total	$	2,504			100	%		$	2,500			100	%

Under the supervision of the Investment Committee, individual investments or fund managers are selected in accordance with standards of prudence applicable to asset diversification and investment suitability. The Company also selects fund managers with differing investment styles and benchmarks their investment returns against appropriate indices. Fund investment performance is continuously monitored. Acceptable performance is determined in the context of the long-term return objectives of the fund and appropriate asset class benchmarks.


NOTE 8. Employee Benefit Plans, continued

Within the Company's equity funds, the U.S. stock segment includes diversification among large and small capitalization stocks. Guidelines established with individual managers limit investment by industry sectors, individual stock issuer concentration and the use of derivatives and CSX securities.

Fixed income securities guidelines established with individual managers specify the types of allowable investments, such as government, corporate and asset-backed bonds, and limit diversification between domestic and foreign investments and the use of derivatives. Additionally, guidelines stipulate minimum credit quality constraints and any prohibited securities.

For detailed information regarding the fair value of pension assets, see Note 13, Fair Value Measurements.

Benefit Obligation, Plan Assets and Funded Status
Changes in benefit obligation and the fair value of plan assets for the 2014 and 2013 calendar plan years are as follows:



	Pension Benefits								Post-retirement Benefits
	Plan Year				Plan Year				Plan Year				Plan Year
(Dollars in Millions)	2014				2013				2014				2013
Actuarial Present Value of Benefit Obligation
Accumulated Benefit Obligation	$	2,849			$	2,538			N/A				N/A
Accumulated Benefit Obligation	$	2,849			$	2,538			N/A				N/A
Projected Benefit Obligation	3,002				2,679				$	340			$	350
Projected Benefit Obligation	3,002				2,679				$	340			$	350

Change in Projected Benefit Obligation:
Change in Projected Benefit Obligation:
Projected Benefit Obligation at Beginning of Plan Year	$	2,679			$	2,954			$	350			$	415
Projected Benefit Obligation at Beginning of Plan Year	$	2,679			$	2,954			$	350			$	415
Service Cost	44				49				3				3
Service Cost	44				49				3				3
Interest Cost	123				108				13				13
Interest Cost	123				108				13				13
Plan Participants' Contributions	—				—				7				8
Plan Participants' Contributions	—				—				7				8
Workforce Reduction Program/Curtailment	27				—				8				—
Workforce Reduction Program/Curtailment	27				—				8				—
Actuarial Loss (Gain)	333				(275		)		(8		)		(49		)
Actuarial Loss (Gain)	333				(275		)		(8		)		(49		)
Benefits Paid	(204		)		(157		)		(33		)		(40		)
Benefit Obligation at End of Plan Year	$	3,002			$	2,679			$	340			$	350
Benefit Obligation at End of Plan Year	$	3,002			$	2,679			$	340			$	350

Change in Plan Assets:
Change in Plan Assets:
Fair Value of Plan Assets at Beginning of Plan Year	$	2,500			$	2,294			$	—			$	—
Fair Value of Plan Assets at Beginning of Plan Year	$	2,500			$	2,294			$	—			$	—
Actual Return on Plan Assets	195				350				—				—
Actual Return on Plan Assets	195				350				—				—
Non-qualified Employer Contributions	13				13				26				32
Non-qualified Employer Contributions	13				13				26				32
Plan Participants' Contributions	—				—				7				8
Plan Participants' Contributions	—				—				7				8
Benefits Paid	(204		)		(157		)		(33		)		(40		)
Fair Value of Plan Assets at End of Plan Year	2,504				2,500				—				—
Fair Value of Plan Assets at End of Plan Year	2,504				2,500				—				—
Funded Status at End of Plan Year	$	(498	)		$	(179	)		$	(340	)		$	(350	)
NOTE 8. Employee Benefit Plans, continued

For qualified plan funding purposes, assets and discounted liabilities are measured in accordance with the Employee Retirement Income Security Act ("ERISA"), as well as other related provisions of the IRC and related regulations. Under these funding provisions and the alternative measurements available thereunder, the Company estimates its unfunded obligation for qualified plans on an annual basis.

In accordance with Compensation-Retirement Benefits Topic in the ASC, an employer must recognize the funded status of a pension or other post-retirement benefit plan by recording a liability (underfunded plan) or asset (overfunded plan) for the difference between the projected benefit obligation (or the accumulated post-retirement benefit obligation for a postretirement benefit plan) and the fair value of plan assets at the plan measurement date. Amounts related to pension and post-retirement benefits recorded in other long-term assets, labor and fringe benefits payable and other long-term liabilities on the balance sheet are as follows:



	Pension Benefits								Post-retirement Benefits
	December				December				December				December
(Dollars in Millions)	2014				2013				2014				2013
Amounts Recorded in Consolidated
Balance Sheets:
Long-term Assets (a)	$	9			$	44			$	—			$	—
Long-term Assets (a)	$	9			$	44			$	—			$	—
Current Liabilities	(15		)		(14		)		(37		)		(38		)
Long-term Liabilities	(492		)		(209		)		(303		)		(312		)
Net Amount Recognized in
Net Amount Recognized in
Consolidated Balance Sheets	$	(498	)		$	(179	)		$	(340	)		$	(350	)


(a)	Long-term assets as of December 2014 relate to one of the qualified pension plans whose assets exceed projected benefit obligations.

The funded status, or amount by which the benefit obligation exceeds the fair value of plan assets, represents a liability. At December 2014, the status of CSX plans only with a net liability is disclosed below. The total fair value of all plans as of December 2014 was $2.5 billion, which includes the qualified pension plans with net assets.



	Aggregate			Aggregate
(Dollars in Millions)	Fair Value			Projected
Benefit Obligations in Excess of Plan Assets	of Plan Assets			Benefit Obligation
Projected Benefit Obligation	$	2,461		$	(2,968	)
Projected Benefit Obligation	$	2,461		$	(2,968	)
Accumulated Benefit Obligation	2,461			(2,815		)
Accumulated Benefit Obligation	2,461			(2,815		)

NOTE 8. Employee Benefit Plans, continued

Net Benefit Expense
The following table describes the components of expense/(income) related to net benefit expense recorded in labor and fringe on the income statement.


	Pension Benefits												Post-retirement Benefits
	Fiscal Years												Fiscal Years
(Dollars in Millions)	2014				2013				2012				2014			2013			2012
Service Cost	$	44			$	49			$	44			$	3		$	3		$	4
Service Cost	$	44			$	49			$	44			$	3		$	3		$	4
Interest Cost	123				108				123				13			13			16
Interest Cost	123				108				123				13			13			16
Expected Return on Plan Assets	(166		)		(162		)		(166		)		—			—			—
Expected Return on Plan Assets	(166		)		(162		)		(166		)		—			—			—
Amortization of Net Loss	57				100				82				5			14			9
Amortization of Net Loss	57				100				82				5			14			9
Amortization of Prior Service Cost	—				—				—				(1		)	(1		)	(1		)
Amortization of Prior Service Cost	—				—				—				(1		)	(1		)	(1		)
Net Periodic Benefit Expense	58				95				83				20			29			28
Net Periodic Benefit Expense	58				95				83				20			29			28
Special Termination Benefits - Workforce Reduction Program/Curtailment(a)	27				—				—				8			—			—
	27				—				—				8			—			—
Settlement Gain(b)	(1		)		(2		)		(2		)		—			—			—
Settlement Gain(b)	(1		)		(2		)		(2		)		—			—			—
Total Expense	$	84			$	93			$	81			$	28		$	29		$	28
Total Expense	$	84			$	93			$	81			$	28		$	29		$	28


(a)	These charges result from a management workforce reduction program that was initiated in 2014. For further information regarding the program, see Note 1. Nature of Operations and Significant Accounting Policies.

(b)	Settlement gains were recognized as one of the pension plan's lump-sum payments exceeded the sum of the service cost and interest cost recognized. The gain is the recognition of a portion of its accumulated other comprehensive income related to that plan.

Pension and Other Post-Employment Benefits Adjustments
The following table shows the pre-tax change in other comprehensive loss (income) attributable to the components of net expense and the change in benefit obligation for CSX for pension and other post-employment benefits.


(Dollars in Millions)	Pension Benefits								Post-retirement Benefits
Components of Other Comprehensive	December				December				December				December
Loss (Income)	2014				2013				2014				2013
Recognized in the balance sheet
Losses (Gains)	$	305			$	(462	)		$	(8	)		$	(48	)
Losses (Gains)	$	305			$	(462	)		$	(8	)		$	(48	)
Expense (Income) recognized in the income statement
Expense (Income) recognized in the income statement
Amortization of net losses (a)	$	57			$	100			$	5			$	14
Amortization of net losses (a)	$	57			$	100			$	5			$	14
Settlement gain	(1		)		(2		)		—				—
Settlement gain	(1		)		(2		)		—				—
Amortization of prior service costs (b)	—				—				(1		)		(1		)
Amortization of prior service costs (b)	—				—				(1		)		(1		)


(a)	Amortization of net losses estimated to be expensed for 2015 is approximately $70 million and $5 million for pension benefits and post-retirement benefits, respectively. The increase in amortization is largely related to the impact of lower discount rates and adoption of new mortality tables, partially offset by favorable pension asset experience.

(b)	Amortization of prior service costs estimated to be expensed in 2015 is less than $1 million for pension benefits. The estimated post-retirement benefits amount to be credited to expense for 2015 is $1 million.
NOTE 8. Employee Benefit Plans, continued

As of December 2014, the balances of pre-tax amounts to be amortized that are included in accumulated other comprehensive loss (a component of shareholders’ equity) are as follows:


	Pension				Post-retirement
	Benefits				Benefits
Losses	$	908			$	59
Losses	$	908			$	59
Prior Service Costs (Credits)	—				(1		)
Prior Service Costs (Credits)	—				(1		)
Total	$	908			$	58
Total	$	908			$	58

Assumptions
The expected long-term average rate of return on plan assets reflects the average rate of earnings expected on the funds invested, or to be invested, to provide for benefits included in the projected benefit obligation. In estimating that rate, the Company gives appropriate consideration to the returns being earned by the plan assets in the funds and the rates of return expected to be available for reinvestment as well as the current and projected asset mix of the funds. Management balances market expectations obtained from various investment managers and economists with both market and actual plan historical returns to develop a reasonable estimate of the expected long-term rate of return on assets. As this assumption is long-term, it is adjusted less frequently than other assumptions used in pension accounting.

Weighted-average assumptions used in accounting for the plans were as follows:



	Pension Benefits						Post-retirement Benefits
	2014			2013			2014			2013
Expected Long-term Return on Plan Assets:
Benefit Cost for Plan Year	7.5	%		7.75	%		N/A			N/A
Benefit Cost for Plan Year	7.5	%		7.75	%		N/A			N/A
Benefit Obligation at End of Plan Year	7.25	%		7.5	%		N/A			N/A
Benefit Obligation at End of Plan Year	7.25	%		7.5	%		N/A			N/A

Discount Rates:
Benefit Cost for Plan Year	4.75	%		3.75	%		4.25	%		3.2	%
Benefit Obligation at End of Plan Year	4	%		4.75	%		3.6	%		4.25	%

Salary Scale Inflation	3.75	%		3.75	%		N/A			N/A
Salary Scale Inflation	3.75	%		3.75	%		N/A			N/A

NOTE 8. Employee Benefit Plans, continued

The net post-retirement benefit obligation for salaried, management personnel was determined using the following assumptions for the health care cost trend rate for medical plans. While it is expected that rates will decrease to 4.75% by 2025 for Medicare and 2027 for Non-Medicare eligible individuals, there may be yearly fluctuations. Additionally, there are cost differentials between Medicare and Non-Medicare eligible individuals which are reflected below.



	Post-retirement Benefits
	2014		2013
Health Care Cost Trend Rate:
Components of Benefit Cost: Non-Medicare Eligible	8.00%		8.50%
Components of Benefit Cost: Medicare Eligible	7.50%		8.00%
Benefit Obligations: Non-Medicare Eligible	8.00%		8.00%
Benefit Obligations: Medicare Eligible	7.50%		7.50%

For every 1% change in the assumed health care cost trend rate, service and interest cost will change by less than $1 million on a pre-tax basis on the consolidated income statements. For every 1% change in the health care cost trend rate, the Company’s benefit obligation will change by less than $1 million on the consolidated balance sheets.

Other Plans
Under collective bargaining agreements, the Company participates in a multi-employer benefit plan, which provides certain post-retirement health care and life insurance benefits to eligible contract employees. Premiums under this plan are expensed as incurred and amounted to $37 million, $41 million and $46 million in 2014, 2013 and 2012, respectively.

The Company maintains savings plans for virtually all full-time salaried employees and certain employees covered by collective bargaining agreements. Expense associated with these plans was $41 million, $37 million and $29 million for 2014, 2013 and 2012, respectively.

Debt_and_Credit_Agreements

Debt and Credit Agreements	12 Months Ended
	Dec. 26, 2014
Debt Disclosure [Abstract]
Debt and Credit Agreements	Debt and Credit Agreements

	Debt at December 2014 and December 2013 is shown in the table below. For information regarding the fair value of debt, see Note 13, Fair Value Measurements.


		Maturity at	Average	December			December
		December	Interest
			Rates at
			December
	(Dollars in Millions)	2014	2014	2014			2013
	Notes	2015-2054	5.50%	$	9,456		$	8,935

	Equipment Obligations(a)	2015-2023	6.30%	277			602

	Capital Leases	2015-2026	13.50%	8			16

	Convertible Debentures	2021	1.00%	1			2

	Subtotal Long-term Debt (including current portion)			$	9,742		$	9,555

	Less Debt Due within One Year			(228		)	(533		)
	Long-term Debt (excluding current portion)			$	9,514		$	9,022

	(a) These obligations are secured by an interest in certain railroad equipment.

	Debt Issuance & Early Redemption of Long-term Debt
	During 2014, CSX issued $550 million of 3.4% notes due 2024 and $450 million of 4.5% notes due 2054. These notes are included in the consolidated balance sheets under long-term debt and may be redeemed by the Company at any time. The net proceeds were used to redeem $263 million of CSXT's 8.375% secured equipment obligations that otherwise matured on October 15, 2014 and $400 million of CSX Corporation’s 6.250% unsecured notes that otherwise matured April 1, 2015. Proceeds may also be used for general corporate purposes, which may include repayment of additional indebtedness outstanding from time to time, repurchases of CSX’s common stock, capital investment, working capital requirements and other cost reduction initiatives. CSX recognized $16 million of other expense for the early redemption premium related to $663 million of note repayments. For more information regarding a non-cash debt transaction with a related party, see Note 12. Related Party Transactions.

	Long-term Debt Maturities


	(Dollars in Millions)	Maturities as of
	Fiscal Years Ending	Dec-14
	2015	$	228

	2016	21

	2017	631

	2018	619

	2019	518

	Thereafter	7,725

	Total Long-term Debt Maturities (including current portion)	$	9,742


	NOTE 9. Debt and Credit Agreements, continued

	Credit Facilities
	CSX has a $1 billion unsecured, revolving credit facility backed by a diverse syndicate of banks. This facility expires in September 2016. As of the date of this filing, the Company has no outstanding balances under this facility. The facility allows borrowings at floating (LIBOR-based) interest rates, plus a spread, depending upon CSX's senior unsecured debt ratings. LIBOR is the London Interbank Offered Rate which is a daily reference rate based on the interest rates at which banks offer to lend unsecured funds.

	Commitment fees and interest rates payable under the facility were similar to fees and rates available to comparably rated investment-grade borrowers. At December 2014, CSX was in compliance with all covenant requirements under the facilities.

	Receivables Securitization Facility
	The Company's $250 million receivables securitization facility has a three-year term expiring in June 2017. The purpose of this facility is to provide an alternative to commercial paper and a low cost source of short-term liquidity. Under the terms of this facility, CSXT transfers eligible third-party receivables to CSX Trade Receivables, LLC ("CSX Trade Receivables"), a bankruptcy-remote special purpose subsidiary. A separate subsidiary of CSX services the receivables. Upon transfer, the receivables become assets of CSX Trade Receivables and are not available to the creditors of CSX or any of its other subsidiaries. In the event CSX Trade Receivables draws under this facility, the Company will record an equivalent amount of debt on its consolidated financial statements. As of the date of this filing, the Company has no outstanding balances under this facility.

Other_Income_Net

Other Income - Net	12 Months Ended
	Dec. 26, 2014
Other Income and Expenses [Abstract]
Other Income - Net	Other Income - Net

	The Company derives income from items that are not considered operating activities. Income from these items is reported net of related expense. Income from real estate operations includes the results of the Company’s non-operating real estate sales, leasing, acquisition and management and development activities and may fluctuate as a function of timing of real estate sales. Miscellaneous income (expense) includes equity earnings or losses, investment gains and losses and other non-operating activities and may fluctuate due to timing. Other income – net consisted of the following:


		Fiscal Years
	(Dollars in Millions)	2014			2013			2012
	Interest Income	$	5		$	8		$	5

	Income from Real Estate Operations	23			23			81

	Miscellaneous Expense (a)	(52		)	(20		)	(13		)
	Total Other (Expense) Income - Net	$	(24	)	$	11		$	73

	Gross Revenue from Real Estate
	Operations included above	$	47		$	48		$	106

	(a) Miscellaneous expense increased $32 million primarily due to an increase in estimated environmental cleanup costs of $17 million related to non-operating activities as well as costs of $16 million associated with the early redemption of long-term debt.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 26, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes

	Earnings before income taxes of $3.0 billion, $2.9 billion and $3.0 billion for fiscal years 2014, 2013 and 2012, respectively, represent earnings from domestic operations. The breakdown of income tax expense between current and deferred is as follows:


		Fiscal Years
	(Dollars in Millions)	2014				2013			2012
	Current:
	Federal	$	729			$	671		$	450

	State	90				87			66

	Subtotal Current	819				758			516


	Deferred:
	Federal	291				285			530

	State	7				15			62

	Subtotal Deferred	298				300			592

	Total	$	1,117			$	1,058		$	1,108


	Income tax expense reconciled to the tax computed at statutory rates is presented in the table below. The Company recorded a tax benefit of $31 million, $42 million and $20 million in 2014, 2013 and 2012, respectively, primarily as a result of federal and state legislative changes as well as the resolution of other federal and state tax matters. Each year's benefit is included in the state income tax and other lines in the table below.


		Fiscal Years
	(Dollars In Millions)	2014						2013						2012

	Federal Income Taxes	$	1,066			35	%	$	1,023		35	%		$	1,040		35	%

	State Income Taxes	61				2	%	65			2.2	%		81			2.8	%

	Other	(10		)		(0.3	)%	(30		)	(1.0	)%		(13		)	(0.4	)%
	Income Tax Expense/Rate	$	1,117			36.7	%	$	1,058		36.2	%		$	1,108		37.4	%


	In September 2013, the IRS issued final regulations governing the income tax treatment of the acquisition, disposition and repair of tangible property. The regulations were effective beginning in 2014. These new regulations did not have a material impact on the financial statements.


	NOTE 11. Income Taxes, continued

	The significant components of deferred income tax assets and liabilities include:


		2014							2013
	(Dollars in Millions)	Assets				Liabilities			Assets			Liabilities
	Pension Plans	$	188			$	—		$	67		$	—

	Other Employee Benefit Plans	306				—			299			—

	Accelerated Depreciation	—				9,133			—			8,868

	Other	256				334			257			262

	Total	$	750			$	9,467		$	623		$	9,130

	Net Deferred Income Tax Liabilities					$	8,717					$	8,507


	The primary factors in the change in year-end net deferred income tax liability balances include:

•	Annual provision for deferred income tax expense; and

•	Accumulated other comprehensive loss.

The Company files a consolidated federal income tax return, which includes its principal domestic subsidiaries. Income tax incurred on the operations of the Company are subject to U.S. federal income tax as well as income tax of multiple state jurisdictions. CSX participated in a contemporaneous IRS audit of tax year 2014. Federal examinations of original federal income tax returns for all years through 2013 are resolved.

As of December 2014, 2013 and 2012, the Company had approximately $21 million, $23 million and $24 million, respectively, of total unrecognized tax benefits. After consideration of the impact of federal tax benefits, $13 million, $15 million and $17 million in 2014, 2013 and 2012, respectively, could favorably affect the effective income tax rate in each year. The Company estimates that approximately $2 million of the unrecognized tax benefits as of December 2014 for various state and federal income tax matters will be resolved over the next 12 months upon the expiration of statutes of limitations. The final outcome of these uncertain tax positions is not yet determinable. The change to the total gross unrecognized tax benefits and prior year audit resolutions of the Company during the fiscal year ended December 2014 is reconciled as follows:



Uncertain Tax Positions:	Fiscal Year
(Dollars in Millions)	2014				2013			2012
Balance at beginning of the year	$	23			$	24		$	22

Additions based on tax positions related to current year	2				2			6

Additions based on tax positions related to prior years	3				5			3

Reductions based on tax positions related to prior years	—				(6		)	(1		)

Settlements with taxing authorities	—				—			—

Lapse of statute of limitations	(7		)		(2		)	(6		)
Balance at end of the year	$	21			$	23		$	24


NOTE 11. Income Taxes, continued

CSX’s continuing practice is to recognize net interest and penalties related to income tax matters in income tax expense. Included in the consolidated income statements are expense of $1 million in 2014 and benefits of $1 million and $8 million in 2013 and 2012, respectively, for changes to reserves for interest and penalties for all prior year tax positions. The current year expense for interest and penalties is due to state tax settlements of prior period tax audits where the Company had previously accrued a liability for interest and penalties. The Company had $1 million, $2 million and $3 million accrued for interest and penalties at 2014, 2013 and 2012, respectively, for all prior year tax positions.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 26, 2014
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions

	Through a limited liability company, CSX and Norfolk Southern Corporation (“NS”) jointly own Conrail. CSX has a 42% economic interest and 50% voting interest in the jointly-owned entity, and NS has the remainder of the economic and voting interests. Pursuant to the Investments-Equity Method and Joint Venture Topic in the ASC, CSX applies the equity method of accounting to its investment in Conrail.

	Conrail owns rail infrastructure and operates for the joint benefit of CSX and NS. This is known as the shared asset area. Conrail charges fees for right-of-way usage, equipment rentals and transportation, switching and terminal service charges in the shared asset area. These expenses are included in materials, supplies and other on the consolidated income statements. Future minimum lease payments due to Conrail under the shared asset area agreements are as follows:


	(Dollars in Millions)	Conrail Shared
	Years	Asset Agreement
	2015	$	26

	2016	26

	2017	26

	2018	26

	2019	26

	Thereafter	124

	Total	$	254


	Also, included in materials, supplies and other are CSX’s 42% share of Conrail’s income and its amortization of the fair value write-up arising from the acquisition of Conrail and certain other adjustments. The amortization primarily represents the additional after-tax depreciation expense related to the write-up of Conrail’s fixed assets when the original purchase price, from the 1997 acquisition of Conrail, was allocated based on fair value. This write-up of fixed assets resulted in a difference between CSX's investment in Conrail and its share of Conrail's underlying net equity, which is $355 million as of December 2014.


	NOTE 12. Related Party Transactions, continued

	The following table details the related Conrail amounts included in materials, supplies and other in the Company’s consolidated income statements:



		Fiscal Years
	(Dollars in Millions)	2014			2013			2012
	Rents, Fees and Services	$	124		$	115		$	139

	Purchase Price Amortization and Other	4			4			4

	Equity earnings of Conrail	(31		)	(35		)	(26		)
	Total Conrail Rents, Fees and Services	$	97		$	84		$	117


	As required by the Related Party Disclosures Topic in the ASC, the Company has identified amounts below owed to Conrail, or its subsidiaries, representing liabilities under the operating, equipment and shared area agreements with Conrail. The Company also executed two promissory notes with a subsidiary of Conrail which were included in long-term debt on the consolidated balance sheets. Interest expense from these promissory notes was $3 million for 2014 and $4 million for 2013 and 2012, respectively.


		December			December
	(Dollars in Millions)	2014			2013
	Balance Sheet Information:
	CSX Payable to Conrail	$	54		$	172

	Promissory Notes Payable to Conrail Subsidiary (a)
	2.89% CSX Promissory Note due October 2044 (a)	73			—

	2.89% CSXT Promissory Note due October 2044 (a)	151			—

	4.40% CSX Promissory Note due October 2035	—			73

	4.52% CSXT Promissory Note due March 2035	—			23


	(a) Promissory notes payable to Conrail are included on the consolidated balance sheet of CSX as long-term debt.

	In October 2014, the Company converted its existing short term payable balance of approximately $125 million for operation of the shared asset area as well as its $23 million, 4.52% note due 2035 and its $73 million, 4.40% note due 2035 plus accrued interest of $3 million, into $224 million, 2.89% notes due 2044. The transaction is non-cash in nature.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 26, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements

	The Financial Instruments Topic in the ASC requires disclosures about fair value of financial instruments in annual reports as well as in quarterly reports. For CSX, this statement applies to certain investments, pension plan assets and long-term debt. Also, the Fair Value Measurements and Disclosures Topic in the ASC clarifies the definition of fair value for financial reporting, establishes a framework for measuring fair value and requires additional disclosures about the use of fair value measurements.

	Various inputs are considered when determining the value of the Company's investments, pension plan assets and long-term debt. The inputs or methodologies used for valuing securities are not necessarily an indication of the risk associated with investing in these securities. These inputs are summarized in the three broad levels listed below.

	•	Level 1 – observable market inputs that are unadjusted quoted prices for identical assets or liabilities in active markets

	•	Level 2 – other significant observable inputs (including quoted prices for similar securities, interest rates, credit risk, etc.)

	•	Level 3 – significant unobservable inputs (including the Company’s own assumptions about the assumptions market participants would use in determining the fair value of investments)

	The valuation methods described below may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. Furthermore, while the Company believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date.

	Investments
	The Company's investment assets, valued with assistance from a third-party trustee, consist of certificates of deposits, commercial paper, corporate bonds, government securities and auction rate securities and are carried at fair value on the consolidated balance sheet per the Fair Value Measurements and Disclosures Topic in the ASC. There are several valuation methodologies used for those assets as described below.


	•	Certificates of Deposit and Commercial Paper (Level 2): Valued at amortized cost, which approximates fair value.


	•	Corporate Bonds and Government Securities (Level 2): Valued using broker quotes that utilize observable market inputs.


	•	Auction Rate Securities (Level 3): Valued using pricing models for which the assumptions utilize management’s estimates of market participant assumptions, because there is currently no active market for trading.
	NOTE 13. Fair Value Measurements, continued

	The Company's investment assets are carried at fair value on the consolidated balance sheets as summarized in the table below. Additionally, the amortized cost basis of these investments was $453 million and $668 million as of December 26, 2014 and December 27, 2013, respectively.



		Fiscal Years
		2014												2013
	(Dollars in Millions)	Level 1		Level 2			Level 3			Total				Level 1			Level 2		Level 3		Total
	Certificates of Deposit and Commercial Paper	$	—	$	250		$	—		$	250			$	—		$	472	$	—	$	472

	Corporate Bonds	—		141			—			141				—			132		—		132

	Government Securities	—		51			—			51				—			49		—		49

	Auction Rate Securities	—		—			11			11				—			—		15		15

	Total investments at fair value	$	—	$	442		$	11		$	453			$	—		$	653	$	15	$	668


	These investments have the following maturities and are represented on the consolidated balance sheet within short-term investments for investments with maturities within one year or less, and other long-term assets for investments with maturities greater than one year:



	(Dollars in Millions)	Dec-14			Dec-13
	Less than 1 year	$	292		$	487

	1 - 2 years	45			58

	2 - 5 years	100			105

	Greater than 5 years	16			18

	Total investments at fair value	$	453		$	668


	Long-term Debt
	Long-term debt is reported at carrying amount on the consolidated balance sheets and is the Company's only financial instrument with fair values significantly different from their carrying amounts. The majority of the Company's long-term debt is valued with assistance from a third party that utilizes closing transactions, market quotes or market values of comparable debt. For those instruments not valued by the third party, the fair value has been estimated by applying market rates of similar instruments to the scheduled contractual debt payments and maturities. These market rates are provided by the same third party. All of the inputs used to determine the fair value of the Company's long-term debt are Level 2 inputs.

The fair value of outstanding debt fluctuates with changes in a number of factors. Such factors include, but are not limited to, interest rates, market conditions, values of similar financial instruments, size of the transaction, cash flow projections and comparable trades. Fair value will exceed carrying value when the current market interest rate is lower than the interest rate at which the debt was originally issued. The fair value of a company's debt is a measure of its current value under present market conditions. It does not impact the financial statements under current accounting rules.

NOTE 13. Fair Value Measurements, continued

The fair value and carrying value of the Company's long-term debt is as follows:


(Dollars in Millions)	Dec-14			Dec-13
Long-term Debt (Including Current Maturities):
Fair Value	$	11,042		$	10,354

Carrying Value	9,742			9,555


Pension Plan Assets
Pension plan assets are reported at fair value on the consolidated balance sheet. The Investment Committee targets an allocation of pension assets to be generally 70% equity and 30% fixed income. There are several valuation methodologies used for those assets as described below.

•	Common stock (Level 1): Valued at the closing price reported on the active market on which the individual securities are traded on the last day of the year and classified in level 1 of the fair value hierarchy.

•	Mutual funds (Level 1): Valued at the net asset value of shares held at year end based on quoted market prices determined in an active market. These assets are classified in level 1 of the fair value hierarchy.

•	Common collective trust funds (Level 2): This class consists of private funds that invest in government and corporate securities and various short-term debt instruments. The net asset value of the investments is determined by reference to the fair value of the underlying securities, which are valued primarily through the use of directly or indirectly observable inputs. These assets are classified in level 2 of the fair value hierarchy.

•	Corporate bonds, derivatives, government securities, and asset-backed securities (Level 2): Valued using price evaluations reflecting the bid and/or ask sides of the market for a similar investment at year end. Asset-backed securities include commercial mortgage-backed securities and collateralized mortgage obligations. These assets are classified in level 2 of the fair value hierarchy.

•	Partnerships (Level 2): Net asset value of private equity based on the fair market values associated with the underlying investments at year end and is classified in level 2 of the fair value hierarchy.

NOTE 13. Fair Value Measurements, continued

The pension plan assets at fair value by level, within the fair value hierarchy, as of calendar plan years 2014 and 2013 are shown in the table below. For additional information related to pension assets, see Note 8, Employee Benefit Plans.



	Fiscal Years
	2014															2013
(Dollars in Millions)	Level 1			Level 2				Level 3				Total				Level 1			Level 2			Level 3		Total
Common Stock:

Information technology	$	177		$	—			$	—			$	177			$	173		$	—		$	—	$	173

Health care	133			—				—				133				126			—			—		126

Consumer discretionary	125			—				—				125				152			—			—		152

Financials	116			—				—				116				116			—			—		116

Industrials	90			—				—				90				108			—			—		108

Energy	51			—				—				51				59			—			—		59

Consumer staples	42			—				—				42				43			—			—		43

Materials	20			—				—				20				29			—			—		29

Other	33			—				—				33				31			—			—		31

Mutual funds	20			—				—				20				17			—			—		17

Cash equivalents	1			—				—				1				—			—			—		—

Common trust funds	—			611				—				611				—			553			—		553

Corporate bonds	—			539				—				539				—			568			—		568

Partnerships	—			365				—				365				—			314			—		314

Government securities	—			164				—				164				—			186			—		186

Asset-backed securities	—			15				—				15				—			24			—		24

Derivatives and other	—			2				—				2				—			1			—		1

Total investments at	$	808		$	1,696			$	—			$	2,504			$	854		$	1,646		$	—	$	2,500
fair value

Other_Comprehensive_Income

Other Comprehensive Income	12 Months Ended
	Dec. 26, 2014
Equity [Abstract]
Other Comprehensive Income	Other Comprehensive Income

	CSX reports comprehensive earnings or loss in accordance with the Comprehensive Income Topic in the ASC in the Consolidated Comprehensive Income Statement. Total comprehensive earnings are defined as all changes in shareholders' equity during a period, other than those resulting from investments by and distributions to shareholders (e.g. issuance of equity securities and dividends). Generally, for CSX, total comprehensive earnings equal net earnings plus or minus adjustments for pension and other post-retirement liabilities. Total comprehensive earnings represent the activity for a period net of tax and were $1.8 billion, $2.3 billion and $1.8 billion for 2014, 2013 and 2012, respectively.

	While total comprehensive earnings is the activity in a period and is largely driven by net earnings in that period, accumulated other comprehensive income or loss (“AOCI”) represents the cumulative balance of other comprehensive income, net of tax, as of the balance sheet date. For CSX, AOCI is primarily the cumulative balance related to pension and other post-retirement benefit adjustments and CSX's share of AOCI of equity method investees.

	Changes in the AOCI balance by component are shown in the table below. Amounts reclassified in pension and other post-employment benefits to net earnings relate to the amortization of actuarial losses and are included in labor and fringe on the consolidated income statements. See Note 8. Employee Benefit Plans for further information. Other primarily represents CSX's share of AOCI of equity method investees. Amounts reclassified in other to net earnings are included in materials, supplies and other on the consolidated income statements.



		Pension and Other Post-Employment Benefits			Other			Accumulated Other Comprehensive Income (Loss)
	(Dollars in millions)
	Balance December 30, 2011, Net of Tax	$	(799	)	$	(76	)	$	(875	)
	Other Comprehensive Loss
	Loss Before Reclassifications	(172		)	(9		)	(181		)
	Amounts Reclassified to Net Earnings	88			(1		)	87

	Tax Benefit	32			1			33

	Total Other Comprehensive Loss	(52		)	(9		)	(61		)
	Balance December 28, 2012, Net of Tax	(851		)	(85		)	(936		)
	Other Comprehensive Income
	Income Before Reclassifications	510			24			534

	Amounts Reclassified to Net Earnings	111			(2		)	109

	Tax (Expense) Benefit	(232		)	2			(230		)

	Total Other Comprehensive Income	389			24			413

	Balance December 27, 2013, Net of Tax	(462		)	(61		)	(523		)
	Other Comprehensive Loss
	(Loss) Income Before Reclassifications	(297		)	4			(293		)

	Amounts Reclassified to Net Earnings	60			2			62

	Tax Benefit	88			—			88

	Total Other Comprehensive (Loss) Income	(149		)	6			(143		)

	Balance December 26, 2014, Net of Tax	$	(611	)	$	(55	)	$	(666	)

Quarterly_Financial_Data_Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 26, 2014
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	Quarterly Financial Data (Unaudited)

	Pursuant to Article 3 of the SEC’s Regulation S-X, the following are selected quarterly financial data:



	Fiscal Year Ended December 2014	Quarters
	(Dollars in Millions, Except Per Share Amounts)	1st		2nd		3rd		4th		Full Year
	Revenue	$	3,012	$	3,244	$	3,221	$	3,192	$	12,669

	Operating Income	739		997		976		901		3,613

	Net Earnings	398		529		509		491		1,927


	Earnings Per Share, Basic	$	0.4	$	0.53	$	0.51	$	0.49	$	1.93

	Earnings Per Share, Assuming Dilution	0.4		0.53		0.51		0.49		1.92


	Fiscal Year Ended December 2013
	Revenue	$	2,963	$	3,046	$	2,985	$	3,032	$	12,026

	Operating Income	880		940		840		813		3,473

	Net Earnings	462		521		455		426		1,864


	Earnings Per Share, Basic	$	0.45	$	0.51	$	0.45	$	0.42	$	1.83

	Earnings Per Share, Assuming Dilution	0.45		0.51		0.45		0.42		1.83

Summarized_Consolidating_Finan

Summarized Consolidating Financial Data	12 Months Ended
	Dec. 26, 2014
Summarized Consolidating Financial Data [Abstract]
Summarized Consolidating Financial Data	Summarized Consolidating Financial Data

	In 2007, CSXT, a wholly-owned subsidiary of CSX Corporation, sold secured equipment notes maturing in 2023 in a registered public offering. CSX has fully and unconditionally guaranteed the notes. In connection with the notes, the Company is providing the following condensed consolidating financial information in accordance with SEC disclosure requirements. Each entity in the consolidating financial information follows the same accounting policies as described in the consolidated financial statements, except for the use of the equity method of accounting to reflect ownership interests in subsidiaries which are eliminated upon consolidation and the allocation of certain expenses of CSX incurred for the benefit of its subsidiaries. Condensed consolidating financial information for the obligor, CSXT, and parent guarantor, CSX, is shown in the tables below.

	NOTE 16. Summarized Consolidating Financial Data, continued

	Consolidating Income Statements
	(Dollars in Millions)



	Fiscal Year Ended December 2014	CSX				CSX				Eliminations and Other				Consolidated
		Corporation				Transportation
	Revenue	$	—			$	12,590			$	79			$	12,669

	Expense	(427		)		9,585				(102		)		9,056

	Operating Income	427				3,005				181				3,613

	Equity in Earnings of Subsidiaries	1,996				1				(1,997		)		—

	Interest Expense	(520		)		(46		)		21				(545		)

	Other Income - Net	(19		)		(4		)		(1		)		(24		)
	Earnings Before Income Taxes	1,884				2,956				(1,796		)		3,044

	Income Tax Benefit (Expense)	43				(1,093		)		(67		)		(1,117		)

	Net Earnings	$	1,927			$	1,863			$	(1,863	)		$	1,927


	Total Comprehensive Earnings	$	1,784			$	1,875			$	(1,875	)		$	1,784


	Fiscal Year Ended December 2013
	Revenue	$	—			$	11,950			$	76			$	12,026

	Expense	(371		)		9,091				(167		)		8,553

	Operating Income	371				2,859				243				3,473

	Equity in Earnings of Subsidiaries	1,964				(1		)		(1,963		)		—

	Interest Expense	(516		)		(62		)		16				(562		)

	Other Income - Net	(7		)		(2		)		20				11

	Earnings Before Income Taxes	1,812				2,794				(1,684		)		2,922

	Income Tax Benefit (Expense)	52				(1,028		)		(82		)		(1,058		)

	Net Earnings	$	1,864			$	1,766			$	(1,766	)		$	1,864


	Total Comprehensive Earnings	$	2,277			$	1,825			$	(1,825	)		$	2,277


	Fiscal Year Ended December 2012
	Revenue	$	—			$	11,696			$	67			$	11,763

	Expense	(355		)		8,779				(125		)		8,299

	Operating Income	355				2,917				192				3,464

Equity in Earnings of Subsidiaries	1,992				(2		)		(1,990		)		—

Interest Expense	(513		)		(70		)		17				(566		)

Other Income - Net	(3		)		61				15				73

Earnings Before Income Taxes	1,831				2,906				(1,766		)		2,971

Income Tax Benefit (Expense)	32				(1,065		)		(75		)		(1,108		)

Net Earnings	$	1,863			$	1,841			$	(1,841	)		$	1,863


Total Comprehensive Earnings	$	1,802			$	1,818			$	(1,818	)		$	1,802




NOTE 16. Summarized Consolidating Financial Data, continued

Consolidating Balance Sheets
(Dollars in Millions)


As of December 26, 2014	CSX				CSX				Eliminations and Other				Consolidated
	Corporation				Transportation
ASSETS
Current Assets:
Cash and Cash Equivalents	$	510			$	100			$	59			$	669

Short-term Investments	250				—				42				292

Accounts Receivable - Net	2				206				921				1,129

Receivable from Affiliates	1,211				2,418				(3,629		)		—

Materials and Supplies	—				272				1				273

Deferred Income Taxes	3				139				(1		)		141

Other Current Assets	—				61				7				68

Total Current Assets	1,976				3,196				(2,600		)		2,572

Properties	1				36,888				2,454				39,343

Accumulated Depreciation	(1		)		(9,516		)		(1,242		)		(10,759		)
Properties - Net	—				27,372				1,212				28,584

Investments in Conrail	—				—				779				779

Affiliates and Other Companies	(39		)		644				(28		)		577

Investment in Consolidated Subsidiaries	21,570				—				(21,570		)		—

Other Long-term Assets	178				387				(24		)		541

Total Assets	$	23,685			$	31,599			$	(22,231	)		$	33,053

LIABILITIES AND SHAREHOLDERS' EQUITY
Current Liabilities:
Accounts Payable	$	106			$	707			$	32			$	845

Labor and Fringe Benefits Payable	38				511				64				613

Payable to Affiliates	3,053				514				(3,567		)		—

Casualty, Environmental and Other Reserves	—				126				16				142

Current Maturities of Long-term Debt	200				29				(1		)		228

Income and Other Taxes Payable	(150		)		293				20				163

Other Current Liabilities	—				111				5				116

Total Current Liabilities	3,247				2,291				(3,431		)		2,107

Casualty, Environmental and Other Reserves	—				213				63				276

Long-term Debt	8,705				809				—				9,514

Deferred Income Taxes	(172		)		8,827				203				8,858

Other Long-term Liabilities	753				487				(118		)		1,122

Total Liabilities	12,533				12,627				(3,283		)		21,877

Shareholders' Equity:
Common Stock, $1 Par Value	992				181				(181		)		992

Other Capital	92				5,077				(5,077		)		92

Retained Earnings	10,734				13,717				(13,717		)		10,734

Accumulated Other Comprehensive Loss	(666		)		(31		)		31				(666		)

Noncontrolling Minority Interest	—				28				(4		)		24

Total Shareholders' Equity	11,152				18,972				(18,948		)		11,176

Total Liabilities and Shareholders' Equity	$	23,685			$	31,599			$	(22,231	)		$	33,053

NOTE 16. Summarized Consolidating Financial Data, continued

Consolidating Balance Sheets
(Dollars in Millions)


As of December 27, 2013	CSX Corporation				CSX Transportation				Eliminations and Other				Consolidated
ASSETS
Current Assets

Cash and Cash Equivalents	$	439			$	91			$	62			$	592

Short-term Investments	472				—				15				487

Accounts Receivable - Net	3				240				809				1,052

Receivable from Affiliates	1,141				2,635				(3,776		)		—

Materials and Supplies	—				252				—				252

Deferred Income Taxes	(5		)		161				(1		)		155

Other Current Assets	1				57				6				64

Total Current Assets	2,051				3,436				(2,885		)		2,602

Properties	1				34,987				2,196				37,184

Accumulated Depreciation	(1		)		(8,778		)		(1,114		)		(9,893		)
Properties - Net	—				26,209				1,082				27,291

Investments in Conrail	—				—				752				752

Affiliates and Other Companies	(39		)		612				(27		)		546

Investment in Consolidated Subsidiaries	20,226				—				(20,226		)		—

Other Long-term Assets	217				388				(14		)		591

Total Assets	$	22,455			$	30,645			$	(21,318	)		$	31,782

LIABILITIES AND SHAREHOLDERS' EQUITY
Current Liabilities
Accounts Payable	$	110			$	809			$	38			$	957

Labor and Fringe Benefits Payable	38				491				58				587

Payable to Affiliates	3,298				535				(3,833		)		—

Casualty, Environmental and Other Reserves	—				136				15				151

Current Maturities of Long-term Debt	200				333				—				533

Income and Other Taxes Payable	(397		)		479				9				91

Other Current Liabilities	—				103				2				105

Total Current Liabilities	3,249				2,886				(3,711		)		2,424

Casualty, Environmental and Other Reserves	—				231				69				300

Long-term Debt	8,308				714				—				9,022

Deferred Income Taxes	(64		)		8,548				178				8,662

Other Long-term Liabilities	479				512				(121		)		870

Total Liabilities	11,972				12,891				(3,585		)		21,278

Shareholders' Equity
Common Stock, $1 Par Value	1,009				181				(181		)		1,009

Other Capital	61				5,077				(5,077		)		61

Retained Earnings	9,936				12,514				(12,514		)		9,936

Accumulated Other Comprehensive Loss	(523		)		(43		)		43				(523		)

Noncontrolling Minority Interest	—				25				(4		)		21

Total Shareholders' Equity	10,483				17,754				(17,733		)		10,504

Total Liabilities and Shareholders' Equity	$	22,455			$	30,645			$	(21,318	)		$	31,782



NOTE 16. Summarized Consolidating Financial Data, continued

Consolidating Cash Flow Statements
(Dollars in Millions)


Fiscal Year Ended December 2014	CSX Corporation				CSX Transportation				Eliminations and Other				Consolidated
Operating Activities
Net Cash Provided by (Used in) Operating Activities	$	583			$	3,278			$	(518	)		$	3,343


Investing Activities
Property Additions	—				(2,192		)		(257		)		(2,449		)

Purchases of Short-term Investments	(1,419		)		—				(14		)		(1,433		)

Proceeds from Sales of Short-term Investments	1,642				—				32				1,674

Proceeds from Property Dispositions	—				62				—				62

Other Investing Activities	—				(128		)		91				(37		)

Net Cash Provided by (Used in) Investing Activities	223				(2,258		)		(148		)		(2,183		)


Financing Activities
Long-term Debt Issued	1,000				—				—				1,000

Long-term Debt Repaid	(600		)		(333		)		—				(933		)

Dividends Paid	(629		)		(660		)		660				(629		)

Stock Options Exercised	—				—				—				—

Shares Repurchased	(517		)		—				—				(517		)

Other Financing Activities	11				(18		)		3				(4		)

Net Cash Provided by (Used in) Financing Activities	(735		)		(1,011		)		663				(1,083		)

Net Decrease in Cash and Cash Equivalents	71				9				(3		)		77

Cash and Cash Equivalents at Beginning of Period	439				91				62				592

Cash and Cash Equivalents at End of Period	$	510			$	100			$	59			$	669

NOTE 16. Summarized Consolidating Financial Data, continued

Consolidating Cash Flow Statements
(Dollars in Millions)


Fiscal Year Ended December 2013	CSX Corporation				CSX Transportation				Eliminations and Other				Consolidated
Operating Activities

Net Cash Provided by (Used in) Operating Activities	$	1,004			$	3,005			$	(742	)		$	3,267


Investing Activities
Property Additions	—				(2,053		)		(260		)		(2,313		)

Purchases of Short-term Investments	(1,251		)		—				(5		)		(1,256		)

Proceeds from Sales of Short-term Investments	1,335				—				66				1,401

Proceeds from Property Dispositions	—				53				—				53

Other Investing Activities	(134		)		(315		)		337				(112		)

Net Cash Provided by (Used in) Investing Activities	(50		)		(2,315		)		138				(2,227		)


Financing Activities
Long-term Debt Issued	500				—				—				500

Long-term Debt Repaid	(700		)		(80		)		—				(780		)

Dividends Paid	(600		)		(730		)		730				(600		)

Stock Options Exercised	9				—				—				9

Shares Repurchased	(353		)		—				—				(353		)

Other Financing Activities	148				(24		)		(132		)		(8		)

Net Cash Provided by (Used in) Financing Activities	(996		)		(834		)		598				(1,232		)

Net (Decrease) Increase in	(42		)		(144		)		(6		)		(192		)
Cash and Cash Equivalents
Cash and Cash Equivalents at Beginning of Period	481				235				68				784

Cash and Cash Equivalents at End of Period	$	439			$	91			$	62			$	592





NOTE 16. Summarized Consolidating Financial Data, continued

Consolidating Cash Flow Statements
(Dollars in Millions)


Fiscal Year Ended December 2012	CSX Corporation				CSX Transportation				Eliminations and Other				Consolidated
Operating Activities
Net Cash Provided by (Used in) Operating Activities	$	579			$	2,716			$	(349	)		$	2,946


Investing Activities
Property Additions	—				(2,104		)		(237		)		(2,341		)

Purchases of Short-term Investments	(605		)		—				(28		)		(633		)

Proceeds from Sales of Short-term Investments	525				—				56				581

Proceeds from Property Dispositions	—				186				—				186

Other Investing Activities	(10		)		102				(162		)		(70		)

Net Cash Provided by (Used in) Investing Activities	(90		)		(1,816		)		(371		)		(2,277		)

Financing Activities
Long-term Debt Issued	1,100				—				—				1,100

Long-term Debt Repaid	(400		)		(106		)		(2		)		(508		)
Dividends Paid	(558		)		(715		)		715				(558		)

Stock Options Exercised	14				—				—				14

Shares Repurchased	(734		)		—				—				(734		)

Other Financing Activities	21				2				(5		)		18

Net Cash Provided by (Used in) Financing Activities	(557		)		(819		)		708				(668		)

Net (Decrease) Increase in	(68		)		81				(12		)		1
Cash and Cash Equivalents
Cash and Cash Equivalents at Beginning of Period	549				154				80				783

Cash and Cash Equivalents at End of Period	$	481			$	235			$	68			$	784

Nature_of_Operations_and_Signi1

Nature of Operations and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 26, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Fiscal Year	CSX follows a 52/53 week fiscal reporting calendar. This fiscal calendar allows every quarter to consistently end on a Friday and typically, to be of equal duration (13 weeks), resulting in a 52 week fiscal year. To maintain this type of reporting calendar every fifth or sixth year (depending on the Gregorian calendar and when leap year falls), an extra week will be included in the fourth quarter (a 14-week fiscal quarter) and, therefore, that full fiscal year will have 53 weeks. The next 53 week fiscal year will be 2016, which will end on December 30, 2016.

	Fiscal years 2014, 2013 and 2012 each consisted of 52 weeks ending on December 26, 2014, December 27, 2013 and December 28, 2012, respectively. Except as otherwise specified, references to full year indicate CSX’s fiscal periods ended on these dates
Principles of Consolidation	The consolidated financial statements include results of operations of CSX and subsidiaries over which CSX has majority ownership or financial control. All significant intercompany accounts and transactions have been eliminated. Most investments in companies that were not majority-owned were carried at cost (if less than 20% owned and the Company has no significant influence) or were accounted for under the equity method (if the Company has significant influence but does not control).
Cash, Cash Equivalents and Short-term Investments	On a daily basis, cash in excess of current operating requirements is invested in various highly liquid investments having a typical maturity date of three months or less at the date of acquisition. These investments were carried at cost, which approximated market value, and were classified as cash equivalents.

	Investments
	Investments in instruments with original maturities greater than three months but will mature in less than one year were classified as short-term investments.
Allowance for Doubtfull Accounts	The Company maintains an allowance for doubtful accounts on uncollectible amounts related to freight receivables, government reimbursement receivables, claims for damages and other various receivables. The allowance is based upon the credit worthiness of customers, historical experience, the age of the receivable and current market and economic conditions. Uncollectible amounts are charged against the allowance account.
Materials and Supplies	Materials and supplies in the consolidated balance sheets are carried at average costs and consist primarily of fuel and parts used in the repair and maintenance of CSXT’s freight car and locomotive fleets, equipment and track structure.
Goodwill	Goodwill represents purchase price in excess of fair value and is related to affiliates of CSXT, primarily P&L Transportation, Inc. Goodwill of $63 million and $64 million is recorded in other long-term assets in the consolidated balance sheets as of December 2014 and 2013, respectively.
Revenue and Expense Recognition	The Company recognizes freight revenue using Free-On-Board Origin pursuant to the Revenue Recognition Topic in the ASC. Accounting guidance in this topic provides for the allocation of revenue between reporting periods based on relative transit time in each reporting period. Expenses are recognized as incurred.

	The certain key estimates included in the recognition and measurement of revenue and related accounts receivable under the policies described above are as follows:

	•	revenue associated with shipments in transit is recognized ratably over transit time and is based on average cycle times to move commodities and products from their origin to their final destination or interchange;

	•	adjustments to revenue for billing corrections, billing discounts and bad debts or to accounts receivable for allowances for doubtful accounts;

	•	adjustments to revenue for overcharge claims filed by customers, which are based on historical cash paid to customers for rate overcharges as a percentage of total billing;

	NOTE 1. Nature of Operations and Significant Accounting Policies, continued


	•	incentive-based refunds to customers, which are primarily based on customers achieving certain volume thresholds and are recorded as a reduction to revenue on the basis of management’s best estimate of the projected liability (this estimate is based on historical activity, current volume levels and a forecast of future volume);
	The Company regularly updates the estimates described above based on historical experience and current conditions. All other revenue, such as demurrage, switching and other incidental charges are recorded upon completion of the service.
New Accounting Pronouncements	In May 2014, the FASB issued an Accounting Standards Update, Revenue from Contracts with Customers, which supersedes previous revenue recognition guidance. The new standard requires that a company recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration the company expects to receive in exchange for those goods or services. Companies will need to use more judgment and estimates than under the guidance currently in effect, including estimating the amount of variable revenue to recognize over each identified performance obligation. Additional disclosures will be required to help users of financial statements understand the nature, amount and timing of revenue and cash flows arising from contracts. The new standard will become effective for CSX beginning with the first quarter 2017 and can be adopted either retrospectively to each prior reporting period presented or as a cumulative effect adjustment as of the date of adoption. The Company is currently evaluating the impact of adopting this new guidance on the consolidated financial statements.

	In February 2013, the FASB issued an Accounting Standards Update to the Comprehensive Income Topic in the Accounting Standards Codifications ("ASC"). This update requires separate presentation of the components that are reclassified out of accumulated other comprehensive income either on the face of the financial statements or in the notes to the financial statements. This update also requires companies to disclose the income statement line items impacted by any significant reclassifications, such as the amortization of pension and other post-employment benefits adjustments. These items are required for both interim and annual reporting for public companies and became effective for CSX beginning with the first quarter 2013 Form 10-Q filing.
Use of Estimates	The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires that management make estimates in reporting the amounts of certain assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amount of certain revenues and expenses during the reporting period. Actual results may differ from those estimates. Critical accounting estimates using management judgment are made for the following areas:

	•	casualty, environmental and legal reserves (see Note 5, Casualty, Environmental and Other Reserves);

	•	pension and post-retirement medical plan accounting (see Note 8, Employee Benefit Plans);

	•	depreciation policies for assets under the group-life method (see Note 6, Properties); and

	•	income taxes (see Note 11, Income Taxes).
Other Items - Share Repurchases	In accordance with the Equity Topic in the ASC, the excess of repurchase price over par value is recorded in retained earnings. Generally, retained earnings is only impacted by net earnings and dividends.
Earnings Per Share	Basic earnings per share is based on the weighted-average number of shares of common stock outstanding. Earnings per share, assuming dilution, is based on the weighted-average number of shares of common stock equivalents outstanding adjusted for the effects of common stock that may be issued as a result of the following types of potentially dilutive instruments:
	NOTE 2. Earnings Per Share, continued


	•	equity awards, which include long-term incentive awards; and

	•	in prior periods, employee stock options (all stock options expired in May 2013).

	The Earnings Per Share Topic in the ASC requires CSX to include additional shares in the computation of earnings per share, assuming dilution. The additional shares included in diluted earnings per share represent the number of shares that would be issued if all of the above potentially dilutive instruments were converted into CSX common stock.
Share-based Compensation Expense	Share-based compensation expense is measured at the fair market value of the Company’s stock on the grant date and is recognized on a straight-line basis over the service period of the respective award.
Casualty Reserves	In accordance with the Contingencies Topic in the ASC, to the extent the value of an individual claim exceeds the self-insured retention amount, the Company would present the liability on a gross basis with a corresponding receivable for insurance recoveries. These reserves fluctuate based upon the timing of payments as well as changes in independent third-party estimates, which are reviewed by management. Actual results may vary from estimates due to the number, type and severity of the injury, costs of medical treatments and uncertainties in litigation. Most of the Company's casualty claims relate to CSXT unless otherwise noted below. Defense and processing costs, which historically have been insignificant and are anticipated to be insignificant in the future, are not included in the recorded liabilities.
Asset Retirement and Environmental Obligations	In accordance with the Asset Retirement and Environmental Obligations Topic in the ASC, the Company reviews its role with respect to each site identified at least quarterly, giving consideration to a number of factors such as:

	•	type of clean-up required;

	•	nature of the Company’s alleged connection to the location (e.g., generator of waste sent to the site or owner or operator of the site);

	•	extent of the Company’s alleged connection (e.g., volume of waste sent to the location and other relevant factors); and

	•	number, connection and financial viability of other named and unnamed potentially responsible parties at the location.
Property and Equipment Depreciation	The Company depreciates its rail assets, including main-line track, locomotives and freight cars, using the group-life method of accounting. Assets depreciated under the group-life method of accounting comprise 85% of total fixed assets of $39 billion on a gross basis as of December 2014. All other depreciable assets of the Company are depreciated on a straight-line basis. The group-life method aggregates assets with similar lives and characteristics into groups and depreciates each of these groups as a whole. When using the group-life method, an underlying assumption is that each group of assets, as a whole, is used and depreciated to the end of its recoverable life.
Impairment Review of Property and Other Long-lived Assets	Properties and other long-lived assets are reviewed for impairment whenever events or business conditions indicate the carrying amount of such assets may not be fully recoverable. Initial assessments of recoverability are based on estimates of undiscounted future net cash flows associated with an asset or a group of assets in accordance with the Property, Plant, and Equipment Topic in the ASC. Where impairment is indicated, the assets are evaluated and their carrying amount is reduced to fair value based on discounted net cash flows or other estimates of fair value.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Dec. 26, 2014
Earnings Per Share [Abstract]
Computation of basic and diluted earnings per share	The following table sets forth the computation of basic earnings per share and earnings per share, assuming dilution:


		Fiscal Years
		2014			2013		2012
	Numerator (Dollars in Millions):
	Net Earnings	$	1,927		$	1,864	$	1,863

	Dividend Equivalents on Restricted Stock	(1		)	—		—

	Net Earnings, Attributable to Common Shareholders	$	1,926		$	1,864	$	1,863


	Denominator (Units in Millions):
	Average Common Shares Outstanding	1,001			1,019		1,038

	Other Potentially Dilutive Common Shares	1			—		2

	Average Common Shares Outstanding, Assuming Dilution	1,002			1,019		1,040


	Net Earnings Per Share, Basic	$	1.93		$	1.83	$	1.8

	Net Earnings Per Share, Assuming Dilution	$	1.92		$	1.83	$	1.79

Shareholders_Equity_Tables

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 26, 2014
Stockholders' Equity Note [Abstract]
Schedule of common and preferred stock	Common and preferred stock consists of the following:




	Common Stock, $1 Par Value	Dec-14
		(Units in Millions)
	Common Shares Authorized	1,800

	Common Shares Issued and Outstanding	992


	Preferred Stock
	Preferred Shares Authorized	25

	Preferred Shares Issued and Outstanding	—

Stock_Plans_and_ShareBased_Com1

Stock Plans and Share-Based Compensation (Tables)	12 Months Ended
	Dec. 26, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of share-based compensation and related income tax benefit	Total pre-tax expense associated with share-based compensation and its related income tax benefit is as follows:

	NOTE 4. Stock Plans and Share-Based Compensation, continued


		Fiscal Years
	(Dollars in Millions)	2014			2013				2012
	Share-Based Compensation Expense	$	33		$	14			$	14

	Income Tax Benefit	13			6				5

Schedule of outstanding restricted stock awards	he following table provides information about outstanding restricted stock units and awards combined. As of December 2014, unrecognized compensation expense for these awards and units was approximately $16 million, which will be expensed over a weighted-average remaining period of 2 years.



		Fiscal Years
		2014		2013			2012
	Restricted Stock Units and Awards Outstanding (Thousands)(a)	1,383		1,462			1,353

	Weighted-Average Fair Value at Grant Date	$	25.03	$	23.89		$	21.38

	Restricted Stock Units and Awards Expense (Millions)(a)	11		10			9

	Unvested Restricted Stock Units and Awards Outstanding (Thousands)	601		705			629

	Weighted-Average Fair Value of Unvested Units and Awards Outstanding	$	26.4	$	24.17		$	22.48


	(a) Time-based restricted stock units were granted to certain employees under the respective Long-term Incentive Plans in the amount of 371,000, 524,000, and 433,000 in 2014, 2013 and 2012, respectively, as described below. These units vest over three years, therefore only a partial amount of expense was recognized in 2014, 2013, and 2012, respectively.

Schedule of target units granted and weighted-average fair value calculations

		LTIP Plan (Plan Ended In)
		2014			2015				2016
	Number of target units outstanding (Thousands)(a)	1,338			1,330				1,119

	Weighted-average fair value at grant date (a)	$	22.23		$	25.5			$	28.03

	Payout Range	0% - 200%			0% - 200%				0% - 200%

	(a) Number of target units granted and weighted-average fair value calculations above include the value of both initial grants and subsequent, smaller grants issued at different prices based on grant date fair value to new or promoted employees not previously included.
Schedule of outstanding long-term incentive plans	The activity related to each of the outstanding long-term incentive plans is summarized as follows:


		LTIP Plan (Plan Ended In)							Weighted-Average Fair Value at Grant Date
	(Units Outstanding, in Thousands)	2014		2015			2016
	Unvested at December 28, 2012	1,237		—			—		$	21.98

	Granted in 2013	85		1,354			—		25.26

	Forfeited in 2013	(4	)	(75	)		—		(25.19		)

	Unvested at December 27, 2013	1,318		1,279			—		23.7



	Granted in 2014	20		52			1,144		28.13

	Forfeited in 2014	—		(1	)		(25	)	(28.07		)

	Cancelled due to performance conditions(a)	(1,338	)	—			—		(22.23		)

	Vested at December 26, 2014	—		—			—		—

	Unvested at December 26, 2014	—		1,330			1,119		$	26.66

	(a) The minimum financial target was not met in 2014. As a result, there was no performance unit payout for the LTIP ended December 26, 2014.
Schedule of shares issued to directors	The following table provides information about shares issued to directors.


		Fiscal Years
		2014			2013				2012
	Shares Issued to Directors (Thousands)	79			105				102

	Expense (Millions)	$	2		$	2			$	2

	Weighted Average Grant Date Stock Price	$	28.01		$	23.12			$	21.92

Casualty_Environmental_and_Oth1

Casualty, Environmental and Other Reserves (Tables)	12 Months Ended
Casualty, Environmental and Other Reserves (Tables)	Dec. 26, 2014
Casualty, Environmental and Other Reserves [Abstract]
Casualty, environmental and other reserves	Activity related to casualty, environmental and other reserves is as follows:


		Casualty				Environmental			Other
	(Dollars in Millions)	Reserves				Reserves			Reserves			Total
	30-Dec-11	$	372			$	83		$	64		$	519
	30-Dec-11	$	372			$	83		$	64		$	519
	Charged to Expense	51				35			36			122
	Charged to Expense	51				35			36			122
	Payments	(98		)		(30		)	(36		)	(164		)
	28-Dec-12	325				88			64			477
	28-Dec-12	325				88			64			477
	Charged to Expense	54				48			38			140
	Charged to Expense	54				48			38			140
	Payments	(99		)		(36		)	(31		)	(166		)
	27-Dec-13	280				100			71			451
	27-Dec-13	280				100			71			451
	Charged to Expense (a)	89				57			30			176
	Charged to Expense (a)	89				57			30			176
	Payments	(104		)		(63		)	(42		)	(209		)
	26-Dec-14	$	265			$	94		$	59		$	418
	26-Dec-14	$	265			$	94		$	59		$	418

	(a)	Increase in expense in 2014 is primarily due to the resolution of personal injury claims for prior years.


	NOTE 5. Casualty, Environmental and Other Reserves, continued

	These reserves are considered critical accounting estimates due to the need for significant management judgment. They are provided for in the consolidated balance sheets as follows:


		Dec-14										Dec-13
	(Dollars in Millions)	Current				Long-term			Total			Current			Long-term		Total
	Casualty:
	Personal Injury	$	68			$	123		$	191		$	59		$	148	$	207
	Personal Injury	$	68			$	123		$	191		$	59		$	148	$	207
	Occupational	3				15			18			3			20		23
	Occupational	3				15			18			3			20		23
	Asbestos	5				51			56			10			40		50
	Asbestos	5				51			56			10			40		50
	Total Casualty	76				189			265			72			208		280
	Total Casualty	76				189			265			72			208		280
	Environmental	48				46			94			59			41		100
	Environmental	48				46			94			59			41		100
	Other	18				41			59			20			51		71
	Other	18				41			59			20			51		71
	Total	$	142			$	276		$	418		$	151		$	300	$	451
	Total	$	142			$	276		$	418		$	151		$	300	$	451
Schedule of Liability for Unpaid Claims and Claims Adjustment Expense	Undiscounted liabilities recorded related to occupational and asbestos claims were as follows:


		December				December
	(Dollars in Millions)	2014				2013
	Occupational:
	Incurred but not reported claims	$	12			$	15
	Incurred but not reported claims	$	12			$	15
	Asserted claims	6				8
	Asserted claims	6				8
	Total liability	$	18			$	23
	Total liability	$	18			$	23

	Asbestos:
	Incurred but not reported claims	$	45			$	35
	Incurred but not reported claims	$	45			$	35
	Asserted claims	11				15
	Asserted claims	11				15
	Total liability	$	56			$	50
	Total liability	$	56			$	50
Schedule of Claims Activity	A summary of occupational and asbestos claims activity is as follows:


		Fiscal Years
		2014			2013
	Asserted Claims
	Open Claims - Beginning of Year	392			523
	Open Claims - Beginning of Year	392			523
	New Claims Filed	136			165
	New Claims Filed	136			165
	Claims Settled	(128	)		(146	)
	Claims Dismissed	(130	)		(150	)
	Open Claims - End of Year	270			392
	Open Claims - End of Year	270			392

Properties_Tables

Properties (Tables)	12 Months Ended
	Dec. 26, 2014
Property, Plant and Equipment [Abstract]
Schedule of net properties	A detail of the Company’s net properties are as follows:



	(Dollars in Millions)							Accumulated				Net Book				Annual Depreciation		Depreciation		Estimated Useful
	Dec-14				Cost			Depreciation				Value				Rate		Method		Life
	Road
			Rail and Other Track Material		$	6,771		$	(1,400	)		$	5,371			2.50%		Group Life

			Ties		4,807			(1,060		)		3,747				3.70%		Group Life

			Grading		2,460			(481		)		1,979				1.40%		Group Life

			Ballast		2,693			(679		)		2,014				2.70%		Group Life

			Bridges, Trestles, and Culverts		2,119			(278		)		1,841				1.60%		Group Life

			Signals and Interlockers		2,103			(356		)		1,747				4.00%		Group Life

			Buildings		1,102			(377		)		725				2.50%		Group Life

			Other		4,070			(1,517		)		2,553				4.20%		Group Life

	Total Road				26,125			(6,148		)		19,977								8-90 Years

	Equipment

			Locomotive		5,036			(2,325		)		2,711				3.60%		Group Life

			Freight Cars		3,244			(1,169		)		2,075				3.20%		Group Life

			Work Equipment and Other		1,828			(1,032		)		796				7.10%		Group Life

	Total Equipment				10,108			(4,526		)		5,582								3-38 Years

	Land				1,875			—				1,875				N/A		N/A		N/A

	Construction In Progress				1,196			—				1,196				N/A		N/A		N/A

	Other				39			(85		)		(46		)		N/A		Straight Line		4-30 Years

	Total Properties				$	39,343		$	(10,759	)		$	28,584



	NOTE 6. Properties, continued



	(Dollars in Millions)							Accumulated				Net Book				Annual Depreciation		Depreciation		Estimated Useful
	Dec-13				Cost			Depreciation				Value				Rate		Method		Life
	Road
			Rail and Other Track Material		$	6,452		$	(1,270	)		$	5,182			2.90%		Group Life

			Ties		4,534			(947		)		3,587				4.00%		Group Life

			Grading		2,425			(448		)		1,977				1.50%		Group Life

			Ballast		2,612			(645		)		1,967				2.80%		Group Life

			Bridges, Trestles, and Culverts		2,008			(250		)		1,758				1.60%		Group Life

			Signals and Interlockers		1,922			(291		)		1,631				3.40%		Group Life

		Buildings		1,011			(355		)		656				2.50%		Group Life

		Other		3,654			(1,386		)		2,268				4.70%		Group Life

Total Road				24,618			(5,592		)		19,026								6-80 Years

Equipment
		Locomotive		4,987			(2,176		)		2,811				3.60%		Group Life

		Freight Cars		3,111			(1,135		)		1,976				3.10%		Group Life

		Work Equipment and Other		1,666			(914		)		752				7.10%		Group Life

Total Equipment				9,764			(4,225		)		5,539								5-38 Years

Land				1,842			—				1,842				N/A		N/A		N/A

Construction In Progress				854			—				854				N/A		N/A		N/A

Other				106			(76		)		30				N/A		Straight Line		4-30 Years

Total Properties				$	37,184		$	(9,893	)		$	27,291

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 26, 2014
Commitments and Contingencies Disclosure [Abstract]
Schedule of rent expense associated with operting leases	The Company uses the straight-line method to recognize rent expense associated with operating leases that include escalations over their terms. These amounts are shown in the table below.



		Fiscal Years
	(Dollars in Millions)	2014		2013			2012
	Rent Expense on Operating Leases	$	61	$	60		$	73

Schedule of minimum rentals and commitments under operating leases	At December 2014, minimum rentals on land, buildings, track and equipment under operating leases are disclosed in the table below. Also, payments to Conrail for leases on shared rail infrastructure are included in these amounts. (See Note 12, Related Party Transactions).


	(Dollars in Millions)	Operating		Sublease			Net Lease
	Years	Leases		Income			Commitments
	2015	$	78	$	(3	)	$	75

	2016	71		(2		)	69

	2017	62		(2		)	60

	2018	54		(2		)	52

	2019	45		(2		)	43

	Thereafter	210		(11		)	199

	Total	$	520	$	(22	)	$	498

Schedule of number of locomotives and payments under long-term maintenance program	The following table summarizes the number of locomotives covered and CSXT’s payments under the long-term maintenance program.


		Fiscal Years
	(Dollars in Millions)	2014		2013			2012

	Amounts Paid	$	247	$	287		$	287

	Number of Locomotives	1,886		1,886			1,899

Schedule of annual payments under long-term maintenance program	Additionally, the Company has various other commitments to purchase technology, communications, railcar maintenance and other services from various suppliers. Total annual payments under all of these purchase commitments are also estimated in the table below.


	(Dollars in Millions)	Locomotive & Maintenance Payments		Other			Total
				Commitments
	2015	$	727	$	236		$	963

	2016	474		22			496

	2017	177		13			190

	2018	169		12			181

	2019	159		11			170

	Thereafter	1,203		69			1,272

	Total	$	2,909	$	363		$	3,272

Employee_Benefit_Plans_Tables

Employee Benefit Plans (Tables)	12 Months Ended
Employee Benefit Plans (Tables)	Dec. 26, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Schedule of summary of participants	The Company engages independent actuaries to compute the amounts of liabilities and expenses relating to these plans subject to the assumptions that the Company selects. In order to perform this valuation, the actuaries are provided with the details of the population covered at the beginning of the year, summarized in the table below, and projects that population forward to the end of the year. These amounts are reviewed by management.



		Summary of Participants as of
		January 1, 2014
		Pension Plans			Post-retirement Medical Plan
	Active Employees	5,136			2,031
	Active Employees	5,136			2,031
	Retirees and Beneficiaries	11,699			12,148
	Retirees and Beneficiaries	11,699			12,148
	Other(a)	5,444			87
	Other(a)	5,444			87
	Total	22,279			14,266
	Total	22,279			14,266
	(a) For pension plans, the other category consists mostly of terminated but vested former employees. For post-retirement plans, the other category consists of employees on long-term disability that have not yet retired.
Schedule of future expected benefit payments	Future expected benefit payments are as follows:


		Expected Cash Flows
	(Dollars in Millions)	Pension Benefits				Post-retirement Benefits
	2015	$	207			$	37
	2015	$	207			$	37
	2016	188				34
	2016	188				34
	2017	188				33
	2017	188				33
	2018	185				30
	2018	185				30
	2019	186				28
	2019	186				28
	2020-2024	931				114
	2020-2024	931				114
	Total	$	1,885			$	276
	Total	$	1,885			$	276
Schedule of allocation of plan assets	The distribution of pension plan assets as of the measurement date is shown in the table below, and these assets are netted against the pension liabilities on the balance sheet.



		Dec-14							Dec-13
						Percent of							Percent of
	(Dollars in Millions)	Amount				Total Assets			Amount				Total Assets
	Equity	$	1,715			68	%		$	1,619			65	%
	Equity	$	1,715			68	%		$	1,619			65	%
	Fixed Income	740				30			795				32
	Fixed Income	740				30			795				32
	Cash and Cash Equivalents	49				2			86				3
	Cash and Cash Equivalents	49				2			86				3
	Total	$	2,504			100	%		$	2,500			100	%
	Total	$	2,504			100	%		$	2,500			100	%
Schedule of changes in benefit obligation and fair value of plan assets	Changes in benefit obligation and the fair value of plan assets for the 2014 and 2013 calendar plan years are as follows:



		Pension Benefits								Post-retirement Benefits
		Plan Year				Plan Year				Plan Year				Plan Year
	(Dollars in Millions)	2014				2013				2014				2013
	Actuarial Present Value of Benefit Obligation
	Accumulated Benefit Obligation	$	2,849			$	2,538			N/A				N/A
	Accumulated Benefit Obligation	$	2,849			$	2,538			N/A				N/A
	Projected Benefit Obligation	3,002				2,679				$	340			$	350
	Projected Benefit Obligation	3,002				2,679				$	340			$	350

	Change in Projected Benefit Obligation:
	Change in Projected Benefit Obligation:
	Projected Benefit Obligation at Beginning of Plan Year	$	2,679			$	2,954			$	350			$	415
	Projected Benefit Obligation at Beginning of Plan Year	$	2,679			$	2,954			$	350			$	415
	Service Cost	44				49				3				3
	Service Cost	44				49				3				3
	Interest Cost	123				108				13				13
	Interest Cost	123				108				13				13
	Plan Participants' Contributions	—				—				7				8
	Plan Participants' Contributions	—				—				7				8
	Workforce Reduction Program/Curtailment	27				—				8				—
	Workforce Reduction Program/Curtailment	27				—				8				—
	Actuarial Loss (Gain)	333				(275		)		(8		)		(49		)
	Actuarial Loss (Gain)	333				(275		)		(8		)		(49		)
	Benefits Paid	(204		)		(157		)		(33		)		(40		)
	Benefit Obligation at End of Plan Year	$	3,002			$	2,679			$	340			$	350
	Benefit Obligation at End of Plan Year	$	3,002			$	2,679			$	340			$	350

	Change in Plan Assets:
	Change in Plan Assets:
	Fair Value of Plan Assets at Beginning of Plan Year	$	2,500			$	2,294			$	—			$	—
	Fair Value of Plan Assets at Beginning of Plan Year	$	2,500			$	2,294			$	—			$	—
	Actual Return on Plan Assets	195				350				—				—
	Actual Return on Plan Assets	195				350				—				—
	Non-qualified Employer Contributions	13				13				26				32
	Non-qualified Employer Contributions	13				13				26				32
	Plan Participants' Contributions	—				—				7				8
	Plan Participants' Contributions	—				—				7				8
	Benefits Paid	(204		)		(157		)		(33		)		(40		)
	Fair Value of Plan Assets at End of Plan Year	2,504				2,500				—				—
	Fair Value of Plan Assets at End of Plan Year	2,504				2,500				—				—
	Funded Status at End of Plan Year	$	(498	)		$	(179	)		$	(340	)		$	(350	)
Schedule of amount recognized in balance sheet	Amounts related to pension and post-retirement benefits recorded in other long-term assets, labor and fringe benefits payable and other long-term liabilities on the balance sheet are as follows:



		Pension Benefits								Post-retirement Benefits
		December				December				December				December
	(Dollars in Millions)	2014				2013				2014				2013
	Amounts Recorded in Consolidated
	Balance Sheets:
	Long-term Assets (a)	$	9			$	44			$	—			$	—
	Long-term Assets (a)	$	9			$	44			$	—			$	—
	Current Liabilities	(15		)		(14		)		(37		)		(38		)
	Long-term Liabilities	(492		)		(209		)		(303		)		(312		)
	Net Amount Recognized in
	Net Amount Recognized in
	Consolidated Balance Sheets	$	(498	)		$	(179	)		$	(340	)		$	(350	)


	(a)	Long-term assets as of December 2014 relate to one of the qualified pension plans whose assets exceed projected benefit obligations.
Benefit obligations in excess of plan assets	At December 2014, the status of CSX plans only with a net liability is disclosed below. The total fair value of all plans as of December 2014 was $2.5 billion, which includes the qualified pension plans with net assets.



		Aggregate			Aggregate
	(Dollars in Millions)	Fair Value			Projected
	Benefit Obligations in Excess of Plan Assets	of Plan Assets			Benefit Obligation
	Projected Benefit Obligation	$	2,461		$	(2,968	)
	Projected Benefit Obligation	$	2,461		$	(2,968	)
	Accumulated Benefit Obligation	2,461			(2,815		)
	Accumulated Benefit Obligation	2,461			(2,815		)
Schedule of net benefit expense	The following table describes the components of expense/(income) related to net benefit expense recorded in labor and fringe on the income statement.


		Pension Benefits												Post-retirement Benefits
		Fiscal Years												Fiscal Years
	(Dollars in Millions)	2014				2013				2012				2014			2013			2012
	Service Cost	$	44			$	49			$	44			$	3		$	3		$	4
	Service Cost	$	44			$	49			$	44			$	3		$	3		$	4
	Interest Cost	123				108				123				13			13			16
	Interest Cost	123				108				123				13			13			16
	Expected Return on Plan Assets	(166		)		(162		)		(166		)		—			—			—
	Expected Return on Plan Assets	(166		)		(162		)		(166		)		—			—			—
	Amortization of Net Loss	57				100				82				5			14			9
	Amortization of Net Loss	57				100				82				5			14			9
	Amortization of Prior Service Cost	—				—				—				(1		)	(1		)	(1		)
	Amortization of Prior Service Cost	—				—				—				(1		)	(1		)	(1		)
	Net Periodic Benefit Expense	58				95				83				20			29			28
	Net Periodic Benefit Expense	58				95				83				20			29			28
	Special Termination Benefits - Workforce Reduction Program/Curtailment(a)	27				—				—				8			—			—
		27				—				—				8			—			—
	Settlement Gain(b)	(1		)		(2		)		(2		)		—			—			—
	Settlement Gain(b)	(1		)		(2		)		(2		)		—			—			—
	Total Expense	$	84			$	93			$	81			$	28		$	29		$	28
	Total Expense	$	84			$	93			$	81			$	28		$	29		$	28


	(a)	These charges result from a management workforce reduction program that was initiated in 2014. For further information regarding the program, see Note 1. Nature of Operations and Significant Accounting Policies.

	(b)	Settlement gains were recognized as one of the pension plan's lump-sum payments exceeded the sum of the service cost and interest cost recognized. The gain is the recognition of a portion of its accumulated other comprehensive income related to that plan
Schedule of pre-tax change in other comprehensive loss (income)	The following table shows the pre-tax change in other comprehensive loss (income) attributable to the components of net expense and the change in benefit obligation for CSX for pension and other post-employment benefits.


	(Dollars in Millions)	Pension Benefits								Post-retirement Benefits
	Components of Other Comprehensive	December				December				December				December
	Loss (Income)	2014				2013				2014				2013
	Recognized in the balance sheet
	Losses (Gains)	$	305			$	(462	)		$	(8	)		$	(48	)
	Losses (Gains)	$	305			$	(462	)		$	(8	)		$	(48	)
	Expense (Income) recognized in the income statement
	Expense (Income) recognized in the income statement
	Amortization of net losses (a)	$	57			$	100			$	5			$	14
	Amortization of net losses (a)	$	57			$	100			$	5			$	14
	Settlement gain	(1		)		(2		)		—				—
	Settlement gain	(1		)		(2		)		—				—
	Amortization of prior service costs (b)	—				—				(1		)		(1		)
	Amortization of prior service costs (b)	—				—				(1		)		(1		)


	(a)	Amortization of net losses estimated to be expensed for 2015 is approximately $70 million and $5 million for pension benefits and post-retirement benefits, respectively. The increase in amortization is largely related to the impact of lower discount rates and adoption of new mortality tables, partially offset by favorable pension asset experience.

	(b)	Amortization of prior service costs estimated to be expensed in 2015 is less than $1 million for pension benefits. The estimated post-retirement benefits amount to be credited to expense for 2015 is $1 million.
Schedule of pre-tax amounts to be amortized that included in accumulated other comprehensive loss	As of December 2014, the balances of pre-tax amounts to be amortized that are included in accumulated other comprehensive loss (a component of shareholders’ equity) are as follows:


		Pension				Post-retirement
		Benefits				Benefits
	Losses	$	908			$	59
	Losses	$	908			$	59
	Prior Service Costs (Credits)	—				(1		)
	Prior Service Costs (Credits)	—				(1		)
	Total	$	908			$	58
	Total	$	908			$	58
Schedule of weighted-average assumptions used	Weighted-average assumptions used in accounting for the plans were as follows:



		Pension Benefits						Post-retirement Benefits
		2014			2013			2014			2013
	Expected Long-term Return on Plan Assets:
	Benefit Cost for Plan Year	7.5	%		7.75	%		N/A			N/A
	Benefit Cost for Plan Year	7.5	%		7.75	%		N/A			N/A
	Benefit Obligation at End of Plan Year	7.25	%		7.5	%		N/A			N/A
	Benefit Obligation at End of Plan Year	7.25	%		7.5	%		N/A			N/A

	Discount Rates:
	Benefit Cost for Plan Year	4.75	%		3.75	%		4.25	%		3.2	%
	Benefit Obligation at End of Plan Year	4	%		4.75	%		3.6	%		4.25	%

	Salary Scale Inflation	3.75	%		3.75	%		N/A			N/A
	Salary Scale Inflation	3.75	%		3.75	%		N/A			N/A
Schedule of health care cost trend rates	Additionally, there are cost differentials between Medicare and Non-Medicare eligible individuals which are reflected below.



		Post-retirement Benefits
		2014		2013
	Health Care Cost Trend Rate:
	Components of Benefit Cost: Non-Medicare Eligible	8.00%		8.50%
	Components of Benefit Cost: Medicare Eligible	7.50%		8.00%
	Benefit Obligations: Non-Medicare Eligible	8.00%		8.00%
	Benefit Obligations: Medicare Eligible	7.50%		7.50%

Debt_and_Credit_Agreements_Tab

Debt and Credit Agreements (Tables)	12 Months Ended
	Dec. 26, 2014
Debt Disclosure [Abstract]
Schedule of long-term debt instruments	Debt at December 2014 and December 2013 is shown in the table below. For information regarding the fair value of debt, see Note 13, Fair Value Measurements.


		Maturity at	Average	December			December
		December	Interest
			Rates at
			December
	(Dollars in Millions)	2014	2014	2014			2013
	Notes	2015-2054	5.50%	$	9,456		$	8,935

	Equipment Obligations(a)	2015-2023	6.30%	277			602

	Capital Leases	2015-2026	13.50%	8			16

	Convertible Debentures	2021	1.00%	1			2

	Subtotal Long-term Debt (including current portion)			$	9,742		$	9,555

	Less Debt Due within One Year			(228		)	(533		)
	Long-term Debt (excluding current portion)			$	9,514		$	9,022

	(a) These obligations are secured by an interest in certain railroad equipment.
Schedule of long-ter debt maturities	Long-term Debt Maturities


	(Dollars in Millions)	Maturities as of
	Fiscal Years Ending	Dec-14
	2015	$	228

	2016	21

	2017	631

	2018	619

	2019	518

	Thereafter	7,725

	Total Long-term Debt Maturities (including current portion)	$	9,742

Other_Income_Net_Tables

Other Income - Net (Tables)	12 Months Ended
	Dec. 26, 2014
Other Income and Expenses [Abstract]
Schedule of other Income - Net	Other income – net consisted of the following:


		Fiscal Years
	(Dollars in Millions)	2014			2013			2012
	Interest Income	$	5		$	8		$	5

	Income from Real Estate Operations	23			23			81

	Miscellaneous Expense (a)	(52		)	(20		)	(13		)
	Total Other (Expense) Income - Net	$	(24	)	$	11		$	73

	Gross Revenue from Real Estate
	Operations included above	$	47		$	48		$	106

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 26, 2014
Income Tax Disclosure [Abstract]
Schedule of breakdown of income tax expense between current and deferred	The breakdown of income tax expense between current and deferred is as follows:


		Fiscal Years
	(Dollars in Millions)	2014			2013				2012
	Current:
	Federal	$	729		$	671			$	450

	State	90			87				66

	Subtotal Current	819			758				516


	Deferred:
	Federal	291			285				530

	State	7			15				62

	Subtotal Deferred	298			300				592

	Total	$	1,117		$	1,058			$	1,108

Schedule of income tax expense reconciled to tax computed at statutory rates	Income tax expense reconciled to the tax computed at statutory rates is presented in the table below. The Company recorded a tax benefit of $31 million, $42 million and $20 million in 2014, 2013 and 2012, respectively, primarily as a result of federal and state legislative changes as well as the resolution of other federal and state tax matters. Each year's benefit is included in the state income tax and other lines in the table below.


		Fiscal Years
	(Dollars In Millions)	2014						2013							2012

	Federal Income Taxes	$	1,066		35	%		$	1,023			35	%		$	1,040		35	%

	State Income Taxes	61			2	%		65				2.2	%		81			2.8	%

	Other	(10		)	(0.3	)%		(30		)		(1.0	)%		(13		)	(0.4	)%
	Income Tax Expense/Rate	$	1,117		36.7	%		$	1,058			36.2	%		$	1,108		37.4	%

Schedule of significant components of deferred income tax assets and liabilities	The significant components of deferred income tax assets and liabilities include:


		2014							2013
	(Dollars in Millions)	Assets			Liabilities				Assets				Liabilities
	Pension Plans	$	188		$	—			$	67			$	—

	Other Employee Benefit Plans	306			—				299				—

	Accelerated Depreciation	—			9,133				—				8,868

	Other	256			334				257				262

	Total	$	750		$	9,467			$	623			$	9,130

	Net Deferred Income Tax Liabilities				$	8,717							$	8,507

Schedule of change to total gross unrecognized tax benefits	The change to the total gross unrecognized tax benefits and prior year audit resolutions of the Company during the fiscal year ended December 2014 is reconciled as follows:



	Uncertain Tax Positions:	Fiscal Year
	(Dollars in Millions)	2014			2013				2012
	Balance at beginning of the year	$	23		$	24			$	22

	Additions based on tax positions related to current year	2			2				6

	Additions based on tax positions related to prior years	3			5				3

	Reductions based on tax positions related to prior years	—			(6		)		(1		)

	Settlements with taxing authorities	—			—				—

	Lapse of statute of limitations	(7		)	(2		)		(6		)
	Balance at end of the year	$	21		$	23			$	24

Related_Party_Transactions_Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 26, 2014
Related Party Transaction [Line Items]
Future minimum lease payments	At December 2014, minimum rentals on land, buildings, track and equipment under operating leases are disclosed in the table below. Also, payments to Conrail for leases on shared rail infrastructure are included in these amounts. (See Note 12, Related Party Transactions).


	(Dollars in Millions)	Operating			Sublease			Net Lease
	Years	Leases			Income			Commitments
	2015	$	78		$	(3	)	$	75

	2016	71			(2		)	69

	2017	62			(2		)	60

	2018	54			(2		)	52

	2019	45			(2		)	43

	Thereafter	210			(11		)	199

	Total	$	520		$	(22	)	$	498

Schedule of related Conrail amounts included in Company's consolidated income statements	The following table details the related Conrail amounts included in materials, supplies and other in the Company’s consolidated income statements:



		Fiscal Years
	(Dollars in Millions)	2014			2013			2012
	Rents, Fees and Services	$	124		$	115		$	139

	Purchase Price Amortization and Other	4			4			4

	Equity earnings of Conrail	(31		)	(35		)	(26		)
	Total Conrail Rents, Fees and Services	$	97		$	84		$	117

Schedule of executed promissory notes with Conrail subsidiary	As required by the Related Party Disclosures Topic in the ASC, the Company has identified amounts below owed to Conrail, or its subsidiaries, representing liabilities under the operating, equipment and shared area agreements with Conrail. The Company also executed two promissory notes with a subsidiary of Conrail which were included in long-term debt on the consolidated balance sheets. Interest expense from these promissory notes was $3 million for 2014 and $4 million for 2013 and 2012, respectively.


		December			December
	(Dollars in Millions)	2014			2013
	Balance Sheet Information:
	CSX Payable to Conrail	$	54		$	172

	Promissory Notes Payable to Conrail Subsidiary (a)
	2.89% CSX Promissory Note due October 2044 (a)	73			—

	2.89% CSXT Promissory Note due October 2044 (a)	151			—

	4.40% CSX Promissory Note due October 2035	—			73

	4.52% CSXT Promissory Note due March 2035	—			23


	(a) Promissory notes payable to Conrail are included on the consolidated balance sheet of CSX as long-term debt.
Corporate Joint Venture [Member]
Related Party Transaction [Line Items]
Future minimum lease payments	Future minimum lease payments due to Conrail under the shared asset area agreements are as follows:


	(Dollars in Millions)	Conrail Shared
	Years	Asset Agreement
	2015	$	26

	2016	26

	2017	26

	2018	26

	2019	26

	Thereafter	124

	Total	$	254

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 26, 2014
Fair Value Disclosures [Abstract]
Schedule of fair value of investment assets	The Company's investment assets are carried at fair value on the consolidated balance sheets as summarized in the table below. Additionally, the amortized cost basis of these investments was $453 million and $668 million as of December 26, 2014 and December 27, 2013, respectively.



		Fiscal Years
		2014											2013
	(Dollars in Millions)	Level 1		Level 2			Level 3			Total			Level 1		Level 2		Level 3			Total
	Certificates of Deposit and Commercial Paper	$	—	$	250		$	—		$	250		$	—	$	472	$	—		$	472

	Corporate Bonds	—		141			—			141			—		132		—			132

	Government Securities	—		51			—			51			—		49		—			49

	Auction Rate Securities	—		—			11			11			—		—		15			15

	Total investments at fair value	$	—	$	442		$	11		$	453		$	—	$	653	$	15		$	668

Schedule of investment maturities	These investments have the following maturities and are represented on the consolidated balance sheet within short-term investments for investments with maturities within one year or less, and other long-term assets for investments with maturities greater than one year:



	(Dollars in Millions)	Dec-14			Dec-13
	Less than 1 year	$	292		$	487

	1 - 2 years	45			58

	2 - 5 years	100			105

	Greater than 5 years	16			18

	Total investments at fair value	$	453		$	668

Schedule of fair value and carrying value of long-term debt	The fair value and carrying value of the Company's long-term debt is as follows:


	(Dollars in Millions)	Dec-14			Dec-13
	Long-term Debt (Including Current Maturities):
	Fair Value	$	11,042		$	10,354

	Carrying Value	9,742			9,555

Schedule of pension plan assets at fair value by level	The pension plan assets at fair value by level, within the fair value hierarchy, as of calendar plan years 2014 and 2013 are shown in the table below. For additional information related to pension assets, see Note 8, Employee Benefit Plans.



		Fiscal Years
		2014													2013
	(Dollars in Millions)	Level 1			Level 2				Level 3			Total			Level 1			Level 2				Level 3		Total
	Common Stock:

	Information technology	$	177		$	—			$	—		$	177		$	173		$	—			$	—	$	173

	Health care	133			—				—			133			126			—				—		126

	Consumer discretionary	125			—				—			125			152			—				—		152

	Financials	116			—				—			116			116			—				—		116

	Industrials	90			—				—			90			108			—				—		108

	Energy	51			—				—			51			59			—				—		59

	Consumer staples	42			—				—			42			43			—				—		43

	Materials	20			—				—			20			29			—				—		29

	Other	33			—				—			33			31			—				—		31

	Mutual funds	20			—				—			20			17			—				—		17

	Cash equivalents	1			—				—			1			—			—				—		—

	Common trust funds	—			611				—			611			—			553				—		553

	Corporate bonds	—			539				—			539			—			568				—		568

	Partnerships	—			365				—			365			—			314				—		314

	Government securities	—			164				—			164			—			186				—		186

	Asset-backed securities	—			15				—			15			—			24				—		24

	Derivatives and other	—			2				—			2			—			1				—		1

	Total investments at	$	808		$	1,696			$	—		$	2,504		$	854		$	1,646			$	—	$	2,500
	fair value

Other_Comprehensive_Income_Tab

Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 26, 2014
Equity [Abstract]
Changes in the AOCI balance by component	Changes in the AOCI balance by component are shown in the table below. Amounts reclassified in pension and other post-employment benefits to net earnings relate to the amortization of actuarial losses and are included in labor and fringe on the consolidated income statements. See Note 8. Employee Benefit Plans for further information. Other primarily represents CSX's share of AOCI of equity method investees. Amounts reclassified in other to net earnings are included in materials, supplies and other on the consolidated income statements.



		Pension and Other Post-Employment Benefits			Other			Accumulated Other Comprehensive Income (Loss)
	(Dollars in millions)
	Balance December 30, 2011, Net of Tax	$	(799	)	$	(76	)	$	(875	)
	Other Comprehensive Loss
	Loss Before Reclassifications	(172		)	(9		)	(181		)
	Amounts Reclassified to Net Earnings	88			(1		)	87

	Tax Benefit	32			1			33

	Total Other Comprehensive Loss	(52		)	(9		)	(61		)
	Balance December 28, 2012, Net of Tax	(851		)	(85		)	(936		)
	Other Comprehensive Income
	Income Before Reclassifications	510			24			534

	Amounts Reclassified to Net Earnings	111			(2		)	109

	Tax (Expense) Benefit	(232		)	2			(230		)

	Total Other Comprehensive Income	389			24			413

	Balance December 27, 2013, Net of Tax	(462		)	(61		)	(523		)
	Other Comprehensive Loss
	(Loss) Income Before Reclassifications	(297		)	4			(293		)

	Amounts Reclassified to Net Earnings	60			2			62

	Tax Benefit	88			—			88

	Total Other Comprehensive (Loss) Income	(149		)	6			(143		)

	Balance December 26, 2014, Net of Tax	$	(611	)	$	(55	)	$	(666	)

Quarterly_Financial_Data_Unaud1

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 26, 2014
Quarterly Financial Information Disclosure [Abstract]
Schedule of quarterly financial data	Pursuant to Article 3 of the SEC’s Regulation S-X, the following are selected quarterly financial data:



	Fiscal Year Ended December 2014	Quarters
	(Dollars in Millions, Except Per Share Amounts)	1st		2nd		3rd		4th		Full Year
	Revenue	$	3,012	$	3,244	$	3,221	$	3,192	$	12,669

	Operating Income	739		997		976		901		3,613

	Net Earnings	398		529		509		491		1,927


	Earnings Per Share, Basic	$	0.4	$	0.53	$	0.51	$	0.49	$	1.93

	Earnings Per Share, Assuming Dilution	0.4		0.53		0.51		0.49		1.92


	Fiscal Year Ended December 2013
	Revenue	$	2,963	$	3,046	$	2,985	$	3,032	$	12,026

	Operating Income	880		940		840		813		3,473

	Net Earnings	462		521		455		426		1,864


	Earnings Per Share, Basic	$	0.45	$	0.51	$	0.45	$	0.42	$	1.83

	Earnings Per Share, Assuming Dilution	0.45		0.51		0.45		0.42		1.83

Summarized_Consolidating_Finan1

Summarized Consolidating Financial Data (Tables)	12 Months Ended
	Dec. 26, 2014
Summarized Consolidating Financial Data [Abstract]
Consolidating Income Statement	Consolidating Income Statements
	(Dollars in Millions)



	Fiscal Year Ended December 2014	CSX				CSX				Eliminations and Other				Consolidated
		Corporation				Transportation
	Revenue	$	—			$	12,590			$	79			$	12,669

	Expense	(427		)		9,585				(102		)		9,056

	Operating Income	427				3,005				181				3,613

	Equity in Earnings of Subsidiaries	1,996				1				(1,997		)		—

	Interest Expense	(520		)		(46		)		21				(545		)

	Other Income - Net	(19		)		(4		)		(1		)		(24		)
	Earnings Before Income Taxes	1,884				2,956				(1,796		)		3,044

	Income Tax Benefit (Expense)	43				(1,093		)		(67		)		(1,117		)

	Net Earnings	$	1,927			$	1,863			$	(1,863	)		$	1,927


	Total Comprehensive Earnings	$	1,784			$	1,875			$	(1,875	)		$	1,784


	Fiscal Year Ended December 2013
	Revenue	$	—			$	11,950			$	76			$	12,026

	Expense	(371		)		9,091				(167		)		8,553

	Operating Income	371				2,859				243				3,473

	Equity in Earnings of Subsidiaries	1,964				(1		)		(1,963		)		—

	Interest Expense	(516		)		(62		)		16				(562		)

	Other Income - Net	(7		)		(2		)		20				11

	Earnings Before Income Taxes	1,812				2,794				(1,684		)		2,922

	Income Tax Benefit (Expense)	52				(1,028		)		(82		)		(1,058		)

	Net Earnings	$	1,864			$	1,766			$	(1,766	)		$	1,864


	Total Comprehensive Earnings	$	2,277			$	1,825			$	(1,825	)		$	2,277


	Fiscal Year Ended December 2012
	Revenue	$	—			$	11,696			$	67			$	11,763

	Expense	(355		)		8,779				(125		)		8,299

	Operating Income	355				2,917				192				3,464

	Equity in Earnings of Subsidiaries	1,992				(2		)		(1,990		)		—

	Interest Expense	(513		)		(70		)		17				(566		)

	Other Income - Net	(3		)		61				15				73

Earnings Before Income Taxes	1,831				2,906				(1,766		)		2,971

Income Tax Benefit (Expense)	32				(1,065		)		(75		)		(1,108		)

Net Earnings	$	1,863			$	1,841			$	(1,841	)		$	1,863


Total Comprehensive Earnings	$	1,802			$	1,818			$	(1,818	)		$	1,802


Consolidating Balance Sheets	Consolidating Balance Sheets
	(Dollars in Millions)


	As of December 26, 2014	CSX				CSX				Eliminations and Other				Consolidated
		Corporation				Transportation
	ASSETS
	Current Assets:
	Cash and Cash Equivalents	$	510			$	100			$	59			$	669

	Short-term Investments	250				—				42				292

	Accounts Receivable - Net	2				206				921				1,129

	Receivable from Affiliates	1,211				2,418				(3,629		)		—

	Materials and Supplies	—				272				1				273

	Deferred Income Taxes	3				139				(1		)		141

	Other Current Assets	—				61				7				68

	Total Current Assets	1,976				3,196				(2,600		)		2,572

	Properties	1				36,888				2,454				39,343

	Accumulated Depreciation	(1		)		(9,516		)		(1,242		)		(10,759		)
	Properties - Net	—				27,372				1,212				28,584

	Investments in Conrail	—				—				779				779

	Affiliates and Other Companies	(39		)		644				(28		)		577

	Investment in Consolidated Subsidiaries	21,570				—				(21,570		)		—

	Other Long-term Assets	178				387				(24		)		541

	Total Assets	$	23,685			$	31,599			$	(22,231	)		$	33,053

	LIABILITIES AND SHAREHOLDERS' EQUITY
	Current Liabilities:
	Accounts Payable	$	106			$	707			$	32			$	845

	Labor and Fringe Benefits Payable	38				511				64				613

	Payable to Affiliates	3,053				514				(3,567		)		—

	Casualty, Environmental and Other Reserves	—				126				16				142

	Current Maturities of Long-term Debt	200				29				(1		)		228

	Income and Other Taxes Payable	(150		)		293				20				163

	Other Current Liabilities	—				111				5				116

	Total Current Liabilities	3,247				2,291				(3,431		)		2,107

	Casualty, Environmental and Other Reserves	—				213				63				276

	Long-term Debt	8,705				809				—				9,514

	Deferred Income Taxes	(172		)		8,827				203				8,858

	Other Long-term Liabilities	753				487				(118		)		1,122

Total Liabilities	12,533				12,627				(3,283		)		21,877

Shareholders' Equity:
Common Stock, $1 Par Value	992				181				(181		)		992

Other Capital	92				5,077				(5,077		)		92

Retained Earnings	10,734				13,717				(13,717		)		10,734

Accumulated Other Comprehensive Loss	(666		)		(31		)		31				(666		)

Noncontrolling Minority Interest	—				28				(4		)		24

Total Shareholders' Equity	11,152				18,972				(18,948		)		11,176

Total Liabilities and Shareholders' Equity	$	23,685			$	31,599			$	(22,231	)		$	33,053

NOTE 16. Summarized Consolidating Financial Data, continued

Consolidating Balance Sheets
(Dollars in Millions)


As of December 27, 2013	CSX Corporation				CSX Transportation				Eliminations and Other				Consolidated
ASSETS
Current Assets

Cash and Cash Equivalents	$	439			$	91			$	62			$	592

Short-term Investments	472				—				15				487

Accounts Receivable - Net	3				240				809				1,052

Receivable from Affiliates	1,141				2,635				(3,776		)		—

Materials and Supplies	—				252				—				252

Deferred Income Taxes	(5		)		161				(1		)		155

Other Current Assets	1				57				6				64

Total Current Assets	2,051				3,436				(2,885		)		2,602

Properties	1				34,987				2,196				37,184

Accumulated Depreciation	(1		)		(8,778		)		(1,114		)		(9,893		)
Properties - Net	—				26,209				1,082				27,291

Investments in Conrail	—				—				752				752

Affiliates and Other Companies	(39		)		612				(27		)		546

Investment in Consolidated Subsidiaries	20,226				—				(20,226		)		—

Other Long-term Assets	217				388				(14		)		591

Total Assets	$	22,455			$	30,645			$	(21,318	)		$	31,782

LIABILITIES AND SHAREHOLDERS' EQUITY
Current Liabilities
Accounts Payable	$	110			$	809			$	38			$	957

Labor and Fringe Benefits Payable	38				491				58				587

Payable to Affiliates	3,298				535				(3,833		)		—

Casualty, Environmental and Other Reserves	—				136				15				151

Current Maturities of Long-term Debt	200				333				—				533

Income and Other Taxes Payable	(397		)		479				9				91

Other Current Liabilities	—				103				2				105

Total Current Liabilities	3,249				2,886				(3,711		)		2,424

Casualty, Environmental and Other Reserves	—				231				69				300

Long-term Debt	8,308				714				—				9,022

Deferred Income Taxes	(64		)		8,548				178				8,662

Other Long-term Liabilities	479				512				(121		)		870

Total Liabilities	11,972				12,891				(3,585		)		21,278

Shareholders' Equity
Common Stock, $1 Par Value	1,009				181				(181		)		1,009

Other Capital	61				5,077				(5,077		)		61

Retained Earnings	9,936				12,514				(12,514		)		9,936

Accumulated Other Comprehensive Loss	(523		)		(43		)		43				(523		)

Noncontrolling Minority Interest	—				25				(4		)		21

Total Shareholders' Equity	10,483				17,754				(17,733		)		10,504

Total Liabilities and Shareholders' Equity	$	22,455			$	30,645			$	(21,318	)		$	31,782

Consolidating Cash Flow Statements	Consolidating Cash Flow Statements
	(Dollars in Millions)


	Fiscal Year Ended December 2014	CSX Corporation				CSX Transportation				Eliminations and Other				Consolidated
	Operating Activities
	Net Cash Provided by (Used in) Operating Activities	$	583			$	3,278			$	(518	)		$	3,343


	Investing Activities
	Property Additions	—				(2,192		)		(257		)		(2,449		)

	Purchases of Short-term Investments	(1,419		)		—				(14		)		(1,433		)

	Proceeds from Sales of Short-term Investments	1,642				—				32				1,674

	Proceeds from Property Dispositions	—				62				—				62

	Other Investing Activities	—				(128		)		91				(37		)

	Net Cash Provided by (Used in) Investing Activities	223				(2,258		)		(148		)		(2,183		)


	Financing Activities
	Long-term Debt Issued	1,000				—				—				1,000

	Long-term Debt Repaid	(600		)		(333		)		—				(933		)

	Dividends Paid	(629		)		(660		)		660				(629		)

	Stock Options Exercised	—				—				—				—

	Shares Repurchased	(517		)		—				—				(517		)

	Other Financing Activities	11				(18		)		3				(4		)

	Net Cash Provided by (Used in) Financing Activities	(735		)		(1,011		)		663				(1,083		)

	Net Decrease in Cash and Cash Equivalents	71				9				(3		)		77

	Cash and Cash Equivalents at Beginning of Period	439				91				62				592

	Cash and Cash Equivalents at End of Period	$	510			$	100			$	59			$	669

	NOTE 16. Summarized Consolidating Financial Data, continued

	Consolidating Cash Flow Statements
	(Dollars in Millions)


	Fiscal Year Ended December 2013	CSX Corporation				CSX Transportation				Eliminations and Other				Consolidated
	Operating Activities

	Net Cash Provided by (Used in) Operating Activities	$	1,004			$	3,005			$	(742	)		$	3,267


	Investing Activities
	Property Additions	—				(2,053		)		(260		)		(2,313		)

	Purchases of Short-term Investments	(1,251		)		—				(5		)		(1,256		)

	Proceeds from Sales of Short-term Investments	1,335				—				66				1,401

	Proceeds from Property Dispositions	—				53				—				53

Other Investing Activities	(134		)		(315		)		337				(112		)

Net Cash Provided by (Used in) Investing Activities	(50		)		(2,315		)		138				(2,227		)


Financing Activities
Long-term Debt Issued	500				—				—				500

Long-term Debt Repaid	(700		)		(80		)		—				(780		)

Dividends Paid	(600		)		(730		)		730				(600		)

Stock Options Exercised	9				—				—				9

Shares Repurchased	(353		)		—				—				(353		)

Other Financing Activities	148				(24		)		(132		)		(8		)

Net Cash Provided by (Used in) Financing Activities	(996		)		(834		)		598				(1,232		)

Net (Decrease) Increase in	(42		)		(144		)		(6		)		(192		)
Cash and Cash Equivalents
Cash and Cash Equivalents at Beginning of Period	481				235				68				784

Cash and Cash Equivalents at End of Period	$	439			$	91			$	62			$	592





NOTE 16. Summarized Consolidating Financial Data, continued

Consolidating Cash Flow Statements
(Dollars in Millions)


Fiscal Year Ended December 2012	CSX Corporation				CSX Transportation				Eliminations and Other				Consolidated
Operating Activities
Net Cash Provided by (Used in) Operating Activities	$	579			$	2,716			$	(349	)		$	2,946


Investing Activities
Property Additions	—				(2,104		)		(237		)		(2,341		)

Purchases of Short-term Investments	(605		)		—				(28		)		(633		)

Proceeds from Sales of Short-term Investments	525				—				56				581

Proceeds from Property Dispositions	—				186				—				186

Other Investing Activities	(10		)		102				(162		)		(70		)

Net Cash Provided by (Used in) Investing Activities	(90		)		(1,816		)		(371		)		(2,277		)

Financing Activities
Long-term Debt Issued	1,100				—				—				1,100

Long-term Debt Repaid	(400		)		(106		)		(2		)		(508		)
Dividends Paid	(558		)		(715		)		715				(558		)

Stock Options Exercised	14				—				—				14

Shares Repurchased	(734		)		—				—				(734		)

Other Financing Activities	21				2				(5		)		18

Net Cash Provided by (Used in) Financing Activities	(557		)		(819		)		708				(668		)

Net (Decrease) Increase in	(68		)		81				(12		)		1
Cash and Cash Equivalents
Cash and Cash Equivalents at Beginning of Period	549				154				80				783

Cash and Cash Equivalents at End of Period	$	481			$	235			$	68			$	784

Nature_of_Operations_and_Signi2

Nature of Operations and Significant Accounting Policies (Business) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Sep. 26, 2014	Jun. 27, 2014	Mar. 28, 2014	Dec. 27, 2013	Sep. 27, 2013	Jun. 28, 2013	Mar. 29, 2013	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
	states								employees
	mi								states
	railroads								mi
	employees								railroads
Revenue from External Customer [Line Items]
Entity Number of Employees	32,000								32,000
Number of Union Employees									26,000
Total number of rail route miles	21,000								21,000
Rail network states number	23								23
Number of short-line and regional railroads served	240								240
Revenue	$3,192	$3,221	$3,244	$3,012	$3,032	$2,985	$3,046	$2,963	$12,669	$12,026	$11,763
Minimum [Member]
Revenue from External Customer [Line Items]
Number of ocean, river and lake ports serviced (more than 70)	70								70
Merchandise business [Member]
Revenue from External Customer [Line Items]
Number of carloads									2,900,000
Percentage of total revenue									60.00%
Percentage of total volume									42.00%
Coal business [Member]
Revenue from External Customer [Line Items]
Number of carloads									1,300,000
Percentage of total revenue									22.00%
Percentage of total volume									18.00%
Intermodal business [Member]
Revenue from External Customer [Line Items]
Percentage of total revenue									14.00%
Percentage of total volume									40.00%
Number of terminals (more than 50)	50								50
Other business [Member]
Revenue from External Customer [Line Items]
Percentage of total revenue									4.00%

Nature_of_Operations_and_Signi3

Nature of Operations and Significant Accounting Policies (Nature of Operations) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Restructuring Cost and Reserve [Line Items]
Number of weeks in fiscal reporting calendar	P52W	P52W	P52W
Number of weeks in fiscal quarter	P13W
Cost method, maximum percentage	20.00%
Cash equivalents, maximum maturity period	3 months
Short-term investments, minimum maturity period	3 months
Short-term investments, maximum maturity period	1 year
Allowance for doubtful accounts	$41	$33
Goodwill	63	64
Workforce Reduction Plan [Member] \| Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Expected number of positions to be reduced	300
Restructuring charges incurred	39
Total expected restructuring charges	$45

Nature_of_Operations_and_Signi4

Nature of Operations and Significant Accounting Policies (Other Items - Share Repurchases) (Details) (USD $)	12 Months Ended
Share data in Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012	Apr. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Share repurchase program				$1,000,000,000
Shares acquired, repurchase amount	$517,000,000	$353,000,000	$734,000,000
Stock repurchased, shares	17	14	34

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. 26, 2014	Sep. 26, 2014	Jun. 27, 2014	Mar. 28, 2014	Dec. 27, 2013	Sep. 27, 2013	Jun. 28, 2013	Mar. 29, 2013	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Numerator:
Net Earnings	$491	$509	$529	$398	$426	$455	$521	$462	$1,927	$1,864	$1,863
Dividend Equivalents on Restricted Stock									-1	0	0
Net Earnings, Attributable to Common Shareholders									$1,926	$1,864	$1,863
Denominator:
Average Common Shares Outstanding									1,001	1,019	1,038
Other Potentially Dilutive Common Shares									1	0	2
Average Common Shares Outstanding, Assuming Dilution									1,002	1,019	1,040
Net Earnings Per Share, Basic (dollars per share)	$0.49	$0.51	$0.53	$0.40	$0.42	$0.45	$0.51	$0.45	$1.93	$1.83	$1.80
Net Earnings Per Share, Assuming Dilution (dollars per share)	$0.49	$0.51	$0.53	$0.40	$0.42	$0.45	$0.51	$0.45	$1.92	$1.83	$1.79

Shareholders_Equity_Details

Shareholders' Equity (Details) (USD $)	12 Months Ended
Shareholders' Equity (Details) (USD $)	Dec. 26, 2014	Dec. 27, 2013
Class of Stock [Line Items]
Common stock par value (dollars per share)	1	$1
Common Stock [Member]
Class of Stock [Line Items]
Common Shares Authorized	1,800,000,000
Common Shares Issued	992,000,000
Common Shares Outstanding	992,000,000
Number of votes for each share held	1
Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Shares Authorized	25,000,000
Preferred Shares Issued	0
Preferred Shares Outstanding	0

Stock_Plans_and_ShareBased_Com2

Stock Plans and Share-Based Compensation (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Net financing cash flows	$3	$13	$37
Share-Based Compensation Expense	33	14	14
Income Tax Benefit	$13	$6	$5

Stock_Plans_and_ShareBased_Com3

Stock Plans and Share-Based Compensation (Restricted Stock Grants) (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 26, 2014		Dec. 27, 2013		Dec. 28, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock Unit and Awards Expense	$33		$14		$14
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance unit equivalent of CSX stock, in shares	1
Share-based compensation arrangement, vesting period	5 years
Unrecognized compensation cost	16
Expected weighted average period of recognition for unrecognized compensation cost (in years)	2 years
Number of Restricted Stock Awards Outstanding	1,383,000	[1]	1,462,000	[1]	1,353,000	[1]
Weighted-average fair value at grant date	$25.03		$23.89		$21.38
Restricted Stock Unit and Awards Expense	11	[1]	10	[1]	9	[1]
Unvested Restricted Stock Units and Awards Outstanding	601,000		705,000		629,000
Weighted-Average Fair Value of Unvested Awards Outstanding	$26.40		$24.17		$22.48
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement, vesting period	3 years
Long-term Incentive Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	39
Expected weighted average period of recognition for unrecognized compensation cost (in years)	2 years
Weighted-average fair value at grant date	$28.13		$25.26
Restricted Stock Unit and Awards Expense	$19		$2		$3
Weighted-Average Fair Value of Unvested Awards Outstanding	$26.66		$23.70		$21.98
Long-term Incentive Plans [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement, vesting period	3 years
Time Based Restricted Stock Unit Granted To Key Member Of Management	371,000		524,000		433,000

[1]	Time-based restricted stock units were granted to certain employees under the respective Long-term Incentive Plans in the amount of 371,000, 524,000, and 433,000 in 2014, 2013 and 2012, respectively, as described below. These units vest over three years, therefore only a partial amount of expense was recognized in 2014, 2013, and 2012, respectively.

Stock_Plans_and_ShareBased_Com4

Stock Plans and Share-Based Compensation (Long-term Incentive Plans) (Details) (USD $)	12 Months Ended						0 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 26, 2014		Dec. 27, 2013		Dec. 28, 2012		7-May-13
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total expense incurred due to long-term incentive plans	$33		$14		$14
Long-term Incentive Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of payout subject to reduction	-30.00%
Total expense incurred due to long-term incentive plans	19		2		3
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Weighted-average fair value at grant date	$28.13		$25.26
Long-term Incentive Plans [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Payout Range	0.00%
Long-term Incentive Plans [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Payout Range	200.00%
Performance Shares [Member] \| Two Thousand Thirteen Long-Term Incentive Plan (2013 LTIP) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage Of Grants With Performance Vesting, Operating Ratio							50.00%
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Percentage Of Grants With Performance Vesting, Return On Assets							50.00%
Performance Units [Member] \| Long-term Incentive Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance unit equivalent of CSX stock, in shares	1
Number of plans	3
Plan duration	3 years
Restricted Stock Units (RSUs) [Member] \| Long Term Incentive Plan - 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Number of target units outstanding	1,338,000	[1]
Weighted-average fair value at grant date	$22.23	[1]
Restricted Stock Units (RSUs) [Member] \| Long Term Incentive Plan - 2014 [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Payout Range	0.00%
Restricted Stock Units (RSUs) [Member] \| Long Term Incentive Plan - 2014 [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Payout Range	200.00%
Restricted Stock Units (RSUs) [Member] \| Long Term Incentive Plan - 2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Number of target units outstanding	1,330,000	[1]
Weighted-average fair value at grant date	$25.50	[1]
Restricted Stock Units (RSUs) [Member] \| Long Term Incentive Plan - 2015 [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Payout Range	0.00%
Restricted Stock Units (RSUs) [Member] \| Long Term Incentive Plan - 2015 [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Payout Range	200.00%
Restricted Stock Units (RSUs) [Member] \| Long Term Incentive Plan - 2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Number of target units outstanding	1,119,000	[1]
Weighted-average fair value at grant date	$28.03	[1]
Restricted Stock Units (RSUs) [Member] \| Long Term Incentive Plan - 2016 [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Payout Range	0.00%
Restricted Stock Units (RSUs) [Member] \| Long Term Incentive Plan - 2016 [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Payout Range	200.00%
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance unit equivalent of CSX stock, in shares	1
Total expense incurred due to long-term incentive plans	$11	[2]	$10	[2]	$9	[2]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Number of target units outstanding	1,383,000	[2]	1,462,000	[2]	1,353,000	[2]
Weighted-average fair value at grant date	$25.03		$23.89		$21.38

[1]	Number of target units granted and weighted-average fair value calculations above include the value of both initial grants and subsequent, smaller grants issued at different prices based on grant date fair value to new or promoted employees not previously included.
[2]	Time-based restricted stock units were granted to certain employees under the respective Long-term Incentive Plans in the amount of 371,000, 524,000, and 433,000 in 2014, 2013 and 2012, respectively, as described below. These units vest over three years, therefore only a partial amount of expense was recognized in 2014, 2013, and 2012, respectively.

Stock_Plans_and_ShareBased_Com5

Stock Plans and Share-Based Compensation (Restricted Stock Units) (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 26, 2014		Dec. 27, 2013	Dec. 28, 2012
Long Term Incentive Plan - 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Unvested, Units Outstanding, beginning balance	1,318,000		1,237,000
Granted, Units Outstanding	20,000		85,000
Forfeited, Units Outstanding	0		-4,000
Cancelled, Units Outstanding	-1,338,000	[1]
Vested, Units Outstanding	0
Unvested, Units Outstanding, beginning balance	0		1,318,000
Long Term Incentive Plan - 2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Unvested, Units Outstanding, beginning balance	1,279,000		0
Granted, Units Outstanding	52,000		1,354,000
Forfeited, Units Outstanding	-1,000		-75,000
Cancelled, Units Outstanding	0	[1]
Vested, Units Outstanding	0
Unvested, Units Outstanding, beginning balance	1,330,000		1,279,000
Long Term Incentive Plan - 2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Unvested, Units Outstanding, beginning balance	0		0
Granted, Units Outstanding	1,144,000		0
Forfeited, Units Outstanding	-25,000		0
Cancelled, Units Outstanding	0	[1]
Vested, Units Outstanding	0
Unvested, Units Outstanding, beginning balance	1,119,000		0
Long-term Incentive Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	39
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Unvested, Weighted-Average Fair Value at Grant Date, beginning balance	23.7		21.98
Granted, Weighted-Average Fair Value at Grant Date	28.13		25.26
Forfeited, Weighted-Average Fair Value at Grant Date	-28.07		-25.19
Cancelled, Weighted-Average Fair Value at Grant Date	-22.23	[1]
Vested, Weighted-Average Fair Value at Grant Date	0
Unvested, Weighted-Average Fair Value at Grant Date, beginning balance	26.66		23.7
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement, vesting period	3 years
Restricted Stock Units (RSUs) [Member] \| Long Term Incentive Plan - 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Granted, Units Outstanding	433,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Granted, Weighted-Average Fair Value at Grant Date	22.23	[2]
Restricted Stock Units (RSUs) [Member] \| Long Term Incentive Plan - 2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Granted, Units Outstanding	524,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Granted, Weighted-Average Fair Value at Grant Date	25.5	[2]
Restricted Stock Units (RSUs) [Member] \| Long Term Incentive Plan - 2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Granted, Units Outstanding	371,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Granted, Weighted-Average Fair Value at Grant Date	28.03	[2]
Restricted Stock Units (RSUs) [Member] \| Long-term Incentive Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement, vesting period	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Granted, Units Outstanding	371,000		524,000	433,000

[1]	(a) The minimum financial target was not met in 2014. As a result, there was no performance unit payout for the LTIP ended December 26, 2014.
[2]	Number of target units granted and weighted-average fair value calculations above include the value of both initial grants and subsequent, smaller grants issued at different prices based on grant date fair value to new or promoted employees not previously included.

Stock_Plans_and_ShareBased_Com6

Stock Plans and Share-Based Compensation (Stock Awards for Directors) (Details) (USD $)	12 Months Ended
Share data in Thousands, except Per Share data, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Compensation Expense	$33,000,000	$14,000,000	$14,000,000
Non-management Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual retainer to be paid to non-management directors, cash option	75,000
Annual retainer to be paid to non-management directors, common stock option	150,000
Shares Issued to Directors	79	105	102
Share-Based Compensation Expense	$2,000,000	$2,000,000	$2,000,000
Weighted Average Grant Date Stock Price	$28.01	$23.12	$21.92

Casualty_Environmental_and_Oth2

Casualty, Environmental and Other Reserves (Loss Contingencies Roll Forward) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014		Dec. 27, 2013	Dec. 28, 2012
Casualty Reserves [Member]
Loss Contingency Accrual [Roll Forward]
Balance at beginning of period	$280		$325	$372
Charged to Expense	89	[1]	54	51
Payments	-104		-99	-98
Balance end of period	265		280	325
Environmental Reserves [Member]
Loss Contingency Accrual [Roll Forward]
Balance at beginning of period	100		88	83
Charged to Expense	57	[1]	48	35
Payments	-63		-36	-30
Balance end of period	94		100	88
Other Reserves [Member]
Loss Contingency Accrual [Roll Forward]
Balance at beginning of period	71		64	64
Charged to Expense	30	[1]	38	36
Payments	-42		-31	-36
Balance end of period	59		71	64
Casualty, Environmental and Other [Member]
Loss Contingency Accrual [Roll Forward]
Balance at beginning of period	451		477	519
Charged to Expense	176	[1]	140	122
Payments	-209		-166	-164
Balance end of period	$418		$451	$477

[1]	Increase in expense in 2014 is primarily due to the resolution of personal injury claims for prior years.

Casualty_Environmental_and_Oth3

Casualty, Environmental and Other Reserves (Loss Contingencies Accrual) (Details) (USD $)	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
Contingencies [Line Items]
Casualty, Environmental and Other Reserves	$142	$151
Loss Contingency, Accrual, Noncurrent	276	300
Casualty [Member]
Contingencies [Line Items]
Casualty, Environmental and Other Reserves	76	72
Loss Contingency, Accrual, Noncurrent	189	208
Loss Contingency Accrual	265	280	325	372
Personal Injury [Member]
Contingencies [Line Items]
Casualty, Environmental and Other Reserves	68	59
Loss Contingency, Accrual, Noncurrent	123	148
Loss Contingency Accrual	191	207
Occupational [Member]
Contingencies [Line Items]
Casualty, Environmental and Other Reserves	3	3
Loss Contingency, Accrual, Noncurrent	15	20
Loss Contingency Accrual	18	23
Asbestos [Member]
Contingencies [Line Items]
Casualty, Environmental and Other Reserves	5	10
Loss Contingency, Accrual, Noncurrent	51	40
Loss Contingency Accrual	56	50
Environmental [Member]
Contingencies [Line Items]
Casualty, Environmental and Other Reserves	48	59
Loss Contingency, Accrual, Noncurrent	46	41
Loss Contingency Accrual	94	100	88	83
Other Reserves [Member]
Contingencies [Line Items]
Casualty, Environmental and Other Reserves	18	20
Loss Contingency, Accrual, Noncurrent	41	51
Loss Contingency Accrual	59	71	64	64
Casualty, Environmental and Other [Member]
Contingencies [Line Items]
Casualty, Environmental and Other Reserves	142	151
Loss Contingency, Accrual, Noncurrent	276	300
Loss Contingency Accrual	$418	$451	$477	$519

Casualty_Environmental_and_Oth4

Casualty, Environmental and Other Reserves (Casualty) (Details) (Casualty [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
	claims	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
Casualty [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual	$265	$280	$325	$372
Self-insured retention amount per injury	50
Individual claims expected to exceed self-insured retention amount	0
Change in estimate recorded to adjust reserves	$0	$0	$0

Casualty_Environmental_and_Oth5

Casualty, Environmental and Other Reserves (Occupational and Asbestos Claims) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013
	claims	claims
Occupational Casualty and Asbestos Issues [Member]
Loss Contingency, Claims Quantities [Roll Forward]
Open Claims - Beginning of Year	392	523
New Claims Filed	136	165
Claims Settled	-128	-146
Claims Dismissed	-130	-150
Open Claims - End of Year	270	392
Occupational [Member]
Loss Contingencies [Line Items]
Time period for estimating probable claims (in years)	7 years
Total liability	18	23
Occupational [Member] \| Incurred but not reported claims [Member]
Loss Contingencies [Line Items]
Incurred but not reported claims	12	15
Occupational [Member] \| Asserted claims [Member]
Loss Contingencies [Line Items]
Asserted claims	6	8
Asbestos [Member]
Loss Contingencies [Line Items]
Total liability	56	50
Asbestos [Member] \| Incurred but not reported claims [Member]
Loss Contingencies [Line Items]
Incurred but not reported claims	45	35
Asbestos [Member] \| Asserted claims [Member]
Loss Contingencies [Line Items]
Asserted claims	11	15
Carpal Tunnel Claims [Member]
Loss Contingencies [Line Items]
Time period for estimating probable claims (in years)	3 years
Minimum [Member] \| Asbestos [Member]
Loss Contingencies [Line Items]
Loss contingency, latency period (in years)	10 years
Maximum [Member] \| Asbestos [Member]
Loss Contingencies [Line Items]
Loss contingency, latency period (in years)	40 years

Casualty_Environmental_and_Oth6

Casualty, Environmental and Other Reserves (Environmental and Other) (Details) (USD $)	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
In Millions, unless otherwise specified	sites	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
Environmental Reserves [Member]
Contingencies [Line Items]
Loss Contingency Accrual	$94	$100	$88	$83
Environmental impaired site	250
Other Reserves [Member]
Contingencies [Line Items]
Loss Contingency Accrual	$59	$71	$64	$64

Properties_Detail_of_Net_Prope

Properties (Detail of Net Properties) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	$39,343	$37,184
Accumulated Depreciation	-10,759	-9,893
Properties - Net	28,584	27,291
Road - Total [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	26,125	24,618
Accumulated Depreciation	-6,148	-5,592
Properties - Net	19,977	19,026
Road - Rail and Other Track Material [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	6,771	6,452
Accumulated Depreciation	-1,400	-1,270
Properties - Net	5,371	5,182
Annual Depreciation Rate	2.50%	2.90%
Depreciation Method	Group Life	Group Life
Road - Ties [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	4,807	4,534
Accumulated Depreciation	-1,060	-947
Properties - Net	3,747	3,587
Annual Depreciation Rate	3.70%	4.00%
Depreciation Method	Group Life	Group Life
Road - Grading [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	2,460	2,425
Accumulated Depreciation	-481	-448
Properties - Net	1,979	1,977
Annual Depreciation Rate	1.40%	1.50%
Depreciation Method	Group Life	Group Life
Road - Ballast [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	2,693	2,612
Accumulated Depreciation	-679	-645
Properties - Net	2,014	1,967
Annual Depreciation Rate	2.70%	2.80%
Depreciation Method	Group Life	Group Life
Road - Bridges, Trestles, and Culverts [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	2,119	2,008
Accumulated Depreciation	-278	-250
Properties - Net	1,841	1,758
Annual Depreciation Rate	1.60%	1.60%
Depreciation Method	Group Life	Group Life
Road - Signals and Interlockers [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	2,103	1,922
Accumulated Depreciation	-356	-291
Properties - Net	1,747	1,631
Annual Depreciation Rate	4.00%	3.40%
Depreciation Method	Group Life	Group Life
Road - Buildings [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	1,102	1,011
Accumulated Depreciation	-377	-355
Properties - Net	725	656
Annual Depreciation Rate	2.50%	2.50%
Depreciation Method	Group Life	Group Life
Road - Other [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	4,070	3,654
Accumulated Depreciation	-1,517	-1,386
Properties - Net	2,553	2,268
Annual Depreciation Rate	4.20%	4.70%
Depreciation Method	Group Life	Group Life
Total Equipment [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	10,108	9,764
Accumulated Depreciation	-4,526	-4,225
Properties - Net	5,582	5,539
Equipment - Locomotive [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	5,036	4,987
Accumulated Depreciation	-2,325	-2,176
Properties - Net	2,711	2,811
Annual Depreciation Rate	3.60%	3.60%
Depreciation Method	Group Life	Group Life
Equipment - Freight Cars [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	3,244	3,111
Accumulated Depreciation	-1,169	-1,135
Properties - Net	2,075	1,976
Annual Depreciation Rate	3.20%	3.10%
Depreciation Method	Group Life	Group Life
Equipment - Work Equipment and Other [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	1,828	1,666
Accumulated Depreciation	-1,032	-914
Properties - Net	796	752
Annual Depreciation Rate	7.10%	7.10%
Depreciation Method	Group Life	Group Life
Land [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	1,875	1,842
Properties - Net	1,875	1,842
Construction in Progress [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	1,196	854
Properties - Net	1,196	854
Other properties [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	39	106
Accumulated Depreciation	-85	-76
Properties - Net	($46)	$30
Depreciation Method	Straight Line	Straight Line
Minimum [Member] \| Road - Total [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	8 years	6 years
Minimum [Member] \| Road - Other [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	8 years
Minimum [Member] \| Total Equipment [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	3 years	5 years
Minimum [Member] \| Other properties [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	4 years	4 years
Maximum [Member] \| Road - Total [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	90 years	80 years
Maximum [Member] \| Road - Grading [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	90 years
Maximum [Member] \| Total Equipment [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	38 years	38 years
Maximum [Member] \| Equipment - Work Equipment and Other [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	38 years
Maximum [Member] \| Other properties [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	30 years	30 years

Properties_Railroad_Assets_Non

Properties (Railroad Assets, Non-Railroad Assets, and Capital Expenditure) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Railroad Assets [Abstract]
Percentage of assets depreciated under the group-life method	85.00%
Total fixed assets	$39,343	$37,184
Annual depreciation expense	1,151	1,104	1,059
Capital Expenditures [Abstract]
Percentage of labor costs relating to the deconstruction of old track (In hundredths)	20.00%
Percentage of labor costs relating to the installation of new track (In hundredths)	80.00%
Road - Total [Member]
Railroad Assets [Abstract]
Total fixed assets	26,125	24,618
Life studies, frequency period	6 years
Road - Ties [Member]
Railroad Assets [Abstract]
Total fixed assets	4,807	4,534
Number of depreciable asset categories for railroad assets	18
Road - System Roadway Machinery [Member]
Railroad Assets [Abstract]
Total fixed assets	4,070	3,654
Road - Grading [Member]
Railroad Assets [Abstract]
Total fixed assets	2,460	2,425
Total Equipment [Member]
Railroad Assets [Abstract]
Total fixed assets	10,108	9,764
Life studies, frequency period	3 years
Equipment - Work Equipment and Other [Member]
Railroad Assets [Abstract]
Total fixed assets	1,828	1,666
Abnormal gain (loss) on operating property [Member]
Railroad Assets [Abstract]
Abnormal gains and losses	0	65	104
Gain (loss) on non-operating property [Member]
Railroad Assets [Abstract]
Abnormal gains and losses		57
Minimum [Member]
Railroad Assets [Abstract]
Number of depreciable asset categories for railroad assets	130
Minimum [Member] \| Road - Total [Member]
Railroad Assets [Abstract]
Estimated useful life	8 years	6 years
Minimum [Member] \| Road - System Roadway Machinery [Member]
Railroad Assets [Abstract]
Estimated useful life	8 years
Minimum [Member] \| Total Equipment [Member]
Railroad Assets [Abstract]
Estimated useful life	3 years	5 years
Minimum [Member] \| Technology Assets [Member]
Railroad Assets [Abstract]
Estimated useful life	3 years
Maximum [Member] \| Road - Total [Member]
Railroad Assets [Abstract]
Estimated useful life	90 years	80 years
Maximum [Member] \| Road - Grading [Member]
Railroad Assets [Abstract]
Estimated useful life	90 years
Maximum [Member] \| Total Equipment [Member]
Railroad Assets [Abstract]
Estimated useful life	38 years	38 years
Maximum [Member] \| Equipment - Work Equipment and Other [Member]
Railroad Assets [Abstract]
Estimated useful life	38 years
SunRail Transaction - Sale of Corridor [Member]
Railroad Assets [Abstract]
Abnormal gains and losses		$43	$94

Commitments_and_Contingencies_1

Commitments and Contingencies (Lease Commitments) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Operating Leased Assets [Line Items]
Maximum lease term	30 years
Operating Leases [Abstract]
2015	$78
2016	71
2017	62
2018	54
2019	45
Thereafter	210
Total	520
Sublease Income [Abstract]
2015	-3
2016	-2
2017	-2
2018	-2
2019	-2
Thereafter	-11
Total	22
Net Lease Commitments [Abstract]
2015	75
2016	69
2017	60
2018	52
2019	43
Thereafter	199
Total	498
Rent Expense on Operating Leases [Member]
Operating Leases, Rent Expense, Net [Abstract]
Rent Expense on Operating Leases	$61	$60	$73

Commitments_and_Contingencies_2

Commitments and Contingencies (Purchase Commitments) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
	locomotives	locomotives	locomotives
Unrecorded Unconditional Purchase Obligation [Line Items]
Percentage of Locomotive Fleet Under Long-Term Maintenance Program	42.00%
Amounts Paid	$247	$287	$287
Number of locomotives under the long term maintenance plan	1,886	1,886	1,899
Unrecorded Unconditional Purchase Obligation [Abstract]
2014	963
2015	496
2016	190
2017	181
2018	170
Thereafter	1,272
Total	3,272
Locomotive & Maintenance Payments [Member]
Unrecorded Unconditional Purchase Obligation [Abstract]
2014	727
2015	474
2016	177
2017	169
2018	159
Thereafter	1,203
Total	2,909
Other Commitments [Member]
Unrecorded Unconditional Purchase Obligation [Abstract]
2014	236
2015	22
2016	13
2017	12
2018	11
Thereafter	69
Total	$363

Commitments_and_Contingencies_3

Commitments and Contingencies (Insurance and Legal) (Details) (USD $)	1 Months Ended
In Millions, unless otherwise specified	31-May-07	Dec. 26, 2014
	entity	Dec. 26, 2014
Insurance
Non-catastrophic property deductible		$25
Casualty and catastrophic property deductible		50
Pending Litigation [Member]
Loss Contingency, Estimate [Abstract]
Minimum range of possible loss for legal proceedings		4
Maximum range of possible loss for legal proceedings		$13
Fuel Surcharge Antitrust Litigation [Member]
Loss Contingency, Estimate [Abstract]
Number of other U.S.-based entities mentioned in class action lawsuit	3

Commitments_and_Contingencies_4

Commitments and Contingencies (Environmental Matters) (Details) (Environmental Litigation [Member])	12 Months Ended
	Dec. 26, 2014
	counterparty
	mi
Environmental Litigation [Member]
Loss Contingencies [Line Items]
Number of miles pertaining to Passaic River tidal reach required to be studied by EPA	17
Number Of Potentially Responsible Parties In Connection With Environmental Liabilities For Operations Conducted Near Passaic River	60

Employee_Benefit_Plans_Summary

Employee Benefit Plans (Summary of Participants) (Details)	Dec. 27, 2013
Employee Benefit Plans (Summary of Participants) (Details)	employees
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Active Employees	5,136
Retirees and Beneficiaries	11,699
Other	5,444	[1]
Total	22,279
Post-retirement Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Active Employees	2,031
Retirees and Beneficiaries	12,148
Other	87	[1]
Total	14,266

[1]	For pension plans, the other category consists mostly of terminated but vested former employees. For post-retirement plans, the other category consists of employees on long-term disability that have not yet retired.

Employee_Benefit_Plans_Cash_Fl

Employee Benefit Plans (Cash Flows) (Details) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Mar. 28, 2014	Dec. 28, 2012	Dec. 26, 2014
Defined Benefit Plan Disclosure [Line Items]
Employer minimum required contribution		$25
Significant expected contributions	0
Pension Benefits [Member]
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2015			207
2016			188
2017			188
2018			185
2019			186
2020-2023			931
Total			1,885
Post-retirement Benefits [Member]
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2015			37
2016			34
2017			33
2018			30
2019			28
2020-2023			114
Total			276
Qualified Employer Contributions [Member] \| Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer Contributions		$275

Employee_Benefit_Plans_Plan_As

Employee Benefit Plans (Plan Assets) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013
Defined Benefit Plan Disclosure [Line Items]
Distribution of pension plan assets	$2,504	$2,500
Equity, Percent of Total Assets	100.00%	100.00%
Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted and established equity allocation (in hundredths)	70.00%
Targeted allocation of total plan assets in domestic equity (in hundredths)	42.00%
Targeted allocation of total plan assets in international equity (in hundredths)	28.00%
Percentage within which the planned allocation is managed (in hundredths)	3.00%
Distribution of pension plan assets	1,715	1,619
Equity, Percent of Total Assets	68.00%	65.00%
Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted and established equity allocation (in hundredths)	30.00%
Distribution of pension plan assets	740	795
Equity, Percent of Total Assets	30.00%	32.00%
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Distribution of pension plan assets	$49	$86
Equity, Percent of Total Assets	2.00%	3.00%

Employee_Benefit_Plans_Benefit

Employee Benefit Plans (Benefit Obligation, Plan Assets and Funded Status) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets at End of Plan Year	$2,504	$2,500
Pension Benefits [Member]
Actuarial Present Value of Benefit Obligation [Abstract]
Accumulated Benefit Obligation	2,849	2,538
Projected Benefit Obligation	3,002	2,679	2,954
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected Benefit Obligation at Beginning of Year	2,679	2,954
Service Cost	44	49	44
Interest Cost	123	108	123
Plan Participants' Contributions	0	0
Workforce Reduction Program/Curtailment	27	0
Actuarial Loss (Gain)	333	-275
Benefits Paid	-204	-157
Benefit Obligation at End of Plan Year	3,002	2,679	2,954
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets at Beginning of Plan Year	2,500	2,294
Actual Return on Plan Assets	195	350
Plan Participants' Contributions	0	0
Benefits Paid	-204	-157
Fair Value of Plan Assets at End of Plan Year	2,504	2,500	2,294
Funded Status at End of Plan Year	-498	-179
Post-retirement Benefits [Member]
Actuarial Present Value of Benefit Obligation [Abstract]
Projected Benefit Obligation	340	350	415
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected Benefit Obligation at Beginning of Year	350	415
Service Cost	3	3	4
Interest Cost	13	13	16
Plan Participants' Contributions	7	8
Workforce Reduction Program/Curtailment	8	0
Actuarial Loss (Gain)	-8	-49
Benefits Paid	-33	-40
Benefit Obligation at End of Plan Year	340	350	415
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets at Beginning of Plan Year	0	0
Actual Return on Plan Assets	0	0
Plan Participants' Contributions	7	8
Benefits Paid	-33	-40
Fair Value of Plan Assets at End of Plan Year	0	0	0
Funded Status at End of Plan Year	-340	-350
Qualified Employer Contributions [Member] \| Pension Benefits [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Employer Contributions			275
Non-qualified Employer Contributions [Member] \| Pension Benefits [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Employer Contributions	13	13
Non-qualified Employer Contributions [Member] \| Post-retirement Benefits [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Employer Contributions	$26	$32

Employee_Benefit_Plans_Amounts

Employee Benefit Plans (Amounts Recoreded in Consolidated Balance Sheets) (Details) (USD $)	Dec. 26, 2014		Dec. 27, 2013
In Millions, unless otherwise specified	Dec. 26, 2014		Dec. 27, 2013
Pension Benefits [Member]
Amounts Recorded in Consolidated Balance Sheets [Abstract]
Long-term Assets	$9	[1]	$44	[1]
Current Liabilities	-15		-14
Long-term Liabilities	-492		-209
Net Amount Recognized in Consolidated Balance Sheet	-498		-179
Post-retirement Benefits [Member]
Amounts Recorded in Consolidated Balance Sheets [Abstract]
Long-term Assets	0		0
Current Liabilities	-37		-38
Long-term Liabilities	-303		-312
Net Amount Recognized in Consolidated Balance Sheet	($340)		($350)

[1]	Long-term assets as of December 2014 relate to one of the qualified pension plans whose assets exceed projected benefit obligations.

Employee_Benefit_Plans_Benefit1

Employee Benefit Plans (Benefit Obligations in Excess of Plan Assets) (Details) (USD $)	Dec. 26, 2014	Dec. 27, 2013
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Total fair value of all plans	$2,504	$2,500
Projected Benefit Obligation:
Aggregate Fair Value of Plan Assets	2,461
Aggregate Projected Benefit Obligation	-2,968
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets [Abstract]
Aggregate Fair Value of Plan Assets	2,461
Aggregate Projected Benefit Obligation	($2,815)

Employee_Benefit_Plans_Net_Ben

Employee Benefit Plans (Net Benefit Expense) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014		Dec. 27, 2013		Dec. 28, 2012
Pension Benefits [Member]
Components of expense/ (income) related to net benefit expense [Abstract]
Service Cost	$44		$49		$44
Interest Cost	123		108		123
Expected Return on Plan Assets	-166		-162		-166
Amortization of Net Loss	57	[1]	100	[1]	82
Amortization of Prior Service Cost	0	[2]	0	[2]	0
Net Periodic Benefit Expense	58		95		83
defined benefit, special termination benefits/curtailments	27	[3]	0	[3]	0	[3]
Settlement gain	-1		-2		-2	[4]
Total Expense	84		93		81
Post-retirement Benefits [Member]
Components of expense/ (income) related to net benefit expense [Abstract]
Service Cost	3		3		4
Interest Cost	13		13		16
Expected Return on Plan Assets	0		0		0
Amortization of Net Loss	5	[1]	14	[1]	9
Amortization of Prior Service Cost	-1	[2]	-1	[2]	-1
Net Periodic Benefit Expense	20		29		28
defined benefit, special termination benefits/curtailments	8	[3]	0	[3]	0	[3]
Settlement gain	0		0		0	[4]
Total Expense	$28		$29		$28

[1]	Amortization of net losses estimated to be expensed for 2015 is approximately $70 million and $5 million for pension benefits and post-retirement benefits, respectively. The increase in amortization is largely related to the impact of lower discount rates and adoption of new mortality tables, partially offset by favorable pension asset experience.
[2]	Amortization of prior service costs estimated to be expensed in 2015 is less than $1 million for pension benefits. The estimated post-retirement benefits amount to be credited to expense for 2015 is $1 million.
[3]	These charges result from a management workforce reduction program that was initiated in 2014. For further information regarding the program, see Note 1. Nature of Operations and Significant Accounting Policies.
[4]	Settlement gains were recognized as one of the pension plan's lump-sum payments exceeded the sum of the service cost and interest cost recognized. The gain is the recognition of a portion of its accumulated other comprehensive income related to that plan.

Employee_Benefit_Plans_Pension

Employee Benefit Plans (Pension and Other Post-Employment Benefits Adjustments) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014		Dec. 27, 2013		Dec. 28, 2012
Pension Benefits [Member]
Components of other comprehensive loss (income) [Abstract]
Losses (Gains)	$305		($462)
Expense (Income) recognized in income statement [Abstract]
Amortization of net losses	57	[1]	100	[1]	82
Settlement gain	-1		-2		-2	[2]
Amortization of prior service cost	0	[3]	0	[3]	0
Estimated amount to be expensed in the future period	70
Remaining prior service costs to be expensed in future period	1
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Losses	908
Prior Service Costs (Credits)	0
Total	908
Post-retirement Benefits [Member]
Components of other comprehensive loss (income) [Abstract]
Losses (Gains)	-8		-48
Expense (Income) recognized in income statement [Abstract]
Amortization of net losses	5	[1]	14	[1]	9
Settlement gain	0		0		0	[2]
Amortization of prior service cost	-1	[3]	-1	[3]	-1
Estimated amount to be expensed in the future period	5
Remaining prior service costs to be expensed in future period	1
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Losses	59
Prior Service Costs (Credits)	-1
Total	$58

[1]	Amortization of net losses estimated to be expensed for 2015 is approximately $70 million and $5 million for pension benefits and post-retirement benefits, respectively. The increase in amortization is largely related to the impact of lower discount rates and adoption of new mortality tables, partially offset by favorable pension asset experience.
[2]	Settlement gains were recognized as one of the pension plan's lump-sum payments exceeded the sum of the service cost and interest cost recognized. The gain is the recognition of a portion of its accumulated other comprehensive income related to that plan.
[3]	Amortization of prior service costs estimated to be expensed in 2015 is less than $1 million for pension benefits. The estimated post-retirement benefits amount to be credited to expense for 2015 is $1 million.

Employee_Benefit_Plans_Weighte

Employee Benefit Plans (Weighted-Average Assumptions) (Details)	12 Months Ended
	Dec. 26, 2014	Dec. 27, 2013
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit Cost for Plan Year	7.50%	7.75%
Benefit Obligation at End of Plan Year	7.25%	7.50%
Benefit Cost for Plan Year	4.75%	3.75%
Benefit Obligation at End of Plan Year	4.00%	4.75%
Salary Scale Inflation	3.75%	3.75%
Post-retirement Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit Cost for Plan Year	4.25%	3.20%
Benefit Obligation at End of Plan Year	3.60%	4.25%

Employee_Benefit_Plans_Health_

Employee Benefit Plans (Health Care Cost Trend Rates) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013
Maximum [Member]
Defined Benefit Plan, Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates [Abstract]
Effect of a one percent increase on service and interest costs	1
Effect of a one percent increase on postretirement benefit obligation	1
Post-retirement Benefits [Member]
Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract]
Expected rates assumed in health care costs trend rates for medical plans (in hundreds)	4.75%
Components of Benefit Cost: Non-Medicare Eligible	8.00%	8.50%
Components of Benefit Cost: Medicare Eligible	7.50%	8.00%
Benefit Obligations: Non-Medicare Eligible	8.00%	8.00%
Benefit Obligations: Medicare Eligible	7.50%	7.50%

Employee_Benefit_Plans_Medicar

Employee Benefit Plans (Medicare Prescription Drug and Other Plans) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Defined Benefit Plan Disclosure [Line Items]
Amount of premium expenses incurred under the plan	$37	$41	$46
Expense associated with savings plans	$41	$37	$29

Debt_and_Credit_Agreements_Lon

Debt and Credit Agreements (Long-term Debt Instruments) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014		Dec. 27, 2013
Debt Instrument [Line Items]
Total Long-term Debt Maturities (including current portion)	$9,742		$9,555
Less Debt Due within One Year	-228		-533
Long-term Debt (excluding current portion)	9,514		9,022
Notes Payable [Member]
Debt Instrument [Line Items]
Average Interest Rates (in hundredths)	5.50%
Total Long-term Debt Maturities (including current portion)	9,456		8,935
Equipment Obligations [Member]
Debt Instrument [Line Items]
Average Interest Rates (in hundredths)	6.30%	[1]
Total Long-term Debt Maturities (including current portion)	277	[1]	602	[1]
Capital Leases [Member]
Debt Instrument [Line Items]
Average Interest Rates (in hundredths)	13.50%
Total Long-term Debt Maturities (including current portion)	8		16
Convertible Debt [Member]
Debt Instrument [Line Items]
Average Interest Rates (in hundredths)	1.00%
Total Long-term Debt Maturities (including current portion)	$1		$2

[1]	These obligations are secured by an interest in certain railroad equipment.

Debt_and_Credit_Agreements_Deb

Debt and Credit Agreements (Debt Issuance) (Details) (USD $)	1 Months Ended
	Jul. 31, 2014
Debt Instrument [Line Items]
Other expense recognized for early redemption premium	$16,000,000
Early redemption amount	663,000,000
Notes Payable [Member] \| Redeemable Notes Due 2024 [Member]
Debt Instrument [Line Items]
Face amount of debt issued	550,000,000
Notes issued, interest rate	3.40%
Notes Payable [Member] \| Redeemable Notes Due 2054 [Member]
Debt Instrument [Line Items]
Face amount of debt issued	450,000,000
Notes issued, interest rate	4.50%
Notes Payable [Member] \| Secured Equipment Notes Due October 15, 2014 [Member]
Debt Instrument [Line Items]
Face amount of debt issued	263,000,000
Notes issued, interest rate	8.38%
Notes Payable [Member] \| CSX's Notes Payable Maturing April 1, 2015 [Member]
Debt Instrument [Line Items]
Face amount of debt issued	$400,000,000
Notes issued, interest rate	6.25%

Debt_and_Credit_Agreements_Lon1

Debt and Credit Agreements (Long-term Debt Maturities) (Details) (USD $)	Dec. 26, 2014	Dec. 27, 2013
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013
Maturities of Long-term Debt [Abstract]
2015	$228	$533
2016	21
2017	631
2018	619
2019	518
Thereafter	7,725
Total Long-term Debt Maturities (including current portion)	$9,742	$9,555

Debt_and_Credit_Agreements_Cre

Debt and Credit Agreements (Credit Facilities and Receivable Securitization Facility) (Details) (USD $)	12 Months Ended
	Dec. 26, 2014
Line of Credit Facility [Line Item]
Line of Credit Facility, Covenant Compliance	At December 2014, CSX was in compliance with all covenant requirements under the facilities.
Accounts Receivable Securitization Credit Facility [Member]
Line of Credit Facility [Line Item]
Line of credit facility, current borrowing capacity	250,000,000
Line of Credit Facility, Expiration Date	20-Jun-17
Line of credit facility, amount outstanding	0
Line of Credit Facility Total Expiration Period	3 years
Unsecured Revolving Credit Facility, Current [Member]
Line of Credit Facility [Line Item]
Line of credit facility, current borrowing capacity	1,000,000,000
Line of credit facility, amount outstanding	0
Revolving Credit Facility [Member]
Line of Credit Facility [Line Item]
Line of Credit Facility, Expiration Date	30-Sep-16

Other_Income_Net_Details

Other Income - Net (Details) (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Jul. 31, 2014	Dec. 26, 2014		Dec. 27, 2013		Dec. 28, 2012
Other Income and Expenses [Abstract]
Interest Income		$5		$8		$5
Income from Real Estate Operations		23		23		81
Miscellaneous Expense		-52	[1]	-20	[1]	-13	[1]
Total Other (Expense) Income - Net		-24		11		73
Gross Revenue from Real Estate Operations included above		47		48		106
Change in Miscellaneous Expense		32
Environmental Remediation Expense		17
Other expense recognized for early redemption premium	$16

[1]	Miscellaneous expense increased $32 million primarily due to an increase in estimated environmental cleanup costs of $17 million related to non-operating activities as well as costs of $16 million associated with the early redemption of long-term debt.

Income_Taxes_Income_Tax_Expens

Income Taxes (Income Tax Expense) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Earnings From Continuing Operations [Abstract]
Earnings Before Income Taxes	$3,044	$2,922	$2,971
Current:
Federal	729	671	450
State	90	87	66
Subtotal Current	819	758	516
Deferred:
Federal	291	285	530
State	7	15	62
Subtotal Deferred	298	300	592
Income Tax Expense (Benefit)	$1,117	$1,058	$1,108

Income_Taxes_Income_Tax_Reconc

Income Taxes (Income Tax Reconciliation) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Reconciliation between the statutory income tax rate and the effective income tax rate [Abstract]
Federal Income Taxes	$1,066	$1,023	$1,040
State Income Taxes	61	65	81
Other	-10	-30	-13
Income Tax Expense (Benefit)	1,117	1,058	1,108
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Federal Income Taxes	35.00%	35.00%	35.00%
State Income Taxes	2.00%	2.20%	2.80%
Other	-0.30%	-1.00%	-0.40%
Income Tax Rate	36.70%	36.20%	37.40%
State and Local Jurisdiction [Member]
Reconciliation between the statutory income tax rate and the effective income tax rate [Abstract]
State Income Taxes	$31	$42	$20

Income_Taxes_Deferred_Income_T

Income Taxes (Deferred Income Tax Assets and Liabilities) (Details) (USD $)	Dec. 26, 2014	Dec. 27, 2013
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013
Components of Deferred Tax Assets [Abstract]
Pension Plans	$188	$67
Other Employee Benefit Plans	306	299
Other	256	257
Total	750	623
Components of Deferred Tax Liabilities [Abstract]
Accelerated Depreciation	9,133	8,868
Other	334	262
Total	9,467	9,130
Net Deferred Income Tax Liabilities	$8,717	$8,507

Income_Taxes_Unrecognized_Tax_

Income Taxes (Unrecognized Tax Benefits) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Income Tax Disclosure [Abstract]
Amount of unrecognized tax benefits that may favorably effect the effective income tax rate	$13	$15	$17
Amount of unrecognized tax benefits that will be resolved over next twelve months	2
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of the year	23	24	22
Additions based on tax positions related to current year	2	2	6
Additions based on tax positions related to prior years	3	5	3
Reductions based on tax positions related to prior years	0	-6	-1
Settlements with taxing authorities	0	0	0
Lapse of statute of limitations	-7	-2	-6
Balance at end of the year	$21	$23	$24

Income_Taxes_Income_Taxes_Unce

Income Taxes (Income Taxes Uncertainties) (Details) (USD $)	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Income Tax Uncertainties [Abstract]
Reduction (Increase) to income tax reserves due to interest and penalties of prior year tax positions	$1	($1)	($8)
Previously recorded liabilities for interest and penalties of prior period tax audits	$1	$2	$3

Related_Party_Transactions_Nar

Related Party Transactions (Narrative) (Details) (Corporate Joint Venture [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014		Dec. 27, 2013	Dec. 28, 2012
Related Party Transaction [Line Items]
Difference between carrying amount and underlying equity	$355
Interest expense	3		4	4
Economic interest in related party which is also an equity method investment [Member]
Related Party Transaction [Line Items]
Percentage economic interest in related party	42.00%
Voting interest in related party which is also an equity method investment [Member]
Related Party Transaction [Line Items]
Percentage economic interest in related party	50.00%
Long-term Debt [Member] \| CSXT Promissory Note Related Party October 2044 [Member]
Related Party Transaction [Line Items]
Promissory Notes Payable to Conrail Subsidiary	151	[1]
Notes issued, interest rate	2.89%	[1]
Long-term Debt [Member] \| CSXT Promissory Note Related Party March 2035 [Member]
Related Party Transaction [Line Items]
Promissory Notes Payable to Conrail Subsidiary			23
Notes issued, interest rate	4.52%		4.52%
Long-term Debt [Member] \| CSX Promissory Note Related Party October 2035 [Member]
Related Party Transaction [Line Items]
Promissory Notes Payable to Conrail Subsidiary			$73
Notes issued, interest rate	4.40%		4.40%

[1]	Promissory notes payable to Conrail are included on the consolidated balance sheet of CSX as long-term debt.

Related_Party_Transactions_Fut

Related Party Transactions (Future Lease Payment under Asset Agreement) (Details) (USD $)	Dec. 26, 2014
In Millions, unless otherwise specified	Dec. 26, 2014
Related Party Transaction [Line Items]
2015	$78
2016	71
2017	62
2018	54
2019	45
Thereafter	210
Total	520
Corporate Joint Venture [Member]
Related Party Transaction [Line Items]
2015	26
2016	26
2017	26
2018	26
2019	26
Thereafter	124
Total	$254

Related_Party_Transactions_Con

Related Party Transactions (Consolidated Income Statements Components) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Related Party Amounts Consolidated Income Statements [Abstract]
Equity earnings of Conrail	$0	$0	$0
Corporate Joint Venture [Member] \| Materials, Supplies and Other [Member]
Related Party Amounts Consolidated Income Statements [Abstract]
Rents, Fees and Services	124	115	139
Purchase Price Amortization and Other	4	4	4
Equity earnings of Conrail	-31	-35	-26
Total Conrail Rents, Fees and Services	$97	$84	$117

Related_Party_Transactions_Con1

Related Party Transactions (Consolidated Balance Sheets Components) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014		Dec. 27, 2013
Related Party Transaction [Line Items]
CSX Payable to Conrail	$0		$0
CSXT Promissory Note Related Party October 2044 [Member]
Related Party Transaction [Line Items]
Due to Related Parties, Current	3
Corporate Joint Venture [Member] \| Accounts Payable [Member]
Related Party Transaction [Line Items]
CSX Payable to Conrail	54		172
Corporate Joint Venture [Member] \| Accounts Payable [Member] \| Related Party Accounts Payable Converted to a Note [Member]
Related Party Transaction [Line Items]
CSX Payable to Conrail	125
Corporate Joint Venture [Member] \| Long-term Debt [Member] \| CSX Promissory Note Related Party October 2044 [Member]
Related Party Transaction [Line Items]
Promissory Notes Payable to Conrail Subsidiary	73	[1]
Notes issued, interest rate	2.89%	[1]
Corporate Joint Venture [Member] \| Long-term Debt [Member] \| CSX Promissory Note Related Party October 2035 [Member]
Related Party Transaction [Line Items]
Promissory Notes Payable to Conrail Subsidiary			73
Notes issued, interest rate	4.40%		4.40%
Corporate Joint Venture [Member] \| Long-term Debt [Member] \| Total Related Party Promissory Notes, October 2044 [Member]
Related Party Transaction [Line Items]
Promissory Notes Payable to Conrail Subsidiary	224
Corporate Joint Venture [Member] \| Long-term Debt [Member] \| CSXT Promissory Note Related Party October 2044 [Member]
Related Party Transaction [Line Items]
Promissory Notes Payable to Conrail Subsidiary	151	[1]
Notes issued, interest rate	2.89%	[1]
Corporate Joint Venture [Member] \| Long-term Debt [Member] \| CSXT Promissory Note Related Party March 2035 [Member]
Related Party Transaction [Line Items]
Promissory Notes Payable to Conrail Subsidiary			$23
Notes issued, interest rate	4.52%		4.52%

[1]	Promissory notes payable to Conrail are included on the consolidated balance sheet of CSX as long-term debt.

Investments_and_Longterm_Debt_

(Investments and Long-term Debt) (Details) (USD $)	Dec. 26, 2014	Dec. 27, 2013
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	$453	$668
Certificates of Deposit and Commercial Paper [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	250	472
Corporate Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	141	132
Government securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	51	49
Auction Rate Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	11	15
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	453	668
Fair Value [Member] \| Less than 1 year [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	292	487
Fair Value [Member] \| 1 - 2 years [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	45	58
Fair Value [Member] \| 2 - 5 years [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	100	105
Fair Value [Member] \| Greater than 5 years [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	16	18
Fair Value [Member] \| Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	0	0
Fair Value [Member] \| Level 1 [Member] \| Certificates of Deposit and Commercial Paper [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	0	0
Fair Value [Member] \| Level 1 [Member] \| Corporate Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	0	0
Fair Value [Member] \| Level 1 [Member] \| Government securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	0	0
Fair Value [Member] \| Level 1 [Member] \| Auction Rate Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	0	0
Fair Value [Member] \| Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	442	653
Long-term Debt Including Current Maturities	11,042	10,354
Fair Value [Member] \| Level 2 [Member] \| Certificates of Deposit and Commercial Paper [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	250	472
Fair Value [Member] \| Level 2 [Member] \| Corporate Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	141	132
Fair Value [Member] \| Level 2 [Member] \| Government securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	51	49
Fair Value [Member] \| Level 2 [Member] \| Auction Rate Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	0	0
Fair Value [Member] \| Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	11	15
Fair Value [Member] \| Level 3 [Member] \| Certificates of Deposit and Commercial Paper [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	0	0
Fair Value [Member] \| Level 3 [Member] \| Corporate Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	0	0
Fair Value [Member] \| Level 3 [Member] \| Government securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	0	0
Fair Value [Member] \| Level 3 [Member] \| Auction Rate Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value	11	15
Amortized Cost Basis [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized cost basis of investments	453	668
Amortized Cost Basis [Member] \| Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt Including Current Maturities	$9,742	$9,555

Fair_Value_Measurements_Pensio

Fair Value Measurements (Pension Plan Assets) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	$2,504	$2,500
Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Investment Committee equity target allocation percentage of pension assets	70.00%
Pension plan assets at fair value	1,715	1,619
Information technology [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	177	173
Health care [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	133	126
Consumer discretionary [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	125	152
Financials [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	116	116
Industrials [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	90	108
Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	51	59
Consumer staples [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	42	43
Materials [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	20	29
Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	33	31
Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Investment Committee equity target allocation percentage of pension assets	30.00%
Pension plan assets at fair value	740	795
Mutual funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	20	17
Cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	1	0
Common trust funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	611	553
Corporate bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	539	568
Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	365	314
Government securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	164	186
Asset-backed securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	15	24
Derivatives and other [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	2	1
Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	808	854
Level 1 [Member] \| Information technology [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	177	173
Level 1 [Member] \| Health care [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	133	126
Level 1 [Member] \| Consumer discretionary [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	125	152
Level 1 [Member] \| Financials [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	116	116
Level 1 [Member] \| Industrials [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	90	108
Level 1 [Member] \| Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	51	59
Level 1 [Member] \| Consumer staples [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	42	43
Level 1 [Member] \| Materials [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	20	29
Level 1 [Member] \| Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	33	31
Level 1 [Member] \| Mutual funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	20	17
Level 1 [Member] \| Cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	1	0
Level 1 [Member] \| Common trust funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 1 [Member] \| Corporate bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 1 [Member] \| Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 1 [Member] \| Government securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 1 [Member] \| Asset-backed securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 1 [Member] \| Derivatives and other [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	1,696	1,646
Level 2 [Member] \| Information technology [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 2 [Member] \| Health care [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 2 [Member] \| Consumer discretionary [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 2 [Member] \| Financials [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 2 [Member] \| Industrials [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 2 [Member] \| Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 2 [Member] \| Consumer staples [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 2 [Member] \| Materials [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 2 [Member] \| Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 2 [Member] \| Mutual funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 2 [Member] \| Cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 2 [Member] \| Common trust funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	611	553
Level 2 [Member] \| Corporate bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	539	568
Level 2 [Member] \| Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	365	314
Level 2 [Member] \| Government securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	164	186
Level 2 [Member] \| Asset-backed securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	15	24
Level 2 [Member] \| Derivatives and other [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	2	1
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Information technology [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Health care [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Consumer discretionary [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Financials [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Industrials [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Consumer staples [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Materials [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Mutual funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Common trust funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Corporate bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Government securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Asset-backed securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 3 [Member] \| Derivatives and other [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	$0	$0

Other_Comprehensive_Income_Det

Other Comprehensive Income (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Comprehensive Earnings	$1,784	$2,277	$1,802
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	-523	-936	-875
Other Comprehensive Income (Loss):
Income (Loss) Before Reclassifications	-293	534	-181
Loss (Income) Reclassified to Net Earnings	62	109	87
Tax (Expense) Benefit	88	-230	33
Other Comprehensive (Loss) Income, Net of Tax	-143	413	-61
Ending Balance	-666	-523	-936
Pension and Other Post-Employment Benefits [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	-462	-851	-799
Other Comprehensive Income (Loss):
Income (Loss) Before Reclassifications	-297	510	-172
Loss (Income) Reclassified to Net Earnings	60	111	88
Tax (Expense) Benefit	88	-232	32
Other Comprehensive (Loss) Income, Net of Tax	-149	389	-52
Ending Balance	-611	-462	-851
Other
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	-61	-85	-76
Other Comprehensive Income (Loss):
Income (Loss) Before Reclassifications	4	24	-9
Loss (Income) Reclassified to Net Earnings	2	-2	-1
Tax (Expense) Benefit	0	2	1
Other Comprehensive (Loss) Income, Net of Tax	6	24	-9
Ending Balance	($55)	($61)	($85)

Quarterly_Financial_Data_Unaud2

Quarterly Financial Data (Unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 26, 2014	Sep. 26, 2014	Jun. 27, 2014	Mar. 28, 2014	Dec. 27, 2013	Sep. 27, 2013	Jun. 28, 2013	Mar. 29, 2013	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Selected Quarterly Financial Information [Abstract]
Revenue	$3,192	$3,221	$3,244	$3,012	$3,032	$2,985	$3,046	$2,963	$12,669	$12,026	$11,763
Operating Income	901	976	997	739	813	840	940	880	3,613	3,473	3,464
Net Earnings	$491	$509	$529	$398	$426	$455	$521	$462	$1,927	$1,864	$1,863
Earnings Per Share, Basic (dollars per share)	$0.49	$0.51	$0.53	$0.40	$0.42	$0.45	$0.51	$0.45	$1.93	$1.83	$1.80
Earnings Per Share, Assuming Dilution (dollars per share)	$0.49	$0.51	$0.53	$0.40	$0.42	$0.45	$0.51	$0.45	$1.92	$1.83	$1.79

Summarized_Consolidating_Finan2

Summarized Consolidating Financial Data (Income Statements) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Sep. 26, 2014	Jun. 27, 2014	Mar. 28, 2014	Dec. 27, 2013	Sep. 27, 2013	Jun. 28, 2013	Mar. 29, 2013	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Consolidated Income Statement
Revenue	$3,192	$3,221	$3,244	$3,012	$3,032	$2,985	$3,046	$2,963	$12,669	$12,026	$11,763
Operating Expenses									9,056	8,553	8,299
Operating Income	901	976	997	739	813	840	940	880	3,613	3,473	3,464
Equity in Earnings of Subsidiaries									0	0	0
Interest Expense									-545	-562	-566
Other Income - Net									-24	11	73
Earnings Before Income Taxes									3,044	2,922	2,971
Income Tax Benefit (Expense)									-1,117	-1,058	-1,108
Net Earnings	491	509	529	398	426	455	521	462	1,927	1,864	1,863
Comprehensive Earnings									1,784	2,277	1,802
CSX Corporation
Consolidated Income Statement
Revenue									0	0	0
Operating Expenses									-427	-371	-355
Operating Income									427	371	355
Equity in Earnings of Subsidiaries									1,996	1,964	1,992
Interest Expense									-520	-516	-513
Nonoperating Income (Expense)											-3
Other Income - Net									-19	-7
Earnings Before Income Taxes									1,884	1,812	1,831
Income Tax Benefit (Expense)									43	52	32
Net Earnings									1,927	1,864	1,863
Comprehensive Earnings									1,784	2,277	1,802
CSX Transportation
Consolidated Income Statement
Revenue									12,590	11,950	11,696
Operating Expenses									9,585	9,091	8,779
Operating Income									3,005	2,859	2,917
Equity in Earnings of Subsidiaries									1	-1	-2
Interest Expense									-46	-62	-70
Nonoperating Income (Expense)											61
Other Income - Net									-4	-2
Earnings Before Income Taxes									2,956	2,794	2,906
Income Tax Benefit (Expense)									-1,093	-1,028	-1,065
Net Earnings									1,863	1,766	1,841
Comprehensive Earnings									1,875	1,825	1,818
Eliminations and Other
Consolidated Income Statement
Revenue									79	76	67
Operating Expenses									-102	-167	-125
Operating Income									181	243	192
Equity in Earnings of Subsidiaries									-1,997	-1,963	-1,990
Interest Expense									21	16	17
Nonoperating Income (Expense)											15
Other Income - Net									-1	20
Earnings Before Income Taxes									-1,796	-1,684	-1,766
Income Tax Benefit (Expense)									-67	-82	-75
Net Earnings									-1,863	-1,766	-1,841
Comprehensive Earnings									($1,875)	($1,825)	($1,818)

Summarized_Consolidating_Finan3

Summarized Consolidating Financial Data (Balance Sheets) (Details) (USD $)	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
Current Assets:
Cash and Cash Equivalents	$669	$592	$784	$783
Short-term Investments	292	487
Accounts Receivable - Net	1,129	1,052
Receivable from Affiliates	0	0
Materials and Supplies	273	252
Deferred Income Taxes	141	155
Other Current Assets	68	64
Total Current Assets	2,572	2,602
Properties	39,343	37,184
Accumulated Depreciation	-10,759	-9,893
Properties - Net	28,584	27,291
Other Long-term Assets	541	591
Total Assets	33,053	31,782
Current Liabilities:
Accounts Payable	845	957
Labor and Fringe Benefits Payable	613	587
CSX Payable to Conrail	0	0
Casualty, Environmental and Other Reserves	142	151
Current Maturities of Long-term Debt	228	533
Income and Other Taxes Payable	163	91
Other Current Liabilities	116	105
Total Current Liabilities	2,107	2,424
Loss Contingency, Accrual, Noncurrent	276	300
Long-term Debt	9,514	9,022
Deferred Income Taxes	8,858	8,662
Other Long-term Liabilities	1,122	870
Total Liabilities	21,877	21,278
Shareholders' Equity:
Common Stock, $1 Par Value	992	1,009
Other Capital	92	61
Retained Earnings	10,734	9,936
Accumulated Other Comprehensive Loss	-666	-523	-936	-875
Noncontrolling Minority Interest	24	21
Total Shareholders' Equity	11,176	10,504	9,136	8,598
Total Liabilities and Shareholders' Equity	33,053	31,782
Investments in Conrail
Current Assets:
Investment in Affiliates, Subsidiaries, and Joint Ventures	779	752
Affiliates and Other Companies
Current Assets:
Investment in Affiliates, Subsidiaries, and Joint Ventures	577	546
Investments in Consolidated Subsidiaries
Current Assets:
Investment in Affiliates, Subsidiaries, and Joint Ventures	0	0
CSX Corporation
Current Assets:
Cash and Cash Equivalents	510	439	481	549
Short-term Investments	250	472
Accounts Receivable - Net	2	3
Receivable from Affiliates	1,211	1,141
Materials and Supplies	0	0
Deferred Income Taxes	3	-5
Other Current Assets	0	1
Total Current Assets	1,976	2,051
Properties	1	1
Accumulated Depreciation	-1	-1
Properties - Net	0	0
Other Long-term Assets	178	217
Total Assets	23,685	22,455
Current Liabilities:
Accounts Payable	106	110
Labor and Fringe Benefits Payable	38	38
CSX Payable to Conrail	3,053	3,298
Casualty, Environmental and Other Reserves	0	0
Current Maturities of Long-term Debt	200	200
Income and Other Taxes Payable	-150	-397
Other Current Liabilities	0	0
Total Current Liabilities	3,247	3,249
Loss Contingency, Accrual, Noncurrent	0	0
Long-term Debt	8,705	8,308
Deferred Income Taxes	-172	-64
Other Long-term Liabilities	753	479
Total Liabilities	12,533	11,972
Shareholders' Equity:
Common Stock, $1 Par Value	992	1,009
Other Capital	92	61
Retained Earnings	10,734	9,936
Accumulated Other Comprehensive Loss	-666	-523
Noncontrolling Minority Interest	0	0
Total Shareholders' Equity	11,152	10,483
Total Liabilities and Shareholders' Equity	23,685	22,455
CSX Corporation \| Investments in Conrail
Current Assets:
Investment in Affiliates, Subsidiaries, and Joint Ventures	0	0
CSX Corporation \| Affiliates and Other Companies
Current Assets:
Investment in Affiliates, Subsidiaries, and Joint Ventures	-39	-39
CSX Corporation \| Investments in Consolidated Subsidiaries
Current Assets:
Investment in Affiliates, Subsidiaries, and Joint Ventures	21,570	20,226
CSX Transportation
Current Assets:
Cash and Cash Equivalents	100	91	235	154
Short-term Investments	0	0
Accounts Receivable - Net	206	240
Receivable from Affiliates	2,418	2,635
Materials and Supplies	272	252
Deferred Income Taxes	139	161
Other Current Assets	61	57
Total Current Assets	3,196	3,436
Properties	36,888	34,987
Accumulated Depreciation	-9,516	-8,778
Properties - Net	27,372	26,209
Other Long-term Assets	387	388
Total Assets	31,599	30,645
Current Liabilities:
Accounts Payable	707	809
Labor and Fringe Benefits Payable	511	491
CSX Payable to Conrail	514	535
Casualty, Environmental and Other Reserves	126	136
Current Maturities of Long-term Debt	29	333
Income and Other Taxes Payable	293	479
Other Current Liabilities	111	103
Total Current Liabilities	2,291	2,886
Loss Contingency, Accrual, Noncurrent	213	231
Long-term Debt	809	714
Deferred Income Taxes	8,827	8,548
Other Long-term Liabilities	487	512
Total Liabilities	12,627	12,891
Shareholders' Equity:
Common Stock, $1 Par Value	181	181
Other Capital	5,077	5,077
Retained Earnings	13,717	12,514
Accumulated Other Comprehensive Loss	-31	-43
Noncontrolling Minority Interest	28	25
Total Shareholders' Equity	18,972	17,754
Total Liabilities and Shareholders' Equity	31,599	30,645
CSX Transportation \| Investments in Conrail
Current Assets:
Investment in Affiliates, Subsidiaries, and Joint Ventures	0	0
CSX Transportation \| Affiliates and Other Companies
Current Assets:
Investment in Affiliates, Subsidiaries, and Joint Ventures	644	612
CSX Transportation \| Investments in Consolidated Subsidiaries
Current Assets:
Investment in Affiliates, Subsidiaries, and Joint Ventures	0	0
Eliminations and Other
Current Assets:
Cash and Cash Equivalents	59	62	68	80
Short-term Investments	42	15
Accounts Receivable - Net	921	809
Receivable from Affiliates	-3,629	-3,776
Materials and Supplies	1	0
Deferred Income Taxes	-1	-1
Other Current Assets	7	6
Total Current Assets	-2,600	-2,885
Properties	2,454	2,196
Accumulated Depreciation	-1,242	-1,114
Properties - Net	1,212	1,082
Other Long-term Assets	-24	-14
Total Assets	-22,231	-21,318
Current Liabilities:
Accounts Payable	32	38
Labor and Fringe Benefits Payable	64	58
CSX Payable to Conrail	-3,567	-3,833
Casualty, Environmental and Other Reserves	16	15
Current Maturities of Long-term Debt	-1	0
Income and Other Taxes Payable	20	9
Other Current Liabilities	5	2
Total Current Liabilities	-3,431	-3,711
Loss Contingency, Accrual, Noncurrent	63	69
Long-term Debt	0	0
Deferred Income Taxes	203	178
Other Long-term Liabilities	-118	-121
Total Liabilities	-3,283	-3,585
Shareholders' Equity:
Common Stock, $1 Par Value	-181	-181
Other Capital	-5,077	-5,077
Retained Earnings	-13,717	-12,514
Accumulated Other Comprehensive Loss	31	43
Noncontrolling Minority Interest	-4	-4
Total Shareholders' Equity	-18,948	-17,733
Total Liabilities and Shareholders' Equity	-22,231	-21,318
Eliminations and Other \| Investments in Conrail
Current Assets:
Investment in Affiliates, Subsidiaries, and Joint Ventures	779	752
Eliminations and Other \| Affiliates and Other Companies
Current Assets:
Investment in Affiliates, Subsidiaries, and Joint Ventures	-28	-27
Eliminations and Other \| Investments in Consolidated Subsidiaries
Current Assets:
Investment in Affiliates, Subsidiaries, and Joint Ventures	($21,570)	($20,226)

Summarized_Consolidating_Finan4

Summarized Consolidating Financial Data (Cash Flow Statements) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 26, 2014	Dec. 27, 2013	Dec. 28, 2012
Operating Activities
Net Cash Provided by Operating Activities	$3,343	$3,267	$2,946
Investing Activities
Property Additions	-2,449	-2,313	-2,341
Purchase of Short-term Investments	-1,433	-1,256	-633
Proceeds from Sales of Short-term Investments	1,674	1,401	581
Proceeds from Property Dispositions	62	53	186
Other Investing Activities	-37	-112	-70
Net Cash Used in Investing Activities	-2,183	-2,227	-2,277
Financing Activities
Long-term Debt Issued	1,000	500	1,100
Long-term Debt Repaid	-933	-780	-508
Payments of Ordinary Dividends, Common Stock	-629	-600	-558
Stock Options Exercised	0	9	14
Shares acquired, repurchase amount	-517	-353	-734
Other Financing Activities	-4	-8	18
Net Cash Used in Financing Activities	-1,083	-1,232	-668
Net (Decrease) Increase in Cash and Cash Equivalents	77	-192	1
Cash and Cash Equivalents at Beginning of Period	592	784	783
Cash and Cash Equivalents at End of Period	669	592	784
CSX Corporation
Operating Activities
Net Cash Provided by Operating Activities	583	1,004	579
Investing Activities
Property Additions	0	0	0
Purchase of Short-term Investments	-1,419	-1,251	-605
Proceeds from Sales of Short-term Investments	1,642	1,335	525
Proceeds from Property Dispositions	0	0	0
Other Investing Activities	0	-134	-10
Net Cash Used in Investing Activities	223	-50	-90
Financing Activities
Long-term Debt Issued	1,000	500	1,100
Long-term Debt Repaid	-600	-700	-400
Payments of Ordinary Dividends, Common Stock	-629	-600	-558
Stock Options Exercised	0	9	14
Shares acquired, repurchase amount	-517	-353	-734
Other Financing Activities	11	148	21
Net Cash Used in Financing Activities	-735	-996	-557
Net (Decrease) Increase in Cash and Cash Equivalents	71	-42	-68
Cash and Cash Equivalents at Beginning of Period	439	481	549
Cash and Cash Equivalents at End of Period	510	439	481
CSX Transportation
Operating Activities
Net Cash Provided by Operating Activities	3,278	3,005	2,716
Investing Activities
Property Additions	-2,192	-2,053	-2,104
Purchase of Short-term Investments	0	0	0
Proceeds from Sales of Short-term Investments	0	0	0
Proceeds from Property Dispositions	62	53	186
Other Investing Activities	-128	-315	102
Net Cash Used in Investing Activities	-2,258	-2,315	-1,816
Financing Activities
Long-term Debt Issued	0	0	0
Long-term Debt Repaid	-333	-80	-106
Payments of Ordinary Dividends, Common Stock	-660	-730	-715
Stock Options Exercised	0	0	0
Shares acquired, repurchase amount	0	0	0
Other Financing Activities	-18	-24	2
Net Cash Used in Financing Activities	-1,011	-834	-819
Net (Decrease) Increase in Cash and Cash Equivalents	9	-144	81
Cash and Cash Equivalents at Beginning of Period	91	235	154
Cash and Cash Equivalents at End of Period	100	91	235
Eliminations and Other
Operating Activities
Net Cash Provided by Operating Activities	-518	-742	-349
Investing Activities
Property Additions	-257	-260	-237
Purchase of Short-term Investments	-14	-5	-28
Proceeds from Sales of Short-term Investments	32	66	56
Proceeds from Property Dispositions	0	0	0
Other Investing Activities	91	337	-162
Net Cash Used in Investing Activities	-148	138	-371
Financing Activities
Long-term Debt Issued	0	0	0
Long-term Debt Repaid	0	0	-2
Payments of Ordinary Dividends, Common Stock	660	730	715
Stock Options Exercised	0	0	0
Shares acquired, repurchase amount	0	0	0
Other Financing Activities	3	-132	-5
Net Cash Used in Financing Activities	663	598	708
Net (Decrease) Increase in Cash and Cash Equivalents	-3	-6	-12
Cash and Cash Equivalents at Beginning of Period	62	68	80
Cash and Cash Equivalents at End of Period	$59	$62	$68