CSX (CSX) 10-K 12 Feb 14 2013 FY Annual report Financial data

Document_And_Entity_Informatio

Document And Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 27, 2013	Jan. 24, 2014	Jun. 28, 2013
Document and Entity Information [Abstract]	'	'	'
Entity Registrant Name	'CSX CORP	'	'
Entity Central Index Key	'0000277948	'	'
Current Fiscal Year End Date	'--12-27	'	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Public Float	'	'	$21
Entity Common Stock, Shares Outstanding	'	1,007,591,673	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	27-Dec-13	'	'

CONSOLIDATED_INCOME_STATEMENTS

CONSOLIDATED INCOME STATEMENTS (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012		Dec. 30, 2011
Income Statement [Abstract]	'	'		'
Revenue	$12,026	$11,763	[1]	$11,795	[1]
Expense	'	'		'
Labor and Fringe	3,138	3,020	[1]	3,073	[1]
Materials, Supplies and Other	2,275	2,156	[1]	2,229	[1]
Fuel	1,656	1,672	[1]	1,668	[1]
Depreciation	1,104	1,059	[1]	976	[1]
Equipment and Other Rents	380	392	[1]	379	[1]
Total Expense	8,553	8,299	[1]	8,325	[1]
Operating Income	3,473	3,464	[1]	3,470	[1]
Interest Expense	-562	-566	[1]	-552	[1]
Other Income - Net	11	73	[1]	22	[1]
Earnings Before Income Taxes	2,922	2,971	[1]	2,940	[1]
Income Tax Expense	-1,058	-1,108	[1]	-1,086	[1]
Net Earnings	$1,864	$1,863	[1]	$1,854	[1]
Net Earnings Per Share, Basic	'	'		'
Earnings Per Share, Basic (dollars per share)	$1.83	$1.80	[1]	$1.71	[1]
Net Earnings Per Common Share, Assuming Dilution	'	'		'
Earnings Per Share, Assuming Dilution (dollars per share)	$1.83	$1.79	[1]	$1.70	[1]
Average Common Shares Outstanding	1,019	1,038	[1]	1,083	[1]
Average Common Shares Outstanding, Assuming Dilution (shares)	1,019	1,040	[1]	1,089	[1]
Cash Dividends Paid Per Common Share	$0.59	$0.54	[1]	$0.45	[1]
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

CONSOLIDATED_COMPREHENSIVE_INC

CONSOLIDATED COMPREHENSIVE INCOME STATEMENTS (USD $)

3 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Dec. 27, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Dec. 30, 2012

Sep. 28, 2012

Jun. 29, 2012

Mar. 30, 2012

Dec. 30, 2011

Sep. 30, 2011

Jul. 01, 2011

Apr. 01, 2011

Dec. 27, 2013

Dec. 28, 2012

Dec. 30, 2011

Net Earnings

$426

$455

$521

$462

$449

$437

$496

$481

$483

$463

$502

$406

$1,864

$1,863

[1]

$1,854

[1]

Other Comprehensive (Loss) Income, Net of Tax

'

'

'

'

'

'

'

'

'

'

'

'

413

-61

[1]

-104

[1]

Comprehensive Earnings

'

'

'

'

'

'

'

'

'

'

'

'

2,277

1,802

[1]

1,750

[1]

Pension and Other Post-Employment Benefits

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other Comprehensive (Loss) Income, Net of Tax

'

'

'

'

'

'

'

'

'

'

'

'

389

-52

[1]

-88

[1]

Other

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other Comprehensive (Loss) Income, Net of Tax

'

'

'

'

'

'

'

'

'

'

'

'

$24

[2]

($9)

[1],[2]

($16)

[1],[2]

[1]

See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

[2]

Other primarily represents CSX's share of AOCI of equity method investees. Amounts reclassified to net earnings are included in other income - net on the consolidated income statements.

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 27, 2013		Dec. 28, 2012		Dec. 30, 2011		Dec. 31, 2010
In Millions, unless otherwise specified
Current Assets	'		'		'		'
Cash and Cash Equivalents	$592	[1]	$784	[1]	$783	[1]	$1,292	[1]
Short-term Investments	487	[1]	587	[1]	'		'
Accounts Receivable - Net	1,052	[1]	1,114	[1]	1,147	[1]	'
Materials and Supplies	252	[1]	274	[1]	'		'
Deferred Income Taxes	155	[1]	119	[1]	'		'
Other Current Assets	64	[1]	75	[1]	'		'
Total Current Assets	2,602		2,953	[1]	2,953		'
Properties	37,184	[1]	35,279	[1]	'		'
Accumulated Depreciation	-9,893	[1]	-9,229	[1]	'		'
Properties - Net	27,291		26,050	[1]	'		'
Other Long-term Assets	591	[1]	514	[1]	'		'
Total Assets	31,782		30,723	[1]	29,491		'
Current Liabilities	'		'		'		'
Accounts Payable	957	[1]	948	[1]	954	[1]	'
Labor and Fringe Benefits Payable	587	[1]	468	[1]	'		'
Current Maturities of Long-term Debt	533	[1]	780	[1]	'		'
Income and Other Taxes Payable	91	[1]	169	[1]	210	[1]	'
Other Current Liabilities	105	[1]	140	[1]	'		'
Total Current Liabilities	2,424		2,645	[1]	2,575		'
Long-term Debt	9,022	[1]	9,052	[1]	'		'
Deferred Income Taxes	8,662	[1]	8,096	[1]	'		'
Other Long-term Liabilities	870	[1]	1,457	[1]	'		'
Total Liabilities	21,278		21,587	[1]	20,893		'
Shareholders' Equity:	'		'		'		'
Common Stock, $1 Par Value	1,009	[1]	1,020	[1]	'		'
Other Capital	61	[1]	28	[1]	'		'
Retained Earnings	9,936	[1]	9,010	[1]	8,405	[1]	'
Accumulated Other Comprehensive Loss	-523	[1]	-936	[1]	-875		-771
Noncontrolling Minority Interest	21	[1]	14	[1]	'		'
Total Shareholders' Equity	10,504		9,136	[1]	8,598		8,798
Total Liabilities and Shareholders' Equity	31,782		30,723	[1]	29,491		'
Investments in Conrail	'		'		'		'
Current Assets	'		'		'		'
Investment in Affiliates and Joint Ventures	752	[1]	695	[1]	'		'
Affiliates and Other Companies	'		'		'		'
Current Assets	'		'		'		'
Investment in Affiliates and Joint Ventures	$546	[1]	$511	[1]	'		'
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 27, 2013	Dec. 28, 2012
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. 27, 2013		Dec. 28, 2012		Dec. 30, 2011
OPERATING ACTIVITIES	'		'		'
Net Earnings	$1,864		$1,863	[1]	$1,854	[1]
Adjustments to Reconcile Net Earnings to Net Cash	'		'		'
Depreciation	1,104		1,059	[1]	976	[1]
Deferred Income Taxes	300		592	[1]	609	[1]
Contributions to Qualified Pension Plans	0		-275	[1]	0	[1]
Gain on Property Dispositions	-70		-166	[1]	-25	[1]
Other Operating Activities	-35		-64	[1]	-10	[1]
Changes in Operating Assets and Liabilities:	'		'		'
Accounts Receivable	-6		61	[1]	-117	[1]
Other Current Assets	36		-32	[1]	-23	[1]
Accounts Payable	28		-4	[1]	76	[1]
Income and Other Taxes Payable	-67		-14	[1]	116	[1]
Other Current Liabilities	113		-74	[1]	35	[1]
Net Cash Provided by Operating Activities	3,267		2,946	[1]	3,491	[1]
INVESTING ACTIVITIES	'		'		'
Property Additions	-2,313		-2,341	[1]	-2,297	[1]
Purchase of Short-term Investments	-1,256		-633	[1]	-492	[1]
Proceeds from Sales of Short-term Investments	1,401		581	[1]	74	[1]
Proceeds from Property Dispositions	53		186	[1]	240	[1]
Other Investing Activities	-112		-70	[1]	-112	[1]
Net Cash Used in Investing Activities	-2,227		-2,277	[1]	-2,587	[1]
FINANCING ACTIVITIES	'		'		'
Long-term Debt Issued	500		1,100	[1]	1,200	[1]
Long-term Debt Repaid	-780		-508	[1]	-605	[1]
Dividends Paid	-600		-558	[1]	-480	[1]
Stock Options Exercised	9		14	[1]	29	[1]
Shares Repurchased	-353		-734	[1]	-1,564	[1]
Other Financing Activities	-8		18	[1]	7	[1]
Net Cash Used in Financing Activities	-1,232		-668	[1]	-1,413	[1]
Net (Decrease) Increase in Cash and Cash Equivalents	-192		1	[1]	-509	[1]
CASH AND CASH EQUIVALENTS	'		'		'
Cash and Cash Equivalents at Beginning of Period	784	[1]	783	[1]	1,292	[1]
Cash and Cash Equivalents at End of Period	592	[1]	784	[1]	783	[1]
SUPPLEMENTAL CASH FLOW INFORMATION	'		'		'
Interest Paid - Net of Amounts Capitalized	595		592	[1]	574	[1]
Income Taxes Paid	$824		$506	[1]	$359	[1]
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

CONSOLIDATED_STATEMENTS_OF_CHA

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS EQUITY (USD $)		Total		Common Shares Outstanding	Common Stock and Other Capital	Retained Earnings		Accumulated Other Comprehensive Income (Loss)		Non-controlling Interest
In Millions, except Share data in Thousands, unless otherwise specified		USD ($)			USD ($)	USD ($)		USD ($)		USD ($)
Shareholders' Equity, beginning balance at Dec. 31, 2010		$8,798		'	$370	$9,185	[1]	($771)	[2]	$14
Common Shares Outstanding, beginning balance at Dec. 31, 2010		'		1,111,026	'	'		'		'
Comprehensive Earnings:		'		'	'	'		'		'
Net Earnings	[1]	1,854		'	'	1,854		'		'
Other Comprehensive (Loss) Income		-104	[1]	'	'	'		-104	[2]	'
Comprehensive Earnings	[1]	1,750		'	'	'		'		'
Common stock dividends		-480		'	'	-480	[1]	'		0
Share Repurchases (shares)		-67,000		-67,406	'	'		'		'
Share Repurchases		-1,564		'	590	-2,154	[1]	'		'
Bond Conversions (shares)		'		675	'	'		'		'
Bond Conversions		5		'	5	'		'		'
Stock Option Exercises and Other (shares)		'		4,862	'	'		'		'
Stock Option Exercises and Other		89		'	90	0	[1]	'		-1
Shareholders' Equity, ending balance at Dec. 30, 2011		8,598		'	1,055	8,405	[1]	-875	[2]	13
Common Shares Outstanding, ending balance at Dec. 30, 2011		'		1,049,157	'	'		'		'
Comprehensive Earnings:		'		'	'	'		'		'
Net Earnings	[1]	1,863		'	'	1,863		'		'
Other Comprehensive (Loss) Income		-61	[1]	'	'	'		-61	[2]	'
Comprehensive Earnings	[1]	1,802		'	'	'		'		'
Common stock dividends		-558		'	'	-558	[1]	'		0
Share Repurchases (shares)		-34,000		-34,088	'	'		'		'
Share Repurchases		-734		'	-34	-700	[1]	'		'
Bond Conversions (shares)		'		155	'	'		'		'
Bond Conversions		1		'	1	'		'		'
Stock Option Exercises and Other (shares)		'		5,261	'	'		'		'
Stock Option Exercises and Other		27		'	26	'		'		1
Shareholders' Equity, ending balance at Dec. 28, 2012		9,136	[1]	'	1,048	9,010	[1]	-936	[2]	14
Common Shares Outstanding, ending balance at Dec. 28, 2012		'		1,020,485	'	'		'		'
Comprehensive Earnings:		'		'	'	'		'		'
Net Earnings		1,864		'	'	1,864	[1]	'		'
Other Comprehensive (Loss) Income		413		'	'	'		413	[2]	'
Comprehensive Earnings		2,277		'	'	'		'		'
Common stock dividends		-600		'	'	-600	[1]	'		0
Share Repurchases (shares)		-14,000		-13,791	'	'		'		'
Share Repurchases		-353		'	-14	-339	[1]	'		'
Bond Conversions (shares)		'		1	'	'		'		'
Bond Conversions		0		'	0	'		'		'
Stock Option Exercises and Other (shares)		'		2,165	'	'		'		'
Stock Option Exercises and Other		44		'	36	1	[1]	'		7
Shareholders' Equity, ending balance at Dec. 27, 2013		$10,504		'	$1,070	$9,936	[1]	($523)	[2]	$21
Common Shares Outstanding, ending balance at Dec. 27, 2013		'		1,008,860	'	'		'		'
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.
[2]	Accumulated Other Comprehensive Loss year-end balances shown above are net of tax. The associated taxes were $463 million, $496 million and $266 million for 2011, 2012 and 2013, 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
In Millions, except Per Share data, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
Statement of Stockholders' Equity [Abstract]	'	'	'
Common Stock Dividends (dollars per share)	$0.59	$0.54	$0.45
Accumulated Other Comprehensive Income (Loss)	'	'	'
Statement [Line Items]	'	'	'
Accumulated Other Comprehensive Loss - Tax amount	$266	$496	$463

Nature_of_Operations_and_Signi

Nature of Operations and Significant Accounting Policies	12 Months Ended
	Dec. 27, 2013
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 31,000 in 2013, 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 2013, CSXT’s transportation services generated $12.0 billion of revenue and served three primary lines of business:
	•	The merchandise business shipped nearly 2.8 million carloads and generated approximately 59% of revenue and 42% of volume in 2013. 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 1.2 million carloads and accounted for 24% of revenue and 18% of volume in 2013.  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 2013. 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.
	NOTE 1.  Nature of Operations and Significant Accounting Policies, continued
	Other revenue accounted for approximately 3% of the Company’s total revenue in 2013.  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.
	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, such as minerals 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 present fairly the financial position of CSX and its subsidiaries at December 27, 2013 and December 28, 2012, and the consolidated statements of income, comprehensive income, cash flows and changes in shareholders’ equity for fiscal years 2013, 2012 and 2011.
	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 2013, 2012 and 2011 each consisted of 52 weeks ending on December 27, 2013, December 28, 2012 and December 30, 2011, respectively.  Except as otherwise specified, references to full year indicate CSX’s fiscal periods ended on these dates.
	NOTE 1.  Nature of Operations and Significant Accounting Policies, continued
	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 equity (if the Company has significant influence).
	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 in instruments with original maturities greater than three months but less than one year were classified as short-term investments.
	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 $33 million and $36 million is included in the consolidated balance sheets as of December 2013 and December 2012, 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 $64 million is recorded in other long-term assets in the consolidated balance sheets as of December 2013 and 2012.
	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.
	NOTE 1.  Nature of Operations and Significant Accounting Policies, continued
	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, which are based on historical freight car movement data as well as 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;
	•	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. Amounts received for customer volume commitments not met are recorded upon the completion of the contract term.
	New Accounting Pronouncements
	In February 2013, the Financial Accounting Standards Board ("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
	Revision of Prior Period Financial Statements
	During the fourth quarter of 2013, CSX completed a review of certain accounts receivable balances which resulted in an adjustment to previously reported revenue. This review identified immaterial differences between estimated and actual revenue earned on a small percentage of transactions as well as a small percentage of revenue over at least a decade.
	In accordance with ASC 250 Accounting Changes and Error Corrections as well as the SEC's Staff Accounting Bulletin No. 99, Materiality, the Company evaluated the materiality of this error on prior period financial statements and determined that it did not result in a material misstatement to the financial conditions, results of operations, or liquidity for any of the periods presented.
	The Company also determined that the effect of recording all corrections during the fourth quarter of 2013 would have been material to the financial statements. As a result, prior period financial statements have been revised to correct the errors in accordance with ASC 250 and the SEC's Staff Accounting Bulletin No. 108, Considering the Effects of Prior Year Misstatements when Quantifying Misstatements in Current Year Financial Statements, as shown in the tables below.
	NOTE 1.  Nature of Operations and Significant Accounting Policies, continued
	Dollars in Millions, Except Per Share Amounts	2012									2011
	Consolidated Income Statements	As Previously Reported			Adjustment			As			As Previously Reported			Adjustment			As
								Revised									Revised
	Revenue	$	11,756		$	7		$	11,763		$	11,743		$	52		$	11,795
	Operating Income	3,457			7			3,464			3,418			52			3,470
	Earnings Before Income Taxes	2,964			7			2,971			2,888			52			2,940
	Income Tax Expense	(1,105		)	(3		)	(1,108		)	(1,066		)	(20		)	(1,086		)
Net Earnings	1,859			4			1,863			1,822			32			1,854
Net Earnings Per Share, Basic	$	1.79		$	0.01		$	1.8		$	1.68		$	0.03		$	1.71
Net Earnings Per Share, Assuming Dilution	$	1.79		$	—		$	1.79		$	1.67		$	0.03		$	1.7
Consolidated Comprehensive Income Statements
Net Earnings	$	1,859		$	4		$	1,863		$	1,822		$	32		$	1,854
Comprehensive Earnings	1,798			4			1,802			1,718			32			1,750
Consolidated Balance Sheets
Accounts Receivable - Net	$	962		$	152		$	1,114		$	1,000		$	147		$	1,147
Total Current Assets	2,801			152			2,953			2,806			147			2,953
Total Assets	30,571			152			30,723			29,344			147			29,491
Accounts Payable	1,014			(66		)	948			1,018			(64		)	954
Income and Other Taxes Payable	85			84			169			129			81			210
Total Current Liabilities	2,627			18			2,645			2,558			17			2,575
Total Liabilities	21,569			18			21,587			20,876			17			20,893
Retained Earnings	8,876			134			9,010			8,275			130			8,405
Total Shareholders' Equity	9,002			134			9,136			8,468			130			8,598
Total Liabilities and Shareholders' Equity	$	30,571		$	152		$	30,723		$	29,344		$	147		$	29,491
Consolidated Cash Flow Statements
Net Earnings	$	1,859		$	4		$	1,863		$	1,822		$	32		$	1,854
Changes in Operating Assets and Liabilities
Accounts Receivable	67			(6		)	61			(59		)	(58		)	(117		)
Accounts Payable	(3		)	(1		)	(4		)	70			6			76
Income and Other Taxes Payable	(17		)	3			(14		)	96			20			116
Net Cash Provided by Operating Activities	$	2,946		$	—		$	2,946		$	3,491		$	—		$	3,491
Statement of Changes in Shareholders' Equity	2010
Retained Earnings	$	9,087		$	98		$	9,185
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 pertinent facts guide the timing and volume of all repurchases. Future share repurchases are expected to be funded by cash on hand, cash generated from operations and debt issuances.
During 2013, CSX repurchased $353 million, or 14 million in shares of common stock under the new share repurchase program. Additionally, the Company repurchased a total of $734 million, or 34 million shares, and $1.6 billion, or 67 million shares, in 2012 and 2011, respectively, under previous share repurchase programs. 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

Earnings Per Share	12 Months Ended
	Dec. 27, 2013
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
		2013		2012 (a)		2011 (a)
	Numerator (Dollars in Millions):
	Net Earnings	$	1,864	$	1,863	$	1,854
	Dividend Equivalents on Restricted Stock	1		1		1
	Net Earnings, Attributable to Common Shareholders	$	1,865	$	1,864	$	1,855
	Denominator (Units in Millions):
	Average Common Shares Outstanding	1,019		1,038		1,083
	Other Potentially Dilutive Common Shares (b)	—		2		6
	Average Common Shares Outstanding, Assuming Dilution	1,019		1,040		1,089
	Net Earnings Per Share, Basic	$	1.83	$	1.8	$	1.71
	Net Earnings Per Share, Assuming Dilution	$	1.83	$	1.79	$	1.7
	(a)	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.
	(b)	Other potentially dilutive common shares include convertible debt, stock options, common stock equivalents and performance units granted under a long-term management incentive compensation plan.
	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 outstanding adjusted for the effects of common stock that may be issued as a result of the following types of potentially dilutive instruments:
	•	convertible debt;
	•	employee stock options; and
	•	other equity awards, which include long-term incentive awards.
	NOTE 2.  Earnings Per Share, continued
	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.
	When calculating diluted earnings per share, the Earnings Per Share Topic in the ASC requires CSX to include the potential shares that would be outstanding if all outstanding stock options were exercised.   This is offset by shares CSX could repurchase using the proceeds from these hypothetical exercises to obtain the common stock equivalent.  This number is different from outstanding stock options, which is included in Note 4, Stock Plans and Share-Based Compensation.  All stock options were dilutive for the periods presented; therefore, no stock options were excluded from the diluted earnings per share calculation.
	Diluted shares outstanding are not impacted when debentures are converted into CSX common stock because those shares were already included in the diluted shares calculation.  Shares outstanding for basic earnings per share, however, are impacted on a weighted-average basis when conversions occur.  During 2013 and 2012, $7 thousand and $2 million, respectively, of face value convertible debentures were converted into approximately 1 thousand shares and 155 thousand shares of CSX common stock, respectively.  As of December 2013, approximately $2 million of convertible debentures at face value remained outstanding, which are convertible into 244 thousand shares of CSX common stock.

Shareholders_Equity

Shareholders' Equity	12 Months Ended
	Dec. 27, 2013
Stockholders' Equity Note [Abstract]	'
Stockholders' Equity	'
	Shareholders’ Equity
	Common and preferred stock consists of the following:
	Common Stock, $1 Par Value	Dec-13
		(Units in Millions)
	Common Shares Authorized	1,800
	Common Shares Issued and Outstanding	1,009
	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. 27, 2013
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, stock options 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 $13 million, $37 million and $35 million for fiscal years 2013, 2012 and 2011, 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:
		Fiscal Years
	(Dollars in Millions)	2013			2012				2011
	Share-Based Compensation Expense	$	14		$	14			$	30
	Income Tax Benefit	6			5				11
	Stock Options
	Stock options have not been granted since 2003. As of December 2013, there were no current or former employees with stock options outstanding, as all remaining stock options expired in May 2013.  The exercise price for options granted equals the market price of the underlying stock on the grant date.  The total intrinsic value of options exercised for fiscal years ended 2013, 2012, and 2011 was $27 million, $37 million, and $84 million, respectively. This value represents the value realized by current and former employees who exercised options.
	A summary of CSX's stock option activity and related information for the fiscal years 2013, 2012 and 2011 is as follows:
		Fiscal Years
		2013						2012					2011
		Options		Weighted-				Options			Weighted-		Options		Weighted-
		Outstanding		Average				Outstanding			Average		Outstanding		Average
		(Thousands)		Exercise				(Thousands)			Exercise		(Thousands)		Exercise
				Price							Price				Price
	Outstanding & Exercisable at Beginning of Year	1,672		$	5.36			4,145			$	5.64	9,111		$	5.82
	Expired or Cancelled	(9	)	5.36				(15	)		6.36		(27	)	6.44
	Exercised	(1,663	)	5.36				(2,458	)		5.83		(4,939	)	5.96
	Outstanding & Exercisable at End of Year	—		$	—			1,672			$	5.36	4,145		$	5.64
	NOTE 4.  Stock Plans and Share-Based Compensation, continued
	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 2013, unrecognized compensation expense for these awards and units was approximately $17 million, which will be expensed over a weighted-average remaining period of 2 years.
		Fiscal Years
		2013			2012				2011
	Restricted Stock Units and Awards Outstanding (Thousands)(a)	1,462			1,353				1,572
	Weighted-Average Fair Value at Grant Date	$	23.89		$	21.38			$	16.91
	Restricted Stock Units and Awards Expense (Millions)(a)	10			9				7
	Unvested Restricted Stock Units and Awards Outstanding (Thousands)	705			629				678
	Weighted-Average Fair Value of Unvested Units and Awards Outstanding	$	24.17		$	22.48			$	20.93
	(a)  Time-based restricted stock units were granted to certain employees under the respective Long-term Incentive Plans in the amount of 524,000, 433,000, and 361,000 in 2013, 2012, and 2011, respectively, as described below.  These units vest over three years, therefore only a partial amount of expense was recognized in 2013, 2012, and 2011, 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.
	In May of 2011, 2012 and 2013, target performance units were granted to certain employees under three separate LTIP plans covering three-year cycles: the 2011-2013 (“2013 LTIP”), 2012-2014 (“2014 LTIP”) and 2013-2015 (“2015 LTIP”) plans (collectively, the “Plans”). The key financial target for the 2013 and 2014 plans 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 key financial targets for the 2015 plan 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.
	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. The 2013 and 2014 plans 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 2015 plan states 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 $2 million, $3 million and $21 million for fiscal years 2013, 2012 and 2011, respectively.
	NOTE 4.  Stock Plans and Share-Based Compensation, continued
	The 2013 plan ended on December 27, 2013, and CSX did not issue any shares in January 2014 as applicable performance targets for the three preceding fiscal years were not met.
		LTIP Plan (Plan Ended In)
		2013			2014				2015
	Number of target units outstanding (Thousands)(a)	1,080			1,340				1,318
	Weighted-average fair value at grant date (a)	$	25.63		$	22.13			$	25.32
	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 2013, 2014 and 2015 plans, 361 thousand, 433 thousand and 524 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 2013, there was $29 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)	2013		2014			2015
	Unvested at December 30, 2011	991		—			—		$	25.92
	Granted in 2012	65		1,325			—		21.97
	Forfeited in 2012	(2	)	(69	)		—		(21.99		)
	Unvested at December 28, 2012	1,054		1,256			—		23.66
	Granted in 2013	26		85			1,354		25.24
	Forfeited in 2013	—		(1	)		(36	)	(25.31		)
	Cancelled due to performance conditions(a)	(1,080	)	—			—		25.63
	Vested at December 27, 2013	—		—			—		—
	Unvested at December 27, 2013	—		1,340			1,318		$	23.73
	(a) The minimum financial target was not met in 2013. As a result, there was no performance unit payout for the LTIP ended December 27, 2013.
	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
	2013			2012				2011
Shares Issued to Directors (Thousands)	105			102				93
Expense (Millions)	$	2		$	2			$	2
Weighted Average Grant Date Stock Price	$	23.12		$	21.92			$	23.46
The directors may elect to defer receipt of their fees, in accordance with Internal Revenue Code 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
	Dec. 27, 2013
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
	31-Dec-10	$	375			$	107		$	59		$	541
	Charged to Expense	68				23			41			132
	Payments	(71		)		(47		)	(36		)	(154		)
	30-Dec-11	372				83			64			519
	Charged to Expense	51				35			36			122
	Payments	(98		)		(30		)	(36		)	(164		)
	28-Dec-12	325				88			64			477
	Charged to Expense	54				48			38			140
	Payments	(99		)		(36		)	(31		)	(166		)
	27-Dec-13	$	280			$	100		$	71		$	451
	NOTE 5.  Casualty, Environmental and Other Reserves, continued
	These reserves are considered critical accounting estimates due to the need for significant management judgments. They are provided for in the consolidated balance sheets as follows:
		Dec-13										Dec-12
	(Dollars in Millions)	Current				Long-term			Total			Current			Long-term		Total
	Casualty:
	Personal Injury	$	59			$	148		$	207		$	75		$	158	$	233
	Occupational	3				20			23			5			31		36
	Asbestos	10				40			50			8			48		56
	Total Casualty	72				208			280			88			237		325
	Environmental	59				41			100			33			55		88
	Other	20				51			71			19			45		64
	Total	$	151			$	300		$	451		$	140		$	337	$	477
	These liabilities are accrued when estimable and probable in accordance with the Contingencies Topic in the ASC. Actual settlements and claims received could differ.  The 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 $280 million for 2013 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 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 2013, 2012 and 2011, 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 the Federal Employers’ Liability Act (“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.
	NOTE 5.  Casualty, Environmental and Other Reserves, continued
	CSXT retains an independent actuarial firm to assist management in assessing the value of personal injury claims.  An analysis is performed by the independent actuarial firm 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.
	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 10 to 40 years after exposure.
	Occupational and asbestos claims are analyzed by a third-party actuary or specialist (the "third-party specialist"), respectively, in order to determine the number of unasserted or incurred but not reported (“IBNR”) claims. Occupational claims analyses are performed by the third-party specialist quarterly and are reviewed by management. Since exposure to asbestos has been substantially eliminated, management reviews asserted asbestos claims quarterly and the review by the third-party specialist is completed annually. With the exception of carpal tunnel, management has determined that seven years is the most probable time period in which unasserted 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.
	The third party specialists 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 CSX’s employment records and industry data. From this analysis, the third-party specialists provide an estimate of the IBNR claims liability.
	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)	2013				2012
	Occupational:
	Incurred but not reported claims	$	15			$	24
	Asserted claims	8				12
	Total liability	$	23			$	36
	Asbestos:
	Incurred but not reported claims	$	35			$	37
	Asserted claims	15				19
	Total liability	$	50			$	56
	During 2013 and 2012, there were no significant changes in estimate of occupational or asbestos reserves. A summary of occupational and asbestos claims activity is as follows:
		Fiscal Years
		2013			2012
	Asserted Claims
	Open Claims - Beginning of Year	523			746
	New Claims Filed	165			160
	Claims Settled	(146	)		(154	)
	Claims Dismissed	(150	)		(229	)
	Open Claims - End of Year	392			523
	Environmental
	Environmental reserves were $100 million for 2013. 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 244 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, or CERCLA, 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.
	NOTE 5.  Casualty, Environmental and Other Reserves, continued
	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.
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 $71 million for 2013 include liabilities for various claims, such as longshoremen disability claims, and claims for property, automobile and general liability.

Properties

Properties	12 Months Ended
	Dec. 27, 2013
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-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
	NOTE 6.  Properties, continued
	(Dollars in Millions)					Accumulated			Net Book		Annual Depreciation	Depreciation	Estimated Useful
	Dec-12			Cost		Depreciation			Value		Rate	Method	Life
	Road
			Rail and Other Track Material	$	6,177	$	(1,131	)	$	5,046	2.90%	Group Life
			Ties	4,287		(861		)	3,426		4.00%	Group Life
			Grading	2,407		(414		)	1,993		1.50%	Group Life
			Ballast	2,528		(624		)	1,904		2.80%	Group Life
			Bridges, Trestles, and Culverts	1,962		(224		)	1,738		1.60%	Group Life
			Signals and Interlockers	1,787		(302		)	1,485		3.40%	Group Life
			Buildings	926		(316		)	610		2.50%	Group Life
			Other	3,345		(1,281		)	2,064		4.70%	Group Life
	Total Road			23,419		(5,153		)	18,266				6-80 Years
	Equipment
			Locomotive	4,747		(2,079		)	2,668		3.60%	Group Life
			Freight Cars	3,088		(1,119		)	1,969		3.10%	Group Life
			Work Equipment and Other	1,466		(810		)	656		7.10%	Group Life
	Total Equipment			9,301		(4,008		)	5,293				5-38 Years
	Land			1,745		—			1,745		N/A	N/A	N/A
	Construction In Progress			602		—			602		N/A	N/A	N/A
	Other			212		(68		)	144		N/A	Straight Line	4-30 Years
	Total Properties			$	35,279	$	(9,229	)	$	26,050
	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 over 86% of total fixed assets of $37 billion on a gross basis as of December 2013.  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.
	NOTE 6.  Properties, continued
	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.
	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 six years for system roadway machinery to 80 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 six 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.  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).  Abnormal operating gains were $65 million in 2013, $104 million in 2012 and $14 million in 2011 and all relate to the disposition of operating rail corridors. Each year includes gains from the 2011 sale of an operating rail corridor to the state of Florida. See the Significant Property Disposition section below for further details on the transaction with 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 $1.1 billion, $1.1 billion, and $976 million for 2013, 2012, and 2011, respectively.  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
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.
NOTE 6.  Properties, continued
Significant Property Disposition
In November 2011, the Company sold 61 miles of operating rail corridor to the Florida Department of Transportation. This corridor will be used by the state of Florida for its new commuter rail operation known as SunRail, which is expected to alleviate highway congestion. The Company diverted a portion of the corridor's existing rail traffic and relocated terminal operations to an adjacent rail corridor in Florida. As part of the transaction, the Company received $173 million in proceeds ($148 million in cash and a $25 million receivable, held in escrow and payable no later than April 2014) and up to $259 million in government grants. These grants are related to reimbursable capital expenditure projects in Florida and are recorded as a reduction of the carrying value of the related asset as received. This agreement also obligated the Company to invest a total of $500 million in routine capital expenditures and maintenance related to transportation capacity, facilities or equipment in Florida, including diversion and relocation costs related to this transaction within an eight year period following the transaction. The Company invested $142 million, $311 million and $47 million in 2013, 2012 and 2011, respectively. The required investment obligation was fulfilled during the second quarter of 2013.
This transaction contains multiple elements with separate accounting recognition for the sale of real estate and receipt of the grants. The proceeds related to the sale of real estate approximate fair value. Fair value was determined by management in accordance with the Fair Value Measurement Topic in the ASC using level 3 measurements and with the assistance of an independent third-party appraiser.
In accordance with the Real Estate Sales Topic in the ASC, this sale of real estate resulted in a deferred gain of $160 million. The deferred gain is primarily recognized into income ratably as the investment obligation is fulfilled. The Company recognized a gain of $43 million, $94 million and $14 million in 2013, 2012 and 2011, respectively. This gain is included in materials, supplies and other in the consolidated income statements. Going forward, the Company expects no further material gains. The deferred gain balance included in the consolidated balance sheets is in the table below.
	Deferred gain as of
(Dollars in Millions)	Dec-13		Dec-12
Current portion, included in Other Current Liabilities	$	9	$	43
Long term portion, included in Other Long-Term Liabilities	—		9
Total	$	9	$	52

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 27, 2013
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)	2013		2012			2011
	Rent Expense on Operating Leases	$	60	$	73		$	68
	At December 2013, minimum rentals on land, buildings, track and equipment under operating leases are disclosed in the table below.  Also, payments to Conrail, Inc. ("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
	2014	$	79	$	(3	)	$	76
	2015	73		(2		)	71
	2016	64		(2		)	62
	2017	55		(2		)	53
	2018	46		(2		)	44
	Thereafter	275		(13		)	262
	Total	$	592	$	(24	)	$	568
	Purchase Commitments
	CSXT has a commitment under a long-term maintenance program that currently covers 44% 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)	2013		2012			2011
	Amounts Paid	$	287	$	287		$	281
	Number of Locomotives	1,886		1,899			1,928
	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
	2014	$	292	$	321		$	613
	2015	253		66			319
	2016	245		15			260
	2017	232		6			238
	2018	220		6			226
	Thereafter	1,314		53			1,367
	Total	$	2,556	$	467		$	3,023
	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.
	NOTE 7.  Commitments and Contingencies, continued
	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 $2 million to $15 million in aggregate at December 27, 2013. 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.
	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 and are now pending in federal court in the District of Columbia. 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, 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. The District Court has ordered briefing on class certification to be completed by the end of May 2014.  In the interim, the District Court has delayed proceedings on the merits of the case.
	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.
	NOTE 7.  Commitments and Contingencies, continued
	Environmental
	CSXT has certain indemnification requirements with respect to Pharmacia LLC (formerly known as Monsanto Company) for certain liabilities associated with real estate formerly owned by Pharmacia that is now owned by CSXT in Kearny, New Jersey (the “Property”).  The indemnification and defense duties arise with respect to several matters.  The State of New Jersey filed suit in 2005 against Occidental Chemical Corporation, Tierra Solutions Inc., Maxus Energy Corporation and five other companies seeking cleanup and removal costs and other damages associated with the presence of dioxin and other hazardous substances in the sediment of the Newark Bay Complex, which includes a 17-mile stretch of the Passaic River near the Property. In 2009, Pharmacia, along with hundreds of other companies, was served with a third-party complaint by Tierra Solutions Inc. and Maxus Energy Corporation seeking contribution towards the costs and damages claimed by the state of New Jersey or incurred by Tierra and Maxus related to the Newark Bay Complex.  CSXT has been participating in the defense of this matter with and on behalf of Pharmacia.  In 2013, Pharmacia, along with most of the other third-party defendants, entered into a settlement agreement with the state of New Jersey for an amount that is not material to CSXT.  The settlement, approved by the Superior Court of New Jersey in December 2013, resolves certain claims or potential claims by the state of New Jersey for costs and damages arising from discharges to the Newark Bay Complex.  CSXT, on behalf of Pharmacia, is also conducting a Remedial Investigation and Feasibility Study of the 17-mile Lower Passaic River Study Area with approximately 70 other parties pursuant to an Administrative Order on Consent with the EPA. 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
	Dec. 27, 2013
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 on or before December 31, 2002, 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. In addition to these plans, the Company sponsors a self-insured, 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.  Prior to 2011, the post-retirement medical plan was partially funded by all participating retirees, with retiree contributions adjusted annually.  Beginning in 2011, 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. The life insurance plan is non-contributory.
	The Company engages independent, external actuaries to compute the amounts of liabilities and expenses related 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.
	NOTE 8.  Employee Benefit Plans, continued
		Summary of Participants as of
		January 1, 2013
		Pension Plans			Post-retirement Medical Plan
	Active Employees	5,153			2,176
	Retirees and Beneficiaries	11,569			12,277
	Other(a)	5,715			112
	Total	22,437			14,565
	(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 prescribed regulatory requirements and with an objective of meeting minimum funding requirements necessary to avoid restrictions on flexibility of plan operation and benefit payments.  During 2012, the Company made a contribution of $275 million to its qualified pension plans, of which $25 million was the required minimum contribution. At this time, the Company anticipates that no further contributions to its qualified pension plans will be required in 2014. 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.
	Future expected benefit payments are as follows:
		Expected Cash Flows
	(Dollars in Millions)	Pension Benefits				Post-retirement Benefits
	2014	$	167			$	38
	2015	171				36
	2016	173				34
	2017	176				32
	2018	179				31
	2019-2023	910				126
	Total	$	1,776			$	297
	NOTE 8.  Employee Benefit Plans, continued
	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 60% equity investments and 40% fixed income investments and cash.  Within equity, a further target is currently established for 40% of total plan assets in domestic equity and 20% 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-13							Dec-12
						Percent of							Percent of
	(Dollars in Millions)	Amount				Total Assets			Amount				Total Assets
	Equity	$	1,619			65	%		$	1,408			61	%
	Fixed Income	795				32			829				36
	Cash and Cash Equivalents	86				3			57				3
	Total	$	2,500			100	%		$	2,294			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.
	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.
	NOTE 8.  Employee Benefit Plans, continued
	Benefit Obligation, Plan Assets and Funded Status
	Changes in benefit obligation and the fair value of plan assets for the 2013 and 2012 calendar plan years are as follows:
		Pension Benefits								Post-retirement Benefits
		Plan Year				Plan Year				Plan Year				Plan Year
	(Dollars in Millions)	2013				2012				2013				2012
	Actuarial Present Value of Benefit Obligation
	Accumulated Benefit Obligation	$	2,538			$	2,806			N/A				N/A
	Projected Benefit Obligation	2,679				2,954				$	350			$	415
	Change in Projected Benefit Obligation:
	Projected Benefit Obligation at Beginning of Plan Year	$	2,954			$	2,668			$	415			$	388
	Service Cost	49				44				3				4
	Interest Cost	108				123				13				16
	Plan Participants' Contributions	—				—				8				8
	Plan Amendments	—				—				—				(1		)
	Actuarial (Gain) Loss	(275		)		274				(49		)		43
	Benefits Paid	(157		)		(155		)		(40		)		(43		)
	Benefit Obligation at End of Plan Year	$	2,679			$	2,954			$	350			$	415
	Change in Plan Assets:
Fair Value of Plan Assets at Beginning of Plan Year	$	2,294			$	1,850			$	—			$	—
Actual Return on Plan Assets	350				311				—				—
Qualified Employer Contributions	—				275				—				—
Non-qualified Employer Contributions	13				13				32				35
Plan Participants' Contributions	—				—				8				8
Benefits Paid	(157		)		(155		)		(40		)		(43		)
Fair Value of Plan Assets at End of Plan Year	2,500				2,294				—				—
Funded Status at End of Plan Year	$	(179	)		$	(660	)		$	(350	)		$	(415	)
NOTE 8.  Employee Benefit Plans, continued
For qualified plan funding purposes, assets and discounted liabilities are measured in accordance with ERISA, as well as other related provisions of the Internal Revenue Code 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)	2013				2012				2013				2012
Amounts Recorded in Consolidated
Balance Sheets:
Long-term Assets (a)	$	44			$	3			$	—			$	—
Current Liabilities	(14		)		(15		)		(38		)		(41		)
Long-term Liabilities	(209		)		(648		)		(312		)		(374		)
Net Amount Recognized in
Consolidated Balance Sheet	$	(179	)		$	(660	)		$	(350	)		$	(415	)
(a)	Long-term assets relate to two 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 2013, the status of CSX plans only with a net liability is disclosed below. The total fair value of all plans as of December 2013 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	$	69		$	(292	)
Accumulated Benefit Obligation	69			(280		)
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)	2013				2012				2011				2013			2012			2011
Service Cost	$	49			$	44			$	40			$	3		$	4		$	2
Interest Cost	108				123				121				13			16			11
Expected Return on Plan Assets	(162		)		(166		)		(157		)		—			—			—
Amortization of Net Loss	100				82				71				14			9			7
Amortization of Prior Service Cost	—				—				—				(1		)	(1		)	(1		)
Net Periodic Benefit Expense	95				83				75				29			28			19
Settlement Gain(a)	(2		)		(2		)		(2		)		—			—			—
Total Expense	$	93			$	81			$	73			$	29		$	28		$	19
(a)	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)	2013				2012				2013				2012
Recognized in the balance sheet
(Gains) Losses	$	(462	)		$	130			$	(48	)		$	43
Prior service credits	—				—				—				(1		)
Expense (Income) recognized in the income statement
Amortization of net losses (a)	$	100			$	82			$	14			$	9
Settlement gain	(2		)		(2		)		—				—
Amortization of prior service costs (b)	—				—				(1		)		(1		)
(a)	Amortization of net losses estimated to be expensed for 2014 is $57 million and $6 million for pension benefits and post-retirement benefits, respectively. The decrease in amortization is largely related to the impact of increasing discount rates.
(b)	Amortization of prior service costs estimated to be expensed in 2014 are less than $1 million for pension benefits. The estimated post-retirement benefits amount to be credited to expense for 2014 is $1 million.
NOTE 8.  Employee Benefit Plans, continued
As of December 2013, 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	$	658			$	73
Prior Service Costs (Credits)	1				(3		)
Total	$	659			$	70
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
	2013			2012			2013			2012
Expected Long-term Return on Plan Assets:
Benefit Cost for Plan Year	7.75	%		8	%		N/A			N/A
Benefit Obligation at End of Plan Year	7.5	%		7.75	%		N/A			N/A
Discount Rates:
Benefit Cost for Plan Year	3.75	%		4.75	%		3.2	%		4.25	%
Benefit Obligation at End of Plan Year	4.75	%		3.75	%		4.25	%		3.2	%
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 5% by 2020 for Medicare and 2021 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
	2013		2012
Health Care Cost Trend Rate:
Components of Benefit Cost:  Non-Medicare Eligible	8.50%		8.50%
Components of Benefit Cost:  Medicare Eligible	8.00%		8.00%
Benefit Obligations:  Non-Medicare Eligible	8.00%		8.50%
Benefit Obligations:  Medicare Eligible	7.50%		8.00%
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 $41 million, $46 million and $48 million in 2013, 2012 and 2011, 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 $37 million, $29 million and $28 million for 2013, 2012 and 2011, respectively.

Debt_and_Credit_Agreements

Debt and Credit Agreements	12 Months Ended
	Dec. 27, 2013
Debt Disclosure [Abstract]	'
Debt and Credit Agreements	'
	Debt and Credit Agreements
	Debt was as follows:
		Maturity at		Average	December			December
		December		Interest
				Rates at
				December
	(Dollars in Millions)	2013		2013	2013			2012
	Notes	2014-2044		5.70%	$	8,935		$	9,151
	Equipment Obligations(a)	2014-2023		7.30%	602			667
	Capital Leases	2014-2026		8.10%	16			12
	Convertible Debentures	2021		1.00%	2			2
	Subtotal Long-term Debt (including current portion)				$	9,555		$	9,832
	Less Debt Due within One Year				(533		)	(780		)
	Long-term Debt				$	9,022		$	9,052
	(excluding current portion)
	(a) These obligations are secured by an interest in certain railroad equipment.
	For information regarding the fair value of debt, see Note 13, Fair Value Measurements.
	Debt Issuance
	During 2013, CSX issued $500 million of 3.7% notes due 2023. 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 for general corporate purposes, which may include repayment of indebtedness (including CSX’s 5.30% notes that mature on February 15, 2014) outstanding from time to time, repurchases of CSX’s common stock, capital investment, working capital requirements, improvements in productivity and other cost reductions at CSX’s major transportation units.
	Long-term Debt Maturities
	(Dollars in Millions)	Maturities as of
	Fiscal Years Ending	Dec-13
	2014	$	533
	2015	629
	2016	22
	2017	631
	2018	619
	Thereafter	7,121
	Total Long-term Debt Maturities (including current portion)	$	9,555
	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, and 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 2013, CSX was in compliance with all covenant requirements under the facilities.
	Receivables Securitization Facility
	The Company's $250 million receivables securitization facility has a 364-day term and expires in December 2014. The purpose of this facility is to provide an alternative to commercial paper and a low cost source of short-term liquidity. The Company anticipates either renewing the facility or replacing it with another liquidity-based solution. Under the terms of this facility, CSX Transportation 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. 27, 2013
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)	2013			2012			2011
	Interest Income	$	8		$	5		$	5
	Income from Real Estate Operations	23			81			25
	Miscellaneous Expense	(20		)	(13		)	(8		)
	Total Other Income - Net	$	11		$	73		$	22
	Gross Revenue from Real Estate
	Operations included above	$	48		$	106		$	51

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 27, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	Earnings before income taxes of $2.9 billion, $3.0 billion and $2.9 billion for fiscal years 2013, 2012 and 2011, respectively, represent earnings from domestic operations.
	The breakdown of income tax expense between current and deferred is as follows:
		Fiscal Years
	(Dollars in Millions)	2013			2012 (a)				2011 (a)
	Current:
	Federal	$	671		$	450			$	370
	State	87			66				107
	Subtotal Current	758			516				477
	Deferred:
	Federal	285			530				614
	State	15			62				(5		)
	Subtotal Deferred	300			592				609
	Total	$	1,058		$	1,108			$	1,086
	(a) See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.
	Income tax expense reconciled to the tax computed at statutory rates is presented in the table below.  The Company recorded a tax benefit of $42 million, $20 million and $14 million in 2013, 2012 and 2011, 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)	2013						2012 (a)							2011 (a)
	Federal Income Taxes	$	1,023		35	%		$	1,040			35	%		$	1,029		34.9	%
	State Income Taxes	65			2.2	%		81				2.8	%		65			2.2	%
	Other	(30		)	(1.0	)%		(13		)		(0.4	)%		(8		)	(0.3	)%
	Income Tax Expense/Rate	$	1,058		36.2	%		$	1,108			37.4	%		$	1,086		36.8	%
	(a) See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.
	In September 2013, the Internal Revenue Service issued final regulations governing the income tax treatment of the acquisition, disposition and repair of tangible property. The regulations are effective beginning in 2014. The Company does not expect these new regulations to have a material impact on the financial statements.
	NOTE 11. Income Taxes, continued
	The significant components of deferred income tax assets and liabilities include:
		2013							2012
	(Dollars in Millions)	Assets			Liabilities				Assets				Liabilities
	Pension Plans	$	67		$	—			$	249			$	—
	Other Employee Benefit Plans	299			—				292				—
	Accelerated Depreciation	—			8,868				—				8,544
	Other	257			262				278				252
	Total	$	623		$	9,130			$	819			$	8,796
	Net Deferred Income Tax Liabilities				$	8,507							$	7,977
	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 CSX and its subsidiaries are subject to U.S. federal income tax as well as income tax of multiple state jurisdictions.  CSX participated in a contemporaneous Internal Revenue Service (“IRS”) audit of tax year 2013.  Federal examinations of original federal income tax returns for all years through 2011 are resolved.
	As of December 2013, 2012 and 2011, the Company had approximately $23 million, $24 million and $22 million, respectively, of total net unrecognized tax benefits.  After consideration of the impact of federal tax benefits, $15 million, $17 million and $15 million in 2013, 2012 and 2011, respectively, could favorably affect the effective income tax rate in each year.  The Company estimates that approximately $3 million of the unrecognized tax benefits as of December 2013 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, however, 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 2013 is reconciled as follows:
	Uncertain Tax Positions:	Fiscal Year
	(Dollars in Millions)	2013			2012				2011
	Balance at beginning of the year	$	24		$	22			$	20
	Additions based on tax positions related to current year	2			6				1
	Additions based on tax positions related to prior years	5			3				10
	Reductions based on tax positions related to prior years	(6		)	(1		)		(3		)
	Settlements with taxing authorities	—			—				(5		)
	Lapse of statute of limitations	(2		)	(6		)		(1		)
	Balance at end of the year	$	23		$	24			$	22
	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 benefits of $1 million and $8 million in 2013 and 2012, respectively, and expense of $1 million in 2011 for changes to reserves for interest and penalties for all prior year tax positions.  The current year benefit for interest and penalties is due to favorable tax settlements of prior period tax audits where the Company had previously accrued a liability for interest and penalties.  The Company had $2 million, $3 million and $11 million accrued for interest and penalties at 2013, 2012 and 2011, respectively, for all prior year tax positions.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 27, 2013
Related Party Transactions [Abstract]	'
Related Party Transactions	'
	Related Party Transactions
	Through a limited liability company, CSX and Norfolk Southern Corporation (“NS”) jointly own Conrail, Inc. 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
	2014	$	25
	2015	25
	2016	25
	2017	25
	2018	25
	Thereafter	144
	Total	$	269
	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 $362 million as of December 2013.
	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)	2013			2012			2011
	Rents, Fees and Services	$	115		$	139		$	111
	Purchase Price Amortization and Other	4			4			4
	Equity in Income of Conrail	(35		)	(26		)	(24		)
	Total Conrail Rents, Fees and Services	$	84		$	117		$	91
	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.
		December			December
	(Dollars in Millions)	2013			2012
	Balance Sheet Information:
	CSX Payable to Conrail (a)	$	172		$	175
	Promissory Notes Payable to Conrail Subsidiary (b)
	4.40% CSX Promissory Note due October 2035	73			73
	4.52% CSXT Promissory Note due March 2035	23			23
	(a) CSX Payable to Conrail is included on the consolidated balance sheet of CSX as accounts payable because it is short term in nature.
	(b) Promissory notes payable to Conrail are included on the consolidated balance sheet of CSX as long-term debt.
	Interest expense from the promissory notes payable to a Conrail subsidiary was $4 million for 2013, 2012 and 2011, respectively.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 27, 2013
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.
	NOTE 13.  Fair Value Measurements, continued
	•	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 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 by discounting the related cash flows based on current yields of similar instruments with comparable durations.
	•	Corporate Bonds and Government Securities (Level 2): Valued using price evaluations reflecting the bid and/or ask sides of the market for a similar investment as of the last day of the period.
	•	Auction Rate Securities (Level 3): Valued using a discounted cash flow model, because there is currently no active market for trading.
	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 investments was $668 million and $742 million as of December 27, 2013 and December 28, 2012, respectively.
		Fiscal Years
		2013											2012
	(Dollars in Millions)	Level 1		Level 2			Level 3			Total			Level 1		Level 2		Level 3			Total
	Certificates of Deposit and Commercial Paper	$	—	$	472		$	—		$	472		$	—	$	555	$	—		$	555
	Corporate Bonds	—		132			—			132			—		142		—			142
	Government Securities	—		49			—			49			—		31		—			31
	Auction Rate Securities	—		—			15			15			—		—		15			15
	Total investments at fair value	$	—	$	653		$	15		$	668		$	—	$	728	$	15		$	743
	NOTE 13.  Fair Value Measurements, continued
	These investments have the following maturities:
	(Dollars in Millions)	Dec-13			Dec-12
	Less than 1 year	$	487		$	587
	1 - 2 years	58			61
	2 - 5 years	105			76
	Greater than 5 years	18			19
	Total investments at fair value	$	668		$	743
	Long-term Debt
	Long-term debt is reported at carrying amount on the consolidated balance sheet 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 an independent third party.  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.  The fair value and carrying value of the Company's long-term debt is as follows:
	(Dollars in Millions)	Dec-13			Dec-12
	Long-term Debt (Including Current Maturities):
	Fair Value	$	10,354		$	11,562
	Carrying Value	9,555			9,832
	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 60% equity and 40% 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.
	NOTE 13.  Fair Value Measurements, continued
	•	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 of the trust, 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 as of the last day of the calendar plan year. 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): Private equity valued using the fair market values associated with the underlying investments at year end using net asset per share and is classified in level 2 of the fair value hierarchy.
	The pension plan assets at fair value by level, within the fair value hierarchy, as of calendar plan years 2013 and 2012:
		Fiscal Years
		2013													2012
	(Dollars in Millions)	Level 1			Level 2				Level 3			Total			Level 1			Level 2				Level 3		Total
	Common Stock:
	Information technology	$	173		$	—			$	—		$	173		$	169		$	—			$	—	$	169
	Consumer discretionary	152			—				—			152			125			—				—		125
	Health care	126			—				—			126			96			—				—		96
	Financials	116			—				—			116			83			—				—		83
	Industrials	108			—				—			108			78			—				—		78
	Energy	59			—				—			59			58			—				—		58
	Consumer staples	43			—				—			43			55			—				—		55
	Materials	29			—				—			29			25			—				—		25
	Other	31			—				—			31			33			—				—		33
	Mutual funds	17			—				—			17			17			—				—		17
	Corporate bonds	—			568				—			568			—			606				—		606
	Common trust funds	—			553				—			553			—			426				—		426
	Partnerships	—			314				—			314			—			296				—		296
Government securities	—			186				—			186			—			178				—		178
Asset-backed securities	—			24				—			24			—			28				—		28
Cash equivalents	—			—				—			—			—			20				—		20
Derivatives and other	—			1				—			1			—			1				—		1
Total investments at	$	854		$	1,646			$	—		$	2,500		$	739		$	1,555			$	—	$	2,294
fair value
For additional information related to pension assets, see Note 8, Employee Benefit Plans.

Other_Comprehensive_Income

Other Comprehensive Income	12 Months Ended
	Dec. 27, 2013
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 equals 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 $2.3 billion, $1.8 billion and $1.8 billion for 2013, 2012 and 2011, respectively. See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.
	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.
		Pension and Other Post-Employment Benefits			Other (a)			Accumulated Other Comprehensive Income (Loss)
	(Dollars in millions)
	Balance December 31, 2010, Net of Tax	$	(711	)	$	(60	)	$	(771	)
	Other Comprehensive Loss
	Loss Before Reclassifications	(216		)	(13		)	(229		)
	Amounts Reclassified to Net Earnings(b)	75			(1		)	74
	Tax (Expense) Benefit	53			(2		)	51
	Total Other Comprehensive Loss	(88		)	(16		)	(104		)
	Balance December 30, 2011, Net of Tax	(799		)	(76		)	(875		)
	Other Comprehensive Loss
	Loss Before Reclassifications	(172		)	(9		)	(181		)
	Amounts Reclassified to Net Earnings(b)	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 Loss
	Income Before Reclassifications	510			24			534
	Amounts Reclassified to Net Earnings(b)	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	)
	(a) Other primarily represents CSX's share of AOCI of equity method investees. Amounts reclassified to net earnings are included in other income - net on the consolidated income statements.
	(b) Amounts reclassified to net earnings primarily 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.

Quarterly_Financial_Data_Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 27, 2013
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, which has been revised for all four quarters of 2011 and 2012 as well as the first three quarters of 2013. See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.
	Fiscal Year Ended December 2013	Quarters
	(Dollars in Millions, Except Per Share Amounts)	1st		2nd		3rd		4th		Full Year
	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
	Fiscal Year Ended December 2012
	Revenue	$	3,018	$	2,986	$	2,864	$	2,895	$	11,763
	Operating Income	908		917		824		815		3,464
	Net Earnings	481		496		437		449		1,863
	Earnings Per Share, Basic	$	0.46	$	0.48	$	0.42	$	0.44	$	1.8
	Earnings Per Share, Assuming Dilution	0.46		0.48		0.42		0.44		1.79
	Fiscal Year Ended December 2011
	Revenue	$	2,827	$	3,013	$	2,962	$	2,993	$	11,795
	Operating Income	790		920		877		883		3,470
	Net Earnings	406		502		463		483		1,854
	Earnings Per Share, Basic	$	0.37	$	0.46	$	0.43	$	0.46	$	1.71
	Earnings Per Share, Assuming Dilution	0.36		0.45		0.43		0.46		1.7

Summarized_Consolidating_Finan

Summarized Consolidating Financial Data	12 Months Ended
	Dec. 27, 2013
Summarized Consolidating Financial Data [Abstract]	'
Summarized Consolidating Financial Data	'
	Summarized Consolidating Financial Data
	In 2007, CSXT, a wholly-own subsidiary of CSX Corporation, sold secured equipment notes maturing in 2023, and in 2008, CSXT sold additional secured equipment notes maturing in 2014 in registered public offerings.  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. Prior period financial information of CSXT has been revised. See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.
	NOTE 16.  Summarized Consolidating Financial Data, continued
	Consolidating Income Statements
	(Dollars in Millions)
	Fiscal Year Ended December 2013	CSX			CSX			Eliminations and Other			Consolidated
		Corporation			Transportation
	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
	Fiscal Year Ended December 2011
	Revenue	$	—		$	11,728		$	67		$	11,795
	Expense	(278		)	8,679			(76		)	8,325
	Operating Income	278			3,049			143			3,470
	Equity in Earnings of Subsidiaries	1,979			3			(1,982		)	—
	Interest Expense	(496		)	(83		)	27			(552		)
	Other Income - Net	2			19			1			22
	Earnings Before Income Taxes	1,763			2,988			(1,811		)	2,940
	Income Tax Benefit (Expense)	91			(1,101		)	(76		)	(1,086		)
	Net Earnings	$	1,854		$	1,887		$	(1,887	)	$	1,854
	Total Comprehensive Earnings	$	1,750		$	1,873		$	(1,873	)	$	1,750
	NOTE 16.  Summarized Consolidating Financial Data, continued
	Consolidating Balance Sheets
	(Dollars in Millions)
	As of December 27, 2013	CSX			CSX			Eliminations and Other			Consolidated
		Corporation			Transportation
	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 Balance Sheets
(Dollars in Millions)
As of December 28, 2012	CSX Corporation			CSX Transportation			Eliminations and Other			Consolidated
ASSETS
Current Assets
Cash and Cash Equivalents	$	481		$	235		$	68		$	784
Short-term Investments	555			—			32			587
Accounts Receivable - Net	3			579			532			1,114
Receivable from Affiliates	993			1,798			(2,791		)	—
Materials and Supplies	—			274			—			274
Deferred Income Taxes	52			62			5			119
Other Current Assets	11			64			—			75
Total Current Assets	2,095			3,012			(2,154		)	2,953
Properties	8			33,333			1,938			35,279
Accumulated Depreciation	(8		)	(8,225		)	(996		)	(9,229		)
Properties - Net	—			25,108			942			26,050
Investments in Conrail	—			—			695			695
Affiliates and Other Companies	(39		)	593			(43		)	511
Investment in Consolidated Subsidiaries	18,917			—			(18,917		)	—
Other Long-term Assets	186			368			(40		)	514
Total Assets	$	21,159		$	29,081		$	(19,517	)	$	30,723
LIABILITIES AND SHAREHOLDERS' EQUITY
Current Liabilities
Accounts Payable	$	133		$	780		$	35		$	948
Labor and Fringe Benefits Payable	35			391			42			468
Payable to Affiliates	2,679			411			(3,090		)	—
Casualty, Environmental and Other Reserves	—			124			16			140
Current Maturities of Long-term Debt	700			80			—			780
Income and Other Taxes Payable	(262		)	418			13			169
Other Current Liabilities	(1		)	139			2			140
Total Current Liabilities	3,284			2,343			(2,982		)	2,645
Casualty, Environmental and Other Reserves	—			256			81			337
Long-term Debt	8,005			1,047			—			9,052
Deferred Income Taxes	(153		)	8,131			118			8,096
Other Long-term Liabilities	901			656			(100		)	1,457
Total Liabilities	12,037			12,433			(2,883		)	21,587
Shareholders' Equity
Common Stock, $1 Par Value	1,020			181			(181		)	1,020
Other Capital	28			5,672			(5,672		)	28
Retained Earnings	9,010			10,874			(10,874		)	9,010
Accumulated Other Comprehensive Loss	(936		)	(102		)	102			(936		)
Noncontrolling Minority Interest	—			23			(9		)	14
Total Shareholders' Equity	9,122			16,648			(16,634		)	9,136
Total Liabilities and Shareholders' Equity	$	21,159		$	29,081		$	(19,517	)	$	30,723
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 in Cash and Cash Equivalents	(42		)	(144		)	(6		)	(192		)
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
NOTE 16.  Summarized Consolidating Financial Data, continued
Consolidating Cash Flow Statements
(Dollars in Millions)
Fiscal Year Ended December 2011	CSX Corporation			CSX Transportation			Eliminations and Other			Consolidated
Operating Activities
Net Cash Provided by (Used in) Operating Activities	$	1,231		$	2,746		$	(486	)	$	3,491
Investing Activities
Property Additions	—			(2,034		)	(263		)	(2,297		)
Purchases of Short-term Investments	(475		)	—			(17		)	(492		)
Proceeds from Sales of Short-term Investments	—			—			74			74
Proceeds from Property Dispositions	—			239			1			240
Other Investing Activities	(20		)	(133		)	41			(112		)
Net Cash Provided by (Used in) Investing Activities	(495		)	(1,928		)	(164		)	(2,587		)
Financing Activities
Long-term Debt Issued	1,200			—			—			1,200
Long-term Debt Repaid	(507		)	(95		)	(3		)	(605		)
Dividends Paid	(480		)	(680		)	680			(480		)
Stock Options Exercised	29			—			—			29
Shares Repurchased	(1,564		)	—			—			(1,564		)
Other Financing Activities	35			(7		)	(21		)	7
Net Cash Provided by (Used in) Financing Activities	(1,287		)	(782		)	656			(1,413		)
Net (Decrease) Increase in	(551		)	36			6			(509		)
Cash and Cash Equivalents
Cash and Cash Equivalents at Beginning of Period	1,100			118			74			1,292
Cash and Cash Equivalents at End of Period	$	549		$	154		$	80		$	783

Nature_of_Operations_and_Signi1

Nature of Operations and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 27, 2013
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 2013, 2012 and 2011 each consisted of 52 weeks ending on December 27, 2013, December 28, 2012 and December 30, 2011, 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 equity (if the Company has significant influence).
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 in instruments with original maturities greater than three months but 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 $64 million is recorded in other long-term assets in the consolidated balance sheets as of December 2013 and 2012.
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.
	NOTE 1.  Nature of Operations and Significant Accounting Policies, continued
	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, which are based on historical freight car movement data as well as 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;
	•	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. Amounts received for customer volume commitments not met are recorded upon the completion of the contract term.
New Accounting Pronouncements	'
	In February 2013, the Financial Accounting Standards Board ("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 outstanding adjusted for the effects of common stock that may be issued as a result of the following types of potentially dilutive instruments:
	•	convertible debt;
	•	employee stock options; and
	•	other equity awards, which include long-term incentive awards.
	NOTE 2.  Earnings Per Share, continued
	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.
	When calculating diluted earnings per share, the Earnings Per Share Topic in the ASC requires CSX to include the potential shares that would be outstanding if all outstanding stock options were exercised.   This is offset by shares CSX could repurchase using the proceeds from these hypothetical exercises to obtain the common stock equivalent.  This number is different from outstanding stock options, which is included in Note 4, Stock Plans and Share-Based Compensation.
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 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 over 86% of total fixed assets of $37 billion on a gross basis as of December 2013.  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.

Nature_of_Operations_and_Signi2

Nature of Operations and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 27, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Schedule of Error Corrections and Prior Period Adjustments	'
	The Company also determined that the effect of recording all corrections during the fourth quarter of 2013 would have been material to the financial statements. As a result, prior period financial statements have been revised to correct the errors in accordance with ASC 250 and the SEC's Staff Accounting Bulletin No. 108, Considering the Effects of Prior Year Misstatements when Quantifying Misstatements in Current Year Financial Statements, as shown in the tables below.
	NOTE 1.  Nature of Operations and Significant Accounting Policies, continued
	Dollars in Millions, Except Per Share Amounts	2012									2011
	Consolidated Income Statements	As Previously Reported			Adjustment			As			As Previously Reported			Adjustment			As
								Revised									Revised
	Revenue	$	11,756		$	7		$	11,763		$	11,743		$	52		$	11,795
	Operating Income	3,457			7			3,464			3,418			52			3,470
	Earnings Before Income Taxes	2,964			7			2,971			2,888			52			2,940
	Income Tax Expense	(1,105		)	(3		)	(1,108		)	(1,066		)	(20		)	(1,086		)
	Net Earnings	1,859			4			1,863			1,822			32			1,854
	Net Earnings Per Share, Basic	$	1.79		$	0.01		$	1.8		$	1.68		$	0.03		$	1.71
	Net Earnings Per Share, Assuming Dilution	$	1.79		$	—		$	1.79		$	1.67		$	0.03		$	1.7
	Consolidated Comprehensive Income Statements
	Net Earnings	$	1,859		$	4		$	1,863		$	1,822		$	32		$	1,854
	Comprehensive Earnings	1,798			4			1,802			1,718			32			1,750
	Consolidated Balance Sheets
	Accounts Receivable - Net	$	962		$	152		$	1,114		$	1,000		$	147		$	1,147
	Total Current Assets	2,801			152			2,953			2,806			147			2,953
	Total Assets	30,571			152			30,723			29,344			147			29,491
	Accounts Payable	1,014			(66		)	948			1,018			(64		)	954
	Income and Other Taxes Payable	85			84			169			129			81			210
	Total Current Liabilities	2,627			18			2,645			2,558			17			2,575
	Total Liabilities	21,569			18			21,587			20,876			17			20,893
	Retained Earnings	8,876			134			9,010			8,275			130			8,405
	Total Shareholders' Equity	9,002			134			9,136			8,468			130			8,598
	Total Liabilities and Shareholders' Equity	$	30,571		$	152		$	30,723		$	29,344		$	147		$	29,491
	Consolidated Cash Flow Statements
	Net Earnings	$	1,859		$	4		$	1,863		$	1,822		$	32		$	1,854
	Changes in Operating Assets and Liabilities
	Accounts Receivable	67			(6		)	61			(59		)	(58		)	(117		)
	Accounts Payable	(3		)	(1		)	(4		)	70			6			76
	Income and Other Taxes Payable	(17		)	3			(14		)	96			20			116
	Net Cash Provided by Operating Activities	$	2,946		$	—		$	2,946		$	3,491		$	—		$	3,491
	Statement of Changes in Shareholders' Equity	2010
	Retained Earnings	$	9,087		$	98		$	9,185

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Dec. 27, 2013
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
		2013		2012 (a)		2011 (a)
	Numerator (Dollars in Millions):
	Net Earnings	$	1,864	$	1,863	$	1,854
	Dividend Equivalents on Restricted Stock	1		1		1
	Net Earnings, Attributable to Common Shareholders	$	1,865	$	1,864	$	1,855
	Denominator (Units in Millions):
	Average Common Shares Outstanding	1,019		1,038		1,083
	Other Potentially Dilutive Common Shares (b)	—		2		6
	Average Common Shares Outstanding, Assuming Dilution	1,019		1,040		1,089
	Net Earnings Per Share, Basic	$	1.83	$	1.8	$	1.71
	Net Earnings Per Share, Assuming Dilution	$	1.83	$	1.79	$	1.7
	(a)	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.
	(b)	Other potentially dilutive common shares include convertible debt, stock options, common stock equivalents and performance units granted under a long-term management incentive compensation plan.

Shareholders_Equity_Tables

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 27, 2013
Stockholders' Equity Note [Abstract]	'
Schedule of common and preferred stock	'
	Common and preferred stock consists of the following:
	Common Stock, $1 Par Value	Dec-13
		(Units in Millions)
	Common Shares Authorized	1,800
	Common Shares Issued and Outstanding	1,009
	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. 27, 2013
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:
		Fiscal Years
	(Dollars in Millions)	2013			2012				2011
	Share-Based Compensation Expense	$	14		$	14			$	30
	Income Tax Benefit	6			5				11
Schedule of stock option activity	'
	A summary of CSX's stock option activity and related information for the fiscal years 2013, 2012 and 2011 is as follows:
		Fiscal Years
		2013						2012					2011
		Options		Weighted-				Options			Weighted-		Options		Weighted-
		Outstanding		Average				Outstanding			Average		Outstanding		Average
		(Thousands)		Exercise				(Thousands)			Exercise		(Thousands)		Exercise
				Price							Price				Price
	Outstanding & Exercisable at Beginning of Year	1,672		$	5.36			4,145			$	5.64	9,111		$	5.82
	Expired or Cancelled	(9	)	5.36				(15	)		6.36		(27	)	6.44
	Exercised	(1,663	)	5.36				(2,458	)		5.83		(4,939	)	5.96
	Outstanding & Exercisable at End of Year	—		$	—			1,672			$	5.36	4,145		$	5.64
Schedule of outstanding restricted stock awards	'
	The following table provides information about outstanding restricted stock units and awards combined.  As of December 2013, unrecognized compensation expense for these awards and units was approximately $17 million, which will be expensed over a weighted-average remaining period of 2 years.
		Fiscal Years
		2013			2012				2011
	Restricted Stock Units and Awards Outstanding (Thousands)(a)	1,462			1,353				1,572
	Weighted-Average Fair Value at Grant Date	$	23.89		$	21.38			$	16.91
	Restricted Stock Units and Awards Expense (Millions)(a)	10			9				7
	Unvested Restricted Stock Units and Awards Outstanding (Thousands)	705			629				678
	Weighted-Average Fair Value of Unvested Units and Awards Outstanding	$	24.17		$	22.48			$	20.93
	(a)  Time-based restricted stock units were granted to certain employees under the respective Long-term Incentive Plans in the amount of 524,000, 433,000, and 361,000 in 2013, 2012, and 2011, respectively, as described below.  These units vest over three years, therefore only a partial amount of expense was recognized in 2013, 2012, and 2011, respectively.
Schedule of target units granted and weighted-average fair value calculations	'
		LTIP Plan (Plan Ended In)
		2013			2014				2015
	Number of target units outstanding (Thousands)(a)	1,080			1,340				1,318
	Weighted-average fair value at grant date (a)	$	25.63		$	22.13			$	25.32
	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)	2013		2014			2015
	Unvested at December 30, 2011	991		—			—		$	25.92
	Granted in 2012	65		1,325			—		21.97
	Forfeited in 2012	(2	)	(69	)		—		(21.99		)
	Unvested at December 28, 2012	1,054		1,256			—		23.66
	Granted in 2013	26		85			1,354		25.24
	Forfeited in 2013	—		(1	)		(36	)	(25.31		)
	Cancelled due to performance conditions(a)	(1,080	)	—			—		25.63
	Vested at December 27, 2013	—		—			—		—
	Unvested at December 27, 2013	—		1,340			1,318		$	23.73
	(a) The minimum financial target was not met in 2013. As a result, there was no performance unit payout for the LTIP ended December 27, 2013.
Schedule of shares issued to directors	'
	The following table provides information about shares issued to directors.
		Fiscal Years
		2013			2012				2011
	Shares Issued to Directors (Thousands)	105			102				93
	Expense (Millions)	$	2		$	2			$	2
	Weighted Average Grant Date Stock Price	$	23.12		$	21.92			$	23.46

Casualty_Environmental_and_Oth1

Casualty, Environmental and Other Reserves (Tables)	12 Months Ended
	Dec. 27, 2013
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
	31-Dec-10	$	375			$	107		$	59		$	541
	Charged to Expense	68				23			41			132
	Payments	(71		)		(47		)	(36		)	(154		)
	30-Dec-11	372				83			64			519
	Charged to Expense	51				35			36			122
	Payments	(98		)		(30		)	(36		)	(164		)
	28-Dec-12	325				88			64			477
	Charged to Expense	54				48			38			140
	Payments	(99		)		(36		)	(31		)	(166		)
	27-Dec-13	$	280			$	100		$	71		$	451
	NOTE 5.  Casualty, Environmental and Other Reserves, continued
	These reserves are considered critical accounting estimates due to the need for significant management judgments. They are provided for in the consolidated balance sheets as follows:
		Dec-13										Dec-12
	(Dollars in Millions)	Current				Long-term			Total			Current			Long-term		Total
	Casualty:
	Personal Injury	$	59			$	148		$	207		$	75		$	158	$	233
	Occupational	3				20			23			5			31		36
	Asbestos	10				40			50			8			48		56
	Total Casualty	72				208			280			88			237		325
	Environmental	59				41			100			33			55		88
	Other	20				51			71			19			45		64
	Total	$	151			$	300		$	451		$	140		$	337	$	477
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)	2013				2012
	Occupational:
	Incurred but not reported claims	$	15			$	24
	Asserted claims	8				12
	Total liability	$	23			$	36
	Asbestos:
	Incurred but not reported claims	$	35			$	37
	Asserted claims	15				19
	Total liability	$	50			$	56
Schedule of Claims Activity	'
	A summary of occupational and asbestos claims activity is as follows:
		Fiscal Years
		2013			2012
	Asserted Claims
	Open Claims - Beginning of Year	523			746
	New Claims Filed	165			160
	Claims Settled	(146	)		(154	)
	Claims Dismissed	(150	)		(229	)
	Open Claims - End of Year	392			523

Properties_Tables

Properties (Tables)	12 Months Ended
	Dec. 27, 2013
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-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
	NOTE 6.  Properties, continued
	(Dollars in Millions)					Accumulated			Net Book		Annual Depreciation	Depreciation	Estimated Useful
	Dec-12			Cost		Depreciation			Value		Rate	Method	Life
	Road
			Rail and Other Track Material	$	6,177	$	(1,131	)	$	5,046	2.90%	Group Life
			Ties	4,287		(861		)	3,426		4.00%	Group Life
			Grading	2,407		(414		)	1,993		1.50%	Group Life
			Ballast	2,528		(624		)	1,904		2.80%	Group Life
			Bridges, Trestles, and Culverts	1,962		(224		)	1,738		1.60%	Group Life
			Signals and Interlockers	1,787		(302		)	1,485		3.40%	Group Life
			Buildings	926		(316		)	610		2.50%	Group Life
			Other	3,345		(1,281		)	2,064		4.70%	Group Life
	Total Road			23,419		(5,153		)	18,266				6-80 Years
	Equipment
			Locomotive	4,747		(2,079		)	2,668		3.60%	Group Life
			Freight Cars	3,088		(1,119		)	1,969		3.10%	Group Life
			Work Equipment and Other	1,466		(810		)	656		7.10%	Group Life
	Total Equipment			9,301		(4,008		)	5,293				5-38 Years
	Land			1,745		—			1,745		N/A	N/A	N/A
	Construction In Progress			602		—			602		N/A	N/A	N/A
	Other			212		(68		)	144		N/A	Straight Line	4-30 Years
	Total Properties			$	35,279	$	(9,229	)	$	26,050
Schedule of deferred gain on sale of real estate	'
	The deferred gain balance included in the consolidated balance sheets is in the table below.
		Deferred gain as of
	(Dollars in Millions)	Dec-13		Dec-12
	Current portion, included in Other Current Liabilities	$	9	$	43
	Long term portion, included in Other Long-Term Liabilities	—		9
	Total	$	9	$	52

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 27, 2013
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)	2013		2012			2011
	Rent Expense on Operating Leases	$	60	$	73		$	68
Schedule of minimum rentals and commitments under operating leases	'
	At December 2013, minimum rentals on land, buildings, track and equipment under operating leases are disclosed in the table below.  Also, payments to Conrail, Inc. ("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
	2014	$	79	$	(3	)	$	76
	2015	73		(2		)	71
	2016	64		(2		)	62
	2017	55		(2		)	53
	2018	46		(2		)	44
	Thereafter	275		(13		)	262
	Total	$	592	$	(24	)	$	568
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)	2013		2012			2011
	Amounts Paid	$	287	$	287		$	281
	Number of Locomotives	1,886		1,899			1,928
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
	2014	$	292	$	321		$	613
	2015	253		66			319
	2016	245		15			260
	2017	232		6			238
	2018	220		6			226
	Thereafter	1,314		53			1,367
	Total	$	2,556	$	467		$	3,023

Employee_Benefit_Plans_Tables

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 27, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]	'
Schedule of summary of participants	'
	The Company engages independent, external actuaries to compute the amounts of liabilities and expenses related 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.
	NOTE 8.  Employee Benefit Plans, continued
		Summary of Participants as of
		January 1, 2013
		Pension Plans			Post-retirement Medical Plan
	Active Employees	5,153			2,176
	Retirees and Beneficiaries	11,569			12,277
	Other(a)	5,715			112
	Total	22,437			14,565
	(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
	2014	$	167			$	38
	2015	171				36
	2016	173				34
	2017	176				32
	2018	179				31
	2019-2023	910				126
	Total	$	1,776			$	297
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-13							Dec-12
						Percent of							Percent of
	(Dollars in Millions)	Amount				Total Assets			Amount				Total Assets
	Equity	$	1,619			65	%		$	1,408			61	%
	Fixed Income	795				32			829				36
	Cash and Cash Equivalents	86				3			57				3
	Total	$	2,500			100	%		$	2,294			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 2013 and 2012 calendar plan years are as follows:
		Pension Benefits								Post-retirement Benefits
		Plan Year				Plan Year				Plan Year				Plan Year
	(Dollars in Millions)	2013				2012				2013				2012
	Actuarial Present Value of Benefit Obligation
	Accumulated Benefit Obligation	$	2,538			$	2,806			N/A				N/A
	Projected Benefit Obligation	2,679				2,954				$	350			$	415
	Change in Projected Benefit Obligation:
	Projected Benefit Obligation at Beginning of Plan Year	$	2,954			$	2,668			$	415			$	388
	Service Cost	49				44				3				4
	Interest Cost	108				123				13				16
	Plan Participants' Contributions	—				—				8				8
	Plan Amendments	—				—				—				(1		)
	Actuarial (Gain) Loss	(275		)		274				(49		)		43
	Benefits Paid	(157		)		(155		)		(40		)		(43		)
	Benefit Obligation at End of Plan Year	$	2,679			$	2,954			$	350			$	415
	Change in Plan Assets:
	Fair Value of Plan Assets at Beginning of Plan Year	$	2,294			$	1,850			$	—			$	—
	Actual Return on Plan Assets	350				311				—				—
	Qualified Employer Contributions	—				275				—				—
	Non-qualified Employer Contributions	13				13				32				35
	Plan Participants' Contributions	—				—				8				8
	Benefits Paid	(157		)		(155		)		(40		)		(43		)
	Fair Value of Plan Assets at End of Plan Year	2,500				2,294				—				—
	Funded Status at End of Plan Year	$	(179	)		$	(660	)		$	(350	)		$	(415	)
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)	2013				2012				2013				2012
	Amounts Recorded in Consolidated
	Balance Sheets:
	Long-term Assets (a)	$	44			$	3			$	—			$	—
	Current Liabilities	(14		)		(15		)		(38		)		(41		)
	Long-term Liabilities	(209		)		(648		)		(312		)		(374		)
	Net Amount Recognized in
	Consolidated Balance Sheet	$	(179	)		$	(660	)		$	(350	)		$	(415	)
	(a)	Long-term assets relate to two of the qualified pension plans whose assets exceed projected benefit obligations.
Benefit obligations in excess of plan assets	'
	At December 2013, the status of CSX plans only with a net liability is disclosed below. The total fair value of all plans as of December 2013 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	$	69		$	(292	)
	Accumulated Benefit Obligation	69			(280		)
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)	2013				2012				2011				2013			2012			2011
	Service Cost	$	49			$	44			$	40			$	3		$	4		$	2
	Interest Cost	108				123				121				13			16			11
	Expected Return on Plan Assets	(162		)		(166		)		(157		)		—			—			—
	Amortization of Net Loss	100				82				71				14			9			7
	Amortization of Prior Service Cost	—				—				—				(1		)	(1		)	(1		)
	Net Periodic Benefit Expense	95				83				75				29			28			19
	Settlement Gain(a)	(2		)		(2		)		(2		)		—			—			—
	Total Expense	$	93			$	81			$	73			$	29		$	28		$	19
	(a)	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)	2013				2012				2013				2012
	Recognized in the balance sheet
	(Gains) Losses	$	(462	)		$	130			$	(48	)		$	43
	Prior service credits	—				—				—				(1		)
	Expense (Income) recognized in the income statement
	Amortization of net losses (a)	$	100			$	82			$	14			$	9
	Settlement gain	(2		)		(2		)		—				—
	Amortization of prior service costs (b)	—				—				(1		)		(1		)
	(a)	Amortization of net losses estimated to be expensed for 2014 is $57 million and $6 million for pension benefits and post-retirement benefits, respectively. The decrease in amortization is largely related to the impact of increasing discount rates.
	(b)	Amortization of prior service costs estimated to be expensed in 2014 are less than $1 million for pension benefits. The estimated post-retirement benefits amount to be credited to expense for 2014 is $1 million.
Schedule of pre-tax amounts to be amortized that included in accumulated other comprehensive loss	'
	As of December 2013, 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	$	658			$	73
	Prior Service Costs (Credits)	1				(3		)
	Total	$	659			$	70
Schedule of weighted-average assumptions used	'
	Weighted-average assumptions used in accounting for the plans were as follows:
		Pension Benefits						Post-retirement Benefits
		2013			2012			2013			2012
	Expected Long-term Return on Plan Assets:
	Benefit Cost for Plan Year	7.75	%		8	%		N/A			N/A
	Benefit Obligation at End of Plan Year	7.5	%		7.75	%		N/A			N/A
	Discount Rates:
	Benefit Cost for Plan Year	3.75	%		4.75	%		3.2	%		4.25	%
	Benefit Obligation at End of Plan Year	4.75	%		3.75	%		4.25	%		3.2	%
	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
		2013		2012
	Health Care Cost Trend Rate:
	Components of Benefit Cost:  Non-Medicare Eligible	8.50%		8.50%
	Components of Benefit Cost:  Medicare Eligible	8.00%		8.00%
	Benefit Obligations:  Non-Medicare Eligible	8.00%		8.50%
	Benefit Obligations:  Medicare Eligible	7.50%		8.00%

Debt_and_Credit_Agreements_Tab

Debt and Credit Agreements (Tables)	12 Months Ended
	Dec. 27, 2013
Debt Disclosure [Abstract]	'
Schedule of long-term debt instruments	'
	Debt was as follows:
		Maturity at		Average	December			December
		December		Interest
				Rates at
				December
	(Dollars in Millions)	2013		2013	2013			2012
	Notes	2014-2044		5.70%	$	8,935		$	9,151
	Equipment Obligations(a)	2014-2023		7.30%	602			667
	Capital Leases	2014-2026		8.10%	16			12
	Convertible Debentures	2021		1.00%	2			2
	Subtotal Long-term Debt (including current portion)				$	9,555		$	9,832
	Less Debt Due within One Year				(533		)	(780		)
	Long-term Debt				$	9,022		$	9,052
	(excluding current portion)
	(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-13
	2014	$	533
	2015	629
	2016	22
	2017	631
	2018	619
	Thereafter	7,121
	Total Long-term Debt Maturities (including current portion)	$	9,555

Other_Income_Net_Tables

Other Income - Net (Tables)	12 Months Ended
	Dec. 27, 2013
Other Income and Expenses [Abstract]	'
Schedule of other Income - Net	'
	Other income – net consisted of the following:
		Fiscal Years
	(Dollars in Millions)	2013			2012			2011
	Interest Income	$	8		$	5		$	5
	Income from Real Estate Operations	23			81			25
	Miscellaneous Expense	(20		)	(13		)	(8		)
	Total Other Income - Net	$	11		$	73		$	22
	Gross Revenue from Real Estate
	Operations included above	$	48		$	106		$	51

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 27, 2013
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)	2013			2012 (a)				2011 (a)
	Current:
	Federal	$	671		$	450			$	370
	State	87			66				107
	Subtotal Current	758			516				477
	Deferred:
	Federal	285			530				614
	State	15			62				(5		)
	Subtotal Deferred	300			592				609
	Total	$	1,058		$	1,108			$	1,086
	(a) See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.
Schedule of income tax expense reconciled to tax computed at statutory rates	'
		Fiscal Years
	(Dollars In Millions)	2013						2012 (a)							2011 (a)
	Federal Income Taxes	$	1,023		35	%		$	1,040			35	%		$	1,029		34.9	%
	State Income Taxes	65			2.2	%		81				2.8	%		65			2.2	%
	Other	(30		)	(1.0	)%		(13		)		(0.4	)%		(8		)	(0.3	)%
	Income Tax Expense/Rate	$	1,058		36.2	%		$	1,108			37.4	%		$	1,086		36.8	%
	(a) See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.
Schedule of significant components of deferred income tax assets and liabilities	'
	The significant components of deferred income tax assets and liabilities include:
		2013							2012
	(Dollars in Millions)	Assets			Liabilities				Assets				Liabilities
	Pension Plans	$	67		$	—			$	249			$	—
	Other Employee Benefit Plans	299			—				292				—
	Accelerated Depreciation	—			8,868				—				8,544
	Other	257			262				278				252
	Total	$	623		$	9,130			$	819			$	8,796
	Net Deferred Income Tax Liabilities				$	8,507							$	7,977
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 2013 is reconciled as follows:
	Uncertain Tax Positions:	Fiscal Year
	(Dollars in Millions)	2013			2012				2011
	Balance at beginning of the year	$	24		$	22			$	20
	Additions based on tax positions related to current year	2			6				1
	Additions based on tax positions related to prior years	5			3				10
	Reductions based on tax positions related to prior years	(6		)	(1		)		(3		)
	Settlements with taxing authorities	—			—				(5		)
	Lapse of statute of limitations	(2		)	(6		)		(1		)
	Balance at end of the year	$	23		$	24			$	22

Related_Party_Transactions_Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 27, 2013
Related Party Transaction [Line Items]	'
Future minimum lease payments	'
	At December 2013, minimum rentals on land, buildings, track and equipment under operating leases are disclosed in the table below.  Also, payments to Conrail, Inc. ("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
	2014	$	79		$	(3	)	$	76
	2015	73			(2		)	71
	2016	64			(2		)	62
	2017	55			(2		)	53
	2018	46			(2		)	44
	Thereafter	275			(13		)	262
	Total	$	592		$	(24	)	$	568
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)	2013			2012			2011
	Rents, Fees and Services	$	115		$	139		$	111
	Purchase Price Amortization and Other	4			4			4
	Equity in Income of Conrail	(35		)	(26		)	(24		)
	Total Conrail Rents, Fees and Services	$	84		$	117		$	91
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.
		December			December
	(Dollars in Millions)	2013			2012
	Balance Sheet Information:
	CSX Payable to Conrail (a)	$	172		$	175
	Promissory Notes Payable to Conrail Subsidiary (b)
	4.40% CSX Promissory Note due October 2035	73			73
	4.52% CSXT Promissory Note due March 2035	23			23
	(a) CSX Payable to Conrail is included on the consolidated balance sheet of CSX as accounts payable because it is short term in nature.
	(b) 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
	2014	$	25
	2015	25
	2016	25
	2017	25
	2018	25
	Thereafter	144
	Total	$	269

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 27, 2013
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 investments was $668 million and $742 million as of December 27, 2013 and December 28, 2012, respectively.
		Fiscal Years
		2013											2012
	(Dollars in Millions)	Level 1		Level 2			Level 3			Total			Level 1		Level 2		Level 3			Total
	Certificates of Deposit and Commercial Paper	$	—	$	472		$	—		$	472		$	—	$	555	$	—		$	555
	Corporate Bonds	—		132			—			132			—		142		—			142
	Government Securities	—		49			—			49			—		31		—			31
	Auction Rate Securities	—		—			15			15			—		—		15			15
	Total investments at fair value	$	—	$	653		$	15		$	668		$	—	$	728	$	15		$	743
Schedule of investment maturities	'
	These investments have the following maturities:
	(Dollars in Millions)	Dec-13			Dec-12
	Less than 1 year	$	487		$	587
	1 - 2 years	58			61
	2 - 5 years	105			76
	Greater than 5 years	18			19
	Total investments at fair value	$	668		$	743
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-13			Dec-12
	Long-term Debt (Including Current Maturities):
	Fair Value	$	10,354		$	11,562
	Carrying Value	9,555			9,832
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 2013 and 2012:
		Fiscal Years
		2013													2012
	(Dollars in Millions)	Level 1			Level 2				Level 3			Total			Level 1			Level 2				Level 3		Total
	Common Stock:
	Information technology	$	173		$	—			$	—		$	173		$	169		$	—			$	—	$	169
	Consumer discretionary	152			—				—			152			125			—				—		125
	Health care	126			—				—			126			96			—				—		96
	Financials	116			—				—			116			83			—				—		83
	Industrials	108			—				—			108			78			—				—		78
	Energy	59			—				—			59			58			—				—		58
	Consumer staples	43			—				—			43			55			—				—		55
	Materials	29			—				—			29			25			—				—		25
	Other	31			—				—			31			33			—				—		33
	Mutual funds	17			—				—			17			17			—				—		17
	Corporate bonds	—			568				—			568			—			606				—		606
	Common trust funds	—			553				—			553			—			426				—		426
	Partnerships	—			314				—			314			—			296				—		296
	Government securities	—			186				—			186			—			178				—		178
	Asset-backed securities	—			24				—			24			—			28				—		28
	Cash equivalents	—			—				—			—			—			20				—		20
	Derivatives and other	—			1				—			1			—			1				—		1
	Total investments at	$	854		$	1,646			$	—		$	2,500		$	739		$	1,555			$	—	$	2,294
	fair value

Other_Comprehensive_Income_Tab

Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 27, 2013
Equity [Abstract]	'
Changes in the AOCI balance by component	'
	Changes in the AOCI balance by component are shown in the table below.
		Pension and Other Post-Employment Benefits			Other (a)			Accumulated Other Comprehensive Income (Loss)
	(Dollars in millions)
	Balance December 31, 2010, Net of Tax	$	(711	)	$	(60	)	$	(771	)
	Other Comprehensive Loss
	Loss Before Reclassifications	(216		)	(13		)	(229		)
	Amounts Reclassified to Net Earnings(b)	75			(1		)	74
	Tax (Expense) Benefit	53			(2		)	51
	Total Other Comprehensive Loss	(88		)	(16		)	(104		)
	Balance December 30, 2011, Net of Tax	(799		)	(76		)	(875		)
	Other Comprehensive Loss
	Loss Before Reclassifications	(172		)	(9		)	(181		)
	Amounts Reclassified to Net Earnings(b)	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 Loss
	Income Before Reclassifications	510			24			534
	Amounts Reclassified to Net Earnings(b)	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	)
	(a) Other primarily represents CSX's share of AOCI of equity method investees. Amounts reclassified to net earnings are included in other income - net on the consolidated income statements.
	(b) Amounts reclassified to net earnings primarily 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.

Quarterly_Financial_Data_Unaud1

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 27, 2013
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, which has been revised for all four quarters of 2011 and 2012 as well as the first three quarters of 2013. See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.
	Fiscal Year Ended December 2013	Quarters
	(Dollars in Millions, Except Per Share Amounts)	1st		2nd		3rd		4th		Full Year
	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
	Fiscal Year Ended December 2012
	Revenue	$	3,018	$	2,986	$	2,864	$	2,895	$	11,763
	Operating Income	908		917		824		815		3,464
	Net Earnings	481		496		437		449		1,863
	Earnings Per Share, Basic	$	0.46	$	0.48	$	0.42	$	0.44	$	1.8
	Earnings Per Share, Assuming Dilution	0.46		0.48		0.42		0.44		1.79
	Fiscal Year Ended December 2011
	Revenue	$	2,827	$	3,013	$	2,962	$	2,993	$	11,795
	Operating Income	790		920		877		883		3,470
	Net Earnings	406		502		463		483		1,854
	Earnings Per Share, Basic	$	0.37	$	0.46	$	0.43	$	0.46	$	1.71
	Earnings Per Share, Assuming Dilution	0.36		0.45		0.43		0.46		1.7

Summarized_Consolidating_Finan1

Summarized Consolidating Financial Data (Tables)	12 Months Ended
	Dec. 27, 2013
Summarized Consolidating Financial Data [Abstract]	'
Consolidating Income Statement	'
	Consolidating Income Statements
	(Dollars in Millions)
	Fiscal Year Ended December 2013	CSX			CSX			Eliminations and Other			Consolidated
		Corporation			Transportation
	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
	Fiscal Year Ended December 2011
	Revenue	$	—		$	11,728		$	67		$	11,795
	Expense	(278		)	8,679			(76		)	8,325
	Operating Income	278			3,049			143			3,470
	Equity in Earnings of Subsidiaries	1,979			3			(1,982		)	—
	Interest Expense	(496		)	(83		)	27			(552		)
	Other Income - Net	2			19			1			22
	Earnings Before Income Taxes	1,763			2,988			(1,811		)	2,940
	Income Tax Benefit (Expense)	91			(1,101		)	(76		)	(1,086		)
	Net Earnings	$	1,854		$	1,887		$	(1,887	)	$	1,854
	Total Comprehensive Earnings	$	1,750		$	1,873		$	(1,873	)	$	1,750
Consolidating Balance Sheets	'
	Consolidating Balance Sheets
	(Dollars in Millions)
	As of December 27, 2013	CSX			CSX			Eliminations and Other			Consolidated
		Corporation			Transportation
	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 Balance Sheets
	(Dollars in Millions)
	As of December 28, 2012	CSX Corporation			CSX Transportation			Eliminations and Other			Consolidated
	ASSETS
	Current Assets
	Cash and Cash Equivalents	$	481		$	235		$	68		$	784
	Short-term Investments	555			—			32			587
	Accounts Receivable - Net	3			579			532			1,114
	Receivable from Affiliates	993			1,798			(2,791		)	—
	Materials and Supplies	—			274			—			274
	Deferred Income Taxes	52			62			5			119
	Other Current Assets	11			64			—			75
	Total Current Assets	2,095			3,012			(2,154		)	2,953
	Properties	8			33,333			1,938			35,279
	Accumulated Depreciation	(8		)	(8,225		)	(996		)	(9,229		)
	Properties - Net	—			25,108			942			26,050
	Investments in Conrail	—			—			695			695
Affiliates and Other Companies	(39		)	593			(43		)	511
Investment in Consolidated Subsidiaries	18,917			—			(18,917		)	—
Other Long-term Assets	186			368			(40		)	514
Total Assets	$	21,159		$	29,081		$	(19,517	)	$	30,723
LIABILITIES AND SHAREHOLDERS' EQUITY
Current Liabilities
Accounts Payable	$	133		$	780		$	35		$	948
Labor and Fringe Benefits Payable	35			391			42			468
Payable to Affiliates	2,679			411			(3,090		)	—
Casualty, Environmental and Other Reserves	—			124			16			140
Current Maturities of Long-term Debt	700			80			—			780
Income and Other Taxes Payable	(262		)	418			13			169
Other Current Liabilities	(1		)	139			2			140
Total Current Liabilities	3,284			2,343			(2,982		)	2,645
Casualty, Environmental and Other Reserves	—			256			81			337
Long-term Debt	8,005			1,047			—			9,052
Deferred Income Taxes	(153		)	8,131			118			8,096
Other Long-term Liabilities	901			656			(100		)	1,457
Total Liabilities	12,037			12,433			(2,883		)	21,587
Shareholders' Equity
Common Stock, $1 Par Value	1,020			181			(181		)	1,020
Other Capital	28			5,672			(5,672		)	28
Retained Earnings	9,010			10,874			(10,874		)	9,010
Accumulated Other Comprehensive Loss	(936		)	(102		)	102			(936		)
Noncontrolling Minority Interest	—			23			(9		)	14
Total Shareholders' Equity	9,122			16,648			(16,634		)	9,136
Total Liabilities and Shareholders' Equity	$	21,159		$	29,081		$	(19,517	)	$	30,723
Consolidating Cash Flow Statements	'
	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 in Cash and Cash Equivalents	(42		)	(144		)	(6		)	(192		)
	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
	NOTE 16.  Summarized Consolidating Financial Data, continued
	Consolidating Cash Flow Statements
	(Dollars in Millions)
	Fiscal Year Ended December 2011	CSX Corporation			CSX Transportation			Eliminations and Other			Consolidated
	Operating Activities
	Net Cash Provided by (Used in) Operating Activities	$	1,231		$	2,746		$	(486	)	$	3,491
	Investing Activities
	Property Additions	—			(2,034		)	(263		)	(2,297		)
	Purchases of Short-term Investments	(475		)	—			(17		)	(492		)
	Proceeds from Sales of Short-term Investments	—			—			74			74
	Proceeds from Property Dispositions	—			239			1			240
	Other Investing Activities	(20		)	(133		)	41			(112		)
	Net Cash Provided by (Used in) Investing Activities	(495		)	(1,928		)	(164		)	(2,587		)
	Financing Activities
	Long-term Debt Issued	1,200			—			—			1,200
Long-term Debt Repaid	(507		)	(95		)	(3		)	(605		)
Dividends Paid	(480		)	(680		)	680			(480		)
Stock Options Exercised	29			—			—			29
Shares Repurchased	(1,564		)	—			—			(1,564		)
Other Financing Activities	35			(7		)	(21		)	7
Net Cash Provided by (Used in) Financing Activities	(1,287		)	(782		)	656			(1,413		)
Net (Decrease) Increase in	(551		)	36			6			(509		)
Cash and Cash Equivalents
Cash and Cash Equivalents at Beginning of Period	1,100			118			74			1,292
Cash and Cash Equivalents at End of Period	$	549		$	154		$	80		$	783

Nature_of_Operations_and_Signi3

Nature of Operations and Significant Accounting Policies (Business) (Details) (USD $)

3 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Dec. 27, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Dec. 30, 2012

Sep. 28, 2012

Jun. 29, 2012

Mar. 30, 2012

Dec. 30, 2011

Sep. 30, 2011

Jul. 01, 2011

Apr. 01, 2011

Dec. 27, 2013

Dec. 28, 2012

Dec. 30, 2011

states

employees

mi

states

railroads

mi

employees

railroads

Revenue from External Customer [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Entity Number of Employees

31,000

'

'

'

'

'

'

'

'

'

'

'

31,000

'

'

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

$3,032

$2,985

$3,046

$2,963

$2,895

$2,864

$2,986

$3,018

$2,993

$2,962

$3,013

$2,827

$12,026

$11,763

[1]

$11,795

[1]

Minimum [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenue from External Customer [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of ocean, river and lake ports serviced

70

'

'

'

'

'

'

'

'

'

'

'

70

'

'

Merchandise business [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenue from External Customer [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of carloads

'

'

'

'

'

'

'

'

'

'

'

'

2,800,000

'

'

Percentage of total revenue

'

'

'

'

'

'

'

'

'

'

'

'

59.00%

'

'

Percentage of total volume

'

'

'

'

'

'

'

'

'

'

'

'

42.00%

'

'

Coal business [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenue from External Customer [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of carloads

'

'

'

'

'

'

'

'

'

'

'

'

1,200,000

'

'

Percentage of total revenue

'

'

'

'

'

'

'

'

'

'

'

'

24.00%

'

'

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%

'

'

Minimum number of terminals

50

'

'

'

'

'

'

'

'

'

'

'

50

'

'

Other business [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenue from External Customer [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of total revenue

'

'

'

'

'

'

'

'

'

'

'

'

3.00%

'

'

[1]

See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

Nature_of_Operations_and_Signi4

Nature of Operations and Significant Accounting Policies (Nature of Operations) (Details) Phantom (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'	'	'
Number of weeks in fiscal reporting calendar	'P52W	'P52W	'P52W
Number of weeks in fiscal quarter	'P13W	'	'
Cost Method Investment, Maximum Percentage for Treatment	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 Receivable, Current	$33	$36	'
Goodwill	$64	'	'

Nature_of_Operations_and_Signi5

Nature of Operations and Significant Accounting Policies (Revision of Prior Period Financial Statements) (Details) (USD $)

3 Months Ended

12 Months Ended

In Millions, except Per Share data, unless otherwise specified

Dec. 27, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Dec. 30, 2012

Sep. 28, 2012

Jun. 29, 2012

Mar. 30, 2012

Dec. 30, 2011

Sep. 30, 2011

Jul. 01, 2011

Apr. 01, 2011

Dec. 27, 2013

Dec. 28, 2012

Dec. 30, 2011

Dec. 31, 2010

Revenue

$3,032

$2,985

$3,046

$2,963

$2,895

$2,864

$2,986

$3,018

$2,993

$2,962

$3,013

$2,827

$12,026

$11,763

[1]

$11,795

[1]

'

Operating Income

813

840

940

880

815

824

917

908

883

877

920

790

3,473

3,464

[1]

3,470

[1]

'

Earnings Before Income Taxes

'

'

'

'

'

'

'

'

'

'

'

'

2,922

2,971

[1]

2,940

[1]

'

Income Tax Expense

'

'

'

'

'

'

'

'

'

'

'

'

-1,058

-1,108

[1]

-1,086

[1]

'

Net Earnings

426

455

521

462

449

437

496

481

483

463

502

406

1,864

1,863

[1]

1,854

[1]

'

Net Earnings Per Share, Basic (dollars per share)

$0.42

$0.45

$0.51

$0.45

$0.44

$0.42

$0.48

$0.46

$0.46

$0.43

$0.46

$0.37

$1.83

$1.80

[1]

$1.71

[1]

'

Net Earnings Per Share, Assuming Dilution (dollars per share)

$0.42

$0.45

$0.51

$0.45

$0.44

$0.42

$0.48

$0.46

$0.46

$0.43

$0.45

$0.36

$1.83

$1.79

[1]

$1.70

[1]

'

Comprehensive Earnings

'

'

'

'

'

'

'

'

'

'

'

'

2,277

1,802

[1]

1,750

[1]

'

Accounts Receivable - Net

1,052

[1]

'

'

'

'

'

'

'

1,147

[1]

'

'

'

1,052

[1]

1,114

[1]

1,147

[1]

'

Total Current Assets

2,602

'

'

'

'

'

'

'

2,953

'

'

'

2,602

2,953

[1]

2,953

'

Total Assets

31,782

'

'

'

'

'

'

'

29,491

'

'

'

31,782

30,723

[1]

29,491

'

Accounts Payable

957

[1]

'

'

'

'

'

'

'

954

[1]

'

'

'

957

[1]

948

[1]

954

[1]

'

Income and Other Taxes Payable

91

[1]

'

'

'

'

'

'

'

210

[1]

'

'

'

91

[1]

169

[1]

210

[1]

'

Total Current Liabilities

2,424

'

'

'

'

'

'

'

2,575

'

'

'

2,424

2,645

[1]

2,575

'

Total Liabilities

21,278

'

'

'

'

'

'

'

20,893

'

'

'

21,278

21,587

[1]

20,893

'

Retained Earnings

9,936

[1]

'

'

'

'

'

'

'

8,405

[1]

'

'

'

9,936

[1]

9,010

[1]

8,405

[1]

'

Total Shareholders' Equity

10,504

'

'

'

'

'

'

'

8,598

'

'

'

10,504

9,136

[1]

8,598

8,798

Total Liabilities and Shareholders' Equity

31,782

'

'

'

'

'

'

'

29,491

'

'

'

31,782

30,723

[1]

29,491

'

Accounts Receivable

'

'

'

'

'

'

'

'

'

'

'

'

-6

61

[1]

-117

[1]

'

Accounts Payable

'

'

'

'

'

'

'

'

'

'

'

'

28

-4

[1]

76

[1]

'

Income and Other Taxes Payable

'

'

'

'

'

'

'

'

'

'

'

'

-67

-14

[1]

116

[1]

'

Net Cash Provided by Operating Activities

'

'

'

'

'

'

'

'

'

'

'

'

3,267

2,946

[1]

3,491

[1]

'

As Previously Reported

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

'

'

'

'

'

11,756

11,743

'

Operating Income

'

'

'

'

'

'

'

'

'

'

'

'

'

3,457

3,418

'

Earnings Before Income Taxes

'

'

'

'

'

'

'

'

'

'

'

'

'

2,964

2,888

'

Income Tax Expense

'

'

'

'

'

'

'

'

'

'

'

'

'

-1,105

-1,066

'

Net Earnings

'

'

'

'

'

'

'

'

'

'

'

'

'

1,859

1,822

'

Net Earnings Per Share, Basic (dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

$1.79

$1.68

'

Net Earnings Per Share, Assuming Dilution (dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

$1.79

$1.67

'

Comprehensive Earnings

'

'

'

'

'

'

'

'

'

'

'

'

'

1,798

1,718

'

Accounts Receivable - Net

'

'

'

'

'

'

'

'

1,000

'

'

'

'

962

1,000

'

Total Current Assets

'

'

'

'

'

'

'

'

2,806

'

'

'

'

2,801

2,806

'

Total Assets

'

'

'

'

'

'

'

'

29,344

'

'

'

'

30,571

29,344

'

Accounts Payable

'

'

'

'

'

'

'

'

1,018

'

'

'

'

1,014

1,018

'

Income and Other Taxes Payable

'

'

'

'

'

'

'

'

129

'

'

'

'

85

129

'

Total Current Liabilities

'

'

'

'

'

'

'

'

2,558

'

'

'

'

2,627

2,558

'

Total Liabilities

'

'

'

'

'

'

'

'

20,876

'

'

'

'

21,569

20,876

'

Retained Earnings

'

'

'

'

'

'

'

'

8,275

'

'

'

'

8,876

8,275

'

Total Shareholders' Equity

'

'

'

'

'

'

'

'

8,468

'

'

'

'

9,002

8,468

'

Total Liabilities and Shareholders' Equity

'

'

'

'

'

'

'

'

29,344

'

'

'

'

30,571

29,344

'

Accounts Receivable

'

'

'

'

'

'

'

'

'

'

'

'

'

-67

59

'

Accounts Payable

'

'

'

'

'

'

'

'

'

'

'

'

'

-3

70

'

Income and Other Taxes Payable

'

'

'

'

'

'

'

'

'

'

'

'

'

-17

96

'

Net Cash Provided by Operating Activities

'

'

'

'

'

'

'

'

'

'

'

'

'

2,946

3,491

'

Adjustment

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

'

'

'

'

'

7

52

'

Operating Income

'

'

'

'

'

'

'

'

'

'

'

'

'

7

52

'

Earnings Before Income Taxes

'

'

'

'

'

'

'

'

'

'

'

'

'

7

52

'

Income Tax Expense

'

'

'

'

'

'

'

'

'

'

'

'

'

-3

-20

'

Net Earnings

'

'

'

'

'

'

'

'

'

'

'

'

'

4

32

'

Net Earnings Per Share, Basic (dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

$0.01

$0.03

'

Net Earnings Per Share, Assuming Dilution (dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

$0

$0.03

'

Comprehensive Earnings

'

'

'

'

'

'

'

'

'

'

'

'

'

4

32

'

Accounts Receivable - Net

'

'

'

'

'

'

'

'

147

'

'

'

'

152

147

'

Total Current Assets

'

'

'

'

'

'

'

'

147

'

'

'

'

152

147

'

Total Assets

'

'

'

'

'

'

'

'

147

'

'

'

'

152

147

'

Accounts Payable

'

'

'

'

'

'

'

'

-64

'

'

'

'

-66

-64

'

Income and Other Taxes Payable

'

'

'

'

'

'

'

'

81

'

'

'

'

84

81

'

Total Current Liabilities

'

'

'

'

'

'

'

'

17

'

'

'

'

18

17

'

Total Liabilities

'

'

'

'

'

'

'

'

17

'

'

'

'

18

17

'

Retained Earnings

'

'

'

'

'

'

'

'

130

'

'

'

'

134

130

'

Total Shareholders' Equity

'

'

'

'

'

'

'

'

130

'

'

'

'

134

130

'

Total Liabilities and Shareholders' Equity

'

'

'

'

'

'

'

'

147

'

'

'

'

152

147

'

Accounts Receivable

'

'

'

'

'

'

'

'

'

'

'

'

'

6

58

'

Accounts Payable

'

'

'

'

'

'

'

'

'

'

'

'

'

-1

6

'

Income and Other Taxes Payable

'

'

'

'

'

'

'

'

'

'

'

'

'

3

20

'

Net Cash Provided by Operating Activities

'

'

'

'

'

'

'

'

'

'

'

'

'

0

0

'

Retained Earnings

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net Earnings

'

'

'

'

'

'

'

'

'

'

'

'

1,864

[1]

1,863

[1]

1,854

[1]

'

Total Shareholders' Equity

9,936

[1]

'

'

'

'

'

'

'

8,405

[1]

'

'

'

9,936

[1]

9,010

[1]

8,405

[1]

9,185

[1]

Retained Earnings | As Previously Reported

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total Shareholders' Equity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9,087

Retained Earnings | Adjustment

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total Shareholders' Equity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$98

[1]

See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

Nature_of_Operations_and_Signi6

Nature of Operations and Significant Accounting Policies (Other Items - Share Repurchases) (Details) (USD $)	1 Months Ended	12 Months Ended
Share data in Millions, unless otherwise specified	Apr. 30, 2013	Dec. 27, 2013	Dec. 28, 2012		Dec. 30, 2011
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'	'	'		'
Share repurchase program	$1,000,000,000	'	'		'
Shares acquired, repurchase amount	'	$353,000,000	$734,000,000	[1]	$1,564,000,000	[1]
Stock Repurchased and Retired During Period, Shares	'	14	34		67
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)

3 Months Ended

12 Months Ended

Dec. 27, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Dec. 30, 2012

Sep. 28, 2012

Jun. 29, 2012

Mar. 30, 2012

Dec. 30, 2011

Sep. 30, 2011

Jul. 01, 2011

Apr. 01, 2011

Dec. 27, 2013

Dec. 28, 2012

Dec. 30, 2011

Numerator:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net Earnings

$426,000,000

$455,000,000

$521,000,000

$462,000,000

$449,000,000

$437,000,000

$496,000,000

$481,000,000

$483,000,000

$463,000,000

$502,000,000

$406,000,000

$1,864,000,000

$1,863,000,000

[1]

$1,854,000,000

[1]

Dividend Equivalents on Restricted Stock

'

'

'

'

'

'

'

'

'

'

'

'

1,000,000

1,000,000

[1]

1,000,000

[1]

Net Earnings, Attributable to Common Shareholders

'

'

'

'

'

'

'

'

'

'

'

'

1,865,000,000

1,864,000,000

[1]

1,855,000,000

[1]

Denominator:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Average Common Shares Outstanding

'

'

'

'

'

'

'

'

'

'

'

'

1,019,000,000

1,038,000,000

[1]

1,083,000,000

[1]

Other Potentially Dilutive Common Shares

'

'

'

'

'

'

'

'

'

'

'

'

0

[2]

2,000,000

[1],[2]

6,000,000

[1],[2]

Average Common Shares Outstanding, Assuming Dilution

'

'

'

'

'

'

'

'

'

'

'

'

1,019,000,000

1,040,000,000

[1]

1,089,000,000

[1]

Net Earnings Per Share, Basic (dollars per share)

$0.42

$0.45

$0.51

$0.45

$0.44

$0.42

$0.48

$0.46

$0.46

$0.43

$0.46

$0.37

$1.83

$1.80

[1]

$1.71

[1]

Net Earnings Per Share, Assuming Dilution (dollars per share)

$0.42

$0.45

$0.51

$0.45

$0.44

$0.42

$0.48

$0.46

$0.46

$0.43

$0.45

$0.36

$1.83

$1.79

[1]

$1.70

[1]

Number of stock options excluded from the diluted earnings per share

'

'

'

'

'

'

'

'

'

'

'

'

0

'

'

Convertible Debt [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Denominator:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Face value of convertible debentures

'

'

'

'

'

'

'

'

'

'

'

'

7,000

2,000,000

'

Face value of convertible debentures still outstanding at the end of the period

$2,000,000

'

'

'

'

'

'

'

'

'

'

'

$2,000,000

'

'

Common Stock [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Denominator:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares of common stock converted from convetible debentures

'

'

'

'

'

'

'

'

'

'

'

'

1,000

155,000

'

Number of shares of common stock converted from outstanding convetible debentures

'

'

'

'

'

'

'

'

'

'

'

'

244,000

'

'

[1]

See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

[2]

Other potentially dilutive common shares include convertible debt, stock options, common stock equivalents and performance units granted under a long-term management incentive compensation plan.

Shareholders_Equity_Details

Shareholders' Equity (Details) (USD $)	Dec. 27, 2013	Dec. 28, 2012	Dec. 27, 2013	Dec. 27, 2013
			Common Stock [Member]	Preferred Stock [Member]
Class of Stock [Line Items]	'	'	'	'
Common stock par value (dollars per share)	$1	$1	'	'
Common Shares Authorized	'	'	1,800,000,000	'
Common Shares Issued	'	'	1,009,000,000	'
Common Shares Outstanding	'	'	1,009,000,000	'
Preferred Shares Authorized	'	'	'	25,000,000
Preferred Shares Issued	'	'	'	0
Preferred Shares Outstanding	'	'	'	0
Number of votes for each share held	'	'	1	'

Stock_Plans_and_ShareBased_Com2

Stock Plans and Share-Based Compensation (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'	'	'
Net financing cash flows	$13	$37	$35
Share-Based Compensation Expense	14	14	30
Income Tax Benefit	$6	$5	$11

Stock_Plans_and_ShareBased_Com3

Stock Plans and Share-Based Compensation (Stock Options) (Details) (USD $)	12 Months Ended						0 Months Ended
In Millions, except Share data in Thousands, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011	7-May-13
				Employee Stock Option [Member]	Employee Stock Option [Member]	Employee Stock Option [Member]	Two Thousand Thirteen Long-Term Incentive Plan (2013 LTIP) [Member]
				employees			Performance Shares [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 Number Of Current Or Former Employees With Outstanding Stock Optons	'	'	'	0	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	'	'	'	$27	$37	$84	'
Percentage Of Grants With Performance Vesting, Return On Assets	'	'	'	'	'	'	50.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]	'	'	'	'	'	'	'
Outstanding & Exercisable at Beginning of Year (in shares)	1,672	4,145	9,111	'	'	'	'
Expired or Cancelled (in shares)	-9	-15	-27	'	'	'	'
Exercised (in shares)	-1,663	-2,458	-4,939	'	'	'	'
Outstanding & Exercisable at End of Year (in shares)	0	1,672	4,145	'	'	'	'
Weighted-Average Exercise Price [Abstract]	'	'	'	'	'	'	'
Outstanding & Exercisable (in dollars per share)	$5.36	$5.64	$5.82	'	'	'	'
Expired or cancelled (in dollars per share)	$5.36	$6.36	$6.44	'	'	'	'
Exercised (in dollars per share)	$5.36	$5.83	$5.96	'	'	'	'
Outstanding & Exercisable (in dollars per share)	$0	$5.36	$5.64	'	'	'	'

Stock_Plans_and_ShareBased_Com4

Stock Plans and Share-Based Compensation (Restricted Stock Grants) (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 27, 2013		Dec. 28, 2012		Dec. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'
Restricted Stock Unit and Awards Expense	$14		$14		$30
Restricted Stock [Member]	'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'
Share-based compensation arrangement, vesting period	'5 years		'		'
Unrecognized compensation cost	17		'		'
Expected weighted average period of recognition for unrecognized compensation cost (in years)	'2 years		'		'
Number of Restricted Stock Awards Outstanding	1,462,000	[1]	1,353,000	[1]	1,572,000	[1]
Weighted-average fair value at grant date	$23.89		$21.38		$16.91
Restricted Stock Unit and Awards Expense	10	[1]	9	[1]	7	[1]
Unvested Restricted Stock Units and Awards Outstanding	705,000		629,000		678,000
Weighted-Average Fair Value of Unvested Awards Outstanding	$24.17		$22.48		$20.93
Restricted Stock Units (RSUs) [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	'3 years		'		'
Long-term Incentive Plans [Member]	'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'
Unrecognized compensation cost	29		'		'
Expected weighted average period of recognition for unrecognized compensation cost (in years)	'2 years		'		'
Weighted-average fair value at grant date	$25.24		$21.97		'
Restricted Stock Unit and Awards Expense	$2		$3		$21
Weighted-Average Fair Value of Unvested Awards Outstanding	$23.73		$23.66		$25.92
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	524,000		433,000		361,000
[1]	Time-based restricted stock units were granted to certain employees under the respective Long-term Incentive Plans in the amount of 524,000, 433,000, and 361,000 in 2013, 2012, and 2011, respectively, as described below. These units vest over three years, therefore only a partial amount of expense was recognized in 2013, 2012, and 2011, respectively.

Stock_Plans_and_ShareBased_Com5

Stock Plans and Share-Based Compensation (Long-term Incentive Plans) (Details) (USD $)

12 Months Ended

0 Months Ended

12 Months Ended

In Millions, except Share data, unless otherwise specified

Dec. 27, 2013

Dec. 28, 2012

Dec. 30, 2011

Dec. 27, 2013

Dec. 28, 2012

Dec. 30, 2011

7-May-13

Dec. 27, 2013

Dec. 27, 2013

Dec. 27, 2013

Dec. 27, 2013

Dec. 27, 2013

Dec. 27, 2013

Dec. 27, 2013

Dec. 27, 2013

Dec. 27, 2013

Dec. 27, 2013

Dec. 27, 2013

Long-term Incentive Plans [Member]

Long-term Incentive Plans [Member]

Long-term Incentive Plans [Member]

Performance Shares [Member]

Performance Units [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Two Thousand Thirteen Long-Term Incentive Plan (2013 LTIP) [Member]

Long-term Incentive Plans [Member]

Long Term Incentive Plan - 2013 [Member]

Long Term Incentive Plan - 2013 [Member]

Long Term Incentive Plan - 2013 [Member]

Long Term Incentive Plan - 2014 [Member]

Long Term Incentive Plan - 2014 [Member]

Long Term Incentive Plan - 2014 [Member]

Long Term Incentive Plan - 2015 [Member]

Long Term Incentive Plan - 2015 [Member]

Long Term Incentive Plan - 2015 [Member]

plan

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage Of Grants With Performance Vesting, Operating Ratio

'

'

'

'

'

'

50.00%

'

'

'

'

'

'

'

'

'

'

'

Number of plans

'

'

'

'

'

'

'

3

'

'

'

'

'

'

'

'

'

'

Plan duration

'

'

'

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

Performance unit equivalent of CSX stock, in shares

'

'

'

'

'

'

'

'

1

'

'

'

'

'

'

'

'

'

Percentage of payout subject to reduction

'

'

'

-30.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total expense incurred due to long-term incentive plans

$14

$14

$30

$2

$3

$21

'

'

'

'

'

'

'

'

'

'

'

'

Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of target units outstanding

'

'

'

'

'

'

'

'

'

1,080,000

[1]

'

'

1,340,000

[1]

'

'

1,318,000

[1]

'

'

Weighted-average fair value at grant date

'

'

'

$25.24

$21.97

'

'

'

'

$25.63

[1]

'

'

$22.13

[1]

'

'

$25.32

[1]

'

'

Payout Range

'

'

'

'

'

'

'

'

'

'

0.00%

200.00%

'

0.00%

200.00%

'

0.00%

200.00%

Percentage Of Grants With Performance Vesting, Return On Assets

'

'

'

'

'

'

50.00%

'

'

'

'

'

'

'

'

'

'

'

[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.

Stock_Plans_and_ShareBased_Com6

Stock Plans and Share-Based Compensation (Restricted Stock Units) (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 27, 2013		Dec. 28, 2012	Dec. 30, 2011
Long Term Incentive Plan - 2013 [Member]	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]	'		'	'
Unvested, Units Outstanding, beginning balance	1,054,000		991,000	'
Granted, Units Outstanding	26,000		65,000	'
Forfeited, Units Outstanding	0		-2,000	'
Cancelled, Units Outstanding	-1,080,000		'	'
Vested, Units Outstanding	0	[1]	'	'
Unvested, Units Outstanding, beginning balance	0		1,054,000	'
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	1,256,000		0	'
Granted, Units Outstanding	85,000		1,325,000	'
Forfeited, Units Outstanding	-1,000		-69,000	'
Cancelled, Units Outstanding	0		'	'
Vested, Units Outstanding	0	[1]	'	'
Unvested, Units Outstanding, beginning balance	1,340,000		1,256,000	'
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	0		0	'
Granted, Units Outstanding	1,354,000		0	'
Forfeited, Units Outstanding	-36,000		0	'
Cancelled, Units Outstanding	0		'	'
Vested, Units Outstanding	0	[1]	'	'
Unvested, Units Outstanding, beginning balance	1,318,000		0	'
Long-term Incentive Plans [Member]	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'	'
Unrecognized compensation cost	29		'	'
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	23.66		25.92	'
Granted, Weighted-Average Fair Value at Grant Date	25.24		21.97	'
Forfeited, Weighted-Average Fair Value at Grant Date	-25.31		-21.99	'
Cancelled, Weighted-Average Fair Value at Grant Date	25.63		'	'
Vested, Weighted-Average Fair Value at Grant Date	0	[1]	'	'
Unvested, Weighted-Average Fair Value at Grant Date, beginning balance	23.73		23.66	'
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 - 2013 [Member]	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]	'		'	'
Granted, Units Outstanding	361,000		'	'
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	25.63	[2]	'	'
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	22.13	[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	25.32	[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	524,000		433,000	361,000
[1]	The minimum financial target was not met in 2013. As a result, there was no performance unit payout for the LTIP ended December 27, 2013.
[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_Com7

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. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share-Based Compensation Expense	$14,000,000	$14,000,000	$30,000,000
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	105	102	93
Share-Based Compensation Expense	$2,000,000	$2,000,000	$2,000,000
Weighted Average Grant Date Stock Price	$23.12	$21.92	$23.46

Casualty_Environmental_and_Oth2

Casualty, Environmental and Other Reserves (Loss Contingencies Roll Forward) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
Casualty Reserves [Member]	'	'	'
Loss Contingency Accrual [Roll Forward]	'	'	'
Balance at beginning of period	$325	$372	$375
Charged to Expense	54	51	68
Payments	-99	-98	-71
Balance end of period	280	325	372
Environmental Reserves [Member]	'	'	'
Loss Contingency Accrual [Roll Forward]	'	'	'
Balance at beginning of period	88	83	107
Charged to Expense	48	35	23
Payments	-36	-30	-47
Balance end of period	100	88	83
Other Reserves [Member]	'	'	'
Loss Contingency Accrual [Roll Forward]	'	'	'
Balance at beginning of period	64	64	59
Charged to Expense	38	36	41
Payments	-31	-36	-36
Balance end of period	71	64	64
Casualty, Environmental and Other [Member]	'	'	'
Loss Contingency Accrual [Roll Forward]	'	'	'
Balance at beginning of period	477	519	541
Charged to Expense	140	122	132
Payments	-166	-164	-154
Balance end of period	$451	$477	$519

Casualty_Environmental_and_Oth3

Casualty, Environmental and Other Reserves (Loss Contingencies Accrual) (Details) (USD $)	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011	Dec. 31, 2010
In Millions, unless otherwise specified
Casualty [Member]	'	'	'	'
Contingencies [Line Items]	'	'	'	'
Loss Contingency, Accrual, Current	$72	$88	'	'
Loss Contingency, Accrual, Noncurrent	208	237	'	'
Loss Contingency Accrual	280	325	372	375
Personal Injury [Member]	'	'	'	'
Contingencies [Line Items]	'	'	'	'
Loss Contingency, Accrual, Current	59	75	'	'
Loss Contingency, Accrual, Noncurrent	148	158	'	'
Loss Contingency Accrual	207	233	'	'
Occupational [Member]	'	'	'	'
Contingencies [Line Items]	'	'	'	'
Loss Contingency, Accrual, Current	3	5	'	'
Loss Contingency, Accrual, Noncurrent	20	31	'	'
Loss Contingency Accrual	23	36	'	'
Asbestos [Member]	'	'	'	'
Contingencies [Line Items]	'	'	'	'
Loss Contingency, Accrual, Current	10	8	'	'
Loss Contingency, Accrual, Noncurrent	40	48	'	'
Loss Contingency Accrual	50	56	'	'
Environmental [Member]	'	'	'	'
Contingencies [Line Items]	'	'	'	'
Loss Contingency, Accrual, Current	59	33	'	'
Loss Contingency, Accrual, Noncurrent	41	55	'	'
Loss Contingency Accrual	100	88	83	107
Other [Member]	'	'	'	'
Contingencies [Line Items]	'	'	'	'
Loss Contingency, Accrual, Current	20	19	'	'
Loss Contingency, Accrual, Noncurrent	51	45	'	'
Loss Contingency Accrual	71	64	64	59
Casualty, Environmental and Other [Member]	'	'	'	'
Contingencies [Line Items]	'	'	'	'
Loss Contingency, Accrual, Current	151	140	'	'
Loss Contingency, Accrual, Noncurrent	300	337	'	'
Loss Contingency Accrual	$451	$477	$519	$541

Casualty_Environmental_and_Oth4

Casualty, Environmental and Other Reserves (Casualty) (Details) (Casualty [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011	Dec. 31, 2010
	claims
Casualty [Member]	'	'	'	'
Loss Contingencies [Line Items]	'	'	'	'
Loss Contingency Accrual	$280	$325	$372	$375
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. 27, 2013	Dec. 28, 2012
	claims	claims
Occupational Casualty and Asbestos Issues [Member]	'	'
Loss Contingencies [Line Items]	'	'
Change in estimate recorded to adjust reserves	$0	'
Loss Contingency, Claims Quantities [Roll Forward]	'	'
Open Claims - Beginning of Year	523	746
New Claims Filed	165	160
Claims Settled	-146	-154
Claims Dismissed	-150	-229
Open Claims - End of Year	392	523
Occupational [Member]	'	'
Loss Contingencies [Line Items]	'	'
Time period for estimating probable claims (in years)	'7 years	'
Total liability	23	36
Occupational [Member] | Incurred but not reported claims [Member]	'	'
Loss Contingencies [Line Items]	'	'
Incurred but not reported claims	15	24
Occupational [Member] | Asserted claims [Member]	'	'
Loss Contingencies [Line Items]	'	'
Asserted claims	8	12
Asbestos [Member]	'	'
Loss Contingencies [Line Items]	'	'
Total liability	50	56
Asbestos [Member] | Incurred but not reported claims [Member]	'	'
Loss Contingencies [Line Items]	'	'
Incurred but not reported claims	35	37
Asbestos [Member] | Asserted claims [Member]	'	'
Loss Contingencies [Line Items]	'	'
Asserted claims	$15	19
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. 27, 2013	Dec. 28, 2012	Dec. 30, 2011	Dec. 31, 2010
In Millions, unless otherwise specified	sites
Environmental Reserves [Member]	'	'	'	'
Contingencies [Line Items]	'	'	'	'
Loss Contingency Accrual	$100	$88	$83	$107
Environmental impaired site	244	'	'	'
Other Reserves [Member]	'	'	'	'
Contingencies [Line Items]	'	'	'	'
Loss Contingency Accrual	$71	$64	$64	$59

Properties_Detail_of_Net_Prope

Properties (Detail of Net Properties) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013		Dec. 28, 2012
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Cost	$37,184	[1]	$35,279	[1]
Accumulated Depreciation	-9,893	[1]	-9,229	[1]
Properties - Net	27,291		26,050	[1]
Road - Total [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Cost	24,618		23,419
Accumulated Depreciation	-5,592		-5,153
Properties - Net	19,026		18,266
Road - Rail and Other Track Material [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Cost	6,452		6,177
Accumulated Depreciation	-1,270		-1,131
Properties - Net	5,182		5,046
Annual Depreciation Rate	2.90%		2.90%
Depreciation Method	'Group Life		'Group Life
Road - Ties [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Cost	4,534		4,287
Accumulated Depreciation	-947		-861
Properties - Net	3,587		3,426
Annual Depreciation Rate	4.00%		4.00%
Depreciation Method	'Group Life		'Group Life
Road - Grading [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Cost	2,425		2,407
Accumulated Depreciation	-448		-414
Properties - Net	1,977		1,993
Annual Depreciation Rate	1.50%		1.50%
Depreciation Method	'Group Life		'Group Life
Road - Ballast [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Cost	2,612		2,528
Accumulated Depreciation	-645		-624
Properties - Net	1,967		1,904
Annual Depreciation Rate	2.80%		2.80%
Depreciation Method	'Group Life		'Group Life
Road - Bridges, Trestles, and Culverts [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Cost	2,008		1,962
Accumulated Depreciation	-250		-224
Properties - Net	1,758		1,738
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	1,922		1,787
Accumulated Depreciation	-291		-302
Properties - Net	1,631		1,485
Annual Depreciation Rate	3.40%		3.40%
Depreciation Method	'Group Life		'Group Life
Road - Buildings [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Cost	1,011		926
Accumulated Depreciation	-355		-316
Properties - Net	656		610
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	3,654		3,345
Accumulated Depreciation	-1,386		-1,281
Properties - Net	2,268		2,064
Annual Depreciation Rate	4.70%		4.70%
Depreciation Method	'Group Life		'Group Life
Total Equipment [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Cost	9,764		9,301
Accumulated Depreciation	-4,225		-4,008
Properties - Net	5,539		5,293
Equipment - Locomotive [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Cost	4,987		4,747
Accumulated Depreciation	-2,176		-2,079
Properties - Net	2,811		2,668
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	3,111		3,088
Accumulated Depreciation	-1,135		-1,119
Properties - Net	1,976		1,969
Annual Depreciation Rate	3.10%		3.10%
Depreciation Method	'Group Life		'Group Life
Equipment - Work Equipment and Other [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Cost	1,666		1,466
Accumulated Depreciation	-914		-810
Properties - Net	752		656
Annual Depreciation Rate	7.10%		7.10%
Depreciation Method	'Group Life		'Group Life
Land [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Cost	1,842		1,745
Properties - Net	1,842		1,745
Construction in Progress [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Cost	854		602
Properties - Net	854		602
Other properties [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Cost	106		212
Accumulated Depreciation	-76		-68
Properties - Net	$30		$144
Depreciation Method	'Straight Line		'Straight Line
Minimum [Member] | Road - Total [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Estimated useful life	'6 years		'6 years
Minimum [Member] | Road - Other [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Estimated useful life	'6 years		'
Minimum [Member] | Total Equipment [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Estimated useful life	'5 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	'80 years		'80 years
Maximum [Member] | Road - Grading [Member]	'		'
Property, Plant and Equipment, Net, by Type [Abstract]	'		'
Estimated useful life	'80 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
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

Properties_Railroad_Assets_Non

Properties (Railroad Assets, Non-Railroad Assets, and Capital Expenditure) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013		Dec. 28, 2012		Dec. 30, 2011
Railroad Assets [Abstract]	'		'		'
Percentage of assets depreciated under the group-life method	86.00%		'		'
Total fixed assets	$37,184	[1]	$35,279	[1]	'
Annual depreciation expense	1,104		1,059	[1]	976	[1]
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	24,618		23,419		'
Life studies, frequency period	'6 years		'		'
Road - Ties [Member]	'		'		'
Railroad Assets [Abstract]	'		'		'
Total fixed assets	4,534		4,287		'
Number of depreciable asset categories for railroad assets	18		'		'
Road - System Roadway Machinery [Member]	'		'		'
Railroad Assets [Abstract]	'		'		'
Total fixed assets	3,654		3,345		'
Road - Grading [Member]	'		'		'
Railroad Assets [Abstract]	'		'		'
Total fixed assets	2,425		2,407		'
Total Equipment [Member]	'		'		'
Railroad Assets [Abstract]	'		'		'
Total fixed assets	9,764		9,301		'
Life studies, frequency period	'3 years		'		'
Equipment - Work Equipment and Other [Member]	'		'		'
Railroad Assets [Abstract]	'		'		'
Total fixed assets	1,666		1,466		'
Abnormal gain (loss) on operating property [Member]	'		'		'
Railroad Assets [Abstract]	'		'		'
Abnormal gains and losses	65		104		14
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	'6 years		'6 years		'
Minimum [Member] | Road - System Roadway Machinery [Member]	'		'		'
Railroad Assets [Abstract]	'		'		'
Estimated useful life	'6 years		'		'
Minimum [Member] | Total Equipment [Member]	'		'		'
Railroad Assets [Abstract]	'		'		'
Estimated useful life	'5 years		'5 years		'
Minimum [Member] | Technology Assets [Member]	'		'		'
Railroad Assets [Abstract]	'		'		'
Estimated useful life	'6 years		'		'
Maximum [Member] | Road - Total [Member]	'		'		'
Railroad Assets [Abstract]	'		'		'
Estimated useful life	'80 years		'80 years		'
Maximum [Member] | Road - Grading [Member]	'		'		'
Railroad Assets [Abstract]	'		'		'
Estimated useful life	'80 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		'		'
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

Properties_Significant_Propert

Properties (Significant Property Disposition) (Details) (USD $)	0 Months Ended	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2011	Nov. 30, 2011	Dec. 27, 2013	Dec. 28, 2012		Dec. 30, 2011
Significant Acquisitions and Disposals [Line Items]	'	'	'	'		'
Total number of rail route miles	'	'	21,000	'		'
Proceeds from property dispositions	'	'	$53	$186	[1]	$240	[1]
Payments to Acquire Property, Plant, and Equipment	'	'	2,313	2,341	[1]	2,297	[1]
Other Current Liabilities [Member]	'	'	'	'		'
Significant Acquisitions and Disposals [Line Items]	'	'	'	'		'
Deferred gain on sale of real estate	'	'	9	43		'
Other Long-term Liabilities [Member]	'	'	'	'		'
Significant Acquisitions and Disposals [Line Items]	'	'	'	'		'
Deferred gain on sale of real estate	'	'	0	9		'
SunRail Transaction - Sale of Corridor [Member]	'	'	'	'		'
Significant Acquisitions and Disposals [Line Items]	'	'	'	'		'
Total number of rail route miles	61	61	'	'		'
Proceeds from property dispositions	173	'	'	'		'
Deferred gain on sale of real estate	160	160	9	52		'
Abnormal gains	'	'	43	94		14
SunRail Transaction - Sale of Corridor [Member] | Maximum [Member]	'	'	'	'		'
Significant Acquisitions and Disposals [Line Items]	'	'	'	'		'
Proceeds from property dispositions in form of government grants	259	'	'	'		'
SunRail Transaction - Sale of Corridor [Member] | Cash [Member]	'	'	'	'		'
Significant Acquisitions and Disposals [Line Items]	'	'	'	'		'
Proceeds from property dispositions	148	'	'	'		'
SunRail Transaction - Sale of Corridor [Member] | Accounts Receivable [Member]	'	'	'	'		'
Significant Acquisitions and Disposals [Line Items]	'	'	'	'		'
Proceeds from property dispositions in form of receivables held in escrow	25	'	'	'		'
Capital Addition Purchase Commitments [Member] | SunRail Transaction - Sale of Corridor [Member]	'	'	'	'		'
Significant Acquisitions and Disposals [Line Items]	'	'	'	'		'
Long-term purchase commitment	500	'	'	'		'
Long-term purchase commitment, period	'	'8 years	'	'		'
Payments to Acquire Property, Plant, and Equipment	'	'	$142	$311		$47
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

Commitments_and_Contingencies_1

Commitments and Contingencies (Lease Commitments) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
Operating Leased Assets [Line Items]	'	'	'
Maximum lease term	'30 years	'	'
Operating Leases [Abstract]	'	'	'
2014	$79	'	'
2015	73	'	'
2016	64	'	'
2017	55	'	'
2018	46	'	'
Thereafter	275	'	'
Total	592	'	'
Sublease Income [Abstract]	'	'	'
2014	-3	'	'
2015	-2	'	'
2016	-2	'	'
2017	-2	'	'
2018	-2	'	'
Thereafter	-13	'	'
Total	24	'	'
Net Lease Commitments [Abstract]	'	'	'
2014	76	'	'
2015	71	'	'
2016	62	'	'
2017	53	'	'
2018	44	'	'
Thereafter	262	'	'
Total	568	'	'
Rent Expense on Operating Leases [Member]	'	'	'
Operating Leases, Rent Expense, Net [Abstract]	'	'	'
Rent Expense on Operating Leases	$60	$73	$68

Commitments_and_Contingencies_2

Commitments and Contingencies (Purchase Commitments) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
	locomotives	locomotives	locomotives
Unrecorded Unconditional Purchase Obligation [Line Items]	'	'	'
Percentage of Locomotive Fleet Under Long-Term Maintenance Program	44.00%	'	'
Amounts Paid	$287	$287	$281
Number of locomotives under the long term maintenance plan	1,886	1,899	1,928
Unrecorded Unconditional Purchase Obligation [Abstract]	'	'	'
2014	613	'	'
2015	319	'	'
2016	260	'	'
2017	238	'	'
2018	226	'	'
Thereafter	1,367	'	'
Total	3,023	'	'
Locomotive & Maintenance Payments [Member]	'	'	'
Unrecorded Unconditional Purchase Obligation [Abstract]	'	'	'
2014	292	'	'
2015	253	'	'
2016	245	'	'
2017	232	'	'
2018	220	'	'
Thereafter	1,314	'	'
Total	2,556	'	'
Other Commitments [Member]	'	'	'
Unrecorded Unconditional Purchase Obligation [Abstract]	'	'	'
2014	321	'	'
2015	66	'	'
2016	15	'	'
2017	6	'	'
2018	6	'	'
Thereafter	53	'	'
Total	$467	'	'

Commitments_and_Contingencies_3

Commitments and Contingencies (Insurance and Legal) (Details) (USD $)	Dec. 27, 2013	Dec. 27, 2013	31-May-07
In Millions, unless otherwise specified		Pending Litigation [Member]	Fuel Surcharge Antitrust Litigation [Member]
			entity
Insurance	'	'	'
Non-catastrophic property deductible	$25	'	'
Casualty and catastrophic property deductible	50	'	'
Loss Contingency, Estimate [Abstract]	'	'	'
Minimum range of possible loss for legal proceedings	'	2	'
Maximum range of possible loss for legal proceedings	'	$15	'
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. 27, 2013
	counterparty
	mi
	company
Environmental Litigation [Member]	'
Loss Contingencies [Line Items]	'
Additional Companies Involved in Passaic River Complaint	5
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	70

Employee_Benefit_Plans_Summary

Employee Benefit Plans (Summary of Participants) (Details)	Dec. 28, 2012
	employees
Pension Plan, Defined Benefit [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Active Employees	5,153
Retirees And Beneficiaries	11,569
Other	5,715	[1]
Total	22,437
Other Postretirement Benefit Plan, Defined Benefit [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Active Employees	2,176
Retirees And Beneficiaries	12,277
Other	112	[1]
Total	14,565
[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			12 Months Ended
In Millions, unless otherwise specified	Mar. 29, 2013	Dec. 28, 2012	Dec. 27, 2013	Dec. 27, 2013	Dec. 27, 2013	Dec. 28, 2012	Dec. 27, 2013	Dec. 28, 2012
			Pension Plan, Defined Benefit [Member]	Other Postretirement Benefit Plan, Defined Benefit [Member]	Qualified Employer Contributions [Member]	Qualified Employer Contributions [Member]	Qualified Employer Contributions [Member]	Qualified Employer Contributions [Member]
					Pension Plan, Defined Benefit [Member]	Pension Plan, Defined Benefit [Member]	Other Postretirement Benefit Plan, Defined Benefit [Member]	Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'	'	'	'	'
Employer Contributions	'	'	'	'	$0	$275	$0	$0
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]	'	'	'	'	'	'	'	'
2014	'	'	167	38	'	'	'	'
2015	'	'	171	36	'	'	'	'
2016	'	'	173	34	'	'	'	'
2017	'	'	176	32	'	'	'	'
2018	'	'	179	31	'	'	'	'
2019-2023	'	'	910	126	'	'	'	'
Total	'	'	1,776	297	'	'	'	'
Defined Benefit Plan, Contributions By Employer, Required Minimum Amount	'	25	'	'	'	'	'	'
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	$0	'	'	'	'	'	'	'

Employee_Benefit_Plans_Plan_As

Employee Benefit Plans (Plan Assets) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012
Defined Benefit Plan Disclosure [Line Items]	'	'
Distribution of pension plan assets	$2,500	$2,294
Equity, Percent of Total Assets	100.00%	100.00%
Equity [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Targeted and established equity allocation (in hundredths)	60.00%	'
Targeted allocation of total plan assets in domestic equity (in hundredths)	40.00%	'
Targeted allocation of total plan assets in international equity (in hundredths)	20.00%	'
Percentage within which the planned allocation is managed (in hundredths)	3.00%	'
Distribution of pension plan assets	1,619	1,408
Equity, Percent of Total Assets	65.00%	61.00%
Fixed Income Funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Targeted and established equity allocation (in hundredths)	40.00%	'
Distribution of pension plan assets	795	829
Equity, Percent of Total Assets	32.00%	36.00%
Cash and Cash Equivalents [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Distribution of pension plan assets	$86	$57
Equity, Percent of Total Assets	3.00%	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. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'	'
Fair Value of Plan Assets at End of Plan Year	$2,500	$2,294	'
Pension Plan, Defined Benefit [Member]	'	'	'
Actuarial Present Value of Benefit Obligation [Abstract]	'	'	'
Accumulated Benefit Obligation	2,538	2,806	'
Projected Benefit Obligation	2,679	2,954	2,668
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]	'	'	'
Projected Benefit Obligation at Beginning of Year	2,954	2,668	'
Service Cost	49	44	40
Interest Cost	108	123	121
Plan Participants Contributions	0	0	'
Plan Amendments	0	0	'
Actuarial Net (Gains) Losses	-275	274	'
Benefits Paid	-157	-155	'
Benefit Obligation at End of Plan Year	2,679	2,954	2,668
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'	'
Fair Value of Plan Assets at Beginning of Plan Year	2,294	1,850	'
Actual Return on Plan Assets	350	311	'
Plan Participants Contributions	0	0	'
Benefits Paid	-157	-155	'
Fair Value of Plan Assets at End of Plan Year	2,500	2,294	1,850
Funded Status at End of Plan Year	-179	-660	'
Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'	'
Actuarial Present Value of Benefit Obligation [Abstract]	'	'	'
Projected Benefit Obligation	350	415	388
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]	'	'	'
Projected Benefit Obligation at Beginning of Year	415	388	'
Service Cost	3	4	2
Interest Cost	13	16	11
Plan Participants Contributions	8	8	'
Plan Amendments	0	-1	'
Actuarial Net (Gains) Losses	-49	43	'
Benefits Paid	-40	-43	'
Benefit Obligation at End of Plan Year	350	415	388
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	8	8	'
Benefits Paid	-40	-43	'
Fair Value of Plan Assets at End of Plan Year	0	0	0
Funded Status at End of Plan Year	-350	-415	'
Qualified Employer Contributions [Member] | Pension Plan, Defined Benefit [Member]	'	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'	'
Employer Contributions	0	275	'
Qualified Employer Contributions [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'	'
Employer Contributions	0	0	'
Non-qualified Employer Contributions [Member] | Pension Plan, Defined Benefit [Member]	'	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'	'
Employer Contributions	13	13	'
Non-qualified Employer Contributions [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'	'
Employer Contributions	$32	$35	'

Employee_Benefit_Plans_Amounts

Employee Benefit Plans (Amounts Recoreded in Consolidated Balance Sheets) (Details) (USD $)	Dec. 27, 2013		Dec. 28, 2012
In Millions, unless otherwise specified
Pension Plan, Defined Benefit [Member]	'		'
Amounts Recorded in Consolidated Balance Sheets [Abstract]	'		'
Long-term Assets	$44	[1]	$3	[1]
Current Liabilities	-14		-15
Long-term Liabilities	-209		-648
Net Amount Recognized in Consolidated Balance Sheet	-179		-660
Other Postretirement Benefit Plan, Defined Benefit [Member]	'		'
Amounts Recorded in Consolidated Balance Sheets [Abstract]	'		'
Long-term Assets	0		0
Current Liabilities	-38		-41
Long-term Liabilities	-312		-374
Net Amount Recognized in Consolidated Balance Sheet	($350)		($415)
[1]	Long-term assets relate to two 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. 27, 2013	Dec. 28, 2012
In Millions, unless otherwise specified
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]	'	'
Total fair value of all plans	$2,500	$2,294
Projected Benefit Obligation:	'	'
Aggregate Fair Value of Plan Assets	69	'
Aggregate Projected Benefit Obligation	-292	'
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets [Abstract]	'	'
Aggregate Fair Value of Plan Assets	69	'
Aggregate Projected Benefit Obligation	($280)	'

Employee_Benefit_Plans_Net_Ben

Employee Benefit Plans (Net Benefit Expense) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013		Dec. 28, 2012		Dec. 30, 2011
Pension Plans, Defined Benefit [Member]	'		'		'
Components of expense/ (income) related to net benefit expense [Abstract]	'		'		'
Service Cost	$49		$44		$40
Interest Cost	108		123		121
Expected Return on Plan Assets	-162		-166		-157
Amortization of Net Loss	100	[1]	82	[1]	71
Amortization of Prior Service Cost	0	[2]	0	[2]	0
Net Periodic Benefit Expense	95		83		75
Settlement gain	-2	[3]	-2	[3]	-2	[3]
Total Expense	93		81		73
Other Post-Retirement Benefits	'		'		'
Components of expense/ (income) related to net benefit expense [Abstract]	'		'		'
Service Cost	3		4		2
Interest Cost	13		16		11
Expected Return on Plan Assets	0		0		0
Amortization of Net Loss	14	[1]	9	[1]	7
Amortization of Prior Service Cost	-1	[2]	-1	[2]	-1
Net Periodic Benefit Expense	29		28		19
Settlement gain	0	[3]	0	[3]	0	[3]
Total Expense	$29		$28		$19
[1]	Amortization of net losses estimated to be expensed for 2014 is $57 million and $6 million for pension benefits and post-retirement benefits, respectively. The decrease in amortization is largely related to the impact of increasing discount rates.
[2]	Amortization of prior service costs estimated to be expensed in 2014 are less than $1 million for pension benefits. The estimated post-retirement benefits amount to be credited to expense for 2014 is $1 million.
[3]	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. 27, 2013		Dec. 28, 2012		Dec. 30, 2011
Pension Plan, Defined Benefit [Member]	'		'		'
Components of other comprehensive loss (income) [Abstract]	'		'		'
(Gains) Losses	($462)		$130		'
Prior service credits	0		0		'
Expense (Income) recognized in income statement [Abstract]	'		'		'
Amortization of net losses	100	[1]	82	[1]	71
Settlement gain	-2	[2]	-2	[2]	-2	[2]
Amortization of prior service cost	0	[3]	0	[3]	0
Estimated amount to be expensed in the future period	57		'		'
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	658		'		'
Prior Service Costs (Credits)	1		'		'
Total	659		'		'
Other Postretirement Benefit Plan, Defined Benefit [Member]	'		'		'
Components of other comprehensive loss (income) [Abstract]	'		'		'
(Gains) Losses	-48		43		'
Prior service credits	0		-1		'
Expense (Income) recognized in income statement [Abstract]	'		'		'
Amortization of net losses	14	[1]	9	[1]	7
Settlement gain	0	[2]	0	[2]	0	[2]
Amortization of prior service cost	-1	[3]	-1	[3]	-1
Estimated amount to be expensed in the future period	6		'		'
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	73		'		'
Prior Service Costs (Credits)	-3		'		'
Total	$70		'		'
[1]	Amortization of net losses estimated to be expensed for 2014 is $57 million and $6 million for pension benefits and post-retirement benefits, respectively. The decrease in amortization is largely related to the impact of increasing discount rates.
[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 2014 are less than $1 million for pension benefits. The estimated post-retirement benefits amount to be credited to expense for 2014 is $1 million.

Employee_Benefit_Plans_Weighte

Employee Benefit Plans (Weighted-Average Assumptions) (Details)	12 Months Ended
	Dec. 27, 2013	Dec. 28, 2012
Pension Plan, Defined Benefit [Member]	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'
Benefit Cost for Plan Year	7.75%	8.00%
Benefit Obligation at End of Plan Year	7.50%	7.75%
Benefit Cost for Plan Year	3.75%	4.75%
Benefit Obligation at End of Plan Year	4.75%	3.75%
Salary Scale Inflation	3.75%	3.75%
Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'
Benefit Cost for Plan Year	3.20%	4.25%
Benefit Obligation at End of Plan Year	4.25%	3.20%

Employee_Benefit_Plans_Health_

Employee Benefit Plans (Health Care Cost Trend Rates) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012
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	'
Other Postretirement Benefit Plan, Defined Benefit [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)	5.00%	'
Components of Benefit Cost: Non-Medicare Eligible	8.50%	8.50%
Components of Benefit Cost: Medicare Eligible	8.00%	8.00%
Benefit Obligations: Non-Medicare Eligible	8.00%	8.50%
Benefit Obligations: Medicare Eligible	7.50%	8.00%

Employee_Benefit_Plans_Medicar

Employee Benefit Plans (Medicare Prescription Drug and Other Plans) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Amount of premium expenses incurred under the plan	$41	$46	$48
Expense associated with savings plans	$37	$29	$28

Debt_and_Credit_Agreements_Lon

Debt and Credit Agreements (Long-term Debt Instruments) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013		Dec. 28, 2012
Debt Instrument [Line Items]	'		'
Total Long-term Debt Maturities (including current portion)	$9,555		$9,832
Less Debt Due within One Year	-533	[1]	-780	[1]
Long-term Debt (excluding current portion)	9,022	[1]	9,052	[1]
Notes Payable [Member]	'		'
Debt Instrument [Line Items]	'		'
Average Interest Rates (in hundredths)	5.70%		'
Total Long-term Debt Maturities (including current portion)	8,935		9,151
Equipment Obligations [Member]	'		'
Debt Instrument [Line Items]	'		'
Average Interest Rates (in hundredths)	7.30%	[2]	'
Total Long-term Debt Maturities (including current portion)	602	[2]	667	[2]
Capital Leases [Member]	'		'
Debt Instrument [Line Items]	'		'
Average Interest Rates (in hundredths)	8.10%		'
Total Long-term Debt Maturities (including current portion)	16		12
Convertible Debt [Member]	'		'
Debt Instrument [Line Items]	'		'
Average Interest Rates (in hundredths)	1.00%		'
Total Long-term Debt Maturities (including current portion)	$2		$2
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.
[2]	These obligations are secured by an interest in certain railroad equipment.

Debt_and_Credit_Agreements_Deb

Debt and Credit Agreements (Debt Issuance) (Details) (Notes Payable [Member], Note Due 2023 at 3 Point 7 Percent [Member], USD $)	Dec. 27, 2013
In Millions, unless otherwise specified
Notes Payable [Member] | Note Due 2023 at 3 Point 7 Percent [Member]	'
Debt Instrument [Line Items]	'
Face amount of debt issued	$500
Notes issued, interest rate	3.70%

Debt_and_Credit_Agreements_Lon1

Debt and Credit Agreements (Long-term Debt Maturities) (Details) (USD $)	Dec. 27, 2013		Dec. 28, 2012
In Millions, unless otherwise specified
Maturities of Long-term Debt [Abstract]	'		'
2014	$533	[1]	$780	[1]
2015	629		'
2016	22		'
2017	631		'
2018	619		'
Thereafter	7,121		'
Total Long-term Debt Maturities (including current portion)	$9,555		$9,832
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

Debt_and_Credit_Agreements_Cre

Debt and Credit Agreements (Credit Facilities and Receivable Securitization Facility) (Details) (USD $)	12 Months Ended
	Dec. 27, 2013
Line of Credit Facility [Line Item]	'
Line of Credit Facility, Covenant Compliance	'At December 2013, 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	19-Dec-14
Line of credit facility, amount outstanding	0
Line of Credit Facility Total Expiration Period	'364 days
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 $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012		Dec. 30, 2011
Other Income and Expenses [Abstract]	'	'		'
Interest Income	$8	$5		$5
Income from Real Estate Operations	23	81		25
Miscellaneous Expense	-20	-13		-8
Other Income - Net	11	73	[1]	22	[1]
Gross Revenue from Real Estate Operations included above	$48	$106		$51
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

Income_Taxes_Income_Tax_Expens

Income Taxes (Income Tax Expense) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012		Dec. 30, 2011
Earnings From Continuing Operations [Abstract]	'	'		'
Earnings Before Income Taxes	$2,922	$2,971	[1]	$2,940	[1]
Current [Abstract]	'	'		'
Federal	671	450	[1]	370	[1]
State	87	66	[1]	107	[1]
Total Current	758	516	[1]	477	[1]
Deferred [Abstract]	'	'		'
Federal	285	530	[1]	614	[1]
State	15	62	[1]	-5	[1]
Subtotal Deferred	300	592	[1]	609	[1]
Income Tax Expense (Benefit)	$1,058	$1,108	[1]	$1,086	[1]
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

Income_Taxes_Income_Tax_Reconc

Income Taxes (Income Tax Reconciliation) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012		Dec. 30, 2011
Reconciliation between the statutory income tax rate and the effective income tax rate [Abstract]	'	'		'
Federal Income Taxes	$1,023	$1,040	[1]	$1,029	[1]
State Income Taxes	65	81	[1]	65	[1]
Other items	-30	-13	[1]	-8	[1]
Income Tax Expense (Benefit)	1,058	1,108	[1]	1,086	[1]
Effective Income Tax Rate Reconciliation, Percent [Abstract]	'	'		'
Federal Income Taxes	35.00%	35.00%	[1]	34.90%	[1]
State Income Taxes	2.20%	2.80%	[1]	2.20%	[1]
Other Items	-1.00%	-0.40%	[1]	-0.30%	[1]
Income Tax Rate	36.20%	37.40%	[1]	36.80%	[1]
State and Local Jurisdiction [Member]	'	'		'
Reconciliation between the statutory income tax rate and the effective income tax rate [Abstract]	'	'		'
State Income Taxes	($42)	($20)		($14)
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

Income_Taxes_Deferred_Income_T

Income Taxes (Deferred Income Tax Assets and Liabilities) (Details) (USD $)	Dec. 27, 2013	Dec. 28, 2012
In Millions, unless otherwise specified
Components of Deferred Tax Assets [Abstract]	'	'
Pension Plans	$67	$249
Other Employee Benefit Plans	299	292
Other	257	278
Total	623	819
Components of Deferred Tax Liabilities [Abstract]	'	'
Accelerated Depreciation	8,868	8,544
Other	262	252
Total	9,130	8,796
Net Deferred Income Tax Liabilities	$8,507	$7,977

Income_Taxes_Unrecognized_Tax_

Income Taxes (Unrecognized Tax Benefits) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
Income Tax Disclosure [Abstract]	'	'	'
Amount of unrecognized tax benefits that may favorably effect the effective income tax rate	$15	$17	$15
Amount of unrecognized tax benefits that will be resolved over next twelve months	3	'	'
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]	'	'	'
Balance at beginning of the year	24	22	20
Additions based on tax positions related to current year	2	6	1
Additions based on tax positions related to prior years	5	3	10
Reductions based on tax positions related to prior years	-6	-1	-3
Settlements with taxing authorities	0	0	-5
Lapse of statute of limitations	-2	-6	-1
Balance at end of the year	$23	$24	$22

Income_Taxes_Income_Taxes_Unce

Income Taxes (Income Taxes Uncertainties) (Details) (USD $)	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
In Millions, unless otherwise specified
Income Tax Uncertainties [Abstract]	'	'	'
Reduction (Increase) to income tax reserves due to interest and penalties of prior year tax positions	$1	$8	($1)
Previously recorded liabilities for interest and penalties of prior period tax audits	$2	$3	$11

Related_Party_Transactions_Nar

Related Party Transactions (Narrative) (Details) (Corporate Joint Venture [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
Related Party Transaction [Line Items]	'	'	'
Difference between carrying amount and underlying equity	$362	'	'
Interest expense	$4	$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%	'	'

Related_Party_Transactions_Fut

Related Party Transactions (Future Lease Payment under Asset Agreement) (Details) (USD $)	Dec. 27, 2013
In Millions, unless otherwise specified
Related Party Transaction [Line Items]	'
2014	$79
2015	73
2016	64
2017	55
2018	46
Thereafter	275
Total	592
Corporate Joint Venture [Member]	'
Related Party Transaction [Line Items]	'
2014	25
2015	25
2016	25
2017	25
2018	25
Thereafter	144
Total	$269

Related_Party_Transactions_Con

Related Party Transactions (Consolidated Income Statements Components) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012	Dec. 30, 2011
Related Party Amounts Consolidated Income Statements [Abstract]	'	'	'
Equity in Income 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	115	139	111
Purchase Price Amortization and Other	4	4	4
Equity in Income of Conrail	-35	-26	-24
Total Related Party Rents Fees And Services	$84	$117	$91

Related_Party_Transactions_Con1

Related Party Transactions (Consolidated Balance Sheets Components) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013		Dec. 28, 2012
Related Party Transaction [Line Items]	'		'
Payable to Affiliates	$0		$0
Corporate Joint Venture [Member] | Accounts Payable [Member]	'		'
Related Party Transaction [Line Items]	'		'
Payable to Affiliates	172	[1]	175	[1]
Corporate Joint Venture [Member] | Long-term Debt [Member] | Promissory Note Related Party October 2035 [Member]	'		'
Related Party Transaction [Line Items]	'		'
Promissory Notes Payable to Conrail Subsidiary	73	[2]	73	[2]
Notes issued, interest rate	4.40%		'
Corporate Joint Venture [Member] | Long-term Debt [Member] | Promissory Note Related Party March 2035 [Member]	'		'
Related Party Transaction [Line Items]	'		'
Promissory Notes Payable to Conrail Subsidiary	$23	[2]	$23	[2]
Notes issued, interest rate	4.52%		'
[1]	CSX Payable to Conrail is included on the consolidated balance sheet of CSX as accounts payable because it is short term in nature.
[2]	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. 27, 2013	Dec. 28, 2012
In Millions, unless otherwise specified
Fair Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments at fair value	$668	$743
Fair Value [Member] | Less than 1 year [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments at fair value	487	587
Fair Value [Member] | 1 - 2 years [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments at fair value	58	61
Fair Value [Member] | 2 - 5 years [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments at fair value	105	76
Fair Value [Member] | Greater than 5 years [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments at fair value	18	19
Fair Value [Member] | Certificates of Deposit and Commercial Paper [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments at fair value	472	555
Fair Value [Member] | Corporate Bonds [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments at fair value	132	142
Fair Value [Member] | Government securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments at fair value	49	31
Fair Value [Member] | Auction Rate Securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments at fair value	15	15
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	653	728
Long-term Debt Including Current Maturities	10,354	11,562
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	472	555
Fair Value [Member] | Level 2 [Member] | Corporate Bonds [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments at fair value	132	142
Fair Value [Member] | Level 2 [Member] | Government securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments at fair value	49	31
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	15	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	15	15
Amortized Cost Basis [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Amortized cost basis of investments	668	742
Amortized Cost Basis [Member] | Level 2 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term Debt Including Current Maturities	$9,555	$9,832

Fair_Value_Measurements_Pensio

Fair Value Measurements (Pension Plan Assets) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013	Dec. 28, 2012
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	$2,500	$2,294
Equity [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Investment Committee equity target allocation percentage of pension assets	60.00%	'
Pension plan assets at fair value	1,619	1,408
Information technology [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	173	169
Consumer discretionary [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	152	125
Health care [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	126	96
Financials [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	116	83
Industrials [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	108	78
Energy [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	59	58
Consumer staples [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	43	55
Materials [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	29	25
Other [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	31	33
Fixed Income Funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Investment Committee equity target allocation percentage of pension assets	40.00%	'
Pension plan assets at fair value	795	829
Mutual Funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	17	17
Corporate securities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	568	606
Common trust funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	553	426
Partnerships [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	314	296
Government securities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	186	178
Asset-backed securities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	24	28
Cash equivalents [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	0	20
Derivatives and other [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	1	1
Level 1 [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	854	739
Level 1 [Member] | Information technology [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	173	169
Level 1 [Member] | Consumer discretionary [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	152	125
Level 1 [Member] | Health care [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	126	96
Level 1 [Member] | Financials [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	116	83
Level 1 [Member] | Industrials [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	108	78
Level 1 [Member] | Energy [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	59	58
Level 1 [Member] | Consumer staples [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	43	55
Level 1 [Member] | Materials [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	29	25
Level 1 [Member] | Other [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	31	33
Level 1 [Member] | Mutual Funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	17	17
Level 1 [Member] | Corporate securities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	0	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] | 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] | Cash equivalents [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	1,646	1,555
Level 2 [Member] | Information technology [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] | Health care [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] | Corporate securities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	568	606
Level 2 [Member] | Common trust funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	553	426
Level 2 [Member] | Partnerships [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	314	296
Level 2 [Member] | Government securities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	186	178
Level 2 [Member] | Asset-backed securities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	24	28
Level 2 [Member] | Cash equivalents [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	0	20
Level 2 [Member] | Derivatives and other [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension plan assets at fair value	1	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] | Consumer discretionary [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] | 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] | Corporate securities [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] | 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] | Cash equivalents [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. 27, 2013		Dec. 28, 2012		Dec. 30, 2011
Accumulated Other Comprehensive Income (Loss) [Line Items]	'		'		'
Comprehensive Earnings	$2,277		$1,802	[1]	$1,750	[1]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]	'		'		'
Beginning Balance	-936	[1]	-875		-771
Other Comprehensive Income (Loss):	'		'		'
Income (Loss) Before Reclassifications	534		-181		-229
Loss (Income) Reclassified to Net Earnings	109	[2]	87	[2]	74	[2]
Tax (Expense) Benefit	-230		33		51
Other Comprehensive (Loss) Income, Net of Tax	413		-61	[1]	-104	[1]
Ending Balance	-523	[1]	-936	[1]	-875
Pension and Other Post-Employment Benefits [Member]	'		'		'
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]	'		'		'
Beginning Balance	-851		-799		-711
Other Comprehensive Income (Loss):	'		'		'
Income (Loss) Before Reclassifications	510		-172		-216
Loss (Income) Reclassified to Net Earnings	111	[2]	88	[2]	75	[2]
Tax (Expense) Benefit	-232		32		53
Other Comprehensive (Loss) Income, Net of Tax	389		-52	[1]	-88	[1]
Ending Balance	-462		-851		-799
Other	'		'		'
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]	'		'		'
Beginning Balance	-85	[3]	-76	[3]	-60	[3]
Other Comprehensive Income (Loss):	'		'		'
Income (Loss) Before Reclassifications	24	[3]	-9	[3]	-13	[3]
Loss (Income) Reclassified to Net Earnings	-2	[2],[3]	-1	[2],[3]	-1	[2],[3]
Tax (Expense) Benefit	2	[3]	1	[3]	-2	[3]
Other Comprehensive (Loss) Income, Net of Tax	24	[3]	-9	[1],[3]	-16	[1],[3]
Ending Balance	($61)	[3]	($85)	[3]	($76)	[3]
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.
[2]	Amounts reclassified to net earnings primarily 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.
[3]	Other primarily represents CSX's share of AOCI of equity method investees. Amounts reclassified to net earnings are included in other income - net on the consolidated income statements.

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. 27, 2013	Sep. 27, 2013	Jun. 28, 2013	Mar. 29, 2013	Dec. 30, 2012	Sep. 28, 2012	Jun. 29, 2012	Mar. 30, 2012	Dec. 30, 2011	Sep. 30, 2011	Jul. 01, 2011	Apr. 01, 2011	Dec. 27, 2013	Dec. 28, 2012		Dec. 30, 2011
Selected Quarterly Financial Information [Abstract]	'	'	'	'	'	'	'	'	'	'	'	'	'	'		'
Revenue	$3,032	$2,985	$3,046	$2,963	$2,895	$2,864	$2,986	$3,018	$2,993	$2,962	$3,013	$2,827	$12,026	$11,763	[1]	$11,795	[1]
Operating Income	813	840	940	880	815	824	917	908	883	877	920	790	3,473	3,464	[1]	3,470	[1]
Net Earnings	$426	$455	$521	$462	$449	$437	$496	$481	$483	$463	$502	$406	$1,864	$1,863	[1]	$1,854	[1]
Earnings Per Share, Basic (dollars per share)	$0.42	$0.45	$0.51	$0.45	$0.44	$0.42	$0.48	$0.46	$0.46	$0.43	$0.46	$0.37	$1.83	$1.80	[1]	$1.71	[1]
Earnings Per Share, Assuming Dilution (dollars per share)	$0.42	$0.45	$0.51	$0.45	$0.44	$0.42	$0.48	$0.46	$0.46	$0.43	$0.45	$0.36	$1.83	$1.79	[1]	$1.70	[1]
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

Summarized_Consolidating_Finan2

Summarized Consolidating Financial Data (Income Statements) (Details) (USD $)

3 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Dec. 27, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Dec. 30, 2012

Sep. 28, 2012

Jun. 29, 2012

Mar. 30, 2012

Dec. 30, 2011

Sep. 30, 2011

Jul. 01, 2011

Apr. 01, 2011

Dec. 27, 2013

Dec. 28, 2012

Dec. 30, 2011

Consolidated Income Statement

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenue

$3,032

$2,985

$3,046

$2,963

$2,895

$2,864

$2,986

$3,018

$2,993

$2,962

$3,013

$2,827

$12,026

$11,763

[1]

$11,795

[1]

Operating Expenses

'

'

'

'

'

'

'

'

'

'

'

'

8,553

8,299

[1]

8,325

[1]

Operating Income

813

840

940

880

815

824

917

908

883

877

920

790

3,473

3,464

[1]

3,470

[1]

Equity in Earnings of Subsidiaries

'

'

'

'

'

'

'

'

'

'

'

'

0

0

0

Interest Expense

'

'

'

'

'

'

'

'

'

'

'

'

-562

-566

[1]

-552

[1]

Other Income - Net

'

'

'

'

'

'

'

'

'

'

'

'

11

73

[1]

22

[1]

Earnings Before Income Taxes

'

'

'

'

'

'

'

'

'

'

'

'

2,922

2,971

[1]

2,940

[1]

Income Tax Benefit (Expense)

'

'

'

'

'

'

'

'

'

'

'

'

-1,058

-1,108

[1]

-1,086

[1]

Net Earnings

426

455

521

462

449

437

496

481

483

463

502

406

1,864

1,863

[1]

1,854

[1]

Comprehensive Earnings

'

'

'

'

'

'

'

'

'

'

'

'

2,277

1,802

[1]

1,750

[1]

CSX Corporation

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Consolidated Income Statement

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

'

'

'

'

0

0

0

Operating Expenses

'

'

'

'

'

'

'

'

'

'

'

'

-371

-355

-278

Operating Income

'

'

'

'

'

'

'

'

'

'

'

'

371

355

278

Equity in Earnings of Subsidiaries

'

'

'

'

'

'

'

'

'

'

'

'

1,964

1,992

1,979

Interest Expense

'

'

'

'

'

'

'

'

'

'

'

'

-516

-513

-496

Other Income - Net

'

'

'

'

'

'

'

'

'

'

'

'

-7

-3

2

Earnings Before Income Taxes

'

'

'

'

'

'

'

'

'

'

'

'

1,812

1,831

1,763

Income Tax Benefit (Expense)

'

'

'

'

'

'

'

'

'

'

'

'

52

32

91

Net Earnings

'

'

'

'

'

'

'

'

'

'

'

'

1,864

1,863

1,854

Comprehensive Earnings

'

'

'

'

'

'

'

'

'

'

'

'

2,277

1,802

1,750

CSX Transportation

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Consolidated Income Statement

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

'

'

'

'

11,950

11,696

11,728

Operating Expenses

'

'

'

'

'

'

'

'

'

'

'

'

9,091

8,779

8,679

Operating Income

'

'

'

'

'

'

'

'

'

'

'

'

2,859

2,917

3,049

Equity in Earnings of Subsidiaries

'

'

'

'

'

'

'

'

'

'

'

'

-1

-2

3

Interest Expense

'

'

'

'

'

'

'

'

'

'

'

'

-62

-70

-83

Other Income - Net

'

'

'

'

'

'

'

'

'

'

'

'

-2

61

19

Earnings Before Income Taxes

'

'

'

'

'

'

'

'

'

'

'

'

2,794

2,906

2,988

Income Tax Benefit (Expense)

'

'

'

'

'

'

'

'

'

'

'

'

-1,028

-1,065

-1,101

Net Earnings

'

'

'

'

'

'

'

'

'

'

'

'

1,766

1,841

1,887

Comprehensive Earnings

'

'

'

'

'

'

'

'

'

'

'

'

1,825

1,818

1,873

Eliminations and Other

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Consolidated Income Statement

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

'

'

'

'

76

67

67

Operating Expenses

'

'

'

'

'

'

'

'

'

'

'

'

-167

-125

-76

Operating Income

'

'

'

'

'

'

'

'

'

'

'

'

243

192

143

Equity in Earnings of Subsidiaries

'

'

'

'

'

'

'

'

'

'

'

'

-1,963

-1,990

-1,982

Interest Expense

'

'

'

'

'

'

'

'

'

'

'

'

16

17

27

Other Income - Net

'

'

'

'

'

'

'

'

'

'

'

'

20

15

1

Earnings Before Income Taxes

'

'

'

'

'

'

'

'

'

'

'

'

-1,684

-1,766

-1,811

Income Tax Benefit (Expense)

'

'

'

'

'

'

'

'

'

'

'

'

-82

-75

-76

Net Earnings

'

'

'

'

'

'

'

'

'

'

'

'

-1,766

-1,841

-1,887

Comprehensive Earnings

'

'

'

'

'

'

'

'

'

'

'

'

-1,825

-1,818

-1,873

Retained Earnings

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Consolidated Income Statement

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net Earnings

'

'

'

'

'

'

'

'

'

'

'

'

$1,864

[1]

$1,863

[1]

$1,854

[1]

[1]

See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

Summarized_Consolidating_Finan3

Summarized Consolidating Financial Data (Balance Sheets) (Details) (USD $)	Dec. 27, 2013		Dec. 28, 2012		Dec. 30, 2011		Dec. 31, 2010
In Millions, unless otherwise specified
Current Assets	'		'		'		'
Cash and Cash Equivalents	$592	[1]	$784	[1]	$783	[1]	$1,292	[1]
Short-term Investments	487	[1]	587	[1]	'		'
Accounts Receivable - Net	1,052	[1]	1,114	[1]	1,147	[1]	'
Receivable from Affiliates	0		0		'		'
Materials and Supplies	252	[1]	274	[1]	'		'
Deferred Income Taxes	155	[1]	119	[1]	'		'
Other Current Assets	64	[1]	75	[1]	'		'
Total Current Assets	2,602		2,953	[1]	2,953		'
Properties	37,184	[1]	35,279	[1]	'		'
Accumulated Depreciation	-9,893	[1]	-9,229	[1]	'		'
Properties - Net	27,291		26,050	[1]	'		'
Other Long-term Assets	591	[1]	514	[1]	'		'
Total Assets	31,782		30,723	[1]	29,491		'
Current Liabilities	'		'		'		'
Accounts Payable	957	[1]	948	[1]	954	[1]	'
Labor and Fringe Benefits Payable	587	[1]	468	[1]	'		'
Payable to Affiliates	0		0		'		'
Current Maturities of Long-term Debt	533	[1]	780	[1]	'		'
Income and Other Taxes Payable	91	[1]	169	[1]	210	[1]	'
Other Current Liabilities	105	[1]	140	[1]	'		'
Total Current Liabilities	2,424		2,645	[1]	2,575		'
Long-term Debt	9,022	[1]	9,052	[1]	'		'
Deferred Income Taxes	8,662	[1]	8,096	[1]	'		'
Other Long-term Liabilities	870	[1]	1,457	[1]	'		'
Total Liabilities	21,278		21,587	[1]	20,893		'
Common Stock, $1 Par Value	1,009	[1]	1,020	[1]	'		'
Other Capital	61	[1]	28	[1]	'		'
Retained Earnings	9,936	[1]	9,010	[1]	8,405	[1]	'
Accumulated Other Comprehensive Loss	-523	[1]	-936	[1]	-875		-771
Noncontrolling Minority Interest	21	[1]	14	[1]	'		'
Total Shareholders' Equity	10,504		9,136	[1]	8,598		8,798
Total Liabilities and Shareholders' Equity	31,782		30,723	[1]	29,491		'
Investments in Conrail	'		'		'		'
Current Assets	'		'		'		'
Investment in Affiliates, Subsidiaries, and Joint Ventures	752	[1]	695	[1]	'		'
Affiliates and Other Companies	'		'		'		'
Current Assets	'		'		'		'
Investment in Affiliates, Subsidiaries, and Joint Ventures	546	[1]	511	[1]	'		'
Investments in Consolidated Subsidiaries	'		'		'		'
Current Assets	'		'		'		'
Investment in Affiliates, Subsidiaries, and Joint Ventures	0		0		'		'
CSX Corporation	'		'		'		'
Current Assets	'		'		'		'
Cash and Cash Equivalents	439		481		549		1,100
Short-term Investments	472		555		'		'
Accounts Receivable - Net	3		3		'		'
Receivable from Affiliates	1,141		993		'		'
Materials and Supplies	0		0		'		'
Deferred Income Taxes	-5		52		'		'
Other Current Assets	1		11		'		'
Total Current Assets	2,051		2,095		'		'
Properties	1		8		'		'
Accumulated Depreciation	-1		-8		'		'
Properties - Net	0		0		'		'
Other Long-term Assets	217		186		'		'
Total Assets	22,455		21,159		'		'
Current Liabilities	'		'		'		'
Accounts Payable	110		133		'		'
Labor and Fringe Benefits Payable	38		35		'		'
Payable to Affiliates	3,298		2,679		'		'
Current Maturities of Long-term Debt	200		700		'		'
Income and Other Taxes Payable	-397		-262		'		'
Other Current Liabilities	0		-1		'		'
Total Current Liabilities	3,249		3,284		'		'
Long-term Debt	8,308		8,005		'		'
Deferred Income Taxes	-64		-153		'		'
Other Long-term Liabilities	479		901		'		'
Total Liabilities	11,972		12,037		'		'
Common Stock, $1 Par Value	1,009		1,020		'		'
Other Capital	61		28		'		'
Retained Earnings	9,936		9,010		'		'
Accumulated Other Comprehensive Loss	-523		-936		'		'
Noncontrolling Minority Interest	0		0		'		'
Total Shareholders' Equity	10,483		9,122		'		'
Total Liabilities and Shareholders' Equity	22,455		21,159		'		'
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	20,226		18,917		'		'
CSX Transportation	'		'		'		'
Current Assets	'		'		'		'
Cash and Cash Equivalents	91		235		154		118
Short-term Investments	0		0		'		'
Accounts Receivable - Net	240		579		'		'
Receivable from Affiliates	2,635		1,798		'		'
Materials and Supplies	252		274		'		'
Deferred Income Taxes	161		62		'		'
Other Current Assets	57		64		'		'
Total Current Assets	3,436		3,012		'		'
Properties	34,987		33,333		'		'
Accumulated Depreciation	-8,778		-8,225		'		'
Properties - Net	26,209		25,108		'		'
Other Long-term Assets	388		368		'		'
Total Assets	30,645		29,081		'		'
Current Liabilities	'		'		'		'
Accounts Payable	809		780		'		'
Labor and Fringe Benefits Payable	491		391		'		'
Payable to Affiliates	535		411		'		'
Current Maturities of Long-term Debt	333		80		'		'
Income and Other Taxes Payable	479		418		'		'
Other Current Liabilities	103		139		'		'
Total Current Liabilities	2,886		2,343		'		'
Long-term Debt	714		1,047		'		'
Deferred Income Taxes	8,548		8,131		'		'
Other Long-term Liabilities	512		656		'		'
Total Liabilities	12,891		12,433		'		'
Common Stock, $1 Par Value	181		181		'		'
Other Capital	5,077		5,672		'		'
Retained Earnings	12,514		10,874		'		'
Accumulated Other Comprehensive Loss	-43		-102		'		'
Noncontrolling Minority Interest	25		23		'		'
Total Shareholders' Equity	17,754		16,648		'		'
Total Liabilities and Shareholders' Equity	30,645		29,081		'		'
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	612		593		'		'
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	62		68		80		74
Short-term Investments	15		32		'		'
Accounts Receivable - Net	809		532		'		'
Receivable from Affiliates	-3,776		-2,791		'		'
Materials and Supplies	0		0		'		'
Deferred Income Taxes	-1		5		'		'
Other Current Assets	6		0		'		'
Total Current Assets	-2,885		-2,154		'		'
Properties	2,196		1,938		'		'
Accumulated Depreciation	-1,114		-996		'		'
Properties - Net	1,082		942		'		'
Other Long-term Assets	-14		-40		'		'
Total Assets	-21,318		-19,517		'		'
Current Liabilities	'		'		'		'
Accounts Payable	38		35		'		'
Labor and Fringe Benefits Payable	58		42		'		'
Payable to Affiliates	-3,833		-3,090		'		'
Current Maturities of Long-term Debt	0		0		'		'
Income and Other Taxes Payable	9		13		'		'
Other Current Liabilities	2		2		'		'
Total Current Liabilities	-3,711		-2,982		'		'
Long-term Debt	0		0		'		'
Deferred Income Taxes	178		118		'		'
Other Long-term Liabilities	-121		-100		'		'
Total Liabilities	-3,585		-2,883		'		'
Common Stock, $1 Par Value	-181		-181		'		'
Other Capital	-5,077		-5,672		'		'
Retained Earnings	-12,514		-10,874		'		'
Accumulated Other Comprehensive Loss	43		102		'		'
Noncontrolling Minority Interest	-4		-9		'		'
Total Shareholders' Equity	-17,733		-16,634		'		'
Total Liabilities and Shareholders' Equity	-21,318		-19,517		'		'
Eliminations and Other | Investments in Conrail	'		'		'		'
Current Assets	'		'		'		'
Investment in Affiliates, Subsidiaries, and Joint Ventures	752		695		'		'
Eliminations and Other | Affiliates and Other Companies	'		'		'		'
Current Assets	'		'		'		'
Investment in Affiliates, Subsidiaries, and Joint Ventures	-27		-43		'		'
Eliminations and Other | Investments in Consolidated Subsidiaries	'		'		'		'
Current Assets	'		'		'		'
Investment in Affiliates, Subsidiaries, and Joint Ventures	-20,226		-18,917		'		'
Casualty, Environmental and Other [Member]	'		'		'		'
Current Liabilities	'		'		'		'
Loss Contingency, Accrual, Noncurrent	300		337		'		'
Loss Contingency, Accrual, Current	151		140		'		'
Casualty, Environmental and Other [Member] | CSX Corporation	'		'		'		'
Current Liabilities	'		'		'		'
Loss Contingency, Accrual, Noncurrent	0		0		'		'
Loss Contingency, Accrual, Current	0		0		'		'
Casualty, Environmental and Other [Member] | CSX Transportation	'		'		'		'
Current Liabilities	'		'		'		'
Loss Contingency, Accrual, Noncurrent	231		256		'		'
Loss Contingency, Accrual, Current	136		124		'		'
Casualty, Environmental and Other [Member] | Eliminations and Other	'		'		'		'
Current Liabilities	'		'		'		'
Loss Contingency, Accrual, Noncurrent	69		81		'		'
Loss Contingency, Accrual, Current	$15		$16		'		'
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.

Summarized_Consolidating_Finan4

Summarized Consolidating Financial Data (Cash Flow Statements) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 27, 2013		Dec. 28, 2012		Dec. 30, 2011
Operating Activities	'		'		'
Net Cash Provided by Operating Activities	$3,267		$2,946	[1]	$3,491	[1]
Investing Activities	'		'		'
Property Additions	-2,313		-2,341	[1]	-2,297	[1]
Purchase of Short-term Investments	-1,256		-633	[1]	-492	[1]
Proceeds from Sales of Short-term Investments	1,401		581	[1]	74	[1]
Proceeds from Property Dispositions	53		186	[1]	240	[1]
Other Investing Activities	-112		-70	[1]	-112	[1]
Net Cash Used in Investing Activities	-2,227		-2,277	[1]	-2,587	[1]
Financing Activities	'		'		'
Long-term Debt Issued	500		1,100	[1]	1,200	[1]
Long-term Debt Repaid	-780		-508	[1]	-605	[1]
Payments of Ordinary Dividends, Common Stock	-600		-558	[1]	-480	[1]
Stock Options Exercised	9		14	[1]	29	[1]
Shares acquired, repurchase amount	-353		-734	[1]	-1,564	[1]
Other Financing Activities	-8		18	[1]	7	[1]
Net Cash Used in Financing Activities	-1,232		-668	[1]	-1,413	[1]
Net (Decrease) Increase in Cash and Cash Equivalents	-192		1	[1]	-509	[1]
Cash and Cash Equivalents at Beginning of Period	784	[1]	783	[1]	1,292	[1]
Cash and Cash Equivalents at End of Period	592	[1]	784	[1]	783	[1]
CSX Corporation	'		'		'
Operating Activities	'		'		'
Net Cash Provided by Operating Activities	1,004		579		1,231
Investing Activities	'		'		'
Property Additions	0		0		0
Purchase of Short-term Investments	-1,251		-605		-475
Proceeds from Sales of Short-term Investments	1,335		525		0
Proceeds from Property Dispositions	0		0		0
Other Investing Activities	-134		-10		-20
Net Cash Used in Investing Activities	-50		-90		-495
Financing Activities	'		'		'
Long-term Debt Issued	500		1,100		1,200
Long-term Debt Repaid	-700		-400		-507
Payments of Ordinary Dividends, Common Stock	-600		-558		-480
Stock Options Exercised	9		14		29
Shares acquired, repurchase amount	-353		-734		-1,564
Other Financing Activities	148		21		35
Net Cash Used in Financing Activities	-996		-557		-1,287
Net (Decrease) Increase in Cash and Cash Equivalents	-42		-68		-551
Cash and Cash Equivalents at Beginning of Period	481		549		1,100
Cash and Cash Equivalents at End of Period	439		481		549
CSX Transportation	'		'		'
Operating Activities	'		'		'
Net Cash Provided by Operating Activities	3,005		2,716		2,746
Investing Activities	'		'		'
Property Additions	-2,053		-2,104		-2,034
Purchase of Short-term Investments	0		0		0
Proceeds from Sales of Short-term Investments	0		0		0
Proceeds from Property Dispositions	53		186		239
Other Investing Activities	-315		102		-133
Net Cash Used in Investing Activities	-2,315		-1,816		-1,928
Financing Activities	'		'		'
Long-term Debt Issued	0		0		0
Long-term Debt Repaid	-80		-106		-95
Payments of Ordinary Dividends, Common Stock	-730		-715		-680
Stock Options Exercised	0		0		0
Shares acquired, repurchase amount	0		0		0
Other Financing Activities	-24		2		-7
Net Cash Used in Financing Activities	-834		-819		-782
Net (Decrease) Increase in Cash and Cash Equivalents	-144		81		36
Cash and Cash Equivalents at Beginning of Period	235		154		118
Cash and Cash Equivalents at End of Period	91		235		154
Eliminations and Other	'		'		'
Operating Activities	'		'		'
Net Cash Provided by Operating Activities	-742		-349		-486
Investing Activities	'		'		'
Property Additions	-260		-237		-263
Purchase of Short-term Investments	-5		-28		-17
Proceeds from Sales of Short-term Investments	66		56		74
Proceeds from Property Dispositions	0		0		1
Other Investing Activities	337		-162		41
Net Cash Used in Investing Activities	138		-371		-164
Financing Activities	'		'		'
Long-term Debt Issued	0		0		0
Long-term Debt Repaid	0		-2		-3
Payments of Ordinary Dividends, Common Stock	730		715		680
Stock Options Exercised	0		0		0
Shares acquired, repurchase amount	0		0		0
Other Financing Activities	-132		-5		-21
Net Cash Used in Financing Activities	598		708		656
Net (Decrease) Increase in Cash and Cash Equivalents	-6		-12		6
Cash and Cash Equivalents at Beginning of Period	68		80		74
Cash and Cash Equivalents at End of Period	$62		$68		$80
[1]	See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.