CSX (CSX) 10-Q 16 Oct 13 2013 Q3 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	9 Months Ended
	Sep. 27, 2013
Document and Entity Information [Abstract]
Entity Registrant Name	CSX CORP
Entity Central Index Key	277948
Current Fiscal Year End Date	-15
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	1,013,674,361
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q3
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	27-Sep-13

CONSOLIDATED_INCOME_STATEMENTS

CONSOLIDATED INCOME STATEMENTS (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012
Income Statement
Revenue	$2,999	$2,894	$9,026	$8,872
Expense
Labor and Fringe	791	754	2,335	2,268
Materials, Supplies and Other	576	525	1,643	1,617
Fuel	407	397	1,248	1,251
Depreciation	277	268	823	788
Equipment and Other Rents	94	96	285	295
Total Expense	2,145	2,040	6,334	6,219
Operating Income	854	854	2,692	2,653
Interest Expense	-136	-138	-423	-421
Other Income - Net	5	5	11	14
Earnings Before Income Taxes	723	721	2,280	2,246
Income Tax Expense	-260	-266	-823	-830
Net Earnings	$463	$455	$1,457	$1,416
Per Common Share (Note 2)
Net Earnings Per Share, Basic (in dollars per share)	$0.46	$0.44	$1.43	$1.36
Net Earnings Per Share, Assuming Dilution (in dollars per share)	$0.46	$0.44	$1.43	$1.36
Average Shares Outstanding (in shares)	1,017	1,038	1,021	1,042
Average Shares Outstanding, Assuming Dilution (in shares)	1,018	1,040	1,021	1,044
Cash Dividends Paid Per Common Share (in dollars per share)	$0.15	$0.14	$0.44	$0.40

CONSOLIDATED_COMPREHENSIVE_INC

CONSOLIDATED COMPREHENSIVE INCOME STATEMENTS (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012
Statement of Comprehensive Income [Abstract]
Total Comprehensive Earnings (Note 10)	$479	$471	$1,507	$1,458

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 27, 2013	Dec. 28, 2012	Sep. 28, 2012	Dec. 30, 2011
In Millions, unless otherwise specified
Current Assets
Cash and Cash Equivalents	$591	$784	$693	$783
Short-term Investments	128	587
Accounts Receivable - Net (Note 1)	981	962
Materials and Supplies	267	274
Deferred Income Taxes	148	119
Other Current Assets	85	75
Total Current Assets	2,200	2,801
Properties	36,637	35,279
Accumulated Depreciation	-9,691	-9,229
Properties - Net	26,946	26,050
Other Long-term Assets	556	514
Total Assets	30,943	30,571
Current Liabilities
Accounts Payable	1,078	1,014
Labor and Fringe Benefits Payable	511	468
Current Maturities of Long-term Debt (Note 7)	264	780
Income and Other Taxes Payable	138	85
Other Current Liabilities	111	140
Total Current Liabilities	2,251	2,627
Long-term Debt (Note 7)	8,787	9,052
Deferred Income Taxes	8,387	8,096
Other Long-term Liabilities	1,366	1,457
Total Liabilities	21,075	21,569
Common Stock $1 Par Value	1,014	1,020
Other Capital	50	28
Retained Earnings	9,670	8,876
Accumulated Other Comprehensive Loss (Note 10)	-886	-936
Noncontrolling Interest	20	14
Total Shareholders' Equity	9,868	9,002
Total Liabilities and Shareholders' Equity	30,943	30,571
Casualty, Environmental and Other [Member]
Current Liabilities
Casualty, Environment and Otehr Reserves	149	140
Casualty, Environemnt and Other Reserves (Note 4)	284	337
Investments in Conrail [Member]
Current Assets
Investment in Affiliates and Joint Ventures	715	695
Affiliates and Other Companies [Member]
Current Assets
Investment in Affiliates and Joint Ventures	$526	$511

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Sep. 27, 2013	Dec. 28, 2012
Stockholders' Equity:
Common stock, par value (in dollars per share)	$1	$1

CONSOLIDATED_CASH_FLOW_STATEME

CONSOLIDATED CASH FLOW STATEMENTS (Unaudited) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012
OPERATING ACTIVITIES
Net Earnings	$1,457	$1,416
Adjustments to Reconcile Net Earnings to Net Cash Provided by Operating Activities:
Depreciation	823	788
Deferred Income Taxes	229	456
Contributions to Qualified Pension Plans	0	-275
Gain on Property Dispositions	-68	-72
Other Operating Activities	-53	-39
Changes in Operating Assets and Liabilities:
Accounts Receivable	-76	12
Other Current Assets	-6	-57
Accounts Payable	85	48
Income and Other Taxes Payable	66	148
Other Current Liabilities	42	-121
Net Cash Provided by Operating Activities	2,499	2,304
INVESTING ACTIVITIES
Property Additions	-1,687	-1,830
Purchase of Short-term Investments	-809	-78
Proceeds from Sales of Short-term Investments	1,307	573
Other Investing Activities	-54	10
Net Cash Used in Investing Activities	-1,243	-1,325
FINANCING ACTIVITIES
Long-term Debt Issued (Note 7)	0	300
Long-term Debt Repaid (Note 7)	-779	-481
Dividends Paid	-448	-415
Stock Options Exercised (Note 3)	9	11
Share Repurchased	-224	-500
Other Financing Activities	-7	16
Net Cash Used in Financing Activities	-1,449	-1,069
Net Decrease in Cash and Cash Equivalents	-193	-90
CASH AND CASH EQUIVALENTS
Cash and Cash Equivalents at Beginning of Period	784	783
Cash and Cash Equivalents at End of Period	$591	$693

Nature_of_Operations_and_Signi

Nature of Operations and Significant Accounting Policies	9 Months Ended
	Sep. 27, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations and Significant Accounting Policies	Nature of Operations and Significant Accounting Policies
	Background
	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.
	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. The Company's intermodal business, also part of CSXT, links customers to railroads via trucks and terminals.
	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 fairly present the following:
	•	Consolidated income statements for the quarters and nine months ended September 27, 2013 and September 28, 2012;
	•	Consolidated comprehensive income statements for the quarters and nine months ended September 27, 2013 and September 28, 2012;
	•	Consolidated balance sheets at September 27, 2013 and December 28, 2012; and
	•	Consolidated cash flow statements for the nine months ended September 27, 2013 and September 28, 2012.
	NOTE 1.	Nature of Operations and Significant Accounting Policies, continued
	Pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”), certain information and disclosures normally included in the notes to the annual financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) have been omitted from these interim financial statements. CSX suggests that these financial statements be read in conjunction with the audited financial statements and the notes included in CSX's most recent annual report on Form 10-K and any subsequently filed current reports on Form 8-K.
	Fiscal Year
	CSX follows a 52/53 week fiscal reporting calendar with the last day of each reporting period ending on a Friday:
	•	The third fiscal quarters of 2013 and 2012 consisted of 13 weeks ending on September 27, 2013 and September 28, 2012, respectively.
	•	Fiscal year 2013 and 2012 will each consist of 52 weeks ending on December 27, 2013 and December 28, 2012, respectively.
	Except as otherwise specified, references to “third quarter(s)” or “nine months” indicate CSX's fiscal periods ending September 27, 2013 and September 28, 2012, and references to "year-end" indicate the fiscal year ended December 28, 2012.
	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 the end of third quarter 2013 and December 2012, respectively.
	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.
	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. During third quarter 2013, CSX repurchased $129 million in shares. 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.
	Amortization of Gain from Property Disposition
	In November 2011, the Company sold an operating rail corridor to the state of Florida for a new commuter rail operation known as SunRail. This agreement 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 the eight year period following the transaction. The Company invested $80 million during third quarter 2012, and $142 million and $225 million for nine months 2013 and 2012, respectively. The required investment obligation was fulfilled during the second quarter of 2013.
	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 $30 million in the third quarter of 2012, and $43 million and $69 million for the nine months ended 2013 and 2012, respectively. No gains were recognized in the third quarter of 2013. This gain is included in materials, supplies and other in the consolidated income statements. Going forward, the Company expects no further material gains.

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 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:
		Third Quarters				Nine Months
		2013		2012		2013		2012
	Numerator (Dollars in millions):
	Net Earnings	$	463	$	455	$	1,457	$	1,416
	Denominator (Units in millions):
	Average Common Shares Outstanding	1,017		1,038		1,021		1,042
	Other Potentially Dilutive Common Shares (a)	1		2		—		2
	Average Common Shares Outstanding,	1,018		1,040		1,021		1,044
	Assuming Dilution
	Net Earnings Per Share, Basic	$	0.46	$	0.44	$	1.43	$	1.36
	Net Earnings Per Share, Assuming Dilution	$	0.46	$	0.44	$	1.43	$	1.36
	(a) 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.
	NOTE 2.    Earnings Per Share, continued
	Basic earnings per share is based on the weighted-average number 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.
	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 3, 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.  An immaterial amount of conversions occurred during third quarters 2013 and 2012. As of the end of third quarter 2013, approximately $2 million of convertible debentures at face value remained outstanding, which are convertible into approximately 244 thousand shares of CSX common stock.

ShareBased_Compensation

Share-Based Compensation	9 Months Ended
	Sep. 27, 2013
Share-based Compensation [Abstract]
Share-Based Compensation	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. CSX has not granted stock options since 2003. 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.
	On May 7, 2013, approximately 1.3 million performance units were granted to certain employees under a new long-term incentive plan ("LTIP") adopted under the CSX Stock and Incentive Award Plan.  This LTIP provides for a three-year cycle ending in fiscal year 2015.  Payouts of performance units will be based on the achievement of goals related to both operating ratio (operating expense divided by operating revenue) and return on assets (tax-adjusted operating income divided by net property) excluding non-recurring items as disclosed in the Company's financial statements. Operating ratio and return on assets will each comprise 50% of the payout and are measured independently of the other.
	NOTE 3.    Share-Based Compensation, continued
	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 the three-year cycle ending with fiscal year 2015.  Payouts for certain executive officers are subject to downward adjustment by up to 30% based upon total shareholder return relative to specified comparable groups.
	Additionally, as part of the 2013 LTIP, the Company granted approximately 439 thousand restricted stock units to certain employees on May 7, 2013.  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.
	Both performance units and restricted stock units require participants to be employed through the final day of the respective vesting period except in the case of death, disability or retirement.  For information related to the Company's other outstanding long-term incentive compensation, see CSX's most recent annual report on Form 10-K.
	Total pre-tax expense associated with all share-based compensation and the related income tax benefit are as follows:
		Third Quarters						Nine Months
	(Dollars in millions)	2013			2012			2013		2012
	Share-Based Compensation Expense	$	7		$	6		$	9	$	10
	Income Tax Benefit	3			3			4		4
	The following table provides information about stock options exercised and expired.
		Third Quarters					Nine Months
	(In thousands)	2013		2012			2013	2012
	Number of Stock Options Exercised	—		273			—	1,891
	Number of Stock Options Expired	—		—			—	15
	As of December 2009, all outstanding options were vested, and therefore, there will be no future expense related to these options.  As of the end of third quarter 2013, CSX had no stock options outstanding, as all remaining stock options expired in May 2013.

Casualty_Environmental_and_Oth

Casualty, Environmental and Other Reserves	9 Months Ended
	Sep. 27, 2013
Casualty, Environmental and Other Reserves [Abstract]
Casualty, Environmental and Other Reserves	Casualty, Environmental and Other Reserves
	Casualty, environmental and other 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:
		September 27,						December 28,
		2013						2012
	(Dollars in millions)	Current		Long-term		Total		Current		Long-term		Total
	Casualty:
	Personal Injury	$	79	$	122	$	201	$	75	$	158	$	233
	Occupational	4		23		27		5		31		36
	Asbestos	7		44		51		8		48		56
	Total Casualty	90		189		279		88		237		325
	Environmental	41		47		88		33		55		88
	Other	18		48		66		19		45		64
	Total	$	149	$	284	$	433	$	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 $279 million for the third quarter 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.
	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 4. 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 current or former employees alleging exposure to asbestos in the workplace.
	An analysis of occupational claims is performed quarterly by an independent third-party actuarial firm and reviewed by management. Management performs a quarterly review of asserted asbestos claims, and an analysis is performed annually by an independent third-party specialist and reviewed by management. The objective of the occupational and asbestos claims analyses performed by the third-party actuarial firm and specialist (the "third-party specialists") is to determine the number of incurred but not reported (“IBNR”) claims. 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.
	Environmental
	Environmental reserves were $88 million for the third quarter 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 242 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.
	In any such proceedings, the Company is subject to environmental clean-up and enforcement actions under the Superfund Law, as well as similar state laws that may impose joint and several liability for clean-up and enforcement costs on current and former owners and operators of a site without regard to fault or the legality of the original conduct. These costs could be substantial.
	NOTE 4. Casualty, Environmental and Other Reserves, continued
	In accordance with the Asset Retirement and Environmental Obligations Topic in the ASC, the Company reviews its role with respect to each site identified at least quarterly, giving consideration to a number of factors such as:
	•	type of clean-up required;
	•	nature of the Company's alleged connection to the location (e.g., generator of waste sent to the site or owner or operator of the site);
	•	extent of the Company's alleged connection (e.g., volume of waste sent to the location and other relevant factors); and
	•	number, connection and financial viability of other named and unnamed potentially responsible parties at the location.
	Based on the review process, the Company has recorded amounts to cover contingent anticipated future environmental remediation costs with respect to each site to the extent such costs are estimable and probable. The recorded liabilities for estimated future environmental costs are undiscounted. The liability includes future costs for remediation and restoration of sites as well as any significant ongoing monitoring costs, but excludes any anticipated insurance recoveries. Payments related to these liabilities are expected to be made over the next several years.
	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 $66 million for the third quarter 2013 include liabilities for various claims, such as longshoremen disability claims, and claims for property, automobile and general liability.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 27, 2013
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	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 liability and property 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 current insurance coverage is adequate to cover its damages, future claims could exceed existing insurance coverage or insurance may not continue to be available at commercially reasonable rates.
	NOTE 5.    Commitments and Contingencies, continued
	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 reasonably determined, considering, among other things, the legal defenses available and liabilities that have been recorded along with applicable insurance, it is currently the opinion of CSX management that none of these pending items will have a material adverse effect on the Company's financial condition, results of operations or liquidity. An unexpected adverse resolution of one or more of these items, however, could have a material adverse effect on the Company's financial condition, results of operations or liquidity in that particular period.
	The Company is able to estimate a range of possible loss for certain legal proceedings for which a loss is reasonably possible in excess of reserves established. The Company has estimated this range to be $3 million to $17 million in aggregate at September 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. On October 15, 2013, the District Court held a case management conference to determine the scope and schedule of the remand proceedings.  The parties were directed to confer and propose a schedule to the District Court on the remand proceedings. 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.

Employee_Benefit_Plans

Employee Benefit Plans	9 Months Ended
	Sep. 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.  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 actuaries to compute the amounts of liabilities and expenses relating to these plans subject to the assumptions that the Company selects.  These amounts are reviewed by management.  The following table describes the components of expense / (income) related to net benefit expense:
		Pension Benefits
	(Dollars in millions)	Third Quarters						Nine Months
		2013			2012			2013			2012
	Service Cost	$	12		$	11		$	37		$	33
	Interest Cost	27			31			81			92
	Expected Return on Plan Assets	(41		)	(43		)	(122		)	(124		)
	Amortization of Net Loss	25			21			75			62
	Total Expense	$	23		$	20		$	71		$	63
		Other Post-retirement Benefits
	(Dollars in millions)	Third Quarters						Nine Months
		2013			2012			2013			2012
	Service Cost	$	1		$	1		$	3		$	3
	Interest Cost	3			4			9			12
	Amortization of Net Loss	3			2			10			7
	Amortization of Prior Service Costs	—			—			(1		)	(1		)
	Total Expense	$	7		$	7		$	21		$	21
	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.  At this time, the Company anticipates that no contributions to its qualified pension plans will be required in 2013.

Debt_and_Credit_Agreements

Debt and Credit Agreements	9 Months Ended
	Sep. 27, 2013
Debt Disclosure [Abstract]
Debt and Credit Agreements	Debt and Credit Agreements
	Total activity related to long-term debt as of the end of third quarter 2013 was as follows:
	(Dollars in millions)	Current Portion			Long-term Portion			Total
	Long-term debt as of December 2012	$	780		$	9,052		$	9,832
	2013 activity:
	Long-term debt repaid	(779		)	—			(779		)
	Reclassifications	263			(263		)	—
	Discount and premium activity	—			(2		)	(2		)
	Long-term debt as of third quarter 2013	$	264		$	8,787		$	9,051
	For fair value information related to the Company's long-term debt, see Note 9, Fair Value Measurements.
	Credit Facility
	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. As of third quarter 2013, CSX was in compliance with all covenant requirements under this facility.
	Receivables Securitization Facility
	The Company's $250 million receivables securitization facility has a 364-day term and expires in June 2014. The Company's intention is to continue to renew this facility prior to its expiration. The purpose of this facility is to provide an alternative to commercial paper and a low cost source of short-term liquidity. As of the date of this filing, the Company has no outstanding balances under this facility.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 27, 2013
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	During third quarter 2013, the Company recorded an income tax benefit of $11 million, or $0.01 per share, primarily as a result of changes in state legislation. During the prior year's third quarter, the Company recorded an income tax benefit of $8 million, or $0.01 per share, primarily due to a property disposition that occurred in the period.
	There have been no material changes to the balance of unrecognized tax benefits during third quarters 2013 and 2012.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 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 and long-term debt. Disclosure of the fair value of pension plan assets is only required annually. Also, this rule clarifies the definition of fair value for financial reporting, establishes a framework for measuring fair value and requires additional disclosures about the use of fair value measurements.
	Various inputs are considered when determining the value of the Company's investments, pension plan assets and long-term debt. The inputs or methodologies used for valuing securities are not necessarily an indication of the risk associated with investing in these securities. These inputs are summarized in the three broad levels listed below.
	•	Level 1 - observable market inputs that are unadjusted quoted prices for identical assets or liabilities in active markets
	•	Level 2 - other significant observable inputs (including quoted prices for similar securities, interest rates, credit risk, etc.)
	•	Level 3 - significant unobservable inputs (including the Company's own assumptions 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.
	NOTE 9.    Fair Value Measurements, continued
	The Company's investment assets are carried at fair value on the consolidated balance sheets as summarized in the table below. Additionally, the amortized cost basis of these investments was $315 million and $742 million as of September 27, 2013 and December 28, 2012, respectively.
		September 27,									December 28,
		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	$	—	$	119		$	—	$	119	$	—	$	555	$	—	$	555
	Corporate Bonds	—		132			—		132		—		122		—		122
	Government Securities	—		50			—		50		—		51		—		51
	Auction Rate Securities	—		—			15		15		—		—		15		15
	Total investments at fair value	$	—	$	301		$	15	$	316	$	—	$	728	$	15	$	743
	Certain prior year amounts have been reclassified to conform to the current year presentation.
	These investments have the following maturities:
	(Dollars in millions)	September 27,			December 28,
		2013			2012
	Less than 1 year	$	128		$	587
	1 - 2 years	30			61
	2 - 5 years	140			76
	Greater than 5 years	18			19
	Total	$	316		$	743
	Long-term Debt
	Long-term debt is reported at carrying amount on the consolidated balance sheets and is the Company's only financial instrument with fair values significantly different from their carrying amounts. The majority of the Company's long-term debt is valued with assistance from an independent third party who utilizes closing transactions, market quotes or market values of comparable debt. For those instruments not valued by the third party, the fair value has been estimated by applying market rates of similar instruments to the scheduled contractual debt payments and maturities. These market rates are provided by the same third party. All of the inputs used to determine the fair value of the Company's long-term debt are Level 2 inputs.
	The fair value of outstanding debt fluctuates with changes in a number of factors. Such factors include, but are not limited to, interest rates, market conditions, values of similar financial instruments, size of the transaction, cash flow projections and comparable trades. Fair value will exceed carrying value when the current market interest rate is lower than the interest rate at which the debt was originally issued. The fair value of a company's debt is a measure of its current value under present market conditions. It does not impact the financial statements under current accounting rules.
	NOTE 9.    Fair Value Measurements, continued
	The fair value and carrying value of the Company's long-term debt is as follows:
	(Dollars in millions)	September 27,			December 28, 2012
		2013
	Long-term Debt (Including Current Maturities):
	Fair Value	$	9,884		$	11,562
	Carrying Value	$	9,051		$	9,832

Other_Comprehensive_Income

Other Comprehensive Income	9 Months Ended
	Sep. 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 $479 million and $471 million for third quarters 2013 and 2012, respectively, and $1,507 million and $1,458 million for nine months 2013 and 2012, respectively.
	While total comprehensive earnings is the activity in a period and is largely driven by net earnings in that period, accumulated other comprehensive income or loss (“AOCI”) represents the cumulative balance of other comprehensive income, net of tax, as of the balance sheet date. For CSX, AOCI is primarily the cumulative balance related to pension and other post-retirement benefit adjustments and CSX's share of AOCI of equity method investees. Changes in the AOCI balance by component are shown in the table below.
		Pension and Other Post-Employment Benefits			Other (b)			Accumulated Other Comprehensive Income (Loss)
	(Dollars in millions)
	Balance December 28, 2012, Net of Tax	$	(851	)	$	(85	)	$	(936	)
	Other Comprehensive Income (Loss)
	Amounts Reclassified to Net Earnings (a)	85			(2		)	83
	Tax Expense	(34		)	1			(33		)
	Total Other Comprehensive Income (Loss)	51			(1		)	50
	Balance September 27, 2013, Net of Tax	$	(800	)	$	(86	)	$	(886	)
	(a) 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 6. Employee Benefit Plans for further information.
	(b) 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.

Summarized_Consolidating_Finan

Summarized Consolidating Financial Data	9 Months Ended
	Sep. 27, 2013
Summarized Consolidating Financial Data [Abstract]
Summarized Consolidating Financial Data	Summarized Consolidating Financial Data
	In 2007, CSXT 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 as follows:
	Consolidating Income Statements
	(Dollars in millions)
	Third Quarter 2013	CSX Corporation			CSX Transportation			Eliminations and Other			Consolidated
	Revenue	$	—		$	2,979		$	20		$	2,999
	Expense	(98		)	2,247			(4		)	2,145
	Operating Income	98			732			24			854
	Equity in Earnings of Subsidiaries	491			—			(491		)	—
	Interest (Expense) / Benefit	(125		)	(15		)	4			(136		)
	Other Income / (Expense) - Net	(2		)	2			5			5
	Earnings Before Income Taxes	462			719			(458		)	723
	Income Tax Benefit / (Expense)	1			(260		)	(1		)	(260		)
	Net Earnings	$	463		$	459		$	(459	)	$	463
	Total Comprehensive Earnings	$	479		$	461		$	(461	)	$	479
	Third Quarter 2012	CSX Corporation			CSX Transportation			Eliminations and Other			Consolidated
	Revenue	$	—		$	2,878		$	16		$	2,894
	Expense	(90		)	2,166			(36		)	2,040
	Operating Income	90			712			52			854
	Equity in Earnings of Subsidiaries	478			—			(478		)	—
	Interest (Expense) / Benefit	(126		)	(17		)	5			(138		)
	Other Income / (Expense) - Net	(1		)	2			4			5
	Earnings Before Income Taxes	441			697			(417		)	721
	Income Tax (Expense) / Benefit	14			(262		)	(18		)	(266		)
	Net Earnings	$	455		$	435		$	(435	)	$	455
	Total Comprehensive Earnings	$	471		$	437		$	(437	)	$	471
	Consolidating Income Statements
	(Dollars in millions)
	Nine Months Ended September 27, 2013	CSX Corporation			CSX Transportation			Eliminations and Other			Consolidated
	Revenue	$	—		$	8,970		$	56		$	9,026
	Expense	(283		)	6,677			(60		)	6,334
	Operating Income	283			2,293			116			2,692
	Equity in Earnings of Subsidiaries	1,527			(1		)	(1,526		)	—
	Interest (Expense) / Benefit	(387		)	(47		)	11			(423		)
	Other Income / (Expense) - Net	(5		)	1			15			11
	Earnings Before Income Taxes	1,418			2,246			(1,384		)	2,280
	Income Tax (Expense) / Benefit	39			(825		)	(37		)	(823		)
	Net Earnings	$	1,457		$	1,421		$	(1,421	)	$	1,457
	Total Comprehensive Earnings	$	1,507		$	1,425		$	(1,425	)	$	1,507
	Nine Months Ended September 28, 2012	CSX Corporation			CSX Transportation			Eliminations and Other			Consolidated
	Revenue	$	—		$	8,823		$	49		$	8,872
	Expense	(266		)	6,587			(102		)	6,219
	Operating Income	266			2,236			151			2,653
	Equity in Earnings of Subsidiaries	1,512			(1		)	(1,511		)	—
	Interest (Expense) / Benefit	(381		)	(53		)	13			(421		)
	Other Income / (Expense) - Net	(3		)	6			11			14
	Earnings Before Income Taxes	1,394			2,188			(1,336		)	2,246
	Income Tax (Expense) / Benefit	22			(795		)	(57		)	(830		)
	Net Earnings	$	1,416		$	1,393		$	(1,393	)	$	1,416
	Total Comprehensive Earnings	$	1,458		$	1,393		$	(1,393	)	$	1,458
	Consolidating Balance Sheet
	(Dollars in millions)
	As of September 2013	CSX Corporation			CSX Transportation			Eliminations and Other			Consolidated
	ASSETS
	Current Assets
	Cash and Cash Equivalents	$	432		$	101		$	58		$	591
	Short-term Investments	120			—			8			128
	Accounts Receivable - Net	2			363			616			981
	Receivable from Affiliates	1,179			2,389			(3,568		)	—
	Materials and Supplies	—			267			—			267
	Deferred Income Taxes	(3		)	152			(1		)	148
	Other Current Assets	11			61			13			85
	Total Current Assets	1,741			3,333			(2,874		)	2,200
Properties	3			34,535			2,099			36,637
Accumulated Depreciation	(3		)	(8,606		)	(1,082		)	(9,691		)
Properties - Net	—			25,929			1,017			26,946
Investments in Conrail	—			—			715			715
Affiliates and Other Companies	(39		)	607			(42		)	526
Investments in Consolidated Subsidiaries	19,766			—			(19,766		)	—
Other Long-term Assets	180			384			(8		)	556
Total Assets	$	21,648		$	30,253		$	(20,958	)	$	30,943
LIABILITIES AND SHAREHOLDERS' EQUITY
Current Liabilities
Accounts Payable	$	143		$	898		$	37		$	1,078
Labor and Fringe Benefits Payable	36			429			46			511
Payable to Affiliates	3,309			481			(3,790		)	—
Casualty, Environmental and Other Reserves	—			134			15			149
Current Maturities of Long-term Debt	200			64			—			264
Income and Other Taxes Payable	(379		)	490			27			138
Other Current Liabilities	—			109			2			111
Total Current Liabilities	3,309			2,605			(3,663		)	2,251
Casualty, Environmental and Other Reserves	—			217			67			284
Long-term Debt	7,808			979			—			8,787
Deferred Income Taxes	(204		)	8,448			143			8,387
Other Long-term Liabilities	887			603			(124		)	1,366
Total Liabilities	$	11,800		$	12,852		$	(3,577	)	$	21,075
Shareholders' Equity
Common Stock, $1 Par Value	$	1,014		$	181		$	(181	)	$	1,014
Other Capital	50			5,077			(5,077		)	50
Retained Earnings	9,670			12,217			(12,217		)	9,670
Accumulated Other Comprehensive Loss	(886		)	(98		)	98			(886		)
Noncontrolling Interest	—			24			(4		)	20
Total Shareholders' Equity	$	9,848		$	17,401		$	(17,381	)	$	9,868
Total Liabilities and Shareholders' Equity	$	21,648		$	30,253		$	(20,958	)	$	30,943
Consolidating Balance Sheet
(Dollars in millions)
As of December 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			427			532			962
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			2,860			(2,154		)	2,801
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	18,783			—			(18,783		)	—
Other Long-term Assets	186			368			(40		)	514
Total Assets	$	21,025		$	28,929		$	(19,383	)	$	30,571
LIABILITIES AND SHAREHOLDERS' EQUITY
Current Liabilities
Accounts Payable	$	133		$	846		$	35		$	1,014
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		)	334			13			85
Other Current Liabilities	(1		)	139			2			140
Total Current Liabilities	3,284			2,325			(2,982		)	2,627
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		$	12,415		$	(2,883	)	$	21,569
Shareholders' Equity
Common Stock, $1 Par Value	$	1,020		$	181		$	(181	)	$	1,020
Other Capital	28			5,672			(5,672		)	28
Retained Earnings	8,876			10,740			(10,740		)	8,876
Accumulated Other Comprehensive Loss	(936		)	(102		)	102			(936		)
Noncontrolling Minority Interest	—			23			(9		)	14
Total Shareholders' Equity	$	8,988		$	16,514		$	(16,500	)	$	9,002
Total Liabilities and Shareholders' Equity	$	21,025		$	28,929		$	(19,383	)	$	30,571
Consolidating Cash Flow Statements
(Dollars in millions)
Nine months ended September 27, 2013	CSX			CSX			Eliminations and Other			Consolidated
	Corporation			Transportation
Operating Activities
Net Cash Provided by (Used in) Operating Activities	$	871		$	2,106		$	(478	)	$	2,499
Investing Activities
Property Additions	—			(1,522		)	(165		)	(1,687		)
Purchases of Short-term Investments	(805		)	—			(4		)	(809		)
Proceeds from Sales of Short-term Investments	1,240			—			67			1,307
Other Investing Activities	(4		)	(76		)	26			(54		)
Net Cash Provided by (Used in) Investing Activities	431			(1,598		)	(76		)	(1,243		)
Financing Activities
Long-term Debt Issued	—			—			—			—
Long-term Debt Repaid	(700		)	(79		)	—			(779		)
Dividends Paid	(448		)	(548		)	548			(448		)
Stock Options Exercised	9			—			—			9
Shares Repurchased	(224		)	—			—			(224		)
Other Financing Activities	12			(15		)	(4		)	(7		)
Net Cash Provided by (Used in) Financing Activities	(1,351		)	(642		)	544			(1,449		)
Net Increase (Decrease) in Cash and Cash Equivalents	(49		)	(134		)	(10		)	(193		)
Cash and Cash Equivalents at Beginning of Period	481			235			68			784
Cash and Cash Equivalents at End of	$	432		$	101		$	58		$	591
Period
NOTE 11.    Summarized Consolidating Financial Data, continued
Consolidating Cash Flow Statements
(Dollars in millions)
Nine months ended September 28, 2012	CSX			CSX			Eliminations and Other			Consolidated
	Corporation			Transportation
Operating Activities
Net Cash Provided by (Used in) Operating Activities	$	429		$	2,202		$	(327	)	$	2,304
Investing Activities
Property Additions	—			(1,669		)	(161		)	(1,830		)
Purchases of Short-term Investments	(50		)	—			(28		)	(78		)
Proceeds from Sales of Short-term Investments	525			—			48			573
Other Investing Activities	(6		)	78			(62		)	10
Net Cash Provided by (Used in) Investing Activities	469			(1,591		)	(203		)	(1,325		)
Financing Activities
Long-term Debt Issued	300			—			—			300
Long-term Debt Repaid	(400		)	(79		)	(2		)	(481		)
Dividends Paid	(415		)	(536		)	536			(415		)
Stock Options Exercised	11			—			—			11
Shares Repurchased	(500		)	—			—			(500		)
Other Financing Activities	15			3			(2		)	16
Net Cash Provided by (Used in) Financing Activities	(989		)	(612		)	532			(1,069		)
Net Increase (Decrease) in Cash and Cash Equivalents	(91		)	(1		)	2			(90		)
Cash and Cash Equivalents at Beginning of Period	549			154			80			783
Cash and Cash Equivalents at End of Period	$	458		$	153		$	82		$	693

Nature_of_Operations_and_Signi1

Nature of Operations and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 27, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation
	In the opinion of management, the accompanying consolidated financial statements contain all normal, recurring adjustments necessary to fairly present the following:
	•	Consolidated income statements for the quarters and nine months ended September 27, 2013 and September 28, 2012;
	•	Consolidated comprehensive income statements for the quarters and nine months ended September 27, 2013 and September 28, 2012;
	•	Consolidated balance sheets at September 27, 2013 and December 28, 2012; and
	•	Consolidated cash flow statements for the nine months ended September 27, 2013 and September 28, 2012.
	NOTE 1.	Nature of Operations and Significant Accounting Policies, continued
	Pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”), certain information and disclosures normally included in the notes to the annual financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) have been omitted from these interim financial statements. CSX suggests that these financial statements be read in conjunction with the audited financial statements and the notes included in CSX's most recent annual report on Form 10-K and any subsequently filed current reports on Form 8-K.
Fiscal Year	Fiscal Year
	CSX follows a 52/53 week fiscal reporting calendar with the last day of each reporting period ending on a Friday:
	•	The third fiscal quarters of 2013 and 2012 consisted of 13 weeks ending on September 27, 2013 and September 28, 2012, respectively.
	•	Fiscal year 2013 and 2012 will each consist of 52 weeks ending on December 27, 2013 and December 28, 2012, respectively.
	Except as otherwise specified, references to “third quarter(s)” or “nine months” indicate CSX's fiscal periods ending September 27, 2013 and September 28, 2012, and references to "year-end" indicate the fiscal year ended December 28, 2012.
Allowance for Doubtfull Accounts	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.
New Accounting Pronouncements	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.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 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:
		Third Quarters				Nine Months
		2013		2012		2013		2012
	Numerator (Dollars in millions):
	Net Earnings	$	463	$	455	$	1,457	$	1,416
	Denominator (Units in millions):
	Average Common Shares Outstanding	1,017		1,038		1,021		1,042
	Other Potentially Dilutive Common Shares (a)	1		2		—		2
	Average Common Shares Outstanding,	1,018		1,040		1,021		1,044
	Assuming Dilution
	Net Earnings Per Share, Basic	$	0.46	$	0.44	$	1.43	$	1.36
	Net Earnings Per Share, Assuming Dilution	$	0.46	$	0.44	$	1.43	$	1.36
	(a) 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.

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 27, 2013
Share-based Compensation [Abstract]
Share-based compensation and related income tax benefit	Total pre-tax expense associated with all share-based compensation and the related income tax benefit are as follows:
		Third Quarters						Nine Months
	(Dollars in millions)	2013			2012			2013		2012
	Share-Based Compensation Expense	$	7		$	6		$	9	$	10
	Income Tax Benefit	3			3			4		4
Stock options exercised	The following table provides information about stock options exercised and expired.
		Third Quarters					Nine Months
	(In thousands)	2013		2012			2013	2012
	Number of Stock Options Exercised	—		273			—	1,891
	Number of Stock Options Expired	—		—			—	15

Casualty_Environmental_and_Oth1

Casualty, Environmental and Other Reserves (Tables)	9 Months Ended
	Sep. 27, 2013
Casualty, Environmental and Other Reserves [Abstract]
Casualty, environmental and other reserves	Casualty, environmental and other 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:
		September 27,						December 28,
		2013						2012
	(Dollars in millions)	Current		Long-term		Total		Current		Long-term		Total
	Casualty:
	Personal Injury	$	79	$	122	$	201	$	75	$	158	$	233
	Occupational	4		23		27		5		31		36
	Asbestos	7		44		51		8		48		56
	Total Casualty	90		189		279		88		237		325
	Environmental	41		47		88		33		55		88
	Other	18		48		66		19		45		64
	Total	$	149	$	284	$	433	$	140	$	337	$	477

Employee_Benefit_Plans_Tables

Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 27, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Components of expense/(income) related to net benefit expense	The following table describes the components of expense / (income) related to net benefit expense:
		Pension Benefits
	(Dollars in millions)	Third Quarters						Nine Months
		2013			2012			2013			2012
	Service Cost	$	12		$	11		$	37		$	33
	Interest Cost	27			31			81			92
	Expected Return on Plan Assets	(41		)	(43		)	(122		)	(124		)
	Amortization of Net Loss	25			21			75			62
	Total Expense	$	23		$	20		$	71		$	63
		Other Post-retirement Benefits
	(Dollars in millions)	Third Quarters						Nine Months
		2013			2012			2013			2012
	Service Cost	$	1		$	1		$	3		$	3
	Interest Cost	3			4			9			12
	Amortization of Net Loss	3			2			10			7
	Amortization of Prior Service Costs	—			—			(1		)	(1		)
	Total Expense	$	7		$	7		$	21		$	21

Debt_and_Credit_Agreements_Tab

Debt and Credit Agreements (Tables)	9 Months Ended
	Sep. 27, 2013
Debt Disclosure [Abstract]
Activity related to long-term debt	Total activity related to long-term debt as of the end of third quarter 2013 was as follows:
	(Dollars in millions)	Current Portion			Long-term Portion			Total
	Long-term debt as of December 2012	$	780		$	9,052		$	9,832
	2013 activity:
	Long-term debt repaid	(779		)	—			(779		)
	Reclassifications	263			(263		)	—
	Discount and premium activity	—			(2		)	(2		)
	Long-term debt as of third quarter 2013	$	264		$	8,787		$	9,051

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 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 these investments was $315 million and $742 million as of September 27, 2013 and December 28, 2012, respectively.
		September 27,									December 28,
		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	$	—	$	119		$	—	$	119	$	—	$	555	$	—	$	555
	Corporate Bonds	—		132			—		132		—		122		—		122
	Government Securities	—		50			—		50		—		51		—		51
	Auction Rate Securities	—		—			15		15		—		—		15		15
	Total investments at fair value	$	—	$	301		$	15	$	316	$	—	$	728	$	15	$	743
	Certain prior year amounts have been reclassified to conform to the current year presentation.
Schedule of investment maturities	These investments have the following maturities:
	(Dollars in millions)	September 27,			December 28,
		2013			2012
	Less than 1 year	$	128		$	587
	1 - 2 years	30			61
	2 - 5 years	140			76
	Greater than 5 years	18			19
	Total	$	316		$	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)	September 27,			December 28, 2012
		2013
	Long-term Debt (Including Current Maturities):
	Fair Value	$	9,884		$	11,562
	Carrying Value	$	9,051		$	9,832

Other_Comprehensive_Income_Tab

Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 27, 2013
Equity [Abstract]
Changes in AOCI balance by component	Changes in the AOCI balance by component are shown in the table below.
		Pension and Other Post-Employment Benefits			Other (b)			Accumulated Other Comprehensive Income (Loss)
	(Dollars in millions)
	Balance December 28, 2012, Net of Tax	$	(851	)	$	(85	)	$	(936	)
	Other Comprehensive Income (Loss)
	Amounts Reclassified to Net Earnings (a)	85			(2		)	83
	Tax Expense	(34		)	1			(33		)
	Total Other Comprehensive Income (Loss)	51			(1		)	50
	Balance September 27, 2013, Net of Tax	$	(800	)	$	(86	)	$	(886	)
	(a) 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 6. Employee Benefit Plans for further information.
	(b) 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.

Summarized_Consolidating_Finan1

Summarized Consolidating Financial Data (Tables)	9 Months Ended
	Sep. 27, 2013
Summarized Consolidating Financial Data [Abstract]
Consolidating Income Statements
	Consolidating Income Statements
	(Dollars in millions)
	Third Quarter 2013	CSX Corporation			CSX Transportation			Eliminations and Other			Consolidated
	Revenue	$	—		$	2,979		$	20		$	2,999
	Expense	(98		)	2,247			(4		)	2,145
	Operating Income	98			732			24			854
	Equity in Earnings of Subsidiaries	491			—			(491		)	—
	Interest (Expense) / Benefit	(125		)	(15		)	4			(136		)
	Other Income / (Expense) - Net	(2		)	2			5			5
	Earnings Before Income Taxes	462			719			(458		)	723
	Income Tax Benefit / (Expense)	1			(260		)	(1		)	(260		)
	Net Earnings	$	463		$	459		$	(459	)	$	463
	Total Comprehensive Earnings	$	479		$	461		$	(461	)	$	479
	Third Quarter 2012	CSX Corporation			CSX Transportation			Eliminations and Other			Consolidated
	Revenue	$	—		$	2,878		$	16		$	2,894
	Expense	(90		)	2,166			(36		)	2,040
	Operating Income	90			712			52			854
	Equity in Earnings of Subsidiaries	478			—			(478		)	—
	Interest (Expense) / Benefit	(126		)	(17		)	5			(138		)
	Other Income / (Expense) - Net	(1		)	2			4			5
	Earnings Before Income Taxes	441			697			(417		)	721
	Income Tax (Expense) / Benefit	14			(262		)	(18		)	(266		)
	Net Earnings	$	455		$	435		$	(435	)	$	455
	Total Comprehensive Earnings	$	471		$	437		$	(437	)	$	471
	Consolidating Income Statements
	(Dollars in millions)
	Nine Months Ended September 27, 2013	CSX Corporation			CSX Transportation			Eliminations and Other			Consolidated
	Revenue	$	—		$	8,970		$	56		$	9,026
	Expense	(283		)	6,677			(60		)	6,334
	Operating Income	283			2,293			116			2,692
	Equity in Earnings of Subsidiaries	1,527			(1		)	(1,526		)	—
	Interest (Expense) / Benefit	(387		)	(47		)	11			(423		)
	Other Income / (Expense) - Net	(5		)	1			15			11
	Earnings Before Income Taxes	1,418			2,246			(1,384		)	2,280
	Income Tax (Expense) / Benefit	39			(825		)	(37		)	(823		)
	Net Earnings	$	1,457		$	1,421		$	(1,421	)	$	1,457
	Total Comprehensive Earnings	$	1,507		$	1,425		$	(1,425	)	$	1,507
	Nine Months Ended September 28, 2012	CSX Corporation			CSX Transportation			Eliminations and Other			Consolidated
	Revenue	$	—		$	8,823		$	49		$	8,872
	Expense	(266		)	6,587			(102		)	6,219
	Operating Income	266			2,236			151			2,653
	Equity in Earnings of Subsidiaries	1,512			(1		)	(1,511		)	—
	Interest (Expense) / Benefit	(381		)	(53		)	13			(421		)
	Other Income / (Expense) - Net	(3		)	6			11			14
	Earnings Before Income Taxes	1,394			2,188			(1,336		)	2,246
	Income Tax (Expense) / Benefit	22			(795		)	(57		)	(830		)
	Net Earnings	$	1,416		$	1,393		$	(1,393	)	$	1,416
	Total Comprehensive Earnings	$	1,458		$	1,393		$	(1,393	)	$	1,458
Consolidating Balance Sheet
	Consolidating Balance Sheet
	(Dollars in millions)
	As of September 2013	CSX Corporation			CSX Transportation			Eliminations and Other			Consolidated
	ASSETS
	Current Assets
	Cash and Cash Equivalents	$	432		$	101		$	58		$	591
	Short-term Investments	120			—			8			128
	Accounts Receivable - Net	2			363			616			981
	Receivable from Affiliates	1,179			2,389			(3,568		)	—
	Materials and Supplies	—			267			—			267
	Deferred Income Taxes	(3		)	152			(1		)	148
	Other Current Assets	11			61			13			85
	Total Current Assets	1,741			3,333			(2,874		)	2,200
	Properties	3			34,535			2,099			36,637
	Accumulated Depreciation	(3		)	(8,606		)	(1,082		)	(9,691		)
	Properties - Net	—			25,929			1,017			26,946
	Investments in Conrail	—			—			715			715
	Affiliates and Other Companies	(39		)	607			(42		)	526
	Investments in Consolidated Subsidiaries	19,766			—			(19,766		)	—
	Other Long-term Assets	180			384			(8		)	556
	Total Assets	$	21,648		$	30,253		$	(20,958	)	$	30,943
	LIABILITIES AND SHAREHOLDERS' EQUITY
	Current Liabilities
	Accounts Payable	$	143		$	898		$	37		$	1,078
	Labor and Fringe Benefits Payable	36			429			46			511
	Payable to Affiliates	3,309			481			(3,790		)	—
	Casualty, Environmental and Other Reserves	—			134			15			149
	Current Maturities of Long-term Debt	200			64			—			264
	Income and Other Taxes Payable	(379		)	490			27			138
	Other Current Liabilities	—			109			2			111
	Total Current Liabilities	3,309			2,605			(3,663		)	2,251
	Casualty, Environmental and Other Reserves	—			217			67			284
	Long-term Debt	7,808			979			—			8,787
	Deferred Income Taxes	(204		)	8,448			143			8,387
	Other Long-term Liabilities	887			603			(124		)	1,366
	Total Liabilities	$	11,800		$	12,852		$	(3,577	)	$	21,075
	Shareholders' Equity
	Common Stock, $1 Par Value	$	1,014		$	181		$	(181	)	$	1,014
	Other Capital	50			5,077			(5,077		)	50
	Retained Earnings	9,670			12,217			(12,217		)	9,670
	Accumulated Other Comprehensive Loss	(886		)	(98		)	98			(886		)
	Noncontrolling Interest	—			24			(4		)	20
	Total Shareholders' Equity	$	9,848		$	17,401		$	(17,381	)	$	9,868
	Total Liabilities and Shareholders' Equity	$	21,648		$	30,253		$	(20,958	)	$	30,943
	Consolidating Balance Sheet
	(Dollars in millions)
	As of December 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			427			532			962
	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			2,860			(2,154		)	2,801
	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	18,783			—			(18,783		)	—
Other Long-term Assets	186			368			(40		)	514
Total Assets	$	21,025		$	28,929		$	(19,383	)	$	30,571
LIABILITIES AND SHAREHOLDERS' EQUITY
Current Liabilities
Accounts Payable	$	133		$	846		$	35		$	1,014
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		)	334			13			85
Other Current Liabilities	(1		)	139			2			140
Total Current Liabilities	3,284			2,325			(2,982		)	2,627
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		$	12,415		$	(2,883	)	$	21,569
Shareholders' Equity
Common Stock, $1 Par Value	$	1,020		$	181		$	(181	)	$	1,020
Other Capital	28			5,672			(5,672		)	28
Retained Earnings	8,876			10,740			(10,740		)	8,876
Accumulated Other Comprehensive Loss	(936		)	(102		)	102			(936		)
Noncontrolling Minority Interest	—			23			(9		)	14
Total Shareholders' Equity	$	8,988		$	16,514		$	(16,500	)	$	9,002
Total Liabilities and Shareholders' Equity	$	21,025		$	28,929		$	(19,383	)	$	30,571
Consolidating Cash Flow Statements
	Consolidating Cash Flow Statements
	(Dollars in millions)
	Nine months ended September 27, 2013	CSX			CSX			Eliminations and Other			Consolidated
		Corporation			Transportation
	Operating Activities
	Net Cash Provided by (Used in) Operating Activities	$	871		$	2,106		$	(478	)	$	2,499
	Investing Activities
	Property Additions	—			(1,522		)	(165		)	(1,687		)
	Purchases of Short-term Investments	(805		)	—			(4		)	(809		)
	Proceeds from Sales of Short-term Investments	1,240			—			67			1,307
	Other Investing Activities	(4		)	(76		)	26			(54		)
	Net Cash Provided by (Used in) Investing Activities	431			(1,598		)	(76		)	(1,243		)
	Financing Activities
	Long-term Debt Issued	—			—			—			—
	Long-term Debt Repaid	(700		)	(79		)	—			(779		)
	Dividends Paid	(448		)	(548		)	548			(448		)
	Stock Options Exercised	9			—			—			9
	Shares Repurchased	(224		)	—			—			(224		)
	Other Financing Activities	12			(15		)	(4		)	(7		)
	Net Cash Provided by (Used in) Financing Activities	(1,351		)	(642		)	544			(1,449		)
	Net Increase (Decrease) in Cash and Cash Equivalents	(49		)	(134		)	(10		)	(193		)
	Cash and Cash Equivalents at Beginning of Period	481			235			68			784
	Cash and Cash Equivalents at End of	$	432		$	101		$	58		$	591
	Period
	NOTE 11.    Summarized Consolidating Financial Data, continued
	Consolidating Cash Flow Statements
	(Dollars in millions)
	Nine months ended September 28, 2012	CSX			CSX			Eliminations and Other			Consolidated
		Corporation			Transportation
	Operating Activities
	Net Cash Provided by (Used in) Operating Activities	$	429		$	2,202		$	(327	)	$	2,304
	Investing Activities
	Property Additions	—			(1,669		)	(161		)	(1,830		)
	Purchases of Short-term Investments	(50		)	—			(28		)	(78		)
	Proceeds from Sales of Short-term Investments	525			—			48			573
	Other Investing Activities	(6		)	78			(62		)	10
	Net Cash Provided by (Used in) Investing Activities	469			(1,591		)	(203		)	(1,325		)
	Financing Activities
	Long-term Debt Issued	300			—			—			300
	Long-term Debt Repaid	(400		)	(79		)	(2		)	(481		)
	Dividends Paid	(415		)	(536		)	536			(415		)
	Stock Options Exercised	11			—			—			11
	Shares Repurchased	(500		)	—			—			(500		)
	Other Financing Activities	15			3			(2		)	16
	Net Cash Provided by (Used in) Financing Activities	(989		)	(612		)	532			(1,069		)
	Net Increase (Decrease) in Cash and Cash Equivalents	(91		)	(1		)	2			(90		)
	Cash and Cash Equivalents at Beginning of Period	549			154			80			783
	Cash and Cash Equivalents at End of Period	$	458		$	153		$	82		$	693

Nature_of_Operations_and_Signi2

Nature of Operations and Significant Accounting Policies (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012	Dec. 28, 2012
	states		states
	mi		mi
Background
Total number of rail route miles	21,000		21,000
Rail network states number	23		23
Fiscal Year
Number of weeks in fiscal quarter	P13W	P13W	P39W	P39W
Number of weeks in fiscal year			P52W		P52W
Allowance for Doubtful Accounts
Allowance for doubtful accounts	$33		$33		$36

Nature_of_Operations_and_Signi3

Nature of Operations and Significant Accounting Policies (Share Repurchases and Dividend Increase) (Details) (USD $)	1 Months Ended	3 Months Ended	9 Months Ended
	Apr. 30, 2013	Sep. 27, 2013	Sep. 27, 2013	Sep. 28, 2012
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Share repurchase program	$1,000,000,000
Share Repurchased		$129,000,000	$224,000,000	$500,000,000

Nature_of_Operations_and_Signi4

Nature of Operations and Significant Accounting Policies (Amortization of Gain from Property Disposition) (Details) (USD $)	9 Months Ended		3 Months Ended		9 Months Ended			1 Months Ended	3 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012	Nov. 30, 2011	Nov. 30, 2011	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012
	mi		SunRail Transaction - Sale of Corridor [Member]	SunRail Transaction - Sale of Corridor [Member]	SunRail Transaction - Sale of Corridor [Member]	SunRail Transaction - Sale of Corridor [Member]	SunRail Transaction - Sale of Corridor [Member]	Capital Additions [Member]	Capital Additions [Member]	Capital Additions [Member]	Capital Additions [Member]
								SunRail Transaction - Sale of Corridor [Member]	SunRail Transaction - Sale of Corridor [Member]	SunRail Transaction - Sale of Corridor [Member]	SunRail Transaction - Sale of Corridor [Member]
Significant Acquisitions and Disposals [Line Items]
Total number of rail route miles	21,000
Obligation to invest in routine captial expenditures and maintenance								$500
Obligation to invest in routine captial expenditures and maintenance, term (in years)								8 years
Investment obligation made during the period	1,687	1,830							80	142	225
Gain on sale of real estate			0	30	43	69
Deferred gain on sale of real estate							$160

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended				9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 27, 2013		Sep. 28, 2012		Sep. 27, 2013		Sep. 28, 2012
Numerator:
Net Earnings	$463		$455		$1,457		$1,416
Denominator:
Average Common Shares Outstanding (in shares)	1,017,000,000		1,038,000,000		1,021,000,000		1,042,000,000
Other Potentially Dilutive Common Shares (in shares)	1,000,000	[1]	2,000,000	[1]	0	[1]	2,000,000	[1]
Average Common Shares Outstanding, Assuming Dilution (in shares)	1,018,000,000		1,040,000,000		1,021,000,000		1,044,000,000
Net Earnings Per Share, Basic (in dollars per share):	$0.46		$0.44		$1.43		$1.36
Net Earnings Per Share, Assuming Dilution (in dollars per share):	$0.46		$0.44		$1.43		$1.36
Number of stock options excluded from the diluted earnings per share					0
Convertible Debt [Member]
Denominator:
Face value of convertible debentures still outstanding at the end of the period	$2				$2
Common Stock [Member]
Denominator:
Number of shares of common stock converted from outstanding convertible debentures					244,000
[1]	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.

ShareBased_Compensation_Detail

Share-Based Compensation (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

0 Months Ended

9 Months Ended

Share data in Thousands, unless otherwise specified

Sep. 27, 2013

Sep. 28, 2012

Sep. 27, 2013

Sep. 28, 2012

Sep. 27, 2013

Sep. 28, 2012

Sep. 27, 2013

Sep. 28, 2012

Dec. 25, 2009

Sep. 27, 2013

7-May-13

7-May-13

Sep. 27, 2013

Sep. 27, 2013

Stock Options [Member]

Stock Options [Member]

Stock Options [Member]

Stock Options [Member]

Stock Options [Member]

2013 LTIP [Member]

2013 LTIP [Member]

2013 LTIP [Member]

2013 LTIP [Member]

2013 LTIP [Member]

Performance Units [Member]

Restricted Stock Units (RSUs) [Member]

Minimum [Member]

Maximum [Member]

Share-based Compensation

Units granted as part of the 2013 LTIP

1,300

439

Percentage Of Grants With Performance Vesting, Operating Ratio

50.00%

Percentage Of Grants With Performance Vesting, Return On Assets

50.00%

Payout percentage of the target awards (percent)

0.00%

200.00%

Maximum downward adjustment to payout percentage

30.00%

Restricted stock vesting period

3 years

Share-Based Compensation Expense

$7,000,000

$6,000,000

$9,000,000

$10,000,000

Income Tax Benefit

3,000,000

3,000,000

4,000,000

4,000,000

Number of Stock Options Exercised

0

273

0

1,891

Number of Stock Options Expired

0

0

0

15

Future expense related to vested options

$0

Number of Stock Options Outstanding

0

0

Casualty_Environmental_and_Oth2

Casualty, Environmental and Other Reserves (Details) (USD $)	Sep. 27, 2013	Dec. 28, 2012
In Millions, unless otherwise specified	claims
Casualty [Member]
All Contingencies Reserves [Line Items]
Loss Contingency, Accrual, Current (Note 4)	$90	$88
Loss Contingency, Accrual, Noncurrent (Note 4)	189	237
Loss Contingency, Accrual, Total	279	325
Self-insured retention amount, per occurrence	50
Number of Claims Expected to Exceed Self Insured Retention Amount	0
Personal Injury [Member]
All Contingencies Reserves [Line Items]
Loss Contingency, Accrual, Current (Note 4)	79	75
Loss Contingency, Accrual, Noncurrent (Note 4)	122	158
Loss Contingency, Accrual, Total	201	233
Occupational [Member]
All Contingencies Reserves [Line Items]
Loss Contingency, Accrual, Current (Note 4)	4	5
Loss Contingency, Accrual, Noncurrent (Note 4)	23	31
Loss Contingency, Accrual, Total	27	36
Asbestos [Member]
All Contingencies Reserves [Line Items]
Loss Contingency, Accrual, Current (Note 4)	7	8
Loss Contingency, Accrual, Noncurrent (Note 4)	44	48
Loss Contingency, Accrual, Total	51	56
Environmental [Member]
All Contingencies Reserves [Line Items]
Loss Contingency, Accrual, Current (Note 4)	41	33
Loss Contingency, Accrual, Noncurrent (Note 4)	47	55
Loss Contingency, Accrual, Total	88	88
Environmental impaired sites	242
Other [Member]
All Contingencies Reserves [Line Items]
Loss Contingency, Accrual, Current (Note 4)	18	19
Loss Contingency, Accrual, Noncurrent (Note 4)	48	45
Loss Contingency, Accrual, Total	66	64
Casualty, Environmental and Other [Member]
All Contingencies Reserves [Line Items]
Loss Contingency, Accrual, Current (Note 4)	149	140
Loss Contingency, Accrual, Noncurrent (Note 4)	284	337
Loss Contingency, Accrual, Total	$433	$477

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	1 Months Ended
In Millions, unless otherwise specified	31-May-07	Sep. 27, 2013
	entity
Insurance
Non-catastrophic property deductible		$25
Casualty and catastrophic property deductible		50
Legal
Range of possible loss for certain legal proceedings, minimum		3
Range of possible loss for certain legal proceedings, maximum		$17
Class action lawsuits filed against U.S.-based Class I railroads, excluding CSXT (number of entities)	3

Employee_Benefit_Plans_Details

Employee Benefit Plans (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012
Components of expense/ (income) related to net benefit expense:
Employer contribution to qualified pension plans, required minimum amount			$0
Pension Benefits [Member]
Components of expense/ (income) related to net benefit expense:
Service Cost	12,000,000	11,000,000	37,000,000	33,000,000
Interest Cost	27,000,000	31,000,000	81,000,000	92,000,000
Expected Return on Plan Assets	-41,000,000	-43,000,000	-122,000,000	-124,000,000
Amortization of Net Loss	25,000,000	21,000,000	75,000,000	62,000,000
Total Expense	23,000,000	20,000,000	71,000,000	63,000,000
Other Post-retirement Benefits [Member]
Components of expense/ (income) related to net benefit expense:
Service Cost	1,000,000	1,000,000	3,000,000	3,000,000
Interest Cost	3,000,000	4,000,000	9,000,000	12,000,000
Amortization of Net Loss	3,000,000	2,000,000	10,000,000	7,000,000
Amortization of Prior Service Costs	0	0	-1,000,000	-1,000,000
Total Expense	$7,000,000	$7,000,000	$21,000,000	$21,000,000

Debt_and_Credit_Agreements_Det

Debt and Credit Agreements (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012
Movement, Debt Instruments [Roll Forward]
Current Portion	$780
Long-term Portion	9,052
Long-term Debt, Total	9,832
Long-term Debt Repaid	-779	-481
Reclassifications	0
Discount and premium activity	-2
Current Portion	264
Long-term Debt Portion	8,787
Long-term Debt, Total	9,051
Current Liabilities [Member]
Movement, Debt Instruments [Roll Forward]
Current Portion	780
Long-term Debt Repaid	-779
Reclassifications	263
Discount and premium activity	0
Current Portion	264
Long Term Liabilities [Member]
Movement, Debt Instruments [Roll Forward]
Long-term Portion	9,052
Long-term Debt Repaid	0
Reclassifications	-263
Discount and premium activity	-2
Long-term Debt Portion	$8,787

Debt_and_Credit_Agreements_Lin

Debt and Credit Agreements - Line of Credit Facility (Details) (USD $)	9 Months Ended
	Sep. 27, 2013
Revolving credit facility
Line of Credit Facility
Line of credit facility, current borrowing capacity	$1,000,000,000
Line of Credit Facility, Expiration Date	30-Sep-16
Line of credit facility, amount outstanding	0
Receivable securitization facility
Line of Credit Facility
Line of credit facility, current borrowing capacity	250,000,000
Debt Instrument, Term	364 days
Line of Credit Facility, Expiration Date	30-Jun-14
Line of credit facility, amount outstanding	$0

Income_Taxes_Income_Taxes_Deta

Income Taxes Income Taxes (Details) (USD $)	3 Months Ended
	Sep. 27, 2013	Sep. 28, 2012
Income Tax Disclosure [Abstract]
Income tax benefit	$11,000,000	$8,000,000
Income tax benefit per share (in dollars per share)	$0.01	$0.01

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Sep. 27, 2013	Dec. 28, 2012
In Millions, unless otherwise specified
Fair Value [Member]
Fair Value, by Balance Sheet Grouping
Investments	$316	$743
Fair Value [Member] | Less than 1 year [Member]
Fair Value, by Balance Sheet Grouping
Investments	128	587
Fair Value [Member] | 1 - 2 years [Member]
Fair Value, by Balance Sheet Grouping
Investments	30	61
Fair Value [Member] | 2 - 5 years [Member]
Fair Value, by Balance Sheet Grouping
Investments	140	76
Fair Value [Member] | Greater than 5 years [Member]
Fair Value, by Balance Sheet Grouping
Investments	18	19
Fair Value [Member] | Certificates of Deposit and Commercial Paper [Member]
Fair Value, by Balance Sheet Grouping
Investments	119	555
Fair Value [Member] | Corporate Bonds [Member]
Fair Value, by Balance Sheet Grouping
Investments	132	122
Fair Value [Member] | Government Securities [Member]
Fair Value, by Balance Sheet Grouping
Investments	50	51
Fair Value [Member] | Auction Rate Securities [Member]
Fair Value, by Balance Sheet Grouping
Investments	15	15
Fair Value [Member] | Level 1 [Member]
Fair Value, by Balance Sheet Grouping
Investments	0	0
Fair Value [Member] | Level 1 [Member] | Certificates of Deposit and Commercial Paper [Member]
Fair Value, by Balance Sheet Grouping
Investments	0	0
Fair Value [Member] | Level 1 [Member] | Corporate Bonds [Member]
Fair Value, by Balance Sheet Grouping
Investments	0	0
Fair Value [Member] | Level 1 [Member] | Government Securities [Member]
Fair Value, by Balance Sheet Grouping
Investments	0	0
Fair Value [Member] | Level 1 [Member] | Auction Rate Securities [Member]
Fair Value, by Balance Sheet Grouping
Investments	0	0
Fair Value [Member] | Level 2 [Member]
Fair Value, by Balance Sheet Grouping
Investments	301	728
Long-term Debt (Including Current Maturities)	9,884	11,562
Fair Value [Member] | Level 2 [Member] | Certificates of Deposit and Commercial Paper [Member]
Fair Value, by Balance Sheet Grouping
Investments	119	555
Fair Value [Member] | Level 2 [Member] | Corporate Bonds [Member]
Fair Value, by Balance Sheet Grouping
Investments	132	122
Fair Value [Member] | Level 2 [Member] | Government Securities [Member]
Fair Value, by Balance Sheet Grouping
Investments	50	51
Fair Value [Member] | Level 2 [Member] | Auction Rate Securities [Member]
Fair Value, by Balance Sheet Grouping
Investments	0	0
Fair Value [Member] | Level 3 [Member]
Fair Value, by Balance Sheet Grouping
Investments	15	15
Fair Value [Member] | Level 3 [Member] | Certificates of Deposit and Commercial Paper [Member]
Fair Value, by Balance Sheet Grouping
Investments	0	0
Fair Value [Member] | Level 3 [Member] | Corporate Bonds [Member]
Fair Value, by Balance Sheet Grouping
Investments	0	0
Fair Value [Member] | Level 3 [Member] | Government Securities [Member]
Fair Value, by Balance Sheet Grouping
Investments	0	0
Fair Value [Member] | Level 3 [Member] | Auction Rate Securities [Member]
Fair Value, by Balance Sheet Grouping
Investments	15	15
Carrying Value [Member]
Fair Value, by Balance Sheet Grouping
Amortized cost basis of investments	315	742
Carrying Value [Member] | Level 2 [Member]
Fair Value, by Balance Sheet Grouping
Long-term Debt (Including Current Maturities)	$9,051	$9,832

Other_Comprehensive_Income_Det

Other Comprehensive Income (Details) (USD $)	3 Months Ended			9 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2013		Sep. 28, 2012	Sep. 27, 2013		Sep. 28, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total Comprehensive Earnings (Note 10)	$479		$471	$1,507		$1,458
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance December 28, 2012, Net of Tax				-936
Other Comprehensive Income (Loss)
Amounts Reclassified to Net Earnings				83	[1]
Tax Expense				-33
Total Other Comprehensive Income (Loss)				50
Balance September 27, 2013, Net of Tax	-886			-886
Pension and Other Post-Employment Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance December 28, 2012, Net of Tax				-851
Other Comprehensive Income (Loss)
Amounts Reclassified to Net Earnings				85	[1]
Tax Expense				-34
Total Other Comprehensive Income (Loss)				51
Balance September 27, 2013, Net of Tax	-800			-800
Other [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance December 28, 2012, Net of Tax				-85	[2]
Other Comprehensive Income (Loss)
Amounts Reclassified to Net Earnings				-2	[1],[2]
Tax Expense				1	[2]
Total Other Comprehensive Income (Loss)				-1	[2]
Balance September 27, 2013, Net of Tax	($86)	[2]		($86)	[2]
[1]	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 6. Employee Benefit Plans for further information.
[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.

Summarized_Consolidating_Incom

Summarized Consolidating Income Statements (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012
Consolidated Income Statement
Revenue	$2,999	$2,894	$9,026	$8,872
Expense	2,145	2,040	6,334	6,219
Operating Income	854	854	2,692	2,653
Equity in Earnings of Subsidiaries	0	0	0	0
Interest (Expense) / Benefit	-136	-138	-423	-421
Other Income / (Expense) - Net	5	5	11	14
Earnings Before Income Taxes	723	721	2,280	2,246
Income Tax (Expense) / Benefit	-260	-266	-823	-830
Net Earnings	463	455	1,457	1,416
Total Comprehensive Earnings	479	471	1,507	1,458
CSX Corporation [Member]
Consolidated Income Statement
Revenue	0	0	0	0
Expense	-98	-90	-283	-266
Operating Income	98	90	283	266
Equity in Earnings of Subsidiaries	491	478	1,527	1,512
Interest (Expense) / Benefit	-125	-126	-387	-381
Other Income / (Expense) - Net	-2	-1	-5	-3
Earnings Before Income Taxes	462	441	1,418	1,394
Income Tax (Expense) / Benefit	1	14	39	22
Net Earnings	463	455	1,457	1,416
Total Comprehensive Earnings	479	471	1,507	1,458
CSX Transportation [Member]
Consolidated Income Statement
Revenue	2,979	2,878	8,970	8,823
Expense	2,247	2,166	6,677	6,587
Operating Income	732	712	2,293	2,236
Equity in Earnings of Subsidiaries	0	0	-1	-1
Interest (Expense) / Benefit	-15	-17	-47	-53
Other Income / (Expense) - Net	2	2	1	6
Earnings Before Income Taxes	719	697	2,246	2,188
Income Tax (Expense) / Benefit	-260	-262	-825	-795
Net Earnings	459	435	1,421	1,393
Total Comprehensive Earnings	461	437	1,425	1,393
Eliminations and Other [Member]
Consolidated Income Statement
Revenue	20	16	56	49
Expense	-4	-36	-60	-102
Operating Income	24	52	116	151
Equity in Earnings of Subsidiaries	-491	-478	-1,526	-1,511
Interest (Expense) / Benefit	4	5	11	13
Other Income / (Expense) - Net	5	4	15	11
Earnings Before Income Taxes	-458	-417	-1,384	-1,336
Income Tax (Expense) / Benefit	-1	-18	-37	-57
Net Earnings	-459	-435	-1,421	-1,393
Total Comprehensive Earnings	($461)	($437)	($1,425)	($1,393)

Summarized_Consolidating_Balan

Summarized Consolidating Balance Sheet (Details) (USD $)	Sep. 27, 2013	Dec. 28, 2012	Sep. 28, 2012	Dec. 30, 2011
In Millions, unless otherwise specified
Current Assets
Cash and Cash Equivalents	$591	$784	$693	$783
Short-term Investments	128	587
Accounts Receivable - Net	981	962
Receivable from Affiliates	0	0
Materials and Supplies	267	274
Deferred Income Taxes	148	119
Other Current Assets	85	75
Total Current Assets	2,200	2,801
Properties	36,637	35,279
Accumulated Depreciation	-9,691	-9,229
Properties - Net	26,946	26,050
Other Long-term Assets	556	514
Total Assets	30,943	30,571
Current Liabilities
Accounts Payable	1,078	1,014
Labor and Fringe Benefits Payable	511	468
Payable to Affiliates	0	0
Current Maturities of Long-term Debt	264	780
Income and Other Taxes Payable	138	85
Other Current Liabilities	111	140
Total Current Liabilities	2,251	2,627
Long-term Debt	8,787	9,052
Deferred Income Taxes	8,387	8,096
Other Long-term Liabilities	1,366	1,457
Total Liabilities	21,075	21,569
Shareholders' Equity
Common Stock $1 Par Value	1,014	1,020
Other Capital	50	28
Retained Earnings	9,670	8,876
Accumulated Other Comprehensive Loss	-886	-936
Noncontrolling Interest	20	14
Total Shareholders' Equity	9,868	9,002
Total Liabilities and Shareholders' Equity	30,943	30,571
Casualty, Environmental and Other [Member]
Current Liabilities
Loss Contingency, Accrual, Current (Note 4)	149	140
Loss Contingency, Accrual, Noncurrent (Note 4)	284	337
Investments in Conrail [Member]
Current Assets
Investment in Affiliates, Subsidiaries, and Joint Ventures	715	695
Affiliates and Other Companies [Member]
Current Assets
Investment in Affiliates, Subsidiaries, and Joint Ventures	526	511
Investments in Consolidated Subsidiaries [Member]
Current Assets
Investment in Affiliates, Subsidiaries, and Joint Ventures	0	0
CSX Corporation [Member]
Current Assets
Cash and Cash Equivalents	432	481	458	549
Short-term Investments	120	555
Accounts Receivable - Net	2	3
Receivable from Affiliates	1,179	993
Materials and Supplies	0	0
Deferred Income Taxes	-3	52
Other Current Assets	11	11
Total Current Assets	1,741	2,095
Properties	3	8
Accumulated Depreciation	-3	-8
Properties - Net	0	0
Other Long-term Assets	180	186
Total Assets	21,648	21,025
Current Liabilities
Accounts Payable	143	133
Labor and Fringe Benefits Payable	36	35
Payable to Affiliates	3,309	2,679
Current Maturities of Long-term Debt	200	700
Income and Other Taxes Payable	-379	-262
Other Current Liabilities	0	-1
Total Current Liabilities	3,309	3,284
Long-term Debt	7,808	8,005
Deferred Income Taxes	-204	-153
Other Long-term Liabilities	887	901
Total Liabilities	11,800	12,037
Shareholders' Equity
Common Stock $1 Par Value	1,014	1,020
Other Capital	50	28
Retained Earnings	9,670	8,876
Accumulated Other Comprehensive Loss	-886	-936
Noncontrolling Interest	0	0
Total Shareholders' Equity	9,848	8,988
Total Liabilities and Shareholders' Equity	21,648	21,025
CSX Corporation [Member] | Casualty, Environmental and Other [Member]
Current Liabilities
Loss Contingency, Accrual, Current (Note 4)	0	0
Loss Contingency, Accrual, Noncurrent (Note 4)	0	0
CSX Corporation [Member] | Investments in Conrail [Member]
Current Assets
Investment in Affiliates, Subsidiaries, and Joint Ventures	0	0
CSX Corporation [Member] | Affiliates and Other Companies [Member]
Current Assets
Investment in Affiliates, Subsidiaries, and Joint Ventures	-39	-39
CSX Corporation [Member] | Investments in Consolidated Subsidiaries [Member]
Current Assets
Investment in Affiliates, Subsidiaries, and Joint Ventures	19,766	18,783
CSX Transportation [Member]
Current Assets
Cash and Cash Equivalents	101	235	153	154
Short-term Investments	0	0
Accounts Receivable - Net	363	427
Receivable from Affiliates	2,389	1,798
Materials and Supplies	267	274
Deferred Income Taxes	152	62
Other Current Assets	61	64
Total Current Assets	3,333	2,860
Properties	34,535	33,333
Accumulated Depreciation	-8,606	-8,225
Properties - Net	25,929	25,108
Other Long-term Assets	384	368
Total Assets	30,253	28,929
Current Liabilities
Accounts Payable	898	846
Labor and Fringe Benefits Payable	429	391
Payable to Affiliates	481	411
Current Maturities of Long-term Debt	64	80
Income and Other Taxes Payable	490	334
Other Current Liabilities	109	139
Total Current Liabilities	2,605	2,325
Long-term Debt	979	1,047
Deferred Income Taxes	8,448	8,131
Other Long-term Liabilities	603	656
Total Liabilities	12,852	12,415
Shareholders' Equity
Common Stock $1 Par Value	181	181
Other Capital	5,077	5,672
Retained Earnings	12,217	10,740
Accumulated Other Comprehensive Loss	-98	-102
Noncontrolling Interest	24	23
Total Shareholders' Equity	17,401	16,514
Total Liabilities and Shareholders' Equity	30,253	28,929
CSX Transportation [Member] | Casualty, Environmental and Other [Member]
Current Liabilities
Loss Contingency, Accrual, Current (Note 4)	134	124
Loss Contingency, Accrual, Noncurrent (Note 4)	217	256
CSX Transportation [Member] | Investments in Conrail [Member]
Current Assets
Investment in Affiliates, Subsidiaries, and Joint Ventures	0	0
CSX Transportation [Member] | Affiliates and Other Companies [Member]
Current Assets
Investment in Affiliates, Subsidiaries, and Joint Ventures	607	593
CSX Transportation [Member] | Investments in Consolidated Subsidiaries [Member]
Current Assets
Investment in Affiliates, Subsidiaries, and Joint Ventures	0	0
Eliminations and Other [Member]
Current Assets
Cash and Cash Equivalents	58	68	82	80
Short-term Investments	8	32
Accounts Receivable - Net	616	532
Receivable from Affiliates	-3,568	-2,791
Materials and Supplies	0	0
Deferred Income Taxes	-1	5
Other Current Assets	13	0
Total Current Assets	-2,874	-2,154
Properties	2,099	1,938
Accumulated Depreciation	-1,082	-996
Properties - Net	1,017	942
Other Long-term Assets	-8	-40
Total Assets	-20,958	-19,383
Current Liabilities
Accounts Payable	37	35
Labor and Fringe Benefits Payable	46	42
Payable to Affiliates	-3,790	-3,090
Current Maturities of Long-term Debt	0	0
Income and Other Taxes Payable	27	13
Other Current Liabilities	2	2
Total Current Liabilities	-3,663	-2,982
Long-term Debt	0	0
Deferred Income Taxes	143	118
Other Long-term Liabilities	-124	-100
Total Liabilities	-3,577	-2,883
Shareholders' Equity
Common Stock $1 Par Value	-181	-181
Other Capital	-5,077	-5,672
Retained Earnings	-12,217	-10,740
Accumulated Other Comprehensive Loss	98	102
Noncontrolling Interest	-4	-9
Total Shareholders' Equity	-17,381	-16,500
Total Liabilities and Shareholders' Equity	-20,958	-19,383
Eliminations and Other [Member] | Casualty, Environmental and Other [Member]
Current Liabilities
Loss Contingency, Accrual, Current (Note 4)	15	16
Loss Contingency, Accrual, Noncurrent (Note 4)	67	81
Eliminations and Other [Member] | Investments in Conrail [Member]
Current Assets
Investment in Affiliates, Subsidiaries, and Joint Ventures	715	695
Eliminations and Other [Member] | Affiliates and Other Companies [Member]
Current Assets
Investment in Affiliates, Subsidiaries, and Joint Ventures	-42	-43
Eliminations and Other [Member] | Investments in Consolidated Subsidiaries [Member]
Current Assets
Investment in Affiliates, Subsidiaries, and Joint Ventures	($19,766)	($18,783)

Summarized_Consolidating_Cash_

Summarized Consolidating Cash Flow Statements (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012
Operating Activities
Net Cash Provided by (Used in) Operating Activities	$2,499	$2,304
Investing Activities
Property Additions	-1,687	-1,830
Purchase of Short-term Investments	-809	-78
Proceeds from Sales of Short-term Investments	1,307	573
Other Investing Activities	-54	10
Net Cash Provided by (Used in) Investing Activities	-1,243	-1,325
Financing Activities
Long-term Debt Issued	0	300
Long-term Debt Repaid	-779	-481
Dividends Paid	-448	-415
Stock Options Exercised	9	11
Share Repurchased	-224	-500
Other Financing Activities	-7	16
Net Cash Used in Financing Activities	-1,449	-1,069
Net Decrease in Cash and Cash Equivalents	-193	-90
Cash and Cash Equivalents at Beginning of Period	784	783
Cash and Cash Equivalents at End of Period	591	693
CSX Corporation [Member]
Operating Activities
Net Cash Provided by (Used in) Operating Activities	871	429
Investing Activities
Property Additions	0	0
Purchase of Short-term Investments	-805	-50
Proceeds from Sales of Short-term Investments	1,240	525
Other Investing Activities	-4	-6
Net Cash Provided by (Used in) Investing Activities	431	469
Financing Activities
Long-term Debt Issued	0	300
Long-term Debt Repaid	-700	-400
Dividends Paid	-448	-415
Stock Options Exercised	9	11
Share Repurchased	-224	-500
Other Financing Activities	12	15
Net Cash Used in Financing Activities	-1,351	-989
Net Decrease in Cash and Cash Equivalents	-49	-91
Cash and Cash Equivalents at Beginning of Period	481	549
Cash and Cash Equivalents at End of Period	432	458
CSX Transportation [Member]
Operating Activities
Net Cash Provided by (Used in) Operating Activities	2,106	2,202
Investing Activities
Property Additions	-1,522	-1,669
Purchase of Short-term Investments	0	0
Proceeds from Sales of Short-term Investments	0	0
Other Investing Activities	-76	78
Net Cash Provided by (Used in) Investing Activities	-1,598	-1,591
Financing Activities
Long-term Debt Issued	0	0
Long-term Debt Repaid	-79	-79
Dividends Paid	-548	-536
Stock Options Exercised	0	0
Share Repurchased	0	0
Other Financing Activities	-15	3
Net Cash Used in Financing Activities	-642	-612
Net Decrease in Cash and Cash Equivalents	-134	-1
Cash and Cash Equivalents at Beginning of Period	235	154
Cash and Cash Equivalents at End of Period	101	153
Eliminations and Other [Member]
Operating Activities
Net Cash Provided by (Used in) Operating Activities	-478	-327
Investing Activities
Property Additions	-165	-161
Purchase of Short-term Investments	-4	-28
Proceeds from Sales of Short-term Investments	67	48
Other Investing Activities	26	-62
Net Cash Provided by (Used in) Investing Activities	-76	-203
Financing Activities
Long-term Debt Issued	0	0
Long-term Debt Repaid	0	-2
Dividends Paid	548	536
Stock Options Exercised	0	0
Share Repurchased	0	0
Other Financing Activities	-4	-2
Net Cash Used in Financing Activities	544	532
Net Decrease in Cash and Cash Equivalents	-10	2
Cash and Cash Equivalents at Beginning of Period	68	80
Cash and Cash Equivalents at End of Period	$58	$82