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

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