Summarized Consolidating Income Statements (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 28, 2013	Jun. 29, 2012	Jun. 28, 2013	Jun. 29, 2012
Consolidated Income Statement
Revenue	$ 3,069	$ 3,012	$ 6,027	$ 5,978
Expense	2,106	2,069	4,189	4,179
Operating Income	963	943	1,838	1,799
Equity in Earnings of Subsidiaries	0	0	0	0
Interest (Expense) / Benefit	(140)	(139)	(287)	(283)
Other Income / (Expense) - Net	9	5	6	9
Earnings Before Income Taxes	832	809	1,557	1,525
Income Tax (Expense) / Benefit	(297)	(297)	(563)	(564)
Net Earnings	535	512	994	961
Total Comprehensive Earnings	552	529	1,028	987
CSX Corporation [Member]
Consolidated Income Statement
Revenue	0	0	0	0
Expense	(92)	(89)	(185)	(176)
Operating Income	92	89	185	176
Equity in Earnings of Subsidiaries	550	557	1,036	1,034
Interest (Expense) / Benefit	(128)	(125)	(262)	(255)
Other Income / (Expense) - Net	(2)	(1)	(3)	(2)
Earnings Before Income Taxes	512	520	956	953
Income Tax (Expense) / Benefit	23	(8)	38	8
Net Earnings	535	512	994	961
Total Comprehensive Earnings	552	529	1,028	987
CSX Transportation [Member]
Consolidated Income Statement
Revenue	3,050	2,995	5,991	5,945
Expense	2,213	2,192	4,430	4,421
Operating Income	837	803	1,561	1,524
Equity in Earnings of Subsidiaries	0	0	(1)	(1)
Interest (Expense) / Benefit	(15)	(17)	(32)	(36)
Other Income / (Expense) - Net	(3)	1	(1)	4
Earnings Before Income Taxes	819	787	1,527	1,491
Income Tax (Expense) / Benefit	(303)	(270)	(565)	(533)
Net Earnings	516	517	962	958
Total Comprehensive Earnings	518	518	964	956
Eliminations and Other [Member]
Consolidated Income Statement
Revenue	19	17	36	33
Expense	(15)	(34)	(56)	(66)
Operating Income	34	51	92	99
Equity in Earnings of Subsidiaries	(550)	(557)	(1,035)	(1,033)
Interest (Expense) / Benefit	3	3	7	8
Other Income / (Expense) - Net	14	5	10	7
Earnings Before Income Taxes	(499)	(498)	(926)	(919)
Income Tax (Expense) / Benefit	(17)	(19)	(36)	(39)
Net Earnings	(516)	(517)	(962)	(958)
Total Comprehensive Earnings	$ (518)	$ (518)	$ (964)	$ (956)