Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended
	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.