Debt and Credit Agreements (Details) (USD $)	6 Months Ended			1 Months Ended		1 Months Ended
	Jul. 01, 2011	Jul. 01, 2011 Current Liabilities	Jul. 01, 2011 Long Term Liabilities	May 31, 2011 Notes Payable 4.25% Note Due June 2021	May 20, 2011 Notes Payable 4.25% Note Due June 2021	May 31, 2011 Notes Payable 5.50% Note Due April 2041	May 20, 2011 Notes Payable 5.50% Note Due April 2041
Current and Long Term Debt Instrument
Debt Instrument, Face Amount					$ 350,000,000		$ 250,000,000
Debt Instrument, Maturity Date				Jun. 01, 2021		Apr. 15, 2041
Movement, Debt Instruments [Roll Forward]
Current Portion	613,000,000	613,000,000
Long-term Portion	8,051,000,000		8,051,000,000
Long-term Debt	8,664,000,000
Long-term debt issued	600,000,000	0	600,000,000
Long-term debt repaid	(570,000,000)	(570,000,000)	0
Reclassifications	0	456,000,000	(456,000,000)
Debt conversions to CSX stock	(5,000,000)	(5,000,000)	0
Discount and premium activity	(9,000,000)	0	(9,000,000)
Current Portion	494,000,000	494,000,000
Long-term Debt Portion	8,186,000,000		8,186,000,000
Long-term Debt	$ 8,680,000,000