Summarized Consolidating Balance Sheet (Details) (USD $) In Millions	Jul. 01, 2011	Dec. 31, 2010	Jun. 25, 2010	Dec. 25, 2009
Current Assets
Cash and Cash Equivalents	$ 1,252	$ 1,292	$ 633	$ 1,029
Short-term Investments	43	54
Accounts Receivable - Net	1,112	993
Receivable from Affiliates	0	0
Materials and Supplies	251	218
Deferred Income Taxes	186	192
Other Current Assets	123	106
Total Current Assets	2,967	2,855
Properties	32,777	32,065
Accumulated Depreciation	(8,575)	(8,266)
Properties - Net	24,202	23,799
Investments in Conrail	681	673
Affiliates and Other Companies	477	461
Investments in Consolidated Subsidiaries	0	0
Other Long-term Assets	378	353
Total Assets	28,705	28,141
Current Liabilities
Accounts Payable	1,076	1,046
Labor and Fringe Benefits Payable	430	520
Payable to Affiliates	0	0
Casualty, Environmental and Other Reserves	180	176
Current Maturities of Long-term Debt	494	613
Income and Other Taxes Payable	137	85
Other Current Liabilities	168	97
Total Current Liabilities	2,485	2,537
Casualty, Evironmental and Other Reserves	468	502
Long-term Debt	8,186	8,051
Deferred Income Taxes	7,340	7,053
Other Long-term Liabilities	1,285	1,298
Total Liabilities	19,764	19,441
Shareholders' Equity
Common Stock, $1 Par Value	1,095	370
Other Capital	0	0
Retained Earnings	8,582	9,087
Accumulated Other Comprehensive Loss	(747)	(771)
Noncontrolling Interest	11	14
Total Shareholders' Equity	8,941	8,700
Total Liabilities and Shareholders' Equity	28,705	28,141
CSX Corporation
Current Assets
Cash and Cash Equivalents	988	1,100	435	918
Short-term Investments	0	0
Accounts Receivable - Net	5	5
Receivable from Affiliates	1,158	1,048
Materials and Supplies	0	0
Deferred Income Taxes	0	15
Other Current Assets	76	46
Total Current Assets	2,227	2,214
Properties	8	8
Accumulated Depreciation	(8)	(8)
Properties - Net	0	0
Investments in Conrail	0	0
Affiliates and Other Companies	0	0
Investments in Consolidated Subsidiaries	16,926	16,278
Other Long-term Assets	167	174
Total Assets	19,320	18,666
Current Liabilities
Accounts Payable	107	116
Labor and Fringe Benefits Payable	34	42
Payable to Affiliates	2,251	1,942
Casualty, Environmental and Other Reserves	0	0
Current Maturities of Long-term Debt	405	517
Income and Other Taxes Payable	465	378
Other Current Liabilities	0	0
Total Current Liabilities	3,262	2,995
Casualty, Evironmental and Other Reserves	0	0
Long-term Debt	7,008	6,815
Deferred Income Taxes	(572)	(526)
Other Long-term Liabilities	693	696
Total Liabilities	10,391	9,980
Shareholders' Equity
Common Stock, $1 Par Value	1,095	370
Other Capital	0	0
Retained Earnings	8,582	9,087
Accumulated Other Comprehensive Loss	(748)	(771)
Noncontrolling Interest	0	0
Total Shareholders' Equity	8,929	8,686
Total Liabilities and Shareholders' Equity	19,320	18,666
CSX Transportation
Current Assets
Cash and Cash Equivalents	190	118	97	30
Short-term Investments	0	0
Accounts Receivable - Net	428	447
Receivable from Affiliates	1,443	943
Materials and Supplies	251	218
Deferred Income Taxes	181	171
Other Current Assets	67	56
Total Current Assets	2,560	1,953
Properties	31,206	30,557
Accumulated Depreciation	(7,683)	(7,405)
Properties - Net	23,523	23,152
Investments in Conrail	0	0
Affiliates and Other Companies	558	595
Investments in Consolidated Subsidiaries	0	0
Other Long-term Assets	108	110
Total Assets	26,749	25,810
Current Liabilities
Accounts Payable	938	904
Labor and Fringe Benefits Payable	373	431
Payable to Affiliates	568	401
Casualty, Environmental and Other Reserves	165	161
Current Maturities of Long-term Debt	87	94
Income and Other Taxes Payable	126	109
Other Current Liabilities	167	96
Total Current Liabilities	2,424	2,196
Casualty, Evironmental and Other Reserves	383	411
Long-term Debt	1,178	1,235
Deferred Income Taxes	7,485	7,228
Other Long-term Liabilities	515	525
Total Liabilities	11,985	11,595
Shareholders' Equity
Common Stock, $1 Par Value	181	181
Other Capital	5,648	5,634
Retained Earnings	8,980	8,443
Accumulated Other Comprehensive Loss	(64)	(65)
Noncontrolling Interest	19	22
Total Shareholders' Equity	14,764	14,215
Total Liabilities and Shareholders' Equity	26,749	25,810
Eliminations
Current Assets
Cash and Cash Equivalents	74	74	101	81
Short-term Investments	43	54
Accounts Receivable - Net	679	541
Receivable from Affiliates	(2,601)	(1,991)
Materials and Supplies	0	0
Deferred Income Taxes	5	6
Other Current Assets	(20)	4
Total Current Assets	(1,820)	(1,312)
Properties	1,563	1,500
Accumulated Depreciation	(884)	(853)
Properties - Net	679	647
Investments in Conrail	681	673
Affiliates and Other Companies	(81)	(134)
Investments in Consolidated Subsidiaries	(16,926)	(16,278)
Other Long-term Assets	103	69
Total Assets	(17,364)	(16,335)
Current Liabilities
Accounts Payable	31	26
Labor and Fringe Benefits Payable	23	47
Payable to Affiliates	(2,819)	(2,343)
Casualty, Environmental and Other Reserves	15	15
Current Maturities of Long-term Debt	2	2
Income and Other Taxes Payable	(454)	(402)
Other Current Liabilities	1	1
Total Current Liabilities	(3,201)	(2,654)
Casualty, Evironmental and Other Reserves	85	91
Long-term Debt	0	1
Deferred Income Taxes	427	351
Other Long-term Liabilities	77	77
Total Liabilities	(2,612)	(2,134)
Shareholders' Equity
Common Stock, $1 Par Value	(181)	(181)
Other Capital	(5,648)	(5,634)
Retained Earnings	(8,980)	(8,443)
Accumulated Other Comprehensive Loss	65	65
Noncontrolling Interest	(8)	(8)
Total Shareholders' Equity	(14,752)	(14,201)
Total Liabilities and Shareholders' Equity	$ (17,364)	$ (16,335)