Summarized Consolidating Cash Flow Statements (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 28, 2014	Mar. 29, 2013
Operating Activities
Net Cash Provided by (Used in) Operating Activities	$ 599	$ 731
Investing Activities
Property Additions	(475)	(491)
Purchase of Short-term Investments	(165)	(290)
Proceeds from Sales of Short-term Investments	409	534
Other Investing Activities	4	(18)
Net Cash Provided by (Used in) Investing Activities	(227)	(265)
Financing Activities
Long-term debt repaid	(209)	(413)
Dividends Paid	(151)	(143)
Stock Options Exercised	0	6
Shares Repurchased	(127)	0
Other Financing Activities	(2)	5
Net Cash Used in Financing Activities	(489)	(545)
Net Decrease in Cash and Cash Equivalents	(117)	(79)
Cash and Cash Equivalents at Beginning of Period	592	784
Cash and Cash Equivalents at End of Period	475	705
CSX Corporation
Operating Activities
Net Cash Provided by (Used in) Operating Activities	113	272
Investing Activities
Property Additions	0	0
Purchase of Short-term Investments	(165)	(285)
Proceeds from Sales of Short-term Investments	407	510
Other Investing Activities	0	0
Net Cash Provided by (Used in) Investing Activities	242	225
Financing Activities
Long-term debt repaid	(200)	(400)
Dividends Paid	(151)	(143)
Stock Options Exercised		6
Shares Repurchased	(127)
Other Financing Activities	5	4
Net Cash Used in Financing Activities	(473)	(533)
Net Decrease in Cash and Cash Equivalents	(118)	(36)
Cash and Cash Equivalents at Beginning of Period	439	481
Cash and Cash Equivalents at End of Period	321	445
CSX Transportation
Operating Activities
Net Cash Provided by (Used in) Operating Activities	669	689
Investing Activities
Property Additions	(443)	(458)
Purchase of Short-term Investments	0	0
Proceeds from Sales of Short-term Investments	0	0
Other Investing Activities	(67)	(63)
Net Cash Provided by (Used in) Investing Activities	(510)	(521)
Financing Activities
Long-term debt repaid	(9)	(13)
Dividends Paid	(143)	(182)
Stock Options Exercised		0
Shares Repurchased	0
Other Financing Activities	(7)	0
Net Cash Used in Financing Activities	(159)	(195)
Net Decrease in Cash and Cash Equivalents	0	(27)
Cash and Cash Equivalents at Beginning of Period	91	235
Cash and Cash Equivalents at End of Period	91	208
Eliminations and Other
Operating Activities
Net Cash Provided by (Used in) Operating Activities	(183)	(230)
Investing Activities
Property Additions	(32)	(33)
Purchase of Short-term Investments	0	(5)
Proceeds from Sales of Short-term Investments	2	24
Other Investing Activities	71	45
Net Cash Provided by (Used in) Investing Activities	41	31
Financing Activities
Long-term debt repaid	0	0
Dividends Paid	143	182
Stock Options Exercised		0
Shares Repurchased	0
Other Financing Activities	0	1
Net Cash Used in Financing Activities	143	183
Net Decrease in Cash and Cash Equivalents	1	(16)
Cash and Cash Equivalents at Beginning of Period	62	68
Cash and Cash Equivalents at End of Period	$ 63	$ 52