Dispositions of Businesses (Details) (USD $)	12 Months Ended				0 Months Ended		3 Months Ended	0 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Nov. 14, 2013 Spinoff [Member]	May 01, 2013 Spinoff [Member]	Jun. 30, 2013 Spinoff [Member]	Nov. 14, 2013 Spinoff [Member] Notes Payable to Banks [Member]	May 01, 2013 Spinoff [Member] Notes Payable to Banks [Member]	Apr. 16, 2013 Spinoff [Member] Sourced From Parent's Short-Term Borrowings [Member] Notes Payable to Banks [Member]	May 01, 2013 Spinoff [Member] Sourced From Entity Spunoff [Member]	May 01, 2013 Spinoff [Member] Cash Proceeds Net of Tax Liability [Member]
Assets
Cash and temporary cash investments	$ 4,292,000,000	$ 1,723,000,000	$ 1,024,000,000	$ 3,334,000,000		$ 315,000,000
Credit card receivables from Valero						44,000,000
Other receivables, net						109,000,000
Inventories	5,758,000,000	5,973,000,000				170,000,000
Deferred income taxes	266,000,000	274,000,000				14,000,000
Prepaid expenses and other	138,000,000	154,000,000				13,000,000
Total current assets	19,277,000,000	16,460,000,000				665,000,000
Property, plant, and equipment, at cost	33,933,000,000	34,132,000,000				1,891,000,000
Accumulated depreciation	(8,226,000,000)	(7,832,000,000)				(611,000,000)
Property, plant, and equipment, net	25,707,000,000	26,300,000,000				1,280,000,000
Intangible assets, net	156,000,000	213,000,000				38,000,000
Deferred charges and other assets, net	2,120,000,000	1,504,000,000				191,000,000
Total assets	47,260,000,000	44,477,000,000				2,174,000,000
Liabilities
Current portion of capital lease obligations	303,000,000	586,000,000				2,000,000
Trade payable to Valero						242,000,000
Other accounts payable						96,000,000
Accrued expenses	522,000,000	590,000,000				31,000,000
Taxes other than income taxes	1,345,000,000	1,026,000,000				20,000,000
Total current liabilities	13,123,000,000	11,929,000,000				391,000,000
Debt and capital lease obligations, less current portion	6,261,000,000	6,463,000,000				1,053,000,000
Deferred income taxes	6,601,000,000	5,860,000,000				83,000,000
Other long-term liabilities	1,329,000,000	2,130,000,000				112,000,000
Total liabilities						1,639,000,000
Separation of Retail Business (Textual)
Spinoff transaction, ownership percentage by Valero stockholders						80.00%
Cash distributed to Valero by CST Brands, Inc.	500,000,000	0	0			1,050,000,000					500,000,000	546,000,000
Proceeds from short-term debt in anticipation of separation	550,000,000	0	0							550,000,000
Senior unsecured bonds of CST issued to us	49,000,000	26,000,000				550,000,000
Cash held and retained by CST Brands, Inc. upon separation	315,000,000	0	0			315,000,000
Tax liability incurred related to business separation						189,000,000
Cost of separation in general and administrative expenses							30,000,000
Ownership percentage retained						20.00%
CST securities exchanged in settlement of short-term borrowings								467,000,000	550,000,000
Gain on disposition of retained interest in CST Brands, Inc.	$ 325,000,000	$ 0	$ 0		$ 325,000,000