Income Taxes (Details) (USD $)	12 Months Ended								12 Months Ended			12 Months Ended			1 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Tax Years 2005 to 2012 [Member]	Dec. 31, 2012 Tax Years 2005 to 2012 [Member]	Dec. 31, 2013 Consolidated Statement Of Income [Member]	Dec. 31, 2013 Additional Paid-in Capital [Member]	Dec. 31, 2013 State and Local Jurisdiction [Member]	Dec. 31, 2013 State and Local Jurisdiction [Member] Minimum [Member]	Dec. 31, 2013 State and Local Jurisdiction [Member] Maximum [Member]	Dec. 31, 2013 State and Local Jurisdiction [Member] U S State Income Tax Credits Limited [Member]	Dec. 31, 2013 State and Local Jurisdiction [Member] U S State Income Tax Credits Limited [Member] Minimum [Member]	Dec. 31, 2013 State and Local Jurisdiction [Member] U S State Income Tax Credits Limited [Member] Maximum [Member]	Dec. 31, 2013 Foreign Tax Authority [Member]	Sep. 30, 2012 Aruba Refinery [Member]	Mar. 31, 2012 Aruba Refinery [Member]	Dec. 31, 2012 Aruba Refinery [Member]
Income from Continuing Operations Before Income Tax Expense from Domestic and Foreign Operations
U.S. operations	$ 3,531,000,000	$ 4,015,000,000	$ 3,190,000,000
International operations	451,000,000	(309,000,000)	132,000,000
Income from continuing operations before income tax expense	3,982,000,000	3,706,000,000	3,322,000,000
Reconciliation of Income Tax Expense Related to Income from Continuing Operations Before Income Tax Expense
Federal income tax expense at the U.S. federal statutory rate	1,394,000,000	1,297,000,000	1,163,000,000
U.S. state income tax expense, net of U.S. federal income tax effect	62,000,000	64,000,000	29,000,000
U.S. manufacturing deduction	(36,000,000)	(33,000,000)	(28,000,000)
International operations	(71,000,000)	266,000,000	46,000,000
Permanent differences	(104,000,000)	20,000,000	8,000,000
Change in tax law	(32,000,000)	0	0
Other, net	41,000,000	12,000,000	8,000,000
Income tax expense	1,254,000,000	1,626,000,000	1,226,000,000
Current:
U.S. federal	635,000,000	515,000,000	562,000,000
U.S. state	36,000,000	22,000,000	13,000,000
International	82,000,000	126,000,000	186,000,000
Total current	753,000,000	663,000,000	761,000,000
Deferred:
U.S. federal	459,000,000	854,000,000	527,000,000
U.S. state	59,000,000	77,000,000	32,000,000
International	(17,000,000)	32,000,000	(94,000,000)
Total deferred	501,000,000	963,000,000	465,000,000
Income tax expense	1,254,000,000	1,626,000,000	1,226,000,000
Deferred income tax assets:
Tax credit carryforwards	48,000,000	61,000,000
Net operating losses (NOLs)	338,000,000	247,000,000
Inventories	264,000,000	258,000,000
Property, plant, and equipment	8,000,000	78,000,000
Compensation and employee benefit liabilities	178,000,000	383,000,000
Environmental liabilities	92,000,000	83,000,000
Other	187,000,000	157,000,000
Total deferred income tax assets	1,115,000,000	1,267,000,000
Less: Valuation allowance	(347,000,000)	(304,000,000)				(340,000,000)	(7,000,000)
Net deferred income tax assets	768,000,000	963,000,000
Deferred income tax liabilities:
Property, plant, and equipment	6,536,000,000	6,143,000,000
Deferred turnaround costs	331,000,000	300,000,000
Inventories	310,000,000	381,000,000
Investments, primarily in VLP and DGD	94,000,000	0
Other	81,000,000	103,000,000
Total deferred income tax liabilities	7,352,000,000	6,927,000,000
Net deferred income tax liabilities	6,584,000,000	5,964,000,000
Income Tax Credit and Loss Carryforwards
U.S. state income tax credits											71,000,000
NOL								5,609,000,000						1,289,000,000
Income tax credits, expiration												Dec. 31, 2014	Dec. 31, 2027
NOL, expiration									Dec. 31, 2014	Dec. 31, 2033
Valuation Allowance Allocation
Deferred tax assets valuation allowance	347,000,000	304,000,000				340,000,000	7,000,000
Reconciliation of the Change in Unrecognized Tax Benefits RollForward
Balance as of beginning of year	341,000,000	326,000,000	330,000,000
Additions based on tax positions related to the current year	64,000,000	11,000,000	14,000,000
Additions for tax positions related to prior years	576,000,000	40,000,000	55,000,000	556,000,000	0
Reductions for tax positions related to prior years	(26,000,000)	(36,000,000)	(66,000,000)
Reductions for tax positions related to the lapse of applicable statute of limitations	(4,000,000)	0	(3,000,000)
Settlements	(1,000,000)	0	(4,000,000)
Balance as of end of year	950,000,000	341,000,000	326,000,000
Reconciliation of Unrecognized Tax Benefits to Uncertain Tax Position Liabilities
Unrecognized tax benefits	950,000,000	341,000,000	326,000,000
Tax refund claim not recognized in our financial statements	(576,000,000)	(40,000,000)	(55,000,000)	(556,000,000)	0
Penalties, interest (net of U.S. federal and state income tax effect), and the U.S. federal income tax effect of state unrecognized tax benefits	49,000,000	50,000,000
Uncertain tax position liabilities	443,000,000	391,000,000
Income Taxes (Textual)
Statutory federal income tax rate	35.00%
Gain on disposition of retained interest in CST Brands, Inc.	325,000,000	0	0
Asset impairment losses	0	1,014,000,000	0												333,000,000	595,000,000	928,000,000
Income tax benefit related to discontinued operations	0	0	4,000,000
Increase in valuation allowance	43,000,000
Cumulative undistributed earnings of foreign subsidiaries	3,500,000,000
Additions for tax positions related to prior years	576,000,000	40,000,000	55,000,000	556,000,000	0
Income tax benefits if recognized that would impact the effective tax rate	763,000,000	144,000,000
Possible reduction to unrecognized tax benefit, lower range	100,000,000
Possible reduction to unrecognized tax benefit, upper range	180,000,000
Interest expense and penalties recognized	12,000,000	23,000,000	1,000,000
Interest expense and penalties accrued	$ 145,000,000	$ 133,000,000