Equity (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended		1 Months Ended	0 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Oct. 31, 2014 Subsequent Event [Member]	Oct. 23, 2014 Dividend Declared [Member] Subsequent Event [Member]	Oct. 23, 2014 Dividend Declared [Member] Subsequent Event [Member]	Sep. 30, 2014 Shares Purchased Related To Stock-Based Compensation Plans [Member]	Sep. 30, 2013 Shares Purchased Related To Stock-Based Compensation Plans [Member]	Sep. 30, 2014 Shares Purchased Under Programs [Member]	Sep. 30, 2013 Shares Purchased Under Programs [Member]	Sep. 30, 2014 Parent [Member]	Sep. 30, 2013 Parent [Member]	Sep. 30, 2014 Parent [Member] Shares Purchased Related To Stock-Based Compensation Plans [Member]	Sep. 30, 2013 Parent [Member] Shares Purchased Related To Stock-Based Compensation Plans [Member]	Sep. 30, 2014 Parent [Member] Shares Purchased Under Programs [Member]	Sep. 30, 2013 Parent [Member] Shares Purchased Under Programs [Member]	Sep. 30, 2014 Common Stock [Member]	Sep. 30, 2013 Common Stock [Member]	Sep. 30, 2014 Treasury Stock [Member]	Sep. 30, 2013 Treasury Stock [Member]	Sep. 30, 2014 Treasury Stock [Member] Shares Purchased Related To Stock-Based Compensation Plans [Member]	Sep. 30, 2013 Treasury Stock [Member] Shares Purchased Related To Stock-Based Compensation Plans [Member]	Sep. 30, 2014 Treasury Stock [Member] Shares Purchased Under Programs [Member]	Sep. 30, 2013 Treasury Stock [Member] Shares Purchased Under Programs [Member]	Sep. 30, 2014 Noncontrolling Interest [Member]	Sep. 30, 2013 Noncontrolling Interest [Member]
Reconciliation of the Beginning and Ending Balances of the Carrying Amounts of Equity
Balance as of beginning of period			$ 19,946	$ 18,095								$ 19,460	$ 18,032													$ 486	$ 63
Net income	1,062	324	2,491	1,441								2,475	1,432													16	9
Dividends			(411)	(342)								(411)	(342)
Stock-based compensation expense			30	31								30	31
Tax deduction in excess of stock-based compensation expense			33	31								33	31
Transactions in connection with stock-based compensation plans:
Stock issuances			37	47								37	47
Stock repurchases								(177)	(220)	(692)	(396)			(177)	(220)	(692)	(396)
Separation of retail business			0	(479)								0	(479)
Contributions from noncontrolling interests			14	45								0	0													14	45
Distributions to public unitholders of Valero Energy Partners LP			(8)	0								0	0													(8)	0
Other comprehensive income (loss)	(277)	182	(201)	134								(201)	134													0	0
Balance as of end of period	$ 21,062	$ 18,387	$ 21,062	$ 18,387								$ 20,554	$ 18,270													$ 508	$ 117
Share Activity
Common stock, shares, beginning balance																		673,000,000	673,000,000
Treasury stock, shares, beginning balance			(137,932,138)																	(138,000,000)	(121,000,000)
Stock issuances																		0	0	3,000,000	3,000,000
Stock repurchases					(1,500,000)																	(2,000,000)	(5,000,000)	(13,000,000)	(9,000,000)
Common stock, shares, ending balance																		673,000,000	673,000,000
Treasury stock, shares, ending balance	(150,357,996)		(150,357,996)																	(150,000,000)	(132,000,000)
Equity (Textual)
Dividends payable, date declared						Oct. 23, 2014
Dividends payable, amount per share							$ 0.275
Dividends payable, date to be paid						Dec. 17, 2014
Dividends payable, date of record						Nov. 19, 2014