Equity (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended		6 Months Ended
		Jul. 20, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Reconciliation of the Beginning and Ending Balances of the Carrying Amounts of Equity
Balance as of beginning of period					$ 22,900	$ 20,854
Net income			$ 875	$ 572	1,457	893
Dividends					(690)	(627)
Stock-based compensation expense					29	25
Transactions in connection with stock-based compensation plans					(134)	(13)
Stock purchases under purchase programs					(508)	(649)
Distributions to noncontrolling interests					(50)	(45)
Other					1	40
Other comprehensive income (loss)			(284)	211	(233)	287
Balance as of end of period			22,804	20,765	22,804	20,765
Dividend Declared [Member] | Subsequent Event [Member]
Equity (Textual)
Dividends payable, date declared		Jul. 20, 2018
Dividends payable, amount per share (in dollars per share)		$ 0.80
Dividends payable, date to be paid		Sep. 05, 2018
Dividends payable, date of record		Aug. 07, 2018
Entities Other Than Valero Energy Partners LP [Member]
Reconciliation of the Beginning and Ending Balances of the Carrying Amounts of Equity
Contribution from noncontrolling interest					32	0
Valero Stockholders' Equity [Member]
Reconciliation of the Beginning and Ending Balances of the Carrying Amounts of Equity
Balance as of beginning of period					21,991	20,024
Net income					1,314	853
Dividends					(690)	(627)
Stock-based compensation expense					29	25
Transactions in connection with stock-based compensation plans					(134)	(13)
Stock purchases under purchase programs					(508)	(649)
Other					(2)	23
Other comprehensive income (loss)					(231)	287
Balance as of end of period			21,769	19,923	21,769	19,923
Noncontrolling Interests [Member]
Reconciliation of the Beginning and Ending Balances of the Carrying Amounts of Equity
Balance as of beginning of period	[1]				909	830
Net income	[1]				143	40
Distributions to noncontrolling interests	[1]				(50)	(45)
Other	[1]				3	17
Other comprehensive income (loss)	[1]				(2)	0
Balance as of end of period	[1]		$ 1,035	$ 842	1,035	842
Noncontrolling Interests [Member] | Entities Other Than Valero Energy Partners LP [Member]
Reconciliation of the Beginning and Ending Balances of the Carrying Amounts of Equity
Contribution from noncontrolling interest	[1]				$ 32	$ 0

[1] The noncontrolling interests relate to third-party ownership interests in VIEs for which we are the primary beneficiary and therefore consolidate. See Note 7 for information about our consolidated VIEs.