Equity, Stock Related Disclosures (Details) - USD ($)		12 Months Ended
	Jan. 24, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 23, 2018	Sep. 21, 2016	Sep. 16, 2016	Jul. 13, 2015
Share Activity Rollforward
Treasury stock, beginning balance (shares)		(239,603,534)
Treasury stock, ending balance (shares)		(255,905,051)	(239,603,534)
Equity (Textual)
Preferred stock authorized (shares)		20,000,000
Preferred stock par value per share (in usd per share)		$ 0.01
Preferred stock outstanding (shares)		0	0
Stock repurchases under buyback program		$ 1,511,000,000	$ 1,307,000,000	$ 1,262,000,000
Remaining amount authorized under stock purchase programs		$ 2,200,000,000
Public Offering [Member] | Valero Energy Partners LP [Member]
Equity (Textual)
Aggregate offering price under equity distribution agreement							$ 350,000,000
Units sold in the offering (shares)		0	742,897	223,083
Proceeds from issuance of Valero Energy Partners LP common units [combine with other financing]			$ 35,000,000	$ 9,000,000
Subsequent Event [Member] | Dividend Declared [Member]
Equity (Textual)
Dividends payable, date declared	Jan. 24, 2019
Dividends payable (in usd per share)	$ 0.90
Dividends payable, date to be paid	Mar. 05, 2019
Dividends payable, date of record	Feb. 13, 2019
Common Stock Repurchase Programs [Member]
Equity (Textual)
Stock repurchases under buyback program		$ 1,500,000,000	$ 1,300,000,000	$ 1,300,000,000
Stock Repurchase Program Approved July 2015 [Member]
Equity (Textual)
Authorized amount under stock purchase program								$ 2,500,000,000
Stock Repurchase Program Approved September 2016 [Member]
Equity (Textual)
Authorized amount under stock purchase program						$ 2,500,000,000
Stock Repurchase Program Approved January 2018 [Member]
Equity (Textual)
Authorized amount under stock purchase program					$ 2,500,000,000
Common Stock [Member]
Share Activity Rollforward
Common stock, beginning balance (shares)		673,000,000	673,000,000	673,000,000
Common stock, ending balance (shares)		673,000,000	673,000,000	673,000,000
Treasury Stock [Member]
Share Activity Rollforward
Treasury stock, beginning balance (shares)		(240,000,000)	(222,000,000)	(200,000,000)
Transactions in connection with stock-based compensation plans (shares)			1,000,000	1,000,000
Stock purchases under purchase programs (shares)		(16,000,000)	(19,000,000)	(23,000,000)
Treasury stock, ending balance (shares)		(256,000,000)	(240,000,000)	(222,000,000)
Equity (Textual)
Stock repurchases under buyback program		$ 1,511,000,000	$ 1,307,000,000	$ 1,262,000,000