Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Less dividends paid:
Weighted-average common shares outstanding (in shares)	439	458	444	465
Earnings per common share – assuming dilution:
Weighted-average common shares outstanding (in shares)	439	458	444	465
Weighted-average common shares outstanding – assuming dilution (in shares)	441	460	446	467
Common Class A [Member]
Earnings per common share:
Net income attributable to Valero stockholders	$ 841	$ 613	$ 1,694	$ 1,922
Less dividends paid:
Common stock	308	275	933	837
Participating securities	1	1	3	3
Undistributed earnings	$ 532	$ 337	$ 758	$ 1,082
Weighted-average common shares outstanding (in shares)	439	458	444	465
Earnings per common share:
Distributed earnings (in usd per share)	$ 0.70	$ 0.60	$ 2.10	$ 1.80
Undistributed earnings (in usd per share)	1.21	0.73	1.70	2.32
Total earnings per common share (in usd per share)	$ 1.91	$ 1.33	$ 3.80	$ 4.12
Earnings per common share – assuming dilution:
Net income attributable to Valero stockholders	$ 841	$ 613	$ 1,694	$ 1,922
Weighted-average common shares outstanding (in shares)	439	458	444	465
Common equivalent shares (in shares)	2	2	2	2
Weighted-average common shares outstanding – assuming dilution (in shares)	441	460	446	467
Earnings per common share – assuming dilution (in usd per share)	$ 1.91	$ 1.33	$ 3.80	$ 4.12
Participating Securities [Member]
Less dividends paid:
Weighted-average common shares outstanding (in shares)	2	1	2	1
Earnings per common share:
Distributed earnings (in usd per share)	$ 0.70	$ 0.60	$ 2.10	$ 1.80
Undistributed earnings (in usd per share)	1.21	0.73	1.70	2.32
Total earnings per common share (in usd per share)	$ 1.91	$ 1.33	$ 3.80	$ 4.12
Earnings per common share – assuming dilution:
Weighted-average common shares outstanding (in shares)	2	1	2	1