Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Less dividends paid:
Weighted-average common shares outstanding (in shares)	467	505	468	509
Earnings per common share – assuming dilution:
Weighted-average common shares outstanding (in shares)	467	505	468	509
Common equivalent shares:
Weighted-average common shares outstanding – assuming dilution (in shares)	470	508	471	512
Common Class A [Member]
Earnings per common share:
Net income attributable to Valero stockholders	$ 814	$ 1,351	$ 1,309	$ 2,315
Less dividends paid:
Common stock	281	203	562	408
Participating securities	1	0	2	1
Undistributed earnings	$ 532	$ 1,148	$ 745	$ 1,906
Weighted-average common shares outstanding (in shares)	467	505	468	509
Earnings per common share:
Distributed earnings (in usd per share)	$ 0.60	$ 0.40	$ 1.20	$ 0.80
Undistributed earnings (in usd per share)	1.14	2.27	1.59	3.73
Total earnings per common share (in usd per share)	$ 1.74	$ 2.67	$ 2.79	$ 4.53
Earnings per common share – assuming dilution:
Net income attributable to Valero stockholders	$ 814	$ 1,351	$ 1,309	$ 2,315
Weighted-average common shares outstanding (in shares)	467	505	468	509
Common equivalent shares:
Stock options (in shares)	2	2	2	2
Performance awards and nonvested restricted stock (in shares)	1	1	1	1
Weighted-average common shares outstanding – assuming dilution (in shares)	470	508	471	512
Earnings per common share – assuming dilution (in usd per share)	$ 1.73	$ 2.66	$ 2.78	$ 4.52
Participating Securities [Member]
Less dividends paid:
Weighted-average common shares outstanding (in shares)	1	2	1	2
Earnings per common share:
Distributed earnings (in usd per share)	$ 0.60	$ 0.40	$ 1.20	$ 0.80
Undistributed earnings (in usd per share)	1.14	2.27	1.59	3.73
Total earnings per common share (in usd per share)	$ 1.74	$ 2.67	$ 2.79	$ 4.53
Earnings per common share – assuming dilution:
Weighted-average common shares outstanding (in shares)	1	2	1	2