Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings per common share:
Net income attributable to Valero stockholders	$ 612	$ 845	$ 753	$ 1,314
Less income allocated to participating securities	2	3	2	4
Net income available to common stockholders	$ 610	$ 842	$ 751	$ 1,310
Weighted-average common shares outstanding (in shares)	415	429	416	430
Earnings per common share (in dollars per share)	$ 1.47	$ 1.96	$ 1.80	$ 3.05
Earnings per common share – assuming dilution:
Net income attributable to Valero stockholders	$ 612	$ 845	$ 753	$ 1,314
Weighted-average common shares outstanding (in shares)	415	429	416	430
Effect of dilutive securities (in shares)	2	2	1	2
Weighted-average common shares outstanding – assuming dilution (in shares)	417	431	417	432
Earnings per common share – assuming dilution (in dollars per share)	$ 1.47	$ 1.96	$ 1.80	$ 3.04