Earnings (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings (loss) per common share
Net income (loss) attributable to Valero stockholders	$ 1,253	$ 612	$ (598)	$ 753
Less: Income allocated to participating securities	4	2	3	2
Net income (loss) available to common stockholders	$ 1,249	$ 610	$ (601)	$ 751
Weighted-average common shares outstanding (in shares)	406	415	407	416
Earnings (loss) per common share (in dollars per share)	$ 3.07	$ 1.47	$ (1.48)	$ 1.80
Earnings (loss) per common share – assuming dilution
Net income (loss) attributable to Valero stockholders	$ 1,253	$ 612	$ (598)	$ 753
Less: Income allocated to participating securities	4	2	3	2
Net income (loss) available to common stockholders	$ 1,249	$ 610	$ (601)	$ 751
Weighted-average common shares outstanding (in shares)	406	415	407	416
Effect of dilutive securities (in shares)	1	2	0	1
Weighted-average common shares outstanding – assuming dilution (in shares)	407	417	407	417
Earnings (loss) per common share – assuming dilution (in dollars per share)	$ 3.07	$ 1.47	$ (1.48)	$ 1.80