Earnings (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings (loss) per common share:
Net income (loss) attributable to Valero stockholders	$ 162	$ 1,253	$ (542)	$ (598)
Less: Income allocated to participating securities	2	4	3	3
Net income (loss) available to common stockholders	$ 160	$ 1,249	$ (545)	$ (601)
Weighted-average common shares outstanding (in shares)	407	406	407	407
Earnings (loss) per common share (in dollars per share)	$ 0.39	$ 3.07	$ (1.34)	$ (1.48)
Earnings (loss) per common share – assuming dilution:
Net income (loss) attributable to Valero stockholders	$ 162	$ 1,253	$ (542)	$ (598)
Less: Income allocated to participating securities	2	4	3	3
Net income (loss) available to common stockholders	$ 160	$ 1,249	$ (545)	$ (601)
Weighted-average common shares outstanding (in shares)	407	406	407	407
Effect of dilutive securities (in shares)	0	1	0	0
Weighted-average common shares outstanding – assuming dilution (in shares)	407	407	407	407
Earnings (loss) per common share – assuming dilution (in dollars per share)	$ 0.39	$ 3.07	$ (1.34)	$ (1.48)