Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings per common share:
Net income attributable to Valero stockholders	$ 609	$ 856	$ 1,362	$ 2,170
Less income allocated to participating securities	1	2	3	6
Net income available to common stockholders	$ 608	$ 854	$ 1,359	$ 2,164
Weighted-average common shares outstanding (in shares)	412	425	415	428
Earnings per common share (in dollars per share)	$ 1.48	$ 2.01	$ 3.28	$ 5.05
Earnings per common share – assuming dilution:
Net income attributable to Valero stockholders	$ 609	$ 856	$ 1,362	$ 2,170
Weighted-average common shares outstanding (in shares)	412	425	415	428
Effect of dilutive securities (in shares)	1	2	1	2
Weighted-average common shares outstanding – assuming dilution (in shares)	413	427	416	430
Earnings per common share – assuming dilution (in dollars per share)	$ 1.48	$ 2.01	$ 3.28	$ 5.05