Earnings Per Common Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Less dividends paid:
Weighted-average common shares outstanding (in shares)	531	550
Earnings per common share – assuming dilution:
Weighted-average common shares outstanding (in shares)	531	550
Common equivalent shares:
Weighted-average common shares outstanding – assuming dilution (in shares)	536	556
Common Stock [Member]
Earnings per common share:
Net income attributable to Valero stockholders	$ 828	$ 654
Less dividends paid:
Common stock	132	110
Nonvested restricted stock	1	1
Undistributed earnings	695	543
Weighted-average common shares outstanding (in shares)	531	550
Earnings per common share:
Distributed earnings (in usd per share)	$ 0.25	$ 0.20
Undistributed earnings (in usd per share)	$ 1.30	$ 0.98
Total earnings per common share (in usd per share)	$ 1.55	$ 1.18
Earnings per common share – assuming dilution:
Net income attributable to Valero stockholders	$ 828	$ 654
Weighted-average common shares outstanding (in shares)	531	550
Common equivalent shares:
Stock options (in shares)	3	4
Performance awards and nonvested restricted stock (in shares)	2	2
Weighted-average common shares outstanding – assuming dilution (in shares)	536	556
Earnings per common share – assuming dilution (in usd per share)	$ 1.54	$ 1.18
Restricted Stock [Member]
Less dividends paid:
Weighted-average common shares outstanding (in shares)	2	3
Earnings per common share:
Distributed earnings (in usd per share)	$ 0.25	$ 0.20
Undistributed earnings (in usd per share)	$ 1.30	$ 0.98
Total earnings per common share (in usd per share)	$ 1.55	$ 1.18
Earnings per common share – assuming dilution:
Weighted-average common shares outstanding (in shares)	2	3