Earnings Per Common Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Earnings per common share from continuing operations:
Net income attributable to Valero stockholders from continuing operations	$ 831	$ 745	$ 399	$ 849
Less dividends paid:
Common stock			166	57
Weighted-average common shares outstanding	550	567	550	567
Earnings per common share from continuing operations:
Distributed earnings	$ 0.15	$ 0.05	$ 0.30	$ 0.10
Total earnings per common share from continuing operations	$ 1.50	$ 1.31	$ 0.72	$ 1.49
Earnings per common share from continuing operations - assuming dilution
Net income attributable to Valero stockholders from continuing operations	831	745	399	849
Weighted-average common shares outstanding	550	567	550	567
Common equivalent shares:
Weighted-average common shares outstanding - assuming dilution	555	574	556	573
Earnings per common share from continuing operations - assuming dilution	$ 1.50	$ 1.30	$ 0.72	$ 1.48
Common Stock [Member]
Earnings per common share from continuing operations:
Net income attributable to Valero stockholders from continuing operations	831	745	399	849
Less dividends paid:
Common stock	82	29	165	57
Nonvested restricted stock	1	0	1	0
Undistributed earnings	748	716	233	792
Weighted-average common shares outstanding	550	567	550	567
Earnings per common share from continuing operations:
Distributed earnings	$ 0.15	$ 0.05	$ 0.30	$ 0.10
Undistributed earnings	$ 1.35	$ 1.26	$ 0.42	$ 1.39
Total earnings per common share from continuing operations	$ 1.50	$ 1.31	$ 0.72	$ 1.49
Earnings per common share from continuing operations - assuming dilution
Net income attributable to Valero stockholders from continuing operations	$ 831	$ 745	$ 399	$ 849
Weighted-average common shares outstanding	550	567	550	567
Common equivalent shares:
Stock options	3	5	4	5
Performance awards and unvested restricted stock	2	2	2	1
Weighted-average common shares outstanding - assuming dilution	555	574	556	573
Earnings per common share from continuing operations - assuming dilution	$ 1.50	$ 1.30	$ 0.72	$ 1.48
Restricted Stock [Member]
Less dividends paid:
Weighted-average common shares outstanding	3	3	3	3
Earnings per common share from continuing operations:
Distributed earnings	$ 0.15	$ 0.05	$ 0.30	$ 0.10
Undistributed earnings	$ 1.35	$ 1.26	$ 0.42	$ 1.39
Total earnings per common share from continuing operations	$ 1.50	$ 1.31	$ 0.72	$ 1.49
Earnings per common share from continuing operations - assuming dilution
Weighted-average common shares outstanding	3	3	3	3