Earnings Per Common Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Earnings per common share from continuing operations:
Net income attributable to Valero stockholders from continuing operations	$ 674	$ 1,203	$ 1,073	$ 2,052
Less dividends paid:
Common stock			263	85
Weighted-average common shares outstanding	549	564	550	566
Earnings per common share from continuing operations:
Distributed earnings	$ 0.175	$ 0.050	$ 0.475	$ 0.150
Total earnings per common share from continuing operations	$ 1.22	$ 2.12	$ 1.94	$ 3.61
Earnings per common share from continuing operations - assuming dilution:
Net income attributable to Valero stockholders from continuing operations	674	1,203	1,073	2,052
Weighted-average common shares outstanding	549	564	550	566
Common equivalent shares:
Weighted-average common shares outstanding - assuming dilution	556	569	556	572
Earnings per common share from continuing operations - assuming dilution	$ 1.21	$ 2.11	$ 1.93	$ 3.59
Common Stock [Member]
Earnings per common share from continuing operations:
Net income attributable to Valero stockholders from continuing operations	674	1,203	1,073	2,052
Less dividends paid:
Common stock	96	28	261	85
Nonvested restricted stock	1	0	2	0
Undistributed earnings	577	1,175	810	1,967
Weighted-average common shares outstanding	549	564	550	566
Earnings per common share from continuing operations:
Distributed earnings	$ 0.18	$ 0.05	$ 0.48	$ 0.15
Undistributed earnings	$ 1.04	$ 2.07	$ 1.46	$ 3.46
Total earnings per common share from continuing operations	$ 1.22	$ 2.12	$ 1.94	$ 3.61
Earnings per common share from continuing operations - assuming dilution:
Net income attributable to Valero stockholders from continuing operations	$ 674	$ 1,203	$ 1,073	$ 2,052
Weighted-average common shares outstanding	549	564	550	566
Common equivalent shares:
Stock options	4	3	4	4
Performance awards and unvested restricted stock	3	2	2	2
Weighted-average common shares outstanding - assuming dilution	556	569	556	572
Earnings per common share from continuing operations - assuming dilution	$ 1.21	$ 2.11	$ 1.93	$ 3.59
Restricted Stock [Member]
Less dividends paid:
Weighted-average common shares outstanding	3	3	3	3
Earnings per common share from continuing operations:
Distributed earnings	$ 0.18	$ 0.05	$ 0.48	$ 0.15
Undistributed earnings	$ 1.04	$ 2.07	$ 1.46	$ 3.46
Total earnings per common share from continuing operations	$ 1.22	$ 2.12	$ 1.94	$ 3.61
Earnings per common share from continuing operations - assuming dilution:
Weighted-average common shares outstanding	3	3	3	3