Earnings Per Common Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings per common share from continuing operations:
Net income attributable to Valero stockholders from continuing operations	$ 1,059	$ 312	$ 2,539	$ 1,426
Less dividends paid:
Weighted-average common shares outstanding (in shares)	526	540	529	544
Earnings per common share from continuing operations:
Total earnings per common share from continuing operations (in usd per share)	$ 2.01	$ 0.58	$ 4.78	$ 2.61
Earnings per common share from continuing operations – assuming dilution:
Net income attributable to Valero stockholders from continuing operations	1,059	312	2,539	1,426
Weighted-average common shares outstanding (in shares)	526	540	529	544
Common equivalent shares:
Weighted-average common shares outstanding – assuming dilution (in shares)	530	545	533	549
Earnings per common share from continuing operations – assuming dilution (in usd per share)	$ 2.00	$ 0.57	$ 4.76	$ 2.60
Common Stock [Member]
Earnings per common share from continuing operations:
Net income attributable to Valero stockholders from continuing operations	1,059	312	2,539	1,426
Less dividends paid:
Common stock	145	121	410	340
Nonvested restricted stock	0	1	1	2
Undistributed earnings	914	190	2,128	1,084
Weighted-average common shares outstanding (in shares)	526	540	529	544
Earnings per common share from continuing operations:
Distributed earnings (in usd per share)	$ 0.28	$ 0.23	$ 0.77	$ 0.63
Undistributed earnings (in usd per share)	$ 1.73	$ 0.35	$ 4.01	$ 1.98
Total earnings per common share from continuing operations (in usd per share)	$ 2.01	$ 0.58	$ 4.78	$ 2.61
Earnings per common share from continuing operations – assuming dilution:
Net income attributable to Valero stockholders from continuing operations	$ 1,059	$ 312	$ 2,539	$ 1,426
Weighted-average common shares outstanding (in shares)	526	540	529	544
Common equivalent shares:
Stock options (in shares)	2	3	3	3
Performance awards and nonvested restricted stock (in shares)	2	2	1	2
Weighted-average common shares outstanding – assuming dilution (in shares)	530	545	533	549
Earnings per common share from continuing operations – assuming dilution (in usd per share)	$ 2.00	$ 0.57	$ 4.76	$ 2.60
Restricted Stock [Member]
Less dividends paid:
Weighted-average common shares outstanding (in shares)	2	3	2	3
Earnings per common share from continuing operations:
Distributed earnings (in usd per share)	$ 0.28	$ 0.23	$ 0.77	$ 0.63
Undistributed earnings (in usd per share)	$ 1.73	$ 0.35	$ 4.01	$ 1.98
Total earnings per common share from continuing operations (in usd per share)	$ 2.01	$ 0.58	$ 4.78	$ 2.61
Earnings per common share from continuing operations – assuming dilution:
Weighted-average common shares outstanding (in shares)	2	3	2	3