Earnings Per Common Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings per common share from continuing operations:
Net income attributable to Valero stockholders from continuing operations	$ 651	$ 463	$ 1,480	$ 1,114
Less dividends paid:
Weighted-average common shares outstanding (in shares)	529	543	530	546
Earnings per common share from continuing operations:
Total earnings per common share from continuing operations (in usd per share)	$ 1.23	$ 0.85	$ 2.78	$ 2.03
Earnings per common share from continuing operations – assuming dilution:
Net income attributable to Valero stockholders from continuing operations	651	463	1,480	1,114
Weighted-average common shares outstanding (in shares)	529	543	530	546
Common equivalent shares:
Weighted-average common shares outstanding – assuming dilution (in shares)	534	548	535	552
Earnings per common share from continuing operations – assuming dilution (in usd per share)	$ 1.22	$ 0.84	$ 2.77	$ 2.02
Common Stock [Member]
Earnings per common share from continuing operations:
Net income attributable to Valero stockholders from continuing operations	651	463	1,480	1,114
Less dividends paid:
Common stock	133	109	265	219
Nonvested restricted stock			1	1
Undistributed earnings	518	354	1,214	894
Weighted-average common shares outstanding (in shares)	529	543	530	546
Earnings per common share from continuing operations:
Distributed earnings (in usd per share)	$ 0.25	$ 0.20	$ 0.50	$ 0.40
Undistributed earnings (in usd per share)	$ 0.98	$ 0.65	$ 2.28	$ 1.63
Total earnings per common share from continuing operations (in usd per share)	$ 1.23	$ 0.85	$ 2.78	$ 2.03
Earnings per common share from continuing operations – assuming dilution:
Net income attributable to Valero stockholders from continuing operations	$ 651	$ 463	$ 1,480	$ 1,114
Weighted-average common shares outstanding (in shares)	529	543	530	546
Common equivalent shares:
Stock options (in shares)	3	3	3	4
Performance awards and nonvested restricted stock (in shares)	2	2	2	2
Weighted-average common shares outstanding – assuming dilution (in shares)	534	548	535	552
Earnings per common share from continuing operations – assuming dilution (in usd per share)	$ 1.22	$ 0.84	$ 2.77	$ 2.02
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)	$ 0.25	$ 0.20	$ 0.50	$ 0.40
Undistributed earnings (in usd per share)	$ 0.98	$ 0.65	$ 2.28	$ 1.63
Total earnings per common share from continuing operations (in usd per share)	$ 1.23	$ 0.85	$ 2.78	$ 2.03
Earnings per common share from continuing operations – assuming dilution:
Weighted-average common shares outstanding (in shares)	2	3	2	3