Variable Interest Entities (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Assets
Cash and temporary cash investments	$ 4,463	$ 4,816	$ 3,778	$ 4,114
Property, plant, and equipment, net	26,991	26,472
Liabilities
Current liabilities	7,899	8,328
Debt and capital lease obligations, less current portion	8,369	$ 7,886
Variable Interest Entity, Primary Beneficiary [Member]
Assets
Cash and temporary cash investments	240		253
Other current assets	50		90
Property, plant, and equipment, net	1,431		1,353
Liabilities
Current liabilities	40		39
Debt and capital lease obligations, less current portion	570		571
Valero Energy Partners LP [Member]
Assets
Cash and temporary cash investments	66		71
Other current assets	2		3
Property, plant, and equipment, net	940		865
Liabilities
Current liabilities	17		15
Debt and capital lease obligations, less current portion	525		525
Diamond Green Diesel Holdings LLC [Member]
Assets
Cash and temporary cash investments	159		167
Other current assets	48		87
Property, plant, and equipment, net	360		355
Liabilities
Current liabilities	16		17
Debt and capital lease obligations, less current portion	0		0
Other Variable Interest Entities [Member]
Assets
Cash and temporary cash investments	15		15
Other current assets	0		0
Property, plant, and equipment, net	131		133
Liabilities
Current liabilities	7		7
Debt and capital lease obligations, less current portion	$ 45		$ 46