Variable Interest Entities, Consolidated (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Assets
Cash and temporary cash investments	$ 5,176	$ 4,816	$ 5,949	$ 4,114
Property, plant, and equipment, net	27,274	26,472
Liabilities
Current liabilities	9,130	8,328
Debt and capital lease obligations, less current portion	8,364	7,886
Variable Interest Entity, Primary Beneficiary [Member]
Assets
Cash and temporary cash investments	278	253
Other current assets	55	90
Property, plant, and equipment, net	1,475	1,353
Liabilities
Current liabilities	58	39
Debt and capital lease obligations, less current portion	570	571
Valero Energy Partners LP [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Assets
Cash and temporary cash investments	116	71
Other current assets	1	3
Property, plant, and equipment, net	955	865
Liabilities
Current liabilities	26	15
Debt and capital lease obligations, less current portion	525	525
Diamond Green Diesel Holdings LLC [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Assets
Cash and temporary cash investments	148	167
Other current assets	54	87
Property, plant, and equipment, net	391	355
Liabilities
Current liabilities	25	17
Debt and capital lease obligations, less current portion	0	0
Other Variable Interest Entities [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Assets
Cash and temporary cash investments	14	15
Other current assets	0	0
Property, plant, and equipment, net	129	133
Liabilities
Current liabilities	7	7
Debt and capital lease obligations, less current portion	$ 45	$ 46