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Variable Interest Entities, Consolidated (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) refinery	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Assets
Cash and temporary cash investments	$ 5,850	$ 4,816	$ 4,114	$ 3,689
Property, plant, and equipment, net	27,480	26,472
Liabilities
Current liabilities	11,071	8,328
Debt and capital lease obligations, less current portion	$ 8,750	7,886
Variable Interest Entity (Textual)
Number of refineries impacted by VLP operations \| refinery	10
Variable Interest Entity, Primary Beneficiary [Member]
Assets
Cash and temporary cash investments	$ 179	253
Other current assets	72	90
Property, plant, and equipment, net	2,029	1,353
Liabilities
Current liabilities	95	39
Debt and capital lease obligations, less current portion	948	571
Variable Interest Entity, Primary Beneficiary [Member] \| Valero Energy Partners LP [Member]
Assets
Cash and temporary cash investments	42	71
Other current assets	2	3
Property, plant, and equipment, net	1,416	865
Liabilities
Current liabilities	27	15
Debt and capital lease obligations, less current portion	905	525
Variable Interest Entity, Primary Beneficiary [Member] \| Diamond Green Diesel Holdings LLC [Member]
Assets
Cash and temporary cash investments	123	167
Other current assets	66	87
Property, plant, and equipment, net	435	355
Liabilities
Current liabilities	33	17
Debt and capital lease obligations, less current portion	$ 0	0
Variable Interest Entity (Textual)
Ownership interest (percent)	50.00%
Maximum percentage of joint venture construction costs financed (percent)	60.00%
Variable Interest Entity, Primary Beneficiary [Member] \| VPM Terminals [Member]
Assets
Cash and temporary cash investments	$ 1
Other current assets	4
Property, plant, and equipment, net	51
Liabilities
Current liabilities	26
Debt and capital lease obligations, less current portion	0
Variable Interest Entity, Primary Beneficiary [Member] \| Other Variable Interest Entities [Member]
Assets
Cash and temporary cash investments	13	15
Other current assets	0	0
Property, plant, and equipment, net	127	133
Liabilities
Current liabilities	9	7
Debt and capital lease obligations, less current portion	$ 43	$ 46
Variable Interest Entity, Primary Beneficiary [Member] \| Limited Partner [Member] \| Valero Energy Partners LP [Member]
Variable Interest Entity (Textual)
Ownership interest (percent)	66.20%
Variable Interest Entity, Primary Beneficiary [Member] \| General Partner [Member] \| Valero Energy Partners LP [Member]
Variable Interest Entity (Textual)
Ownership interest (percent)	2.00%
Variable Interest Entity, Primary Beneficiary, Aggregated Disclosure [Member] \| Other Variable Interest Entities [Member]
Variable Interest Entity (Textual)
Ownership interest (percent)	50.00%
Variable Interest Entity, Not Primary Beneficiary [Member] \| Limited Partner [Member] \| Valero Energy Partners LP [Member]
Variable Interest Entity (Textual)
Ownership interest (percent)	31.80%