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Variable Interest Entities, Consolidated (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) refinery	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Assets
Cash and cash equivalents	$ 2,982	$ 5,850	$ 4,816	$ 4,114
Property, plant, and equipment, net	28,848	27,480
Liabilities
Current liabilities, including current portion of debt and capital lease obligations	10,724	11,071
Debt and capital lease obligations, less current portion	$ 8,871	8,750
Variable Interest Entity (Textual)
Number of refineries impacted by VLP operations \| refinery	10
Variable Interest Entity, Primary Beneficiary [Member]
Assets
Cash and cash equivalents	$ 235	179
Other current assets	198	72
Property, plant, and equipment, net	2,254	2,029
Liabilities
Current liabilities, including current portion of debt and capital lease obligations	182	95
Debt and capital lease obligations, less current portion	1,024	948
Variable Interest Entity, Primary Beneficiary [Member] \| Valero Energy Partners LP [Member]
Assets
Cash and cash equivalents	152	42
Other current assets	2	2
Property, plant, and equipment, net	1,409	1,416
Liabilities
Current liabilities, including current portion of debt and capital lease obligations	27	27
Debt and capital lease obligations, less current portion	990	905
Variable Interest Entity, Primary Beneficiary [Member] \| Diamond Green Diesel Holdings LLC [Member]
Assets
Cash and cash equivalents	65	123
Other current assets	112	66
Property, plant, and equipment, net	576	435
Liabilities
Current liabilities, including current portion of debt and capital lease obligations	28	33
Debt and capital lease obligations, less current portion	$ 0	0
Variable Interest Entity (Textual)
Ownership interest (percent)	50.00%
Variable interest entity, maximum percentage of construction costs financed	60.00%
Variable Interest Entity, Primary Beneficiary [Member] \| Central Mexico Terminals [Member]
Assets
Cash and cash equivalents	$ 0	1
Other current assets	20	4
Property, plant, and equipment, net	156	51
Liabilities
Current liabilities, including current portion of debt and capital lease obligations	118	26
Debt and capital lease obligations, less current portion	0	0
Variable Interest Entity, Primary Beneficiary [Member] \| Other Variable Interest Entities [Member]
Assets
Cash and cash equivalents	18	13
Other current assets	64	0
Property, plant, and equipment, net	113	127
Liabilities
Current liabilities, including current portion of debt and capital lease obligations	9	9
Debt and capital lease obligations, less current portion	$ 34	$ 43
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%