Debt, Narrative (Details) - USD ($)			6 Months Ended
		Apr. 13, 2020	Jun. 30, 2020	Jun. 30, 2019	Jul. 30, 2020	Dec. 31, 2019
364-Day Revolving Credit Facility [Member] | Credit Facilities [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 875,000,000	$ 875,000,000
Line of credit facility, term		364 days
364-Day Revolving Credit Facility [Member] | Credit Facilities [Member] | Minimum [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate		0.15%
364-Day Revolving Credit Facility [Member] | Credit Facilities [Member] | Minimum [Member] | Eurodollar Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate		0.15%
364-Day Revolving Credit Facility [Member] | Credit Facilities [Member] | Maximum [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate		1.70%
364-Day Revolving Credit Facility [Member] | Credit Facilities [Member] | Maximum [Member] | Eurodollar Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate		1.70%
Accounts Receivable Sales Facility [Member] | Credit Facilities [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	[1]		1,300,000,000
Amount of eligible receivables sold under accounts receivable sales facility			300,000,000
Repayments on lines of credit			$ 400,000,000
Weighted-average interest rate on borrowings outstanding (percent)			1.5221%			2.5275%
Accounts Receivable Sales Facility [Member] | Credit Facilities [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	[1]				$ 1,000,000,000.0
Central Mexico Terminals [Member] | IEnova Revolver [Member] | Credit Facilities [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity			$ 612,000,000			$ 491,000,000
Repayments on lines of credit			0	$ 0
Amount borrowed			$ 163,000,000	70,000,000
Variable interest rate (percent)			5.083%			5.749%
Senior Notes [Member]
Debt Instrument [Line Items]
Proceeds from issuance of senior long-term debt			$ 1,499,000,000
Senior Notes [Member] | Senior Notes Due April 15, 2023 [Member]
Debt Instrument [Line Items]
Face amount of long-term debt issuance			$ 850,000,000
Stated rate on debt instrument (percent)			2.70%
Senior Notes [Member] | Senior Notes Due April 15, 2025 [Member]
Debt Instrument [Line Items]
Face amount of long-term debt issuance			$ 650,000,000
Stated rate on debt instrument (percent)			2.85%
Senior Notes [Member] | Senior Notes Due April 1, 2029 [Member]
Debt Instrument [Line Items]
Face amount of long-term debt issuance				$ 1,000,000,000.0
Stated rate on debt instrument (percent)				4.00%
Proceeds from issuance of senior long-term debt				$ 992,000,000
Senior Notes [Member] | Senior Notes Due February 1, 2020 [Member]
Debt Instrument [Line Items]
Stated rate on debt instrument (percent)				6.125%
Early repayment of senior debt				$ 871,000,000
Debt instrument, redemption price, percentage of principal amount redeemed (percent)				102.48%
Early redemption fee				$ 21,000,000
Senior Notes [Member] | VLP Senior Notes Due December 15, 2026 [Member] | Valero Energy Partners LP [Member]
Debt Instrument [Line Items]
Stated rate on debt instrument (percent)			4.375%
Senior Notes [Member] | VLP Senior Notes Due March 15, 2028 [Member] | Valero Energy Partners LP [Member]
Debt Instrument [Line Items]
Stated rate on debt instrument (percent)			4.50%

[1] The available borrowing capacity was lower than the facility amount due to a decline in product prices. In July 2020, we extended the maturity date of this facility to July 2021 and decreased the facility amount from $1.3 billion to $1.0 billion.