Debt and Finance Lease Obligations, Credit Facilities (Details)		12 Months Ended
		Dec. 31, 2019 USD ($)		Dec. 31, 2019 CAD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CAD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2017 CAD ($)	Dec. 31, 2019 CAD ($)	Nov. 30, 2019 USD ($)	Nov. 30, 2019 CAD ($)	Sep. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Feb. 28, 2018 USD ($)
Variable Interest Entity, Primary Beneficiary [Member]
Credit Facilities (Textual)
Amount borrowed		$ 239,000,000			$ 109,000,000		$ 0
Canadian Revolver [Member] | Credit Facilities [Member]
Line of Credit Facility
Facility amount									$ 150,000,000		$ 150,000,000
Outstanding borrowings or letters of credit issued, short-term									0
Availability									145,000,000
Credit Facilities (Textual)
Repayments of lines of credit				$ 0		$ 0		$ 0
Borrowings from short-term lines of credit				$ 0		$ 0		$ 0
Canadian Revolver Letter of Credit [Member] | Credit Facilities [Member]
Line of Credit Facility
Outstanding borrowings or letters of credit issued, short-term	[1]								$ 5,000,000
Committed Letter of Credit Facility Expires November 2019 [Member] | Credit Facilities [Member]
Line of Credit Facility
Facility amount		50,000,000	[2]							$ 50,000,000		$ 100,000,000
Outstanding borrowings or letters of credit issued, short-term	[1],[2]	0
Availability	[2]	50,000,000
Accounts Receivable Sales Facility [Member] | Credit Facilities [Member]
Line of Credit Facility
Facility amount		1,300,000,000
Outstanding borrowings or letters of credit issued, short-term		100,000,000
Availability		$ 1,200,000,000
Credit Facilities (Textual)
Interest rate of credit facility at period end (percent)		2.3866%			3.0618%				2.3866%
Repayments of lines of credit		$ 900,000,000			$ 0		0
Borrowings from short-term lines of credit		900,000,000			0		0
Designated pool of accounts receivable		2,200,000,000			1,800,000,000
Uncommitted Letter of Credit Facility [Member] | Credit Facilities [Member]
Line of Credit Facility
Outstanding borrowings or letters of credit issued, short-term	[1]	121,000,000
Credit Facilities [Member] | Valero Revolver [Member]
Line of Credit Facility
Facility amount		4,000,000,000			3,000,000,000								$ 4,000,000,000
Outstanding borrowings or letters of credit issued		0
Availability		3,966,000,000
Credit Facilities (Textual)
Borrowings from long-term lines of credit		0			0		0
Repayments of long-term lines of credit		0			0		0
Credit Facilities [Member] | Valero Revolver Letter of Credit [Member]
Line of Credit Facility
Facility amount		2,400,000,000
Outstanding borrowings or letters of credit issued	[1]	$ 34,000,000
Credit Facilities [Member] | VLP Revolver [Member] | Valero Energy Partners LP [Member]
Line of Credit Facility
Facility amount					750,000,000
Credit Facilities (Textual)
Borrowings from long-term lines of credit							380,000,000
Repayments of long-term lines of credit					$ 410,000,000		$ 0
Credit Facilities [Member] | IEnova Revolver [Member] | Central Mexico Terminals [Member]
Line of Credit Facility
Facility amount										$ 491,000,000				$ 340,000,000
Credit Facilities (Textual)
Interest rate of credit facility at period end (percent)		5.749%			6.046%				5.749%
Amount borrowed		$ 239,000,000			$ 109,000,000
Repayments of lines of credit		0			0
Credit Facilities [Member] | IEnova Revolver [Member] | Central Mexico Terminals [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Line of Credit Facility
Facility amount	[3]	491,000,000
Outstanding borrowings or letters of credit issued	[3]	348,000,000
Availability	[3]	$ 143,000,000
Senior Notes [Member] | VLP Senior Notes Due in 2028 [Member]
Credit Facilities (Textual)
Interest rate of notes (percent)		4.50%							4.50%
Senior Notes [Member] | Valero Energy Partners LP [Member] | VLP Senior Notes Due in 2028 [Member]
Credit Facilities (Textual)
Face amount of long-term debt issuance					$ 500,000,000
Interest rate of notes (percent)		4.50%			4.50%				4.50%

[1] Letters of credit issued as of December 31, 2019 expire at various times in 2020 through 2021.

[2] The letter of credit facility was amended to reduce the facility from $100 million to $50 million and to extend the maturity date from November 2019 to November 2020.

[3] Creditors of our VIE do not have recourse against us.