Debt, Credit Facilities (Details)		Jul. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2020 CAD ($)	Apr. 13, 2020 USD ($)	Dec. 31, 2019 USD ($)
Valero Revolver [Member] | Credit Facilities [Member]
Line of Credit Facility
Facility amount			$ 4,000,000,000
Outstanding borrowings or letters of credit issued			0
Availability			3,967,000,000
Valero Revolver Letter of Credit [Member] | Credit Facilities [Member]
Line of Credit Facility
Outstanding borrowings or letters of credit issued	[1]		33,000,000
364-Day Revolving Credit Facility [Member] | Credit Facilities [Member]
Line of Credit Facility
Facility amount			875,000,000		$ 875,000,000
Outstanding borrowings or letters of credit issued, short-term			0
Availability			875,000,000
Canadian Revolver [Member] | Credit Facilities [Member]
Line of Credit Facility
Facility amount				$ 150,000,000
Outstanding borrowings or letters of credit issued, short-term				0
Availability				143,000,000
Canadian Revolver Letter of Credit [Member] | Credit Facilities [Member]
Line of Credit Facility
Outstanding borrowings or letters of credit issued, short-term	[1]			$ 7,000,000
Accounts Receivable Sales Facility [Member] | Credit Facilities [Member]
Line of Credit Facility
Facility amount	[2]		1,300,000,000
Outstanding borrowings or letters of credit issued, short-term	[2]		0
Availability	[2]		726,000,000
Accounts Receivable Sales Facility [Member] | Credit Facilities [Member] | Subsequent Event [Member]
Line of Credit Facility
Facility amount	[2]	$ 1,000,000,000.0
Committed Letter of Credit Facility Expires November 2020 [Member] | Credit Facilities [Member]
Line of Credit Facility
Facility amount			50,000,000
Outstanding borrowings or letters of credit issued, short-term	[1]		0
Availability			50,000,000
IEnova Revolver [Member] | Central Mexico Terminals [Member] | Credit Facilities [Member]
Line of Credit Facility
Facility amount			612,000,000			$ 491,000,000
IEnova Revolver [Member] | Central Mexico Terminals [Member] | Credit Facilities [Member] | Variable Interest Entities (VIEs) [Member]
Line of Credit Facility
Facility amount	[3]		612,000,000
Outstanding borrowings or letters of credit issued, short-term	[3]		511,000,000
Availability	[3]		101,000,000
Uncommitted Letter of Credit Facility [Member] | Credit Facilities [Member]
Line of Credit Facility
Outstanding borrowings or letters of credit issued, short-term	[1]		$ 92,000,000

[1] Letters of credit issued as of June 30, 2020 expire at various times in 2020 through 2021.

[2] 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.

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