Debt, Credit Facilities (Details)		Sep. 30, 2020 USD ($)		Sep. 30, 2020 CAD ($)	Jul. 31, 2020 USD ($)	Jun. 30, 2020 USD ($)	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		3,966,000,000
Valero Revolver Letter of Credit [Member] | Credit Facilities [Member]
Line of Credit Facility
Outstanding borrowings or letters of credit issued	[1]	34,000,000
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				145,000,000
Canadian Revolver Letter of Credit [Member] | Credit Facilities [Member]
Line of Credit Facility
Outstanding borrowings or letters of credit issued, short-term	[1]			$ 5,000,000
Accounts Receivable Sales Facility [Member] | Credit Facilities [Member]
Line of Credit Facility
Facility amount		1,000,000,000	[2]		$ 1,000,000,000.0	$ 1,300,000,000
Outstanding borrowings or letters of credit issued, short-term		0	[2]					$ 100,000,000
Availability	[2]	817,000,000
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		660,000,000						491,000,000
Outstanding borrowings or letters of credit issued, short-term		550,000,000						$ 348,000,000
IEnova Revolver [Member] | Central Mexico Terminals [Member] | Credit Facilities [Member] | Variable Interest Entities (VIEs) [Member]
Line of Credit Facility
Facility amount	[3]	660,000,000
Outstanding borrowings or letters of credit issued, short-term	[3]	550,000,000
Availability	[3]	110,000,000
Uncommitted Letter of Credit Facility [Member] | Credit Facilities [Member]
Line of Credit Facility
Outstanding borrowings or letters of credit issued, short-term	[1]	$ 46,000,000

[1] Letters of credit issued as of September 30, 2020 expire at various times in 2020 through 2023.

[2] 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. The available borrowing capacity was lower than the facility amount due to low product prices impacting the amount of eligible receivables.

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