Debt, Credit Facilities (Details)		Mar. 31, 2019 CAD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Valero Revolver [Member] | Credit Facilities [Member]
Line of Credit Facility
Facility amount			$ 4,000,000,000	$ 3,000,000,000
Outstanding borrowings or letters of credit issued			0
Availability			3,945,000,000
Valero Revolver Letter of Credit [Member] | Credit Facilities [Member]
Line of Credit Facility
Facility amount			2,400,000,000
Outstanding borrowings or letters of credit issued	[1]		55,000,000
Canadian Revolver [Member] | Credit Facilities [Member]
Line of Credit Facility
Outstanding borrowings, short-term		$ 0
Canadian Revolver [Member] | Credit Facilities [Member]
Line of Credit Facility
Facility amount		150,000,000
Availability		145,000,000
Canadian Revolver Letter of Credit [Member] | Credit Facilities [Member]
Line of Credit Facility
Outstanding borrowings or letters of credit issued	[1]	$ 5,000,000
Accounts receivable sales facility [Member] | Credit Facilities [Member]
Line of Credit Facility
Outstanding borrowings, short-term			100,000,000
Accounts receivable sales facility [Member] | Credit Facilities [Member]
Line of Credit Facility
Facility amount			1,300,000,000
Availability			1,200,000,000
Committed Letter of Credit Facility Expires November 2019 [Member] | Credit Facilities [Member]
Line of Credit Facility
Facility amount			100,000,000
Outstanding borrowings or letters of credit issued	[1]		0
Availability			100,000,000
IEnova Revolver [Member] | Central Mexico Terminals [Member] | Credit Facilities [Member]
Line of Credit Facility
Facility amount	[2]		340,000,000
Outstanding borrowings or letters of credit issued	[2]		132,000,000
Availability	[2]		208,000,000
Uncommitted Letter of Credit Facility [Member]
Line of Credit Facility
Outstanding borrowings or letters of credit issued	[1]		$ 408,000,000

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

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