Debt, Bank Credit Facilities (Details)	6 Months Ended	9 Months Ended	10 Months Ended	12 Months Ended
	Jun. 29, 2017 USD ($)	Sep. 30, 2017 CAD	Oct. 31, 2017	Dec. 31, 2017 CAD renewal quarter	Dec. 31, 2017 USD ($) quarter	Dec. 31, 2016 CAD	Dec. 31, 2016 USD ($)	Dec. 31, 2015 CAD	Dec. 31, 2015 USD ($)	Dec. 31, 2017 USD ($) renewal
Valero Revolver [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity										$ 3,000,000,000
Line of credit facility, expiration date				Nov. 30, 2020	Nov. 30, 2020
Line of credit facility issued and outstanding										0
Line of credit facility, remaining borrowing capacity										2,946,000,000
Credit Facilities (Textual)
Line of credit facility, accordion feature, higher borrowing capacity option										$ 4,500,000,000
Line of credit facility, number of renewal options | renewal				2						2
Line of credit facility, duration of renewal option (in years)				1 year	1 year
Borrowings from long-term lines of credit					$ 0		$ 0		$ 0
Repayments of long-term lines of credit					$ 0		$ 0		0
Valero Revolver Letter of Credit [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity										$ 2,000,000,000
Line of credit facility issued and outstanding										54,000,000
VLP Revolver [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity										750,000,000
Line of credit facility, expiration date				Nov. 30, 2020	Nov. 30, 2020
Line of credit facility issued and outstanding										410,000,000
Line of credit facility, remaining borrowing capacity										340,000,000
Credit Facilities (Textual)
Line of credit facility, accordion feature, higher borrowing capacity option										$ 1,000,000,000
Line of credit facility, number of renewal options | renewal				2						2
Line of credit facility, duration of renewal option (in years)				1 year	1 year
Interest rate of credit facility at period end (percent)				2.875%			2.3125%			2.875%
Number of prior quarterly reporting periods used for debt to EBITDA ratio | quarter				4	4
Repayments of long-term lines of credit					$ 0		$ 494,000,000		25,000,000
VLP Revolver [Member] | Credit Facilities [Member] | Parkway Pipeline LLC [Member]
Credit Facilities (Textual)
Borrowings from long-term lines of credit					118,000,000
VLP Revolver [Member] | Credit Facilities [Member] | Valero Partners Port Arthur, LLC [Member]
Credit Facilities (Textual)
Borrowings from long-term lines of credit					$ 262,000,000
VLP Revolver [Member] | Credit Facilities [Member] | McKee Terminal Services Business [Member]
Credit Facilities (Textual)
Borrowings from long-term lines of credit							139,000,000
VLP Revolver [Member] | Credit Facilities [Member] | Meraux and Three Rivers Terminal Services Business [Member]
Credit Facilities (Textual)
Borrowings from long-term lines of credit							$ 210,000,000
VLP Revolver [Member] | Credit Facilities [Member] | Houston and St. Charles Terminal Services Business [Member]
Credit Facilities (Textual)
Borrowings from long-term lines of credit									200,000,000
VLP Revolver [Member] | Credit Facilities [Member] | Maximum [Member]
Credit Facilities (Textual)
Debt to EBITDA ratio as per terms of revolver				5.0						5.0
VLP Revolver Letter of Credit [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity										$ 100,000,000
Line of credit facility issued and outstanding										0
Canadian Revolver [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity | CAD		CAD 25,000,000		CAD 75,000,000
Line of credit facility, expiration date		Nov. 30, 2017		Nov. 30, 2018	Nov. 30, 2018
Line of credit facility issued and outstanding | CAD				CAD 0
Line of credit facility, remaining borrowing capacity | CAD				65,000,000
Credit Facilities (Textual)
Borrowings from long-term lines of credit | CAD				0		CAD 0		CAD 0
Repayments of long-term lines of credit | CAD				0		CAD 0		CAD 0
Canadian Revolver Letter of Credit [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility issued and outstanding | CAD				CAD 10,000,000
Accounts Receivable Sales Facility [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity										1,300,000,000
Line of credit facility, expiration date				Jul. 31, 2018	Jul. 31, 2018
Line of credit facility issued and outstanding										100,000,000
Line of credit facility, remaining borrowing capacity										$ 1,200,000,000
Credit Facilities (Textual)
Interest rate of credit facility at period end (percent)				2.0387%			1.3422%			2.0387%
Borrowings from long-term lines of credit					$ 0		$ 0		0
Repayments of long-term lines of credit					$ 0		0		$ 0
Designated pool of accounts receivable							$ 2,000,000,000			$ 2,300,000,000
Committed Letter of Credit Facility Expires November 2018 [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity										100,000,000
Line of credit facility, expiration date			Nov. 30, 2017	Nov. 30, 2018	Nov. 30, 2018
Line of credit facility issued and outstanding										0
Line of credit facility, remaining borrowing capacity										100,000,000
Committed Letter of Credit Facility Expires June 2017 [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity	$ 125,000,000
Line of credit facility, expiration date	Jun. 30, 2017
Uncommitted Letter of Credit Facility [Member]
Line of Credit Facility
Line of credit facility issued and outstanding										$ 249,000,000