Debt, Credit Facilities and Bank Debt (Details) CAD in Millions					12 Months Ended
	Nov. 14, 2013 USD ($)	Oct. 24, 2013 USD ($)	May. 01, 2013 USD ($)	Apr. 16, 2013 USD ($)	Dec. 31, 2015 USD ($) quarter	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2015 CAD renewal	Dec. 31, 2015 USD ($) renewal	Nov. 30, 2015 USD ($)	Oct. 31, 2015 USD ($)	Jul. 31, 2015 USD ($)	Jun. 30, 2015 USD ($)	May. 31, 2015 USD ($)	Mar. 20, 2013 USD ($)
Bank Debt (Textual)
Proceeds from short-term debt in anticipation of separation					$ 0	$ 0	$ 550,000,000
Senior unsecured bonds of CST Brands, Inc. issued to us						256,000,000			$ 247,000,000
Proceeds from short-term debt related to disposition of retained interest					0	0	525,000,000
Fees paid related to disposition of retained interest					55,000,000	28,000,000	(19,000,000)
Gain on disposition of retained interest in CST Brands, Inc.					$ 0	0	325,000,000
Spinoff [Member]
Bank Debt (Textual)
Senior unsecured bonds of CST Brands, Inc. issued to us			$ 550,000,000
Fees paid related to disposition of retained interest	$ 19,000,000
Gain on disposition of retained interest in CST Brands, Inc.	325,000,000
Spinoff [Member] | Notes Payable to Banks [Member]
Bank Debt (Textual)
Proceeds from short-term debt in anticipation of separation				$ 550,000,000
CST Brands, Inc. securities exchanged in settlement of short-term borrowings	467,000,000		$ 550,000,000
Proceeds from short-term debt related to disposition of retained interest		$ 525,000,000
Repayment of short-term debt related to disposition of retained interest	$ 58,000,000
Credit Facilities [Member] | Spinoff [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity															$ 800,000,000
U S 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
Amount outstanding									0
Line of credit facility, remaining borrowing capacity									$ 2,943,000,000
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
U S Revolver Letter of Credit [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity										2,000,000,000
Amount outstanding									$ 57,000,000
VLP Revolver [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity									750,000,000		$ 300,000,000
Line of credit facility, expiration date					Nov. 30, 2020
Amount outstanding									175,000,000
Line of credit facility, remaining borrowing capacity									$ 575,000,000
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
Line of credit facility, interest rate during period					1.50%
Number of prior quarterly reporting periods used for debt to EBITDA ratio | quarter					4
Borrowings from long-term lines of credit					$ 200,000,000	0	0
Repayments of long-term lines of credit					$ 25,000,000	0	$ 0
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
Amount outstanding									$ 0
Canadian Revolver [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity | CAD								CAD 50
Line of credit facility, expiration date					Nov. 30, 2016
Amount outstanding | CAD								0
Line of credit facility, remaining borrowing capacity | CAD								40
Canadian Revolver Letter of Credit [Member] | Credit Facilities [Member]
Line of Credit Facility
Amount outstanding | CAD								CAD 10
A/R Sales Facility [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity									1,400,000,000				$ 1,500,000,000
Line of credit facility, expiration date					Jul. 31, 2016
Amount outstanding									100,000,000
Line of credit facility, remaining borrowing capacity									992,000,000
Credit Facilities (Textual)
Designated pool of accounts receivable						1,700,000,000			1,300,000,000
Bank Debt (Textual)
Proceeds from Other Debt					$ 0
Committed Letter of Credit Facility [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity									275,000,000
Amount outstanding									9,000,000
Line of credit facility, remaining borrowing capacity									266,000,000
Committed Letter of Credit - Expired [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity														$ 300,000,000
Committed Letter of Credit Facility Expires June 2016 [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity												$ 125,000,000	$ 250,000,000
Line of credit facility, expiration date					Jun. 30, 2016
Committed Letter of Credit Facility Expires November 2016 [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity										$ 150,000,000
Line of credit facility, expiration date					Nov. 30, 2016
Uncommitted Letter of Credit Facility [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity									775,000,000
Amount outstanding									87,000,000
Line of credit facility, remaining borrowing capacity									688,000,000
Bank Credit Facilities [Member] | Credit Facilities [Member]
Credit Facilities (Textual)
Long-term debt at stated values						$ 0			$ 175,000,000