Tesoro Logistics LP, Interest in Subsidiary (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Apr. 26, 2011
Related Party Transaction [Line Items]
Overallotment option		1,950,000
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Common limited partner units outstanding	14,950,000
Initial public offering price		$ 21.00
Total proceeds from the Offering	$ 314
Offering Costs, net of debt issuance costs		(26)
Proceeds from the Offering, net of Offering Costs	288
Debt issuance costs	(2)
Net proceeds from the Offering including debt issuance costs	286
Cash retained by TLLP		(3)
Net proceeds distributed to Tesoro from the Offering	283
Distribution to Tesoro	$ 333
Limited Partner [Member]
Related Party Transaction [Line Items]
Interest in subsidiary	52.00%
Public interest in subsidiary		48.00%
General Partner [Member]
Related Party Transaction [Line Items]
Interest in subsidiary	2.00%