Debt, Credit Facilities (Details) (USD $)	12 Months Ended									12 Months Ended
	Dec. 31, 2011 Tesoro Corporation Revolving Credit Facility ($1.85 billion) [Member]		Dec. 31, 2011 TPSA Revolving Credit Facility ($500 million) [Member]		Mar. 31, 2011 TPSA Revolving Credit Facility ($500 million) [Member]	Dec. 31, 2011 TSPA First Facility [Member]	Mar. 31, 2011 TSPA First Facility [Member]	Dec. 31, 2011 TSPA Second Facility [Member]	Mar. 31, 2011 TSPA Second Facility [Member]	Dec. 31, 2011 TLLP Revolving Credit Facility ($150 million) [Member]		Dec. 31, 2011 Letter of Credit Agreements [Member]	Jun. 30, 2011 Letter of Credit Agreements [Member]
Line of Credit Facility [Line Items]
Eurodollar Margin	1.75%	[1]	2.75%	[1]						2.50%	[1]
Eurodollar Rate	0.30%	[1]	0.30%	[1]						0.30%	[1]
Base Rate	3.25%	[1]	3.25%	[1]						3.25%	[1]
Base Rate Margin	0.75%	[1]	1.75%	[1]						1.50%	[1]
Commitment Fee (unused portion)	0.375%									0.50%
Line of Credit Facility, Initiation Date			October 2010							April 26, 2011
Line of Credit Facility, Amended Date	March 2011		October 2011
Line of Credit Facility, Current Borrowing Capacity	$ 1,850,000,000		$ 500,000,000		$ 350,000,000	$ 350,000,000	$ 245,000,000	$ 150,000,000	$ 105,000,000	$ 150,000,000
Line of Credit Facility, Maximum Borrowing Capacity	2,250,000,000		700,000,000			550,000,000		350,000,000		300,000,000
Adjusted Borrowing Capacity	3,200,000,000
West Texas Intermediate Crude Oil Price	100
Letters of Credit Outstanding, Amount	1,040,000,000		169,000,000									398,000,000
Line of Credit Facility, Remaining Borrowing Capacity	$ 810,000,000
Line Of Credit Facility, Remaining Borrowing Capacity Percentage	44.00%
Line of Credit Facility, Expiration Date	March 16, 2016									April 25, 2014
Line of Credit Facility, Collateral	The Revolving Credit Facility is guaranteed by substantially all of Tesoro’s active domestic subsidiaries, excluding TLGP and TLLP and its subsidiaries, and is secured by substantially all of the crude oil and refined product inventories, cash and receivables of Tesoro’s active domestic subsidiaries. TPSA is also not a guarantor of the Revolving Credit Facility.		The TPSA Revolving Credit Facility is non-recourse to Tesoro and is guaranteed by TPSA's assets.							The TLLP Revolving Credit Facility is non-recourse to Tesoro, except for TLGP (which is TLLP's general partner), and is guaranteed by all of TLLP’s subsidiaries and secured by substantially all of its assets.
Line of Credit Facility, Borrowing Capacity, Description	At December 31, 2011, our Revolving Credit Facility provided for borrowings (including letters of credit) up to the lesser of the amount of a periodically adjusted borrowing base of approximately $3.2 billion, consisting of Tesoro’s eligible cash and cash equivalents, receivables and petroleum inventories (based upon a West Texas Intermediate crude oil price of $100 per barrel), net of the standard reserve as defined, or the Revolving Credit Facility's total capacity of $1.85 billion.		At December 31, 2011, our TPSA Revolving Credit Facility provided for borrowings (including letters of credit) up to the lesser of the amount of a periodically adjusted borrowing base consisting of TPSA eligible receivables and petroleum inventories, net of reserves, or the agreement's capacity based on the net worth of TPSA.							Borrowings available under the TLLP Revolving Credit Facility are up to the total available revolving capacity of the facility.
Number of Agreements			2									4	3
Line Of Credit, Length Of Facility			364

[1] We have the option to elect if the borrowings will bear interest at either a base rate plus the base rate margin, or a Eurodollar rate, for the applicable period, plus, the Eurodollar margin at the time of the borrowing.