Debt (Notes)	9 Months Ended
Sep. 30, 2011
Debt [Abstract]
Debt [Text Block]	DEBT We entered into the Revolving Credit Facility, concurrent with the closing of the Offering on April 26, 2011, with a syndicate of banks and financial institutions. The Revolving Credit Facility provides for total loan availability of $150.0 million and allows us to request that the capacity be increased up to an aggregate of $300.0 million, subject to receiving increased commitments from the lenders. The Revolving Credit Facility is non-recourse to Tesoro, except for Tesoro Logistics GP (our general partner) and is guaranteed by all of our subsidiaries and secured by substantially all of our assets. Borrowings available under the Revolving Credit Facility are up to the total available revolving capacity of the facility. As of September 30, 2011, we had $50.0 million of borrowings and $0.3 million in letters of credit outstanding under the Revolving Credit Facility, resulting in a total unused credit availability of $99.7 million or 66% of the borrowing capacity. Borrowings under the Revolving Credit Facility bear interest at either a base rate (3.25% as of September 30, 2011) plus an applicable margin, or a Eurodollar rate (0.24% as of September 30, 2011) plus an applicable margin. The applicable margin at September 30, 2011, was 1.50% in the case of the base rate and 2.50% in the case of the Eurodollar rate but varies based upon a certain coverage ratio, as defined. The annual rate of commitment fees is 0.50%. The Revolving Credit Facility is scheduled to mature on April 25, 2014

DEBT

We entered into the Revolving Credit Facility, concurrent with the closing of the Offering on April 26, 2011, with a syndicate of banks and financial institutions. The Revolving Credit Facility provides for total loan availability of $150.0 million and allows us to request that the capacity be increased up to an aggregate of $300.0 million, subject to receiving increased commitments from the lenders. The Revolving Credit Facility is non-recourse to Tesoro, except for Tesoro Logistics GP (our general partner) and is guaranteed by all of our subsidiaries and secured by substantially all of our assets. Borrowings available under the Revolving Credit Facility are up to the total available revolving capacity of the facility. As of September 30, 2011, we had $50.0 million of borrowings and $0.3 million in letters of credit outstanding under the Revolving Credit Facility, resulting in a total unused credit availability of $99.7 million or 66% of the borrowing capacity.

Borrowings under the Revolving Credit Facility bear interest at either a base rate (3.25% as of September 30, 2011) plus an applicable margin, or a Eurodollar rate (0.24% as of September 30, 2011) plus an applicable margin. The applicable margin at September 30, 2011, was 1.50% in the case of the base rate and 2.50% in the case of the Eurodollar rate but varies based upon a certain coverage ratio, as defined. The annual rate of commitment fees is 0.50%. The Revolving Credit Facility is scheduled to mature on April 25, 2014