Tesoro Logistics LP, Contractual Terms Of Agreements With Tesoro Logistics LP (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Long-term Purchase Commitment [Line Items]
Contract term		7
Number of contract renewals		4
Number of refined products terminals		8
Number of short-haul pipelines		5
High Plains transportation services agreement initial term [Member]
Long-term Purchase Commitment [Line Items]
Contract term		10
Number of contract renewals		2
Term of renewal		5
Termination Provision		1
High Plains trucking transportation services agreement [Member]
Long-term Purchase Commitment [Line Items]
Contract term		2
Termination Provision		1
Amended High Plains trucking transportation services agreement [Member]
Long-term Purchase Commitment [Line Items]
Contract term	5
Number of contract renewals		1
Term of renewal		5
Terminalling services agreement initial term [Member]
Long-term Purchase Commitment [Line Items]
Contract term		10
Number of contract renewals		2
Term of renewal		5
Termination Provision		1
SLC transportation services agreement initial term [Member]
Long-term Purchase Commitment [Line Items]
Contract term		10
Number of contract renewals		2
Term of renewal		5
Termination Provision		1
Utah transportation services agreement initial term [Member]
Long-term Purchase Commitment [Line Items]
Contract term		10
Number of contract renewals		2
Term of renewal		5
Termination Provision		1
Omnibus agreement with subsidiary [Member]
Long-term Purchase Commitment [Line Items]
Omnibus or administrative fees received		2.5