Commitments and Contingencies (Details) (USD $)	6 Months Ended		1 Months Ended	6 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013 claims	Sep. 30, 2013 Tioga Crude Oil Pipeline Release bbl	Jun. 30, 2014 Tioga Crude Oil Pipeline Release	Dec. 31, 2013 Tioga Crude Oil Pipeline Release	Jun. 30, 2014 Chevron Corrective Action Order	Jun. 30, 2014 Other Liabilities	Jun. 30, 2014 PHMSA Chevron Corrective Action Order	Jun. 30, 2014 Department Of Environmental Quality Division Of Water Chevron Corrective Action Order	Jun. 30, 2014 Northwest Products System	Dec. 31, 2013 Northwest Products System
Changes in Environmental Liabilities
Balance at December 31, 2013	$ 24,440,000			$ 11,568,000		$ 8,016,000	$ 4,856,000
Additions	6,207,000			5,636,000		0	571,000
Expenditures	(7,606,000)			(2,122,000)		(5,159,000)	(325,000)
Balance at June 30, 2014	23,041,000			15,082,000		2,857,000	5,102,000
Barrels of oil released (Barrels)			20,000
Insurance Settlements Receivable				17,200,000	14,000,000
Environmental Liability Insurance Deductible				1,000,000
Environmental Liabilities Insurance Coverage Limit				25,000,000
Proceeds from Insurance Settlement				2,400,000
Diesel fuel release, period of occurrence						March 18, 2013
Regulatory Action Issuance Date								Mar. 22, 2013	Apr. 11, 2013
Other Environmental Liabilities, Noncurrent										$ 4,900,000	$ 4,700,000
Number of outstanding lawsuits, administrative proceedings and governmental investigations (claims)		0