Commitments and Contingencies (Details) (USD $)	1 Months Ended	3 Months Ended
	Sep. 30, 2013 bbl	Mar. 31, 2014	Dec. 31, 2013
Changes in Environmental Loss Contingency
Balance at December 31, 2013		$ 24,440,000
Additions		5,831,000
Expenditures		(2,477,000)
Balance at March 31, 2014		27,794,000
Number of outstanding lawsuits, administrative proceedings and governmental investigations (claims)		0
Tioga Crude Oil Pipeline Release
Changes in Environmental Loss Contingency
Balance at December 31, 2013		11,568,000
Additions		5,636,000
Expenditures		(851,000)
Balance at March 31, 2014		16,353,000
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
Chevron Corrective Action Order
Changes in Environmental Loss Contingency
Balance at December 31, 2013		8,016,000
Additions		0
Expenditures		(1,515,000)
Balance at March 31, 2014		6,501,000
Diesel fuel release, period of occurrence		3/18/2013
Other Liabilities
Changes in Environmental Loss Contingency
Balance at December 31, 2013		4,856,000
Additions		195,000
Expenditures		(111,000)
Balance at March 31, 2014		4,940,000
Northwest Products System
Changes in Environmental Loss Contingency
Other Environmental Liabilities, Noncurrent		$ 4,700,000	$ 4,700,000
PHMSA | Chevron Corrective Action Order
Changes in Environmental Loss Contingency
Regulatory Action Issuance Date		Mar. 22, 2013
Department of Environmental Quality Division of Water | Chevron Corrective Action Order
Changes in Environmental Loss Contingency
Regulatory Action Issuance Date		Apr. 11, 2013