Commitments and Contingencies, Washington Refinery Fire (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended				24 Months Ended	12 Months Ended		24 Months Ended
	Jun. 30, 2011	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011 Business Interruption [Member]	Dec. 31, 2010 Business Interruption [Member]	Dec. 31, 2011 Business Interruption [Member]	Dec. 31, 2011 Property Plant and Equipment [Member]	Dec. 31, 2010 Property Plant and Equipment [Member]	Dec. 31, 2011 Property Plant and Equipment [Member]
Information Related To Fire [Line Items]
Number of fatally injured employees in the refinery incident (in ones)			7
Fines and penalties assessed				$ 2.4
Charges related to Washington refinery incident			8	27
Days of operational disruption					60
Losses incurred due to interuption					25
Insurance deductible								10
Insurance recoveries	37	67	37	67		55	87	5	12	17
Proceeds from insurance settlement, operating activities					$ 32