Commitments and Contingencies, Washington Refinery Fire (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended		12 Months Ended	24 Months Ended
	Jun. 30, 2011	Jun. 30, 2011	Jun. 30, 2012 Washington Refinery Fire employees	Dec. 31, 2010 Washington Refinery Fire	Dec. 31, 2011 Washington Refinery Fire
Washington Refinery Fire
Loss contingency, period of occurrence			April 2010
Number of fatally injured employees in the refinery incident (employees)			7
Fines and penalties assessed				$ 2.4
Days of operational disruption (days)			60 days
Losses incurred due to interruption			25
Insurance recoveries	$ 37	$ 37			$ 87
Settlement date			July 2012