Fair Value Measurements Assets Measured on a Non-Recurring Basis (Details) (Fair Value, Inputs, Level 3 [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Fair Value, Inputs, Level 3 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Adjusted basis of inventory	$ 1,975	$ 2,108	$ 3,876	$ 2,350
Impairments	2,136	1,309	4,237	1,876
Initial basis of inventory	$ 4,111	$ 3,417	$ 8,113	$ 4,226