Fair Value Measurements Assets and Liabilities Measured on a Non-Recurring Basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Valuation adjustments to investments in unconsolidated joint ventures	$ 0	$ 1,047	$ 0
Fair Value, Significant Unobservable Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Adjusted basis of inventory	11,885	3,730	5,494
Total losses	3,638	3,457	5,805
Initial basis of inventory	$ 15,523	$ 7,187	$ 11,299