Unconsolidated Subsidiaries (Narrative) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($) Subsidiaries	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)
Variable Interest Entity [Line Items]
Number of wholly owned subsidiaries | Subsidiaries	2
Variable interest entity, reporting entity involvement, maximum risk of loss	$ 3,900	$ 4,000	$ 3,800
Accounts receivable from affiliates	2,793	57,421	44,339
Coyote Creek
Variable Interest Entity [Line Items]
Accounts receivable from affiliates		53,200	42,200
Other noncurrent assets
Variable Interest Entity [Line Items]
Investment in unconsolidated operations and related tax position	$ 25,900	$ 28,200	$ 28,900