Unconsolidated Subsidiaries (Narrative) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2015 USD ($) Subsidiaries	Dec. 31, 2014 USD ($)	Jun. 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	$ 4,000	$ 4,000	$ 4,500
Accounts receivable from affiliates	3,137	57,421	36,351
Coyote Creek
Variable Interest Entity [Line Items]
Accounts receivable from affiliates		53,200	32,500
Other noncurrent assets
Variable Interest Entity [Line Items]
Investment in unconsolidated operations and related tax position	$ 27,100	$ 28,200	$ 30,300