Segment Information (Schedule of Revenue by Geographic Area) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues	$ 137,989	$ 174,475	$ 128,747	$ 134,125	$ 146,237	$ 177,215	$ 143,919	$ 139,579	$ 575,336	$ 606,950	$ 570,289
United States
Revenues									573,398	601,738	558,138
Canada
Revenues									851	2,618	9,645
Mexico
Revenues									919	2,594	2,506
Other
Revenues									$ 168	$ 0	$ 0