Senior Notes - Summary (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Debt
Total Senior Notes	$ 315,000		$ 326,793
Deferred debt issuance costs	(5,480)		(5,877)
Debt discount	(66)		(70)
Total Senior Notes, net	309,454		320,846
Interest paid	12,800	$ 12,300
7.50% Senior Convertible Notes (the "7.50% Notes")
Debt
Total Senior Notes	0		46,793
8.50% Notes
Debt
Total Senior Notes	200,000		200,000
6.00% Notes
Debt
Total Senior Notes	80,000		80,000
Senior Secured Credit Facility
Debt
Total Senior Notes	$ 35,000		$ 0