Senior Notes - Summary (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Debt
Total Senior Notes	$ 315,000		$ 315,000		$ 326,793
Deferred debt issuance costs	(5,082)		(5,082)		(5,877)
Debt discount	(62)		(62)		(70)
Total Senior Notes, net	309,856		309,856		320,846
Interest Paid	0	$ 9,700	12,800	$ 22,000
7.50% Senior Convertible Notes due 2016
Debt
Total Senior Notes	0		0		46,793
8.5% Senior Notes Due 2019
Debt
Total Senior Notes	200,000		200,000		200,000
6.00% Senior Convertible Notes Due 2020
Debt
Total Senior Notes	80,000		80,000		80,000
Senior Secured Credit Facility
Debt
Total Senior Notes	$ 35,000		$ 35,000		$ 0