Long-Term Debt - 9.5% Senior Notes due 2018 (Details) - USD ($) $ in Thousands			12 Months Ended
	Oct. 30, 2014	Sep. 30, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Repayments of long-term debt			$ 0	$ 0	$ 1,264,086
Debt redemption premium					36,100
Loss on extinguishment of debt			$ 0	$ 0	64,859
Gain (loss) on extinguishment of debt, unamortized premium (discount)					(16,900)
Gain (loss) on extinguishment of debt, deferred financing costs					(11,900)
Senior Notes due October 2018, at a fixed rate of 9.5%
Debt Instrument [Line Items]
Repayments of long-term debt	$ 760,800
Senior note interest rate				9.50%
Gain (loss) on extinguishment of debt, make-whole premium	$ (36,100)
Amortization of debt discount					2,800
Amortization of financing costs					2,200
Amended Senior Secured Revolving Credit Facility
Debt Instrument [Line Items]
Outstanding principal balance		$ 463,600
Debt Redemption, After December 2013 and Before October 30, 2014
Debt Instrument [Line Items]
Loss on extinguishment of debt					$ (64,900)