Condensed Consolidating Financial Information - (Comprehensive Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net income (loss)	$ (2,239,643)	$ (326,720)	$ 10,577
Other comprehensive loss
Pension and postretirement benefit plan - net actuarial loss	1,104
Other comprehensive loss	(1,104)
Comprehensive income (loss)	(2,240,747)	(326,720)	10,577
Eliminations
Net income (loss)	1,203,120	271,716	(110,681)
Other comprehensive loss
Comprehensive income (loss)	1,203,120
Parent Company Issuer | Reportable legal entity
Net income (loss)	(2,239,643)	(326,720)	10,577
Other comprehensive loss
Pension and postretirement benefit plan - net actuarial loss	1,104
Other comprehensive loss	(1,104)
Comprehensive income (loss)	(2,240,747)
Guarantor Subsidiaries | Reportable legal entity
Net income (loss)	(1,203,120)	$ (271,716)	$ 110,681
Other comprehensive loss
Comprehensive income (loss)	$ (1,203,120)