Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Components of the provision for income taxes
Federal	$ 0	$ 0	$ 0	$ 0
State	77	10,126	241	10,400
Deferred portion of income tax expense (benefit)	(95,975)	(50,829)	(291,014)	(84,556)
Total income tax expense (benefit)	$ (95,898)	$ (40,703)	$ (290,773)	$ (74,156)
Effective tax rate	36.20%	41.40%	36.00%	40.10%