Income Taxes - Schedule of Income Tax Expense (Benefit) from Continuing Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal	$ (65,034)	$ (82,905)	$ 85,696
State	27	(298)	1,103
Subtotal	(65,007)	(83,203)	86,799
Deferred:
Federal	(998,483)	(117,155)	(109,642)
State	(52,129)	(63,106)	127,518
Subtotal	(1,050,612)	(180,261)	17,876
Total income taxes	$ (1,115,619)	$ (263,464)	$ 104,675