Income Taxes - Summary of Income Tax Benefit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current
Federal	$ (95,191)	$ (9,531)	$ (9,920)
State	6,682	1,816	(1,848)
Total	(88,509)	(7,715)	(11,768)
Deferred
Federal	230,643	(313,938)	(218,357)
State	(1,040)	(7,175)	(12,350)
Total	229,603	(321,113)	(230,707)
Income tax (benefit) expense	$ 141,094	$ (328,828)	$ (242,475)