Income Taxes - Summary of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current
Federal	$ (31,838)	$ (29,584)	$ (95,191)
State	655	4,320	6,682
Total	(31,183)	(25,264)	(88,509)
Deferred
Federal	67,451	233,136	230,643
State	4,326	11,282	(1,040)
Total	71,777	244,418	229,603
Income tax expense	$ 40,594	$ 219,154	$ 141,094