Income Taxes - Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Components Of Income Tax Expense Benefit Continuing Operations [Abstract]
Federal, current	$ (177,159)	$ 241,074	$ 633,868
State, current	(4,298)	62,685	96,622
Foreign, current	18,131	8,981	14,800
Total current	(163,326)	312,740	745,290
Federal, deferred	177,035	101,946	4,953
State, deferred	(25,500)	8,013	6,847
Foreign, deferred	11,301	(10,802)	(8,783)
Total deferred	162,836	99,157	3,017
Total provision for income taxes	$ (490)	$ 411,897	$ 748,307