Income Tax Expense (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Provision of Income Taxes [Line Items]
Current	$ 74,900	$ 170,700	$ (45,700)
Deferred	(44,200)	62,700	30,700
Income taxes	30,734	233,435	(15,062)
Federal
Reconciliation of Provision of Income Taxes [Line Items]
Current	6,900	87,900	(83,300)
Deferred	(45,800)	62,900	29,900
Income taxes	(38,900)	150,800	(53,400)
State
Reconciliation of Provision of Income Taxes [Line Items]
Current	9,700	12,000	5,600
Deferred	800	500	900
Income taxes	10,500	12,500	6,500
Foreign
Reconciliation of Provision of Income Taxes [Line Items]
Current	58,300	70,800	32,000
Deferred	800	(700)	(100)
Income taxes	$ 59,100	$ 70,100	$ 31,900