Income Taxes - Income Tax Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Current income tax expense (benefit)	$ 13,849	$ (33,614)	$ 31,639	$ 20,328
Deferred income tax expense (benefit)	(516)	43,130	4,672	(8,803)
Income tax expense, as reported	$ 13,333	$ 9,516	$ 36,311	$ 11,525
Effective tax rate	11.00%	9.10%	9.60%	4.50%