Company's Deferred Tax Assets, Net of Deferred Tax Liabilities and Valuation Allowance (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Deferred tax assets, net of deferred tax liabilities	$ 260,625	$ (449)
Valuation allowance	(1,298)	(1,259)
Deferred tax assets, net of deferred tax liabilities and valuation allowance	$ 259,327
Deferred tax assets, net of deferred tax liabilities and valuation allowance		$ (1,708)