Goodwill and Other Intangible Assets - Components of Goodwill and Other Intangible Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill	$ 381,752	$ 383,861	$ 355,720	$ 371,773
Other intangible assets (net of accumulated amortization)	195	210
Goodwill and other intangible assets, Total	$ 381,947	$ 384,071