Revenue from Contracts with Customers - Revenue from External Customers by Products and Services (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenue from External Customer [Line Items]
Total noninterest income in-scope of ASC 606	$ 48,697	$ 43,718
Total noninterest (loss) income out-of-scope of ASC 606	(2,282)	11,494
Total noninterest income	46,415	55,212
Insurance commissions
Revenue from External Customer [Line Items]
Total noninterest income in-scope of ASC 606	28,713	28,147
Service charges on deposit accounts
Revenue from External Customer [Line Items]
Total noninterest income in-scope of ASC 606	8,537	5,367
Trust and investment advisory fees
Revenue from External Customer [Line Items]
Total noninterest income in-scope of ASC 606	6,141	5,663
Debit card processing fees
Revenue from External Customer [Line Items]
Total noninterest income in-scope of ASC 606	2,945	2,749
Other noninterest income
Revenue from External Customer [Line Items]
Total noninterest income in-scope of ASC 606	$ 2,361	$ 1,792