Condensed Parent Company Financial Statements - Schedule of Condensed Balance Sheet (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
ASSETS
Cash and due from banks	$ 595,383	$ 408,411
Other assets	388,561	358,122
Total Assets	17,712,374	16,931,905
LIABILITIES
Subordinated debt and junior subordinated debt	279,078	281,404
Total Liabilities	15,179,312	14,505,243
SHAREHOLDERS’ EQUITY	2,533,062	2,426,662	$ 2,693,166	$ 2,756,737
Total Liabilities and Shareholders’ Equity	17,712,374	16,931,905
Parent Company [Member]
ASSETS
Cash and due from banks	250,203	272,179
Investment in subsidiaries—Bank	2,541,168	2,408,260
Investment in subsidiaries—Nonbank	6,207	11,810
Other assets	38,044	39,131
Total Assets	2,835,622	2,731,380
LIABILITIES
Subordinated debt and junior subordinated debt	279,078	281,404
Dividends payable and other liabilities	23,482	23,314
Total Liabilities	302,560	304,718
SHAREHOLDERS’ EQUITY	2,533,062	2,426,662
Total Liabilities and Shareholders’ Equity	$ 2,835,622	$ 2,731,380