Recent Developments Including Mergers and Acquisitions - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Jun. 17, 2021
Business Combination Separately Recognized Transactions [Line Items]
Total assets	$ 12,602,425	$ 12,372,042
Loans held for investment (net of unearned interest)	7,781,860	7,656,645
Deposits	10,909,621	10,700,122
Goodwill	$ 182,263	$ 182,263
Subordinated Notes due 2036 [Member] | Private Placement [Member]
Business Combination Separately Recognized Transactions [Line Items]
Aggregate principal amount			$ 60,000
Fixed-to-floating rate			3.50%