Goodwill and Other Intangibles - Changes In Intangible Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	$ 129,983	$ 131,639
Accumulated amortization	56,923	52,915
Net carrying amount	73,060	78,724
Core Deposit Intangible Assets [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	14,130	16,661
Accumulated amortization	12,776	14,827
Net carrying amount	1,354	1,834
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	115,853	114,978
Accumulated amortization	44,147	38,088
Net carrying amount	$ 71,706	$ 76,890