Premises and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Depreciation and amortization expense charged	$ 14,400	$ 13,000	$ 13,400
Weighted-average lease term	15 years
Operating lease ROU assets	$ 42,100	$ 38,800
Operating lease ROU assets statement of financial position extensible list	Premises and equipment, net	Premises and equipment, net
Operating lease ROU liabilities	$ 46,256	$ 43,000
Operating Lease Liability Statement Of Financial Position Extensible List	Other liabilities	Other liabilities	Other liabilities
Operating lease, expense	$ 4,600	$ 4,600	$ 5,200
Weighted average discount rate	3.04%
Weighted-average finance lease term	10 years
Finance lease ROU assets	$ 29,100	$ 9,200
Finance lease ROU assets statement of financial position extensible list	Premises and equipment, net	Premises and equipment, net
Finance lease ROU liabilities	$ 29,004	$ 9,800
Finance lease ROU liabilities statement of financial position extensible list	Other liabilities	Other liabilities
Weighted average finance lease discount rate	3.75%	3.42%
Amortization cost related to finance lease ROU assets	$ 2,600	$ 500	400
Interest expense related to finance lease ROU assets	$ 200	$ 200	$ 200
Maximum [Member]
Property Plant And Equipment [Line Items]
Operating lease terms	30 years
Operating lease term extensions	10 years
Finance lease terms	25 years
Finance lease term extensions	10 years
Minimum [Member]
Property Plant And Equipment [Line Items]
Operating lease terms	1 year
Operating lease term extensions	5 years
Annual obligation	$ 10,700
Finance lease terms	5 years
Finance lease term extensions	5 years