Premises and Equipment - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Depreciation and amortization expense charged	$ 15,300,000	$ 14,400,000	$ 13,000,000
Weighted-average lease term	14 years
Operating lease ROU assets	$ 34,800,000	$ 42,100,000
Operating lease ROU assets statement of financial position extensible list	Premises and equipment, net	Premises and equipment, net
Operating lease ROU liabilities	$ 38,998,000	$ 46,300,000
Operating Lease Liability Statement Of Financial Position Extensible List	Other liabilities	Other liabilities
Operating lease, expense	$ 5,000,000	$ 4,600,000	4,600,000
Weighted average discount rate	3.10%
Weighted-average finance lease term	0 years
Finance lease ROU assets	$ 26,100,000	$ 29,100,000
Finance lease ROU assets statement of financial position extensible list	Premises and equipment, net	Premises and equipment, net
Finance lease ROU liabilities	$ 26,997,000	$ 29,000,000
Finance lease ROU liabilities statement of financial position extensible list	Other liabilities	Other liabilities
Weighted average finance lease discount rate	3.75%	3.75%
Amortization cost related to finance lease ROU assets	$ 4,000,000	$ 2,600,000	500,000
Interest expense related to finance lease ROU assets	$ 300,000	$ 200,000	$ 200,000
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	$ 11,200
Finance lease terms	5 years
Finance lease term extensions	5 years