Premises and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Depreciation and amortization expense charged	$ 13,400	$ 14,100	$ 11,500
Weighted-average lease term	15 years 10 months 24 days
Operating lease ROU assets	$ 43,100	$ 51,500
Operating lease ROU assets statement of financial position extensible list	Premises and equipment, net	Premises and equipment, net
Operating lease ROU liabilities	$ 47,457	$ 56,000
Operating Lease Liability Statement Of Financial Position Extensible List	Other liabilities	Other liabilities
Operating lease, expense	$ 5,200	$ 5,800	5,400
Weighted average discount rate	2.88%
Weighted-average finance lease term	13 years 7 months 6 days
Finance lease ROU assets	$ 4,100	$ 4,500
Finance lease ROU assets statement of financial position extensible list	Premises and equipment, net	Premises and equipment, net
Finance lease ROU liabilities	$ 4,764	$ 5,200
Finance lease ROU liabilities statement of financial position extensible list	Other liabilities	Other liabilities
Weighted average finance lease discount rate	3.78%	3.78%
Amortization cost related to finance lease ROU assets	$ 400	$ 400	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	20 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