Leases - Schedule of Leases Cost (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Lease liabilities	$ 7,753,000	$ 6,607,000
Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Other liabilities	Other liabilities
Right-of-use assets	$ 7,154,000	$ 6,195,000
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
Weighted-average remaining lease term – operating leases (in months).	173 months 6 days	187 months 15 days
Weighted-average discount rate – operating leases	2.81%	3.12%
Lease Cost
Operating lease cost	$ 693,000	$ 590,000
Total lease costs	693,000	590,000
Cash paid for amounts included in measurement of lease liabilities	$ 590,000	$ 399,000