Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2021 USD ($) segment	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Financing Receivable, Nonaccrual [Line Items]
Number of operating segments | segment	1
Number of reportable segments | segment	1
Debt securities, non-accrual status, past due payment period	30 days
Debt securities, accrual status, sustained interest payment period	6 months
Debt securities, accrued interest after allowance for credit loss	$ 5,300,000	$ 3,300,000
Principal and interest default period	90 days
Residential mortgage loans are placed on non-accrual status at the time principal and interest period	90 days
Period of principal and interest payments in arrears for open-end consumer loans are reviewed for charge-off	4 months
Non-accrual asset satisfactory payments period	6 months
Non-accrual loans with recorded investment, minimum amount			$ 500,000
Maximum amount of individual impaired commercial loans that places into homogeneous pool for collective evaluation	$ 500,000
Amount of loans sold that are being serviced for others	35,300,000	34,100,000
Originated mortgage servicing rights	188,000	129,000
Goodwill	156,277,000	156,277,000
Bank owned life insurance	117,356,000	115,115,000
Income on bank owned life insurance	2,676,000	$ 2,657,000	$ 2,740,000
Company's liability to trusts including investments	$ 30,000,000
Percentage of capital permitted for trust preferred securities	25.00%
Non-owner occupied commercial
Financing Receivable, Nonaccrual [Line Items]
Financing receivable contract term	10 years
Financing receivable, amortization schedule term	25 years
Owner occupied commercial
Financing Receivable, Nonaccrual [Line Items]
Financing receivable contract term	10 years
Financing receivable, amortization schedule term	25 years
Multifamily
Financing Receivable, Nonaccrual [Line Items]
Financing receivable contract term	10 years
Financing receivable, amortization schedule term	30 years
Non-owner occupied residential
Financing Receivable, Nonaccrual [Line Items]
Financing receivable contract term	10 years
Financing receivable, amortization schedule term	25 years
Commercial, industrial and other | Minimum
Financing Receivable, Nonaccrual [Line Items]
Financing receivable contract term	1 year
Commercial, industrial and other | Maximum
Financing Receivable, Nonaccrual [Line Items]
Financing receivable contract term	7 years
Construction | Minimum
Financing Receivable, Nonaccrual [Line Items]
Financing receivable contract term	1 year
Construction | Maximum
Financing Receivable, Nonaccrual [Line Items]
Financing receivable contract term	3 years
Equipment finance | Minimum
Financing Receivable, Nonaccrual [Line Items]
Financing receivable contract term	3 years
Equipment finance | Maximum
Financing Receivable, Nonaccrual [Line Items]
Financing receivable contract term	5 years
Residential mortgage | Minimum
Financing Receivable, Nonaccrual [Line Items]
Financing receivable contract term	15 years
Residential mortgage | Maximum
Financing Receivable, Nonaccrual [Line Items]
Financing receivable contract term	30 years