Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Loans And Leases Receivable Disclosure [Line Items]
Increase (decrease) in allowance for loan and lease losses	$ (757,000)	$ 9,900,000
Commitments outstanding on troubled debt restructurings	0		$ 0
Recorded investment in troubled debt restructurings that subsequently defaulted within twelve months	0	0
Reserve for unfunded commitments	1,800,000		$ 1,900,000
Provisions for (credits to) unfunded commitments	120,000	198,000
Charge-offs or recoveries related to reserve for unfunded commitments	$ 0	0
Paycheck Protection Program
Loans And Leases Receivable Disclosure [Line Items]
Percentage of guarantee on SBA	100.00%
Acquired Impaired Loans
Loans And Leases Receivable Disclosure [Line Items]
Increase (decrease) in allowance for loan and lease losses	$ (2,300,000)	1,500,000
Individually Evaluated For Impairment
Loans And Leases Receivable Disclosure [Line Items]
Increase (decrease) in allowance for loan and lease losses	2,400,000	2,700,000
Collectively Evaluated For Impairment
Loans And Leases Receivable Disclosure [Line Items]
Increase (decrease) in allowance for loan and lease losses	$ (824,000)	$ 5,600,000