Summary of Significant Accounting Policies - Additional Information (Details)		3 Months Ended			9 Months Ended
	Jan. 01, 2020 USD ($)	Sep. 30, 2020 USD ($) loans securities	Mar. 31, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) loans investment Segments securities	Sep. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments | Segments					3
Accrued interest income and fees recognized on outstanding deferrals		$ 695,000			$ 695,000
Financing receivables payment of deferral modification, Number of loans | loans		77			77
Financing receivables payment of deferral modification		$ 102,987,000			$ 102,987,000
Loans, including fees		48,774,000		$ 50,249,000	147,491,000	$ 143,253,000
Held to maturity in subordinated notes		8,057,000			8,057,000
Held to maturity in subordinated notes, allowance for credit loss balances		1,961,000			1,961,000			$ 0
Debt securities accrued interest reversed		0		$ 0	$ 0	$ 0
Number of days within which accrual of interest income discontinues					90 days
Period of consumer loans charged off					120 days
Interest income is not recognized until loan balance reduced amount					$ 0
Useful life of assets					60 months
Change in national retail sales forecast period					1 year
Change in national home price index forecast period					1 year
Change in national gross domestic product forecast period					1 year
Economic projections forecast period					12 months
ASU 2016-13
Summary Of Significant Accounting Policies [Line Items]
Net reduction of retained earnings	$ 1,771,000		$ 1,771,000
Increase in the allowance for credit losses on loans	269,000	$ 0			$ 269,000
Increase in the allowance for credit losses on held to maturity debt securities	126,000
Increase in the allowance for credit losses on off-balance sheet credit exposures	1,918,000
Increases in deferred tax assets	$ 542,000
Fair Value Hedge
Summary Of Significant Accounting Policies [Line Items]
Number of position held | securities		0			0
CLO securities
Summary Of Significant Accounting Policies [Line Items]
Held to maturity in subordinated notes		$ 8,057,000			$ 8,057,000			8,417,000
Number of investments | investment					3
Number of investments impacted | investment					2
Held to maturity in subordinated notes, allowance for credit loss balances		1,961,000			$ 1,961,000		$ 1,855,000	$ 0
Held to maturity in subordinated notes, credit loss expense		106,000			$ 1,835,000
Paycheck Protection Program
Summary Of Significant Accounting Policies [Line Items]
Paycheck protection program loan interest rate coupon					1.00%
Number of PPP loans | loans					2,080
Paycheck protection program loans book value		$ 223,000,000			$ 223,000,000
Total fees received from Small Business Administration					7,700,000
Loans, including fees					$ 2,600,000
Minimum
Summary Of Significant Accounting Policies [Line Items]
Financing receivable payment deferral term					60 days
Number of days within which debt security placed on nonaccrual					90 days
Minimum | Paycheck Protection Program
Summary Of Significant Accounting Policies [Line Items]
Paycheck protection program loan term					2 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Financing receivable payment deferral term					90 days
Maximum | Paycheck Protection Program
Summary Of Significant Accounting Policies [Line Items]
Paycheck protection program loan term					5 years