Commitments and Contingencies - Commitments to Extend Credit and Letters of Credit (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Commitments to Extend Credit
Loan Commitments and Letters of Credit [Line Items]
Notional Amount	$ 431,452	$ 399,882	$ 364,861
Fair Value	0	0	0
Standby Letters of Credit
Loan Commitments and Letters of Credit [Line Items]
Notional Amount	3,392	3,703	3,330
Fair Value	$ 21	$ 28	$ 30
Minimum | Standby Letters of Credit
Loan Commitments and Letters of Credit [Line Items]
Loan commitments, fixed fee percent	1.00%
Maximum | Standby Letters of Credit
Loan Commitments and Letters of Credit [Line Items]
Loan commitments, fixed fee percent	3.00%