Commitments and Loss Contingencies - Financial Instruments with Off-Balance Sheet Risk (Details)	12 Months Ended
	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 12, 2022 item plaintiff	Dec. 11, 2022 item	Dec. 31, 2020 item
Commitments and Contingencies
Reserve for legal settlement		$ 4,500,000
Number of counts not sustained by court without leave to amend | item			2		2
Number of count on which court granted the Bank's motion for judgement | item			1	1
Number of plaintiff on whom bank filed motion | plaintiff			1
Total number of plaintiffs | plaintiff			26
Commitments to extend credit, fixed rate	$ 88,913,000	122,155,000
Commitments to extend credit, variable rate	1,045,706,000	1,028,656,000
Commitment to extend credit, total	$ 1,134,619,000	$ 1,150,811,000
Percentage of unused commitments to outstanding gross loans	34.00%	37.00%
Increase (decrease) to the allowance for credit losses on loans	$ (5,000)
Off-balance sheet, credit loss liability increase due to offsetting increase in loss factors in CECL model	820,000	$ 815,000
Unused lines of credit and commitments to make loans
Commitments and Contingencies
Commitments to extend credit, fixed rate	87,348,000	119,071,000
Commitments to extend credit, variable rate	1,036,847,000	1,015,588,000
Commitment to extend credit, total	1,124,195,000	1,134,659,000
Standby letters of credit
Commitments and Contingencies
Commitments to extend credit, fixed rate	1,565,000	3,084,000
Commitments to extend credit, variable rate	8,859,000	13,068,000
Commitment to extend credit, total	$ 10,424,000	$ 16,152,000