Commitments and Loss Contingencies - Financial Instruments with Off-Balance Sheet Risk (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Commitments and Contingencies
Reserve for litigation			$ 4,500,000
Commitments to extend credit, fixed rate	$ 100,449,000	$ 88,913,000
Commitments to extend credit, variable rate	1,048,607,000	1,045,706,000
Commitment to extend credit, total	$ 1,149,056,000	1,134,619,000
Percentage of unused commitments to outstanding gross loans	34.00%
Increase (decrease) to the allowance for credit losses on loans	$ (53,000)
Off-balance sheet, credit loss liability increase due to offsetting increase in loss factors in CECL model	767,000	820,000
Unused lines of credit and commitments to make loans
Commitments and Contingencies
Commitments to extend credit, fixed rate	96,166,000	87,348,000
Commitments to extend credit, variable rate	1,041,608,000	1,036,847,000
Commitment to extend credit, total	1,137,774,000	1,124,195,000
Standby letters of credit
Commitments and Contingencies
Commitments to extend credit, fixed rate	4,283,000	1,565,000
Commitments to extend credit, variable rate	6,999,000	8,859,000
Commitment to extend credit, total	$ 11,282,000	$ 10,424,000