Commitments and Loss Contingencies - Financial Instruments with Off-Balance Sheet Risk (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2024 USD ($) item	Dec. 31, 2023 USD ($)
Commitments and Contingencies
Number of pending legal proceedings | item	3
Commitments to extend credit, fixed rate	$ 128,649,000	$ 100,449,000
Commitments to extend credit, variable rate	989,126,000	1,048,607,000
Commitment to extend credit, total	$ 1,117,775,000	$ 1,149,056,000
Percentage of unused commitments to outstanding gross loans	33.00%	34.00%
Increase (decrease) to the allowance for credit losses on loans	$ (111,000)
Off-balance sheet, credit loss liability increase due to offsetting increase in loss factors in CECL model	656,000	$ 767,000
Unused lines of credit and commitments to make loans
Commitments and Contingencies
Commitments to extend credit, fixed rate	122,471,000	96,166,000
Commitments to extend credit, variable rate	972,291,000	1,041,608,000
Commitment to extend credit, total	1,094,762,000	1,137,774,000
Standby letters of credit
Commitments and Contingencies
Commitments to extend credit, fixed rate	6,178,000	4,283,000
Commitments to extend credit, variable rate	16,835,000	6,999,000
Commitment to extend credit, total	$ 23,013,000	$ 11,282,000