Derivatives, Hedging Activities and Financial Instruments with Off-Balance Sheet Risk - Commitments (Details) - USD ($)	3 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Company's contractual commitments due to letters of credit
Total letters of credit	$ 27,831,000	$ 31,112,000
Allowance for credit loss on unfunded commitments	2,500,000
Increase In allowance for credit loss on unfunded commitments	2,000
Fixed
Company's contractual commitments due to letters of credit
Total letters of credit	740,000	735,000
Variable
Company's contractual commitments due to letters of credit
Total letters of credit	27,091,000	30,377,000
Commitments to Extend Credit to Borrowers
Company's contractual commitments due to letters of credit
Total letters of credit	27,764,000	31,045,000
Commitments to Extend Credit to Borrowers | Fixed
Company's contractual commitments due to letters of credit
Total letters of credit	740,000	735,000
Commitments to Extend Credit to Borrowers | Variable
Company's contractual commitments due to letters of credit
Total letters of credit	27,024,000	30,310,000
Commitments to Extend Credit to Borrowers | Financial Standby Letter of Credit
Company's contractual commitments due to letters of credit
Total letters of credit	16,428,000	16,794,000
Commitments to Extend Credit to Borrowers | Financial Standby Letter of Credit | Fixed
Company's contractual commitments due to letters of credit
Total letters of credit	188,000	173,000
Commitments to Extend Credit to Borrowers | Financial Standby Letter of Credit | Variable
Company's contractual commitments due to letters of credit
Total letters of credit	16,240,000	16,621,000
Commitments to Extend Credit to Borrowers | Performance Guarantee
Company's contractual commitments due to letters of credit
Total letters of credit	11,336,000	14,251,000
Commitments to Extend Credit to Borrowers | Performance Guarantee | Fixed
Company's contractual commitments due to letters of credit
Total letters of credit	552,000	562,000
Commitments to Extend Credit to Borrowers | Performance Guarantee | Variable
Company's contractual commitments due to letters of credit
Total letters of credit	10,784,000	13,689,000
Commitments to Extend Credit Nonborrowers | Performance Guarantee
Company's contractual commitments due to letters of credit
Total letters of credit	67,000	67,000
Commitments to Extend Credit Nonborrowers | Performance Guarantee | Variable
Company's contractual commitments due to letters of credit
Total letters of credit	67,000	67,000
Unused lines of Credit
Company's contractual commitments due to letters of credit
Loan commitments	777,536,000	835,265,000
Unused lines of Credit | Fixed
Company's contractual commitments due to letters of credit
Loan commitments	153,788,000	140,305,000
Unused lines of Credit | Variable
Company's contractual commitments due to letters of credit
Loan commitments	$ 623,748,000	$ 694,960,000