Servicing Rights - Key Assumptions and the Sensitivity of the Fair Value (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023	Jun. 30, 2024	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Servicing Assets at Fair Value [Line Items]
Balance of mortgage loans serviced for others	$ 1,166,585,000	$ 1,044,516,000
Weighted average rate of note (percent)	4.38%	4.03%
MSR as a percentage of serviced loans	1.85%	1.87%
Mortgage servicing rights
Servicing Assets at Fair Value [Line Items]
Fair value of MSRs	$ 21,570,000	$ 19,564,000	$ 21,077,000	$ 19,396,000	$ 18,248,000	$ 18,635,000
Expected weighted-average life (in years)	10 years 2 months 4 days	10 years 2 months 23 days
Key assumptions:
Constant prepayment rate (percent)	8.51%	8.48%
Constant prepayment rate, impact on fair value from 10% adverse change	$ (1,236,000)	$ (1,754,000)
Constant prepayment rate, impact on fair value from 25% adverse change	$ (2,237,000)	$ (2,552,000)
Discount rate (percent)	10.98%	10.98%
Discount rate, impact on fair value from 100 basis point increase	$ (1,391,000)	$ (811,000)
Discount rate, impact on fair value from 200 basis point increase	(2,201,000)	(1,560,000)
Cost to service assumptions ($ per loan)	81	82
Cost to service assumptions, impact on fair value from 10% adverse change	(164,000)	(160,000)
Cost to service assumptions, impact on fair value from 25% adverse change	$ (410,000)	$ (401,000)