Fair Value Disclosures - Narrative (Details)	3 Months Ended		6 Months Ended
	Mar. 31, 2025 USD ($) loan numberOfSwaps Rate	Mar. 31, 2024 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($) numberOfSwaps Rate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contingent consideration liability, payment	$ 635,000	$ 635,000
Carrying value of individually analyzed loans and leases held for investment	6,822,431,000	6,559,400,000
Servicing rights carrying amount before valuation allowance	6,900,000			$ 7,000,000.0
Servicing rights valuation allowance	26,000			7,000
Other real estate owned	22,400,000			20,100,000
Transfer of loans to other real estate owned	2,526,000	0
Repossessed assets	79,000			76,000
Transfer of leases to repossessed assets	17,000	167,000
Proceeds from Sale of Other Assets	13,000
Lease financings
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value of individually analyzed loans and leases held for investment	0			0
Held for Investment
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value of individually analyzed loans and leases held for investment	10,600,000			12,100,000
Valuation allowance of individually analyzed loans and leases held for investment	2,600,000			1,900,000
Credit derivatives | Fair Value Measure on Recurring Basis
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	79,000			67,000
Level 3 | Credit derivatives | Fair Value Measure on Recurring Basis
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	$ 79,000			$ 67,000
Number of interest rate swaps held | numberOfSwaps	135			135
Notional Amount	$ 854,800,000			$ 860,400,000
Derivative, credit valuation adjustment, loss rate used in calculation | Rate	40.00%			40.00%
Paul I. Scheaffer Insurance Agency
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contingent consideration liability discount rate				0.083
Contingent consideration liability, payment			$ 635,000
Business combination, contingent consideration, liability, current				$ 635,000
Potential cash payments, lower range			0
Potential cash payments, upper range			$ 635,000
Residential secured for personal purpose
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value of individually analyzed loans and leases held for investment	$ 991,535,000	918,566,000
Transfer of loans to other real estate owned	$ 2,500,000
Residential secured for personal purpose | Non Accrual Loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Real estate owned, transfer to real estate owned, number of properties | loan	1
Real estate-residential secured for business purpose
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value of individually analyzed loans and leases held for investment	$ 535,633,000	$ 522,477,000
Real estate owned, sold, number of properties | loan	2
Real Estate Owned, Transfer from Real Estate Owned	$ 226,000