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Loan and Lease Financings (Details 4) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) item	Sep. 30, 2024 USD ($) item	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)
Loan modifications to borrowers experiencing financial difficulties
Percent of Total Segment of Financing Receivable	0.00%	0.03%	0.04%	0.47%
Commitments to lend additional amounts	$ 4,450	$ 0	$ 4,450	$ 0	$ 4,450	$ 0
Weighted Average Interest Rate Reduction					0.00%	0.00%
Weighted Average Term Extension Modification (in months)					11 months	10 months
Weighted Average Payment Delay (in months)					6 months	6 months
Combination Weighted Average Payment Delay and Term Extension (in months)					4 months	4 months
Loan modifications to borrowers experiencing financial difficulties subsequent default | item			1	1
Loans and Leases Receivable Evaluated for Impairment	250	250	$ 250	$ 250	$ 250	$ 250
Payment Delay
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties	0	2,040	0	2,040
Term Extension
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties	0	10	2,654	118
Interest Rate Reduction
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties	0	0	0	0
Combination Payment Delay and Term Extension
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties	$ 300	$ 0	$ 300	$ 28,847
Current
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					4,804	39,650
30 to 59 Days Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					519	0
60 to 89 Days Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					0	0
90 Days or More Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					4,928	0
Total Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					$ 5,447	$ 0
Commercial and agricultural
Loan modifications to borrowers experiencing financial difficulties
Percent of Total Segment of Financing Receivable	0.04%	0.15%	0.33%	0.16%
Weighted Average Interest Rate Reduction					0.00%	0.00%
Weighted Average Term Extension Modification (in months)					11 months	10 months
Weighted Average Payment Delay (in months)					6 months	6 months
Combination Weighted Average Payment Delay and Term Extension (in months)					8 months	3 months
Commercial and agricultural | Payment Delay
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties	$ 0	$ 1,052	$ 0	$ 1,052
Commercial and agricultural | Term Extension
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties	0	10	2,191	118
Commercial and agricultural | Interest Rate Reduction
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties	0	0	0	0
Commercial and agricultural | Combination Payment Delay and Term Extension
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties	$ 300	$ 0	$ 300	$ 0
Commercial and agricultural | Current
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					$ 2,384	$ 1,170
Commercial and agricultural | 30 to 59 Days Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					107	0
Commercial and agricultural | 60 to 89 Days Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					0	0
Commercial and agricultural | 90 Days or More Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					0	0
Commercial and agricultural | Total Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					$ 107	$ 0
Construction equipment
Loan modifications to borrowers experiencing financial difficulties
Percent of Total Segment of Financing Receivable			0.04%
Weighted Average Interest Rate Reduction					0.00%
Weighted Average Term Extension Modification (in months)					5 months
Weighted Average Payment Delay (in months)					0 months
Combination Weighted Average Payment Delay and Term Extension (in months)					0 months
Construction equipment | Payment Delay
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties			$ 0
Construction equipment | Term Extension
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties			463
Construction equipment | Interest Rate Reduction
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties			0
Construction equipment | Combination Payment Delay and Term Extension
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties			$ 0
Construction equipment | Current
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					$ 51
Construction equipment | 30 to 59 Days Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					412
Construction equipment | 60 to 89 Days Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					0
Construction equipment | 90 Days or More Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					0
Construction equipment | Total Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					$ 412
Commercial real estate
Loan modifications to borrowers experiencing financial difficulties
Percent of Total Segment of Financing Receivable		0.09%		0.09%
Weighted Average Interest Rate Reduction					0.00%	0.00%
Weighted Average Term Extension Modification (in months)					0 months	0 months
Weighted Average Payment Delay (in months)					6 months	6 months
Combination Weighted Average Payment Delay and Term Extension (in months)					0 months	0 months
Commercial real estate | Payment Delay
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties		$ 988		$ 988
Commercial real estate | Term Extension
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties		0		0
Commercial real estate | Interest Rate Reduction
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties		0		0
Commercial real estate | Combination Payment Delay and Term Extension
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties		$ 0		$ 0
Commercial real estate | Current
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties						$ 988
Commercial real estate | 30 to 59 Days Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties						0
Commercial real estate | 60 to 89 Days Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties						0
Commercial real estate | 90 Days or More Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties						0
Commercial real estate | Total Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties						$ 0
Auto and light truck
Loan modifications to borrowers experiencing financial difficulties
Percent of Total Segment of Financing Receivable				3.04%
Weighted Average Interest Rate Reduction					0.00%	0.00%
Weighted Average Term Extension Modification (in months)					0 months	0 months
Weighted Average Payment Delay (in months)					0 months	0 months
Combination Weighted Average Payment Delay and Term Extension (in months)					3 months	3 months
Auto and light truck | Payment Delay
Loan modifications to borrowers experiencing financial difficulties
Financing Receivable, Troubled Debt Restructuring, Subsequent Default				$ 0
Auto and light truck | Term Extension
Loan modifications to borrowers experiencing financial difficulties
Financing Receivable, Troubled Debt Restructuring, Subsequent Default				0
Auto and light truck | Interest Rate Reduction
Loan modifications to borrowers experiencing financial difficulties
Financing Receivable, Troubled Debt Restructuring, Subsequent Default				0
Auto and light truck | Combination Payment Delay and Term Extension
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties				$ 28,847
Auto and light truck | Current
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					$ 0	$ 28,847
Auto and light truck | 30 to 59 Days Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					0	0
Auto and light truck | 60 to 89 Days Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					0	0
Auto and light truck | 90 Days or More Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					4,928	0
Auto and light truck | Total Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					$ 4,928	$ 0
Medium and heavy duty truck
Loan modifications to borrowers experiencing financial difficulties
Weighted Average Interest Rate Reduction					0.00%	0.00%
Weighted Average Term Extension Modification (in months)					0 months	0 months
Weighted Average Payment Delay (in months)					0 months	0 months
Combination Weighted Average Payment Delay and Term Extension (in months)					4 months	6 months
Medium and heavy duty truck | Current
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					$ 2,369	$ 8,645
Medium and heavy duty truck | 30 to 59 Days Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					0	0
Medium and heavy duty truck | 60 to 89 Days Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					0	0
Medium and heavy duty truck | 90 Days or More Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					0	0
Medium and heavy duty truck | Total Past Due
Loan modifications to borrowers experiencing financial difficulties
Loan modifications to borrowers experiencing financial difficulties					$ 0	$ 0

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