Fair Value Measurements - Schedule of Fair Value of Assets Measured on Nonrecurring Basis (Details) - Nonrecurring - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans	$ 17,221	$ 32,132	$ 17,221	$ 32,132
Real estate owned	390	0	390	0
Assets, fair value	17,611	32,132	17,611	32,132
Total Gains (Losses)	(2,226)	(5,750)	(7,438)	(11,113)
Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Gains (Losses)	(2,226)	(5,750)	(7,507)	(11,113)
Real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Gains (Losses)	0	0	69	0
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans	0	0	0	0
Real estate owned	0	0	0	0
Assets, fair value	0	0	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans	0	0	0	0
Real estate owned	0	0	0	0
Assets, fair value	0	0	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans	17,221	32,132	17,221	32,132
Real estate owned	390	0	390	0
Assets, fair value	$ 17,611	$ 32,132	$ 17,611	$ 32,132

Amount of addition (reduction) to the amount at which an asset could be incurred (settled) in a current transaction between willing parties.

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Fair value portion of asset recognized for present right to economic benefit.

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Collateral Dependent Loans Receivable, Fair Value Disclosure

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