Fair Value Measurements - Schedule of Fair Value of Assets Measured on Nonrecurring Basis (Details) - Nonrecurring - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2026	Mar. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral Dependent Loans	$ 11,676	$ 9,338	$ 11,676	$ 9,338
Real estate owned	390	0	390	0
Assets, fair value	12,066	9,338	12,066	9,338
Total Gains (Losses)	(771)	(5,092)	(5,212)	(5,363)
Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Gains (Losses)	(771)	(5,092)	(5,281)	(5,363)
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	11,676	9,338	11,676	9,338
Real estate owned	390	0	390	0
Assets, fair value	$ 12,066	$ 9,338	$ 12,066	$ 9,338