FAIR VALUES OF FINANCIAL INSTRUMENTS - Quantitative Information (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)
Valuation, Market Approach | Minimum | Measurement Input, Discount Rate
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Range of estimated selling cost	0.04
Valuation, Market Approach | Maximum | Measurement Input, Discount Rate
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Range of estimated selling cost	0.35
Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired Loans, Net	$ 3,525,803	$ 3,616,646
Impaired Loans | Level 3 | Valuation, Market Approach
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired Loans, Net	$ 1,575	12,775
Impaired Loans | Level 3 | Valuation, Market Approach | Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Range of estimated selling cost	15.00%
Impaired Loans | Level 3 | Valuation, Market Approach | Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Range of estimated selling cost	59.00%
Foreclosed Assets | Level 3 | Valuation, Market Approach
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired Loans, Net	$ 1	$ 2,077
Foreclosed Assets | Level 3 | Valuation, Market Approach | Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Range of estimated selling cost	9.00%
Foreclosed Assets | Level 3 | Valuation, Market Approach | Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Range of estimated selling cost	20.00%