LOANS AND LEASES, NET - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originations of loans held-for-sale	$ 1,208,684	$ 985,330	$ 601,481
Proceeds from held-for-sale loans	1,140,000	1,060,000
Gain on sale of held for sale loans	300	3,700
Loans and leases	4,366,116	3,536,305
Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	3,222,502	2,548,929
Asset Pledged as Collateral | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	117,000	120,700
Other Consumer Finance and SBA/USDA Loans | National Lending
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originations of loans held-for-sale	1,210,000	985,300
Consumer finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	254,400	169,700
Consumer finance | National Lending
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, TDR, postmodification		900
Loans modified in TDR, subsequent default		1,100
Tax services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 5,200	9,100
Commercial finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge off period	90 days
Commercial finance | National Lending
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, TDR, postmodification	$ 1,100	10,500
Loans modified in TDR, subsequent default	$ 900	$ 5,200
Commercial Insurance Premium Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge off period	210 days
Consumer credit products
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge off period	120 days