LOANS AND LEASES, NET - Summary of Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 3,529,280	$ 3,607,815
Net deferred loan origination costs	7,025	1,748
Total gross loans and leases	3,536,305	3,609,563
Allowance for credit losses	(45,947)	(68,281)	$ (56,188)
Total loans and leases, net	3,490,358	3,541,282
Consumer finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total gross loans and leases	169,700	252,900
Tax services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total gross loans and leases	9,100	10,400
National Lending | Term lending
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	1,090,289	961,019
Allowance for credit losses	(24,621)	(29,351)	(15,211)
National Lending | Asset based lending
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	351,696	300,225
Allowance for credit losses	(1,050)	(1,726)	(1,406)
National Lending | Factoring
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	372,595	363,670
Allowance for credit losses	(6,556)	(3,997)	(3,027)
National Lending | Lease financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	210,692	266,050
Allowance for credit losses	(5,902)	(7,629)	(7,023)
National Lending | Insurance premium finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	479,754	428,867
Allowance for credit losses	(1,450)	(1,394)	(2,129)
National Lending | SBA/USDA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	359,238	247,756
Allowance for credit losses	(3,263)	(2,978)	(940)
National Lending | Other commercial finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	159,409	157,908
Allowance for credit losses	(1,310)	(1,168)	(182)
National Lending | Commercial finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	3,023,673	2,725,495
Allowance for credit losses	(44,152)	(48,243)	(29,918)
National Lending | Consumer credit products
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	144,353	129,251
Allowance for credit losses	(1,400)	(1,242)	(845)
National Lending | Other consumer finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	25,306	123,606
Allowance for credit losses	(63)	(6,112)	(2,821)
National Lending | Consumer finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	169,659	252,857
Allowance for credit losses	(1,463)	(7,354)	(3,666)
National Lending | Tax services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	9,098	10,405
Allowance for credit losses	(5)	(2)	(2)
National Lending | Warehouse finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	326,850	419,926
Allowance for credit losses	(327)	(420)	(294)
Community Banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	199,132
Allowance for credit losses	$ 0	$ (12,262)	$ (22,308)