LOANS AND LEASES, NET - Summary of Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 4,071,071	$ 4,359,681
Net deferred loan origination costs	4,124	6,435
Total gross loans and leases	4,075,195	4,366,116
Allowance for credit losses	(45,336)	(49,705)	$ (45,947)	$ (68,281)
Total loans and leases, net	4,029,859	4,316,411
Consumer finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total gross loans and leases	248,800	254,400
Tax services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total gross loans and leases	8,800	5,200
National Lending | Term lending
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	1,554,641	1,308,133
Allowance for credit losses	(30,394)	(25,686)	(24,621)	(29,351)
National Lending | Asset-based lending
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	471,897	382,371
Allowance for credit losses	(1,356)	(2,738)	(1,050)	(1,726)
National Lending | Factoring
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	362,295	358,344
Allowance for credit losses	(5,757)	(6,566)	(6,556)	(3,997)
National Lending | Lease financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	152,174	183,392
Allowance for credit losses	(1,189)	(3,302)	(5,902)	(7,629)
National Lending | Insurance premium finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	800,077
Allowance for credit losses	0	(2,637)	(1,450)	(1,394)
National Lending | SBA/USDA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	568,628	524,750
Allowance for credit losses	(3,273)	(2,962)	(3,263)	(2,978)
National Lending | Other commercial finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	185,964	166,091
Allowance for credit losses	(607)	(3,089)	(1,310)	(1,168)
National Lending | Commercial finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	3,295,599	3,723,158
Allowance for credit losses	(42,576)	(46,980)	(44,152)	(48,243)
National Lending | Consumer finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	248,800	254,416
Allowance for credit losses	(2,240)	(2,346)	(1,463)	(7,354)
National Lending | Tax services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	8,825	5,192
Allowance for credit losses	(2)	(2)	(5)	(2)
National Lending | Warehouse finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	517,847	376,915
Allowance for credit losses	$ (518)	$ (377)	$ (327)	$ (420)