LOANS AND LEASES, NET - Past Due Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Sep. 30, 2022
Financing Receivable, Past Due [Line Items]
Loans and leases	$ 3,725,616	$ 3,536,305
Accruing and Nonaccruing Loans and Leases
Financing Receivable, Past Due [Line Items]
Loans and leases	3,744,678	3,550,351
Accruing and Nonaccruing Loans and Leases | Total loans and leases held for investment
Financing Receivable, Past Due [Line Items]
Loans and leases	3,719,898	3,529,280
Accruing and Nonaccruing Loans and Leases | National Lending | Loans held for sale
Financing Receivable, Past Due [Line Items]
Loans and leases	24,780	21,071
Accruing and Nonaccruing Loans and Leases | National Lending | Term lending
Financing Receivable, Past Due [Line Items]
Loans and leases	1,235,453	1,090,289
Accruing and Nonaccruing Loans and Leases | National Lending | Asset based lending
Financing Receivable, Past Due [Line Items]
Loans and leases	377,965	351,696
Accruing and Nonaccruing Loans and Leases | National Lending | Factoring
Financing Receivable, Past Due [Line Items]
Loans and leases	338,884	372,595
Accruing and Nonaccruing Loans and Leases | National Lending | Lease financing
Financing Receivable, Past Due [Line Items]
Loans and leases	170,645	210,692
Accruing and Nonaccruing Loans and Leases | National Lending | Insurance premium finance
Financing Receivable, Past Due [Line Items]
Loans and leases	437,700	479,754
Accruing and Nonaccruing Loans and Leases | National Lending | SBA/USDA
Financing Receivable, Past Due [Line Items]
Loans and leases	405,612	359,238
Accruing and Nonaccruing Loans and Leases | National Lending | Other commercial finance
Financing Receivable, Past Due [Line Items]
Loans and leases	166,402	159,409
Accruing and Nonaccruing Loans and Leases | National Lending | Commercial finance
Financing Receivable, Past Due [Line Items]
Loans and leases	3,132,661	3,023,673
Accruing and Nonaccruing Loans and Leases | National Lending | Consumer credit products
Financing Receivable, Past Due [Line Items]
Loans and leases	120,739	144,353
Accruing and Nonaccruing Loans and Leases | National Lending | Other consumer finance
Financing Receivable, Past Due [Line Items]
Loans and leases	27,909	25,306
Accruing and Nonaccruing Loans and Leases | National Lending | Consumer finance
Financing Receivable, Past Due [Line Items]
Loans and leases	148,648	169,659
Accruing and Nonaccruing Loans and Leases | National Lending | Tax services
Financing Receivable, Past Due [Line Items]
Loans and leases	61,553	9,098
Accruing and Nonaccruing Loans and Leases | National Lending | Warehouse finance
Financing Receivable, Past Due [Line Items]
Loans and leases	377,036	326,850
Accruing and Nonaccruing Loans and Leases | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	37,965	28,203
Accruing and Nonaccruing Loans and Leases | 30-59 Days Past Due | Total loans and leases held for investment
Financing Receivable, Past Due [Line Items]
Loans and leases	37,965	28,203
Accruing and Nonaccruing Loans and Leases | 30-59 Days Past Due | National Lending | Loans held for sale
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | 30-59 Days Past Due | National Lending | Term lending
Financing Receivable, Past Due [Line Items]
Loans and leases	26,127	14,066
Accruing and Nonaccruing Loans and Leases | 30-59 Days Past Due | National Lending | Asset based lending
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | 30-59 Days Past Due | National Lending | Factoring
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | 30-59 Days Past Due | National Lending | Lease financing
Financing Receivable, Past Due [Line Items]
Loans and leases	3,154	8,265
Accruing and Nonaccruing Loans and Leases | 30-59 Days Past Due | National Lending | Insurance premium finance
Financing Receivable, Past Due [Line Items]
Loans and leases	2,741	2,550
Accruing and Nonaccruing Loans and Leases | 30-59 Days Past Due | National Lending | SBA/USDA
Financing Receivable, Past Due [Line Items]
Loans and leases	2,043	0
Accruing and Nonaccruing Loans and Leases | 30-59 Days Past Due | National Lending | Other commercial finance
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | 30-59 Days Past Due | National Lending | Commercial finance
Financing Receivable, Past Due [Line Items]
Loans and leases	34,065	24,881
Accruing and Nonaccruing Loans and Leases | 30-59 Days Past Due | National Lending | Consumer credit products
Financing Receivable, Past Due [Line Items]
Loans and leases	2,653	3,209
Accruing and Nonaccruing Loans and Leases | 30-59 Days Past Due | National Lending | Other consumer finance
Financing Receivable, Past Due [Line Items]
Loans and leases	608	113
Accruing and Nonaccruing Loans and Leases | 30-59 Days Past Due | National Lending | Consumer finance
Financing Receivable, Past Due [Line Items]
Loans and leases	3,261	3,322
Accruing and Nonaccruing Loans and Leases | 30-59 Days Past Due | National Lending | Tax services
Financing Receivable, Past Due [Line Items]
Loans and leases	639	0
Accruing and Nonaccruing Loans and Leases | 30-59 Days Past Due | National Lending | Warehouse finance
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	8,016	8,817
Accruing and Nonaccruing Loans and Leases | 60-89 Days Past Due | Total loans and leases held for investment
Financing Receivable, Past Due [Line Items]
Loans and leases	8,016	8,817
Accruing and Nonaccruing Loans and Leases | 60-89 Days Past Due | National Lending | Loans held for sale
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | 60-89 Days Past Due | National Lending | Term lending
Financing Receivable, Past Due [Line Items]
Loans and leases	1,170	2,576
Accruing and Nonaccruing Loans and Leases | 60-89 Days Past Due | National Lending | Asset based lending
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | 60-89 Days Past Due | National Lending | Factoring
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | 60-89 Days Past Due | National Lending | Lease financing
Financing Receivable, Past Due [Line Items]
Loans and leases	0	2,253
Accruing and Nonaccruing Loans and Leases | 60-89 Days Past Due | National Lending | Insurance premium finance
Financing Receivable, Past Due [Line Items]
Loans and leases	698	1,379
Accruing and Nonaccruing Loans and Leases | 60-89 Days Past Due | National Lending | SBA/USDA
Financing Receivable, Past Due [Line Items]
Loans and leases	2,291	0
Accruing and Nonaccruing Loans and Leases | 60-89 Days Past Due | National Lending | Other commercial finance
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | 60-89 Days Past Due | National Lending | Commercial finance
Financing Receivable, Past Due [Line Items]
Loans and leases	4,159	6,208
Accruing and Nonaccruing Loans and Leases | 60-89 Days Past Due | National Lending | Consumer credit products
Financing Receivable, Past Due [Line Items]
Loans and leases	2,248	2,558
Accruing and Nonaccruing Loans and Leases | 60-89 Days Past Due | National Lending | Other consumer finance
Financing Receivable, Past Due [Line Items]
Loans and leases	1,609	51
Accruing and Nonaccruing Loans and Leases | 60-89 Days Past Due | National Lending | Consumer finance
Financing Receivable, Past Due [Line Items]
Loans and leases	3,857	2,609
Accruing and Nonaccruing Loans and Leases | 60-89 Days Past Due | National Lending | Tax services
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | 60-89 Days Past Due | National Lending | Warehouse finance
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | > 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	14,342	19,534
Accruing and Nonaccruing Loans and Leases | > 89 Days Past Due | Total loans and leases held for investment
Financing Receivable, Past Due [Line Items]
Loans and leases	14,342	19,534
Accruing and Nonaccruing Loans and Leases | > 89 Days Past Due | National Lending | Loans held for sale
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | > 89 Days Past Due | National Lending | Term lending
Financing Receivable, Past Due [Line Items]
Loans and leases	6,530	4,458
Accruing and Nonaccruing Loans and Leases | > 89 Days Past Due | National Lending | Asset based lending
Financing Receivable, Past Due [Line Items]
Loans and leases	0	68
Accruing and Nonaccruing Loans and Leases | > 89 Days Past Due | National Lending | Factoring
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | > 89 Days Past Due | National Lending | Lease financing
Financing Receivable, Past Due [Line Items]
Loans and leases	2,378	1,714
Accruing and Nonaccruing Loans and Leases | > 89 Days Past Due | National Lending | Insurance premium finance
Financing Receivable, Past Due [Line Items]
Loans and leases	1,871	1,628
Accruing and Nonaccruing Loans and Leases | > 89 Days Past Due | National Lending | SBA/USDA
Financing Receivable, Past Due [Line Items]
Loans and leases	252	0
Accruing and Nonaccruing Loans and Leases | > 89 Days Past Due | National Lending | Other commercial finance
Financing Receivable, Past Due [Line Items]
Loans and leases	94	0
Accruing and Nonaccruing Loans and Leases | > 89 Days Past Due | National Lending | Commercial finance
Financing Receivable, Past Due [Line Items]
Loans and leases	11,125	7,868
Accruing and Nonaccruing Loans and Leases | > 89 Days Past Due | National Lending | Consumer credit products
Financing Receivable, Past Due [Line Items]
Loans and leases	2,140	2,669
Accruing and Nonaccruing Loans and Leases | > 89 Days Past Due | National Lending | Other consumer finance
Financing Receivable, Past Due [Line Items]
Loans and leases	1,077	124
Accruing and Nonaccruing Loans and Leases | > 89 Days Past Due | National Lending | Consumer finance
Financing Receivable, Past Due [Line Items]
Loans and leases	3,217	2,793
Accruing and Nonaccruing Loans and Leases | > 89 Days Past Due | National Lending | Tax services
Financing Receivable, Past Due [Line Items]
Loans and leases	0	8,873
Accruing and Nonaccruing Loans and Leases | > 89 Days Past Due | National Lending | Warehouse finance
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | Total Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	60,323	56,554
Accruing and Nonaccruing Loans and Leases | Total Past Due | Total loans and leases held for investment
Financing Receivable, Past Due [Line Items]
Loans and leases	60,323	56,554
Accruing and Nonaccruing Loans and Leases | Total Past Due | National Lending | Loans held for sale
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | Total Past Due | National Lending | Term lending
Financing Receivable, Past Due [Line Items]
Loans and leases	33,827	21,100
Accruing and Nonaccruing Loans and Leases | Total Past Due | National Lending | Asset based lending
Financing Receivable, Past Due [Line Items]
Loans and leases	0	68
Accruing and Nonaccruing Loans and Leases | Total Past Due | National Lending | Factoring
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | Total Past Due | National Lending | Lease financing
Financing Receivable, Past Due [Line Items]
Loans and leases	5,532	12,232
Accruing and Nonaccruing Loans and Leases | Total Past Due | National Lending | Insurance premium finance
Financing Receivable, Past Due [Line Items]
Loans and leases	5,310	5,557
Accruing and Nonaccruing Loans and Leases | Total Past Due | National Lending | SBA/USDA
Financing Receivable, Past Due [Line Items]
Loans and leases	4,586	0
Accruing and Nonaccruing Loans and Leases | Total Past Due | National Lending | Other commercial finance
Financing Receivable, Past Due [Line Items]
Loans and leases	94	0
Accruing and Nonaccruing Loans and Leases | Total Past Due | National Lending | Commercial finance
Financing Receivable, Past Due [Line Items]
Loans and leases	49,349	38,957
Accruing and Nonaccruing Loans and Leases | Total Past Due | National Lending | Consumer credit products
Financing Receivable, Past Due [Line Items]
Loans and leases	7,041	8,436
Accruing and Nonaccruing Loans and Leases | Total Past Due | National Lending | Other consumer finance
Financing Receivable, Past Due [Line Items]
Loans and leases	3,294	288
Accruing and Nonaccruing Loans and Leases | Total Past Due | National Lending | Consumer finance
Financing Receivable, Past Due [Line Items]
Loans and leases	10,335	8,724
Accruing and Nonaccruing Loans and Leases | Total Past Due | National Lending | Tax services
Financing Receivable, Past Due [Line Items]
Loans and leases	639	8,873
Accruing and Nonaccruing Loans and Leases | Total Past Due | National Lending | Warehouse finance
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Accruing and Nonaccruing Loans and Leases | Current
Financing Receivable, Past Due [Line Items]
Loans and leases	3,684,355	3,493,797
Accruing and Nonaccruing Loans and Leases | Current | Total loans and leases held for investment
Financing Receivable, Past Due [Line Items]
Loans and leases	3,659,575	3,472,726
Accruing and Nonaccruing Loans and Leases | Current | National Lending | Loans held for sale
Financing Receivable, Past Due [Line Items]
Loans and leases	24,780	21,071
Accruing and Nonaccruing Loans and Leases | Current | National Lending | Term lending
Financing Receivable, Past Due [Line Items]
Loans and leases	1,201,626	1,069,189
Accruing and Nonaccruing Loans and Leases | Current | National Lending | Asset based lending
Financing Receivable, Past Due [Line Items]
Loans and leases	377,965	351,628
Accruing and Nonaccruing Loans and Leases | Current | National Lending | Factoring
Financing Receivable, Past Due [Line Items]
Loans and leases	338,884	372,595
Accruing and Nonaccruing Loans and Leases | Current | National Lending | Lease financing
Financing Receivable, Past Due [Line Items]
Loans and leases	165,113	198,460
Accruing and Nonaccruing Loans and Leases | Current | National Lending | Insurance premium finance
Financing Receivable, Past Due [Line Items]
Loans and leases	432,390	474,197
Accruing and Nonaccruing Loans and Leases | Current | National Lending | SBA/USDA
Financing Receivable, Past Due [Line Items]
Loans and leases	401,026	359,238
Accruing and Nonaccruing Loans and Leases | Current | National Lending | Other commercial finance
Financing Receivable, Past Due [Line Items]
Loans and leases	166,308	159,409
Accruing and Nonaccruing Loans and Leases | Current | National Lending | Commercial finance
Financing Receivable, Past Due [Line Items]
Loans and leases	3,083,312	2,984,716
Accruing and Nonaccruing Loans and Leases | Current | National Lending | Consumer credit products
Financing Receivable, Past Due [Line Items]
Loans and leases	113,698	135,917
Accruing and Nonaccruing Loans and Leases | Current | National Lending | Other consumer finance
Financing Receivable, Past Due [Line Items]
Loans and leases	24,615	25,018
Accruing and Nonaccruing Loans and Leases | Current | National Lending | Consumer finance
Financing Receivable, Past Due [Line Items]
Loans and leases	138,313	160,935
Accruing and Nonaccruing Loans and Leases | Current | National Lending | Tax services
Financing Receivable, Past Due [Line Items]
Loans and leases	60,914	225
Accruing and Nonaccruing Loans and Leases | Current | National Lending | Warehouse finance
Financing Receivable, Past Due [Line Items]
Loans and leases	377,036	326,850
Nonperforming Loans and Leases
Financing Receivable, Past Due [Line Items]
Loans and leases	28,526	29,183
Nonaccrual Balance	19,585	13,375
Nonperforming Loans and Leases | Total loans and leases held for investment
Financing Receivable, Past Due [Line Items]
Loans and leases	28,526	29,183
Nonaccrual Balance	19,585	13,375
Nonperforming Loans and Leases | National Lending | Loans held for sale
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Nonaccrual Balance	0	0
Nonperforming Loans and Leases | National Lending | Term lending
Financing Receivable, Past Due [Line Items]
Loans and leases	12,843	9,611
Nonaccrual Balance	10,891	7,576
Nonperforming Loans and Leases | National Lending | Asset based lending
Financing Receivable, Past Due [Line Items]
Loans and leases	3,493	68
Nonaccrual Balance	3,493	29
Nonperforming Loans and Leases | National Lending | Factoring
Financing Receivable, Past Due [Line Items]
Loans and leases	512	569
Nonaccrual Balance	512	569
Nonperforming Loans and Leases | National Lending | Lease financing
Financing Receivable, Past Due [Line Items]
Loans and leases	5,130	4,190
Nonaccrual Balance	3,323	3,750
Nonperforming Loans and Leases | National Lending | Insurance premium finance
Financing Receivable, Past Due [Line Items]
Loans and leases	1,871	1,628
Nonaccrual Balance	0	0
Nonperforming Loans and Leases | National Lending | SBA/USDA
Financing Receivable, Past Due [Line Items]
Loans and leases	1,366	1,451
Nonaccrual Balance	1,366	1,451
Nonperforming Loans and Leases | National Lending | Other commercial finance
Financing Receivable, Past Due [Line Items]
Loans and leases	94	0
Nonaccrual Balance	0	0
Nonperforming Loans and Leases | National Lending | Commercial finance
Financing Receivable, Past Due [Line Items]
Loans and leases	25,309	17,517
Nonaccrual Balance	19,585	13,375
Nonperforming Loans and Leases | National Lending | Consumer credit products
Financing Receivable, Past Due [Line Items]
Loans and leases	2,140	2,669
Nonaccrual Balance	0	0
Nonperforming Loans and Leases | National Lending | Other consumer finance
Financing Receivable, Past Due [Line Items]
Loans and leases	1,077	124
Nonaccrual Balance	0	0
Nonperforming Loans and Leases | National Lending | Consumer finance
Financing Receivable, Past Due [Line Items]
Loans and leases	3,217	2,793
Nonaccrual Balance	0	0
Nonperforming Loans and Leases | National Lending | Tax services
Financing Receivable, Past Due [Line Items]
Loans and leases	0	8,873
Nonaccrual Balance	0	0
Nonperforming Loans and Leases | National Lending | Warehouse finance
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Nonaccrual Balance	0	0
Nonperforming Loans and Leases | > 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	8,941	15,808
Nonperforming Loans and Leases | > 89 Days Past Due | Total loans and leases held for investment
Financing Receivable, Past Due [Line Items]
Loans and leases	8,941	15,808
Nonperforming Loans and Leases | > 89 Days Past Due | National Lending | Loans held for sale
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Nonperforming Loans and Leases | > 89 Days Past Due | National Lending | Term lending
Financing Receivable, Past Due [Line Items]
Loans and leases	1,952	2,035
Nonperforming Loans and Leases | > 89 Days Past Due | National Lending | Asset based lending
Financing Receivable, Past Due [Line Items]
Loans and leases	0	39
Nonperforming Loans and Leases | > 89 Days Past Due | National Lending | Factoring
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Nonperforming Loans and Leases | > 89 Days Past Due | National Lending | Lease financing
Financing Receivable, Past Due [Line Items]
Loans and leases	1,807	440
Nonperforming Loans and Leases | > 89 Days Past Due | National Lending | Insurance premium finance
Financing Receivable, Past Due [Line Items]
Loans and leases	1,871	1,628
Nonperforming Loans and Leases | > 89 Days Past Due | National Lending | SBA/USDA
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Nonperforming Loans and Leases | > 89 Days Past Due | National Lending | Other commercial finance
Financing Receivable, Past Due [Line Items]
Loans and leases	94	0
Nonperforming Loans and Leases | > 89 Days Past Due | National Lending | Commercial finance
Financing Receivable, Past Due [Line Items]
Loans and leases	5,724	4,142
Nonperforming Loans and Leases | > 89 Days Past Due | National Lending | Consumer credit products
Financing Receivable, Past Due [Line Items]
Loans and leases	2,140	2,669
Nonperforming Loans and Leases | > 89 Days Past Due | National Lending | Other consumer finance
Financing Receivable, Past Due [Line Items]
Loans and leases	1,077	124
Nonperforming Loans and Leases | > 89 Days Past Due | National Lending | Consumer finance
Financing Receivable, Past Due [Line Items]
Loans and leases	3,217	2,793
Nonperforming Loans and Leases | > 89 Days Past Due | National Lending | Tax services
Financing Receivable, Past Due [Line Items]
Loans and leases	0	8,873
Nonperforming Loans and Leases | > 89 Days Past Due | National Lending | Warehouse finance
Financing Receivable, Past Due [Line Items]
Loans and leases	$ 0	$ 0