LOANS AND LEASES, NET -Asset Classification of Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Total gross loans and leases	$ 4,075,195	$ 4,366,116
Total, Writeoffs	57,681	59,898	$ 61,061
Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2024	727,446	1,554,843
2023	621,029	333,793
2022	316,217	173,825
2021	117,862	138,032
2020	80,750	37,324
Prior	135,421	175,272
Revolving Loans and Leases	1,043,551	809,413
Total gross loans and leases	3,042,276	3,222,502
Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2024	54,846	105,884
2023	65,301	110,339
2022	35,334	71,265
2021	37,928	16,775
2020	4,092	6,419
Prior	5,378	3,354
Revolving Loans and Leases	283,791	245,076
Total gross loans and leases	486,670	559,112
Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
2024	44,617	26,789
2023	3,356	13,868
2022	9,121	21,840
2021	14,928	1,138
2020	7,412	3,127
Prior	365	75
Revolving Loans and Leases	13,458	35,274
Total gross loans and leases	93,257	102,111
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2024	10,835	38,423
2023	47,309	35,260
2022	33,418	49,237
2021	33,303	33,691
2020	30,482	15,443
Prior	14,368	8,773
Revolving Loans and Leases	11,227	27,366
Total gross loans and leases	180,942	208,193
Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2024	4,314	380
2023	1,650	2,807
2022	2,302	1,762
2021	951	1,182
2020	207	165
Prior	865	1,358
Revolving Loans and Leases	12	501
Total gross loans and leases	10,301	8,155
Total
Financing Receivable, Credit Quality Indicator [Line Items]
2024	842,058	1,726,319
2023	738,645	496,067
2022	396,392	317,929
2021	204,972	190,818
2020	122,943	62,478
Prior	156,397	188,832
Revolving Loans and Leases	1,352,039	1,117,630
Total gross loans and leases	3,813,446	4,100,073
National Lending | Total
Financing Receivable, Credit Quality Indicator [Line Items]
2024, Writeoffs	200
2023, Writeoffs	4,541
2022, Writeoffs	8,754
2021, Writeoffs	3,783
2020, Writeoffs	2,391
Prior, Writeoffs	715
Revolving Loans and Leases, Writeoffs	2,453
Total, Writeoffs	22,837
National Lending | Term lending
Financing Receivable, Credit Quality Indicator [Line Items]
Total, Writeoffs	18,193	11,295	12,629
National Lending | Term lending | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2024	548,597	539,448
2023	398,832	149,190
2022	117,180	99,677
2021	77,585	73,132
2020	42,950	14,368
Prior	24,166	85,812
Revolving Loans and Leases	0	0
Total gross loans and leases	1,209,310	961,627
National Lending | Term lending | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2024	47,765	53,481
2023	52,317	51,036
2022	34,964	58,041
2021	31,025	12,230
2020	2,720	4,483
Prior	2,312	727
Revolving Loans and Leases	0	0
Total gross loans and leases	171,103	179,998
National Lending | Term lending | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
2024	44,617	26,539
2023	3,106	13,853
2022	9,121	20,463
2021	14,772	723
2020	7,238	2,932
Prior	2	75
Revolving Loans and Leases	0	0
Total gross loans and leases	78,856	64,585
National Lending | Term lending | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2024	9,798	20,437
2023	24,187	30,451
2022	18,537	14,729
2021	11,660	24,613
2020	18,894	3,872
Prior	2,631	764
Revolving Loans and Leases	0	0
Total gross loans and leases	85,707	94,866
National Lending | Term lending | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2024	4,314	200
2023	1,465	2,655
2022	2,247	1,691
2021	758	1,121
2020	114	165
Prior	767	1,225
Revolving Loans and Leases	0	0
Total gross loans and leases	9,665	7,057
National Lending | Term lending | Total
Financing Receivable, Credit Quality Indicator [Line Items]
2024	655,091	640,105
2023	479,907	247,185
2022	182,049	194,601
2021	135,800	111,819
2020	71,916	25,820
Prior	29,878	88,603
Revolving Loans and Leases	0	0
Total gross loans and leases	1,554,641	1,308,133
2024, Writeoffs	114
2023, Writeoffs	3,102
2022, Writeoffs	8,502
2021, Writeoffs	3,576
2020, Writeoffs	2,184
Prior, Writeoffs	715
Revolving Loans and Leases, Writeoffs	0
Total, Writeoffs	18,193
National Lending | Asset-based lending
Financing Receivable, Credit Quality Indicator [Line Items]
Total, Writeoffs	0	2,873	16
National Lending | Asset-based lending | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	0	0
Revolving Loans and Leases	233,268	161,744
Total gross loans and leases	233,268	161,744
National Lending | Asset-based lending | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	0	0
Revolving Loans and Leases	221,521	174,243
Total gross loans and leases	221,521	174,243
National Lending | Asset-based lending | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	0	0
Revolving Loans and Leases	13,187	26,382
Total gross loans and leases	13,187	26,382
National Lending | Asset-based lending | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	0	0
Revolving Loans and Leases	3,921	19,501
Total gross loans and leases	3,921	19,501
National Lending | Asset-based lending | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2024		0
2023		0
2022		0
2021		0
2020		0
Prior		0
Revolving Loans and Leases		501
Total gross loans and leases		501
National Lending | Asset-based lending | Total
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	0	0
Revolving Loans and Leases	471,897	382,371
Total gross loans and leases	471,897	382,371
2024, Writeoffs	0
2023, Writeoffs	0
2022, Writeoffs	0
2021, Writeoffs	0
2020, Writeoffs	0
Prior, Writeoffs	0
Revolving Loans and Leases, Writeoffs	0
Total, Writeoffs	0
National Lending | Factoring
Financing Receivable, Credit Quality Indicator [Line Items]
Total, Writeoffs	2,453	1,545	11,057
National Lending | Factoring | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	0	0
Revolving Loans and Leases	292,436	270,754
Total gross loans and leases	292,436	270,754
National Lending | Factoring | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	0	0
Revolving Loans and Leases	62,270	70,833
Total gross loans and leases	62,270	70,833
National Lending | Factoring | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	0	0
Revolving Loans and Leases	271	8,892
Total gross loans and leases	271	8,892
National Lending | Factoring | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	0	0
Revolving Loans and Leases	7,306	7,865
Total gross loans and leases	7,306	7,865
National Lending | Factoring | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0
2022	0
2021	0
2020	0
Prior	0
Revolving Loans and Leases	12
Total gross loans and leases	12
National Lending | Factoring | Total
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	0	0
Revolving Loans and Leases	362,295	358,344
Total gross loans and leases	362,295	358,344
2024, Writeoffs	0
2023, Writeoffs	0
2022, Writeoffs	0
2021, Writeoffs	0
2020, Writeoffs	0
Prior, Writeoffs	0
Revolving Loans and Leases, Writeoffs	2,453
Total, Writeoffs	2,453
National Lending | Lease financing
Financing Receivable, Credit Quality Indicator [Line Items]
2024, Writeoffs	0
2023, Writeoffs	0
2022, Writeoffs	0
2021, Writeoffs	207
2020, Writeoffs	80
Prior, Writeoffs	0
Revolving Loans and Leases, Writeoffs	0
Total, Writeoffs	287	1,479	301
National Lending | Lease financing | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2024	44,883	57,123
2023	48,851	15,941
2022	12,862	15,167
2021	7,101	27,489
2020	7,938	4,036
Prior	1,733	1,281
Revolving Loans and Leases	0	0
Total gross loans and leases	123,368	121,037
National Lending | Lease financing | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2024	1,837	793
2023	3,537	10,436
2022	370	12,566
2021	6,264	4,494
2020	1,362	1,579
Prior	40	55
Revolving Loans and Leases	0	0
Total gross loans and leases	13,410	29,923
National Lending | Lease financing | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	250	0
2022	0	847
2021	0	415
2020	174	195
Prior	0	0
Revolving Loans and Leases	0	0
Total gross loans and leases	424	1,457
National Lending | Lease financing | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	14,890
2023	6,691	1,983
2022	2,723	7,082
2021	2,717	3,660
2020	2,069	3,062
Prior	603	33
Revolving Loans and Leases	0	0
Total gross loans and leases	14,803	30,710
National Lending | Lease financing | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	0
2022	0	71
2021	138	61
2020	31	0
Prior	0	133
Revolving Loans and Leases	0	0
Total gross loans and leases	169	265
National Lending | Lease financing | Total
Financing Receivable, Credit Quality Indicator [Line Items]
2024	46,720	72,806
2023	59,329	28,360
2022	15,955	35,733
2021	16,220	36,119
2020	11,574	8,872
Prior	2,376	1,502
Revolving Loans and Leases	0	0
Total gross loans and leases	152,174	183,392
National Lending | Insurance premium finance
Financing Receivable, Credit Quality Indicator [Line Items]
Total, Writeoffs	1,149	1,659	767
National Lending | Insurance premium finance | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2024		797,267
2023		1,210
2022		0
2021		0
2020		0
Prior		0
Revolving Loans and Leases		0
Total gross loans and leases		798,477
National Lending | Insurance premium finance | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2024		858
2023		34
2022		0
2021		0
2020		0
Prior		0
Revolving Loans and Leases		0
Total gross loans and leases		892
National Lending | Insurance premium finance | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
2024		250
2023		15
2022		0
2021		0
2020		0
Prior		0
Revolving Loans and Leases		0
Total gross loans and leases		265
National Lending | Insurance premium finance | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2024		91
2023		20
2022		0
2021		0
2020		0
Prior		0
Revolving Loans and Leases		0
Total gross loans and leases		111
National Lending | Insurance premium finance | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2024		180
2023		152
2022		0
2021		0
2020		0
Prior		0
Revolving Loans and Leases		0
Total gross loans and leases		332
National Lending | Insurance premium finance | Total
Financing Receivable, Credit Quality Indicator [Line Items]
2024		798,646
2023		1,431
2022		0
2021		0
2020		0
Prior		0
Revolving Loans and Leases		0
Total gross loans and leases		800,077
2024, Writeoffs	86
2023, Writeoffs	890
2022, Writeoffs	173
2021, Writeoffs	0
2020, Writeoffs	0
Prior, Writeoffs	0
Revolving Loans and Leases, Writeoffs	0
Total, Writeoffs	1,149
National Lending | SBA/USDA
Financing Receivable, Credit Quality Indicator [Line Items]
Total, Writeoffs	755	43	652
National Lending | SBA/USDA | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2024	60,636	158,675
2023	171,136	148,525
2022	179,490	26,244
2021	20,825	36,274
2020	28,588	8,798
Prior	39,319	18,252
Revolving Loans and Leases	0	0
Total gross loans and leases	499,994	396,768
National Lending | SBA/USDA | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2024	5,244	49,010
2023	6,967	48,833
2022	0	658
2021	639	51
2020	10	357
Prior	3,026	2,572
Revolving Loans and Leases	0	0
Total gross loans and leases	15,886	101,481
National Lending | SBA/USDA | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	0
2022	0	530
2021	156	0
2020	0	0
Prior	363	0
Revolving Loans and Leases	0	0
Total gross loans and leases	519	530
National Lending | SBA/USDA | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2024	1,037	252
2023	15,923	2,356
2022	12,158	1,718
2021	2,003	5,418
2020	9,519	8,509
Prior	11,134	7,718
Revolving Loans and Leases	0	0
Total gross loans and leases	51,774	25,971
National Lending | SBA/USDA | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	185
2022	55
2021	55
2020	62
Prior	98
Revolving Loans and Leases	0
Total gross loans and leases	455
National Lending | SBA/USDA | Total
Financing Receivable, Credit Quality Indicator [Line Items]
2024	66,917	207,937
2023	194,211	199,714
2022	191,703	29,150
2021	23,678	41,743
2020	38,179	17,664
Prior	53,940	28,542
Revolving Loans and Leases	0	0
Total gross loans and leases	568,628	524,750
2024, Writeoffs	0
2023, Writeoffs	549
2022, Writeoffs	79
2021, Writeoffs	0
2020, Writeoffs	127
Prior, Writeoffs	0
Revolving Loans and Leases, Writeoffs	0
Total, Writeoffs	755
National Lending | Other commercial finance
Financing Receivable, Credit Quality Indicator [Line Items]
Total, Writeoffs	0	0	0
National Lending | Other commercial finance | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2024	73,330	2,330
2023	2,210	18,927
2022	6,685	32,737
2021	12,351	1,137
2020	1,274	10,122
Prior	70,203	69,927
Revolving Loans and Leases	0	0
Total gross loans and leases	166,053	135,180
National Lending | Other commercial finance | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	1,742
2023	2,480	0
2022	0	0
2021	0	0
2020	0	0
Prior	0	0
Revolving Loans and Leases	0	0
Total gross loans and leases	2,480	1,742
National Lending | Other commercial finance | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	2,753
2023	508	450
2022	0	25,708
2021	16,923	0
2020	0	0
Prior	0	258
Revolving Loans and Leases	0	0
Total gross loans and leases	17,431	29,169
National Lending | Other commercial finance | Total
Financing Receivable, Credit Quality Indicator [Line Items]
2024	73,330	6,825
2023	5,198	19,377
2022	6,685	58,445
2021	29,274	1,137
2020	1,274	10,122
Prior	70,203	70,185
Revolving Loans and Leases	0	0
Total gross loans and leases	185,964	166,091
2024, Writeoffs	0
2023, Writeoffs	0
2022, Writeoffs	0
2021, Writeoffs	0
2020, Writeoffs	0
Prior, Writeoffs	0
Revolving Loans and Leases, Writeoffs	0
Total, Writeoffs	0
National Lending | Warehouse finance
Financing Receivable, Credit Quality Indicator [Line Items]
Total, Writeoffs	0	0	$ 0
National Lending | Warehouse finance | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	0	0
Revolving Loans and Leases	517,847	376,915
Total gross loans and leases	517,847	376,915
National Lending | Warehouse finance | Total
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	0	0
Revolving Loans and Leases	517,847	376,915
Total gross loans and leases	517,847	$ 376,915
2024, Writeoffs	0
2023, Writeoffs	0
2022, Writeoffs	0
2021, Writeoffs	0
2020, Writeoffs	0
Prior, Writeoffs	0
Revolving Loans and Leases, Writeoffs	0
Total, Writeoffs	$ 0