LOANS AND ALLOWANCE FOR CREDIT LOSSES - Amount of Business Lending Loans by Credit Quality Categories (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Term Loans Amortized Cost Basis by Origination Year
Total Loans	$ 8,543,607	$ 7,373,639
Legacy Loan
Term Loans Amortized Cost Basis by Origination Year
Total Loans	8,543,607	7,373,639
Business lending
Term Loans Amortized Cost Basis by Origination Year
2022	620,848
2021	428,815	532,141
2020	312,207	341,665
2019	333,463	351,064
2018	291,095	334,790
Prior	831,147
2017		230,502
Prior		705,731
Revolving Loans Amortized Cost Basis	676,850	580,011
Total Loans	3,494,425	3,075,904
Business lending | Pass
Term Loans Amortized Cost Basis by Origination Year
2022	617,776
2021	422,638	524,302
2020	306,960	328,885
2019	325,181	320,638
2018	249,442	248,175
Prior	710,320
2017		186,074
Prior		584,912
Revolving Loans Amortized Cost Basis	636,686	524,553
Total Loans	3,269,003	2,717,539
Business lending | Special mention
Term Loans Amortized Cost Basis by Origination Year
2022	2,236
2021	5,229	5,969
2020	3,988	11,013
2019	4,442	10,111
2018	13,155	46,318
Prior	64,432
2017		22,524
Prior		57,134
Revolving Loans Amortized Cost Basis	31,447	27,444
Total Loans	124,929	180,513
Business lending | Classified
Term Loans Amortized Cost Basis by Origination Year
2022	836
2021	948	1,870
2020	1,259	1,767
2019	3,840	20,315
2018	28,498	40,235
Prior	56,395
2017		21,904
Prior		63,685
Revolving Loans Amortized Cost Basis	8,717	27,511
Total Loans	100,493	177,287
Business lending | Doubtful
Term Loans Amortized Cost Basis by Origination Year
2022	0
2021	0	0
2020	0	0
2019	0	0
2018	0	62
Prior	0
2017		0
Prior		0
Revolving Loans Amortized Cost Basis	0	503
Total Loans	0	565
Consumer mortgage
Term Loans Amortized Cost Basis by Origination Year
2022	471,639
2021	707,391	683,550
2020	354,226	352,373
2019	270,282	269,694
2018	162,830	173,187
Prior	984,139
2017		172,187
Prior		880,095
Revolving Loans Amortized Cost Basis	25,014	25,028
Total Loans	2,975,521	2,556,114
Consumer mortgage | FICO AB
Term Loans Amortized Cost Basis by Origination Year
2022	346,061
2021	516,066	514,680
2020	231,950	229,305
2019	183,330	183,469
2018	104,281	113,749
Prior	634,567
2017		116,852
Prior		569,365
Revolving Loans Amortized Cost Basis	1,799	0
Total Loans	2,018,054	1,727,420
Consumer mortgage | FICO AB | Performing
Term Loans Amortized Cost Basis by Origination Year
2022	346,061
2021	516,066	514,680
2020	231,558	229,039
2019	182,908	183,469
2018	103,874	113,618
Prior	629,948
2017		116,417
Prior		566,129
Revolving Loans Amortized Cost Basis	1,799	0
Total Loans	2,012,214	1,723,352
Consumer mortgage | FICO AB | Nonperforming
Term Loans Amortized Cost Basis by Origination Year
2022	0
2021	0	0
2020	392	266
2019	422	0
2018	407	131
Prior	4,619
2017		435
Prior		3,236
Revolving Loans Amortized Cost Basis	0	0
Total Loans	5,840	4,068
Consumer mortgage | FICO CDE
Term Loans Amortized Cost Basis by Origination Year
2022	125,578
2021	191,325	168,870
2020	122,276	123,068
2019	86,952	86,225
2018	58,549	59,438
Prior	349,572
2017		55,335
Prior		310,730
Revolving Loans Amortized Cost Basis	23,215	25,028
Total Loans	957,467	828,694
Consumer mortgage | FICO CDE | Performing
Term Loans Amortized Cost Basis by Origination Year
2022	125,340
2021	190,264	168,870
2020	120,575	122,546
2019	85,509	85,253
2018	57,082	57,973
Prior	336,435
2017		54,396
Prior		300,341
Revolving Loans Amortized Cost Basis	23,215	25,028
Total Loans	938,420	814,407
Consumer mortgage | FICO CDE | Nonperforming
Term Loans Amortized Cost Basis by Origination Year
2022	238
2021	1,061	0
2020	1,701	522
2019	1,443	972
2018	1,467	1,465
Prior	13,137
2017		939
Prior		10,389
Revolving Loans Amortized Cost Basis	0	0
Total Loans	19,047	14,287
Consumer indirect
Term Loans Amortized Cost Basis by Origination Year
2022	620,718
2021	453,613	590,857
2020	143,737	204,563
2019	115,312	182,458
2018	62,545	107,707
Prior	65,310
2017		39,402
Prior		64,762
Revolving Loans Amortized Cost Basis	0	0
Total Loans	1,461,235	1,189,749
Consumer indirect | Performing
Term Loans Amortized Cost Basis by Origination Year
2022	620,692
2021	453,478	590,857
2020	143,702	204,529
2019	115,304	182,458
2018	62,534	107,683
Prior	65,310
2017		39,385
Prior		64,750
Revolving Loans Amortized Cost Basis	0	0
Total Loans	1,461,020	1,189,662
Consumer indirect | Nonperforming
Term Loans Amortized Cost Basis by Origination Year
2022	26
2021	135	0
2020	35	34
2019	8	0
2018	11	24
Prior	0
2017		17
Prior		12
Revolving Loans Amortized Cost Basis	0	0
Total Loans	215	87
Consumer direct
Term Loans Amortized Cost Basis by Origination Year
2022	72,531
2021	52,234	72,584
2020	19,837	28,909
2019	15,549	24,788
2018	7,074	12,341
Prior	5,627
2017		4,396
Prior		4,575
Revolving Loans Amortized Cost Basis	6,547	6,218
Total Loans	179,399	153,811
Consumer direct | Performing
Term Loans Amortized Cost Basis by Origination Year
2022	72,531
2021	52,234	72,584
2020	19,832	28,905
2019	15,548	24,770
2018	7,045	12,340
Prior	5,615
2017		4,396
Prior		4,575
Revolving Loans Amortized Cost Basis	6,527	6,218
Total Loans	179,332	153,788
Consumer direct | Nonperforming
Term Loans Amortized Cost Basis by Origination Year
2022	0
2021	0	0
2020	5	4
2019	1	18
2018	29	1
Prior	12
2017		0
Prior		0
Revolving Loans Amortized Cost Basis	20	0
Total Loans	67	23
Home equity
Term Loans Amortized Cost Basis by Origination Year
2022	55,553
2021	74,666	76,041
2020	39,580	43,170
2019	33,335	36,037
2018	17,328	18,926
Prior	45,174
2017		15,265
Prior		36,419
Revolving Loans Amortized Cost Basis	167,391	172,203
Total Loans	433,027	398,061
Home equity | Performing
Term Loans Amortized Cost Basis by Origination Year
2022	55,553
2021	74,656	76,041
2020	39,458	43,106
2019	33,137	35,990
2018	17,175	18,824
Prior	44,513
2017		15,134
Prior		35,740
Revolving Loans Amortized Cost Basis	166,060	170,422
Total Loans	430,552	395,257
Home equity | Nonperforming
Term Loans Amortized Cost Basis by Origination Year
2022	0
2021	10	0
2020	122	64
2019	198	47
2018	153	102
Prior	661
2017		131
Prior		679
Revolving Loans Amortized Cost Basis	1,331	1,781
Total Loans	$ 2,475	$ 2,804