ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY INFORMATION - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 11,480,118	$ 7,882,055	$ 8,255,890
Commercial | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	532,422	605,339
Year two, originated, fiscal year before current fiscal year	739,100	436,055
Year three, originated, two years before current fiscal year	527,079	386,061
Year four, originated, three years before current fiscal year	423,861	303,448
Year five, originated, four years before current fiscal year	304,314	159,343
Prior	330,280	171,029
Revolving loans amortized cost basis	7,980	5,580
Revolving loans converted to term	242,704	203,464
Total	3,107,740	2,270,319	2,379,697
Commercial | Commercial and industrial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	492,793	556,896
Year two, originated, fiscal year before current fiscal year	680,564	420,698
Year three, originated, two years before current fiscal year	503,154	329,354
Year four, originated, three years before current fiscal year	343,944	273,345
Year five, originated, four years before current fiscal year	258,950	139,800
Prior	284,041	148,809
Revolving loans amortized cost basis	7,970	5,551
Revolving loans converted to term	215,231	176,006
Total	2,786,647	2,050,459
Commercial | Commercial and industrial | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	28,344	35,910
Year two, originated, fiscal year before current fiscal year	38,417	949
Year three, originated, two years before current fiscal year	8,791	3,052
Year four, originated, three years before current fiscal year	9,304	1,057
Year five, originated, four years before current fiscal year	6,493	429
Prior	1,234	15,299
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	19,939	17,545
Total	112,522	74,241
Commercial | Commercial and industrial | Substandard or Lower
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	11,285	12,533
Year two, originated, fiscal year before current fiscal year	20,119	14,408
Year three, originated, two years before current fiscal year	15,134	53,655
Year four, originated, three years before current fiscal year	70,613	29,046
Year five, originated, four years before current fiscal year	38,871	19,114
Prior	45,005	6,921
Revolving loans amortized cost basis	10	29
Revolving loans converted to term	7,534	9,913
Total	208,571	145,619
Commercial | Owner-occupied commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	134,170	309,286
Year two, originated, fiscal year before current fiscal year	382,322	208,223
Year three, originated, two years before current fiscal year	282,281	179,202
Year four, originated, three years before current fiscal year	260,879	77,835
Year five, originated, four years before current fiscal year	176,695	142,277
Prior	425,540	280,687
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	161,342	144,197
Total	1,823,229	1,341,707	1,360,681
Commercial | Owner-occupied commercial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	133,004	305,156
Year two, originated, fiscal year before current fiscal year	377,379	189,128
Year three, originated, two years before current fiscal year	255,167	172,503
Year four, originated, three years before current fiscal year	256,339	67,526
Year five, originated, four years before current fiscal year	162,461	136,697
Prior	409,964	262,629
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	144,921	128,188
Total	1,739,235	1,261,827
Commercial | Owner-occupied commercial | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	938
Year two, originated, fiscal year before current fiscal year	920	5,359
Year three, originated, two years before current fiscal year	6,994	2,561
Year four, originated, three years before current fiscal year	0	891
Year five, originated, four years before current fiscal year	1,278	0
Prior	7,335	7,019
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	3,467	10,543
Total	19,994	27,311
Commercial | Owner-occupied commercial | Substandard or Lower
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	1,166	3,192
Year two, originated, fiscal year before current fiscal year	4,023	13,736
Year three, originated, two years before current fiscal year	20,120	4,138
Year four, originated, three years before current fiscal year	4,540	9,418
Year five, originated, four years before current fiscal year	12,956	5,580
Prior	8,241	11,039
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	12,954	5,466
Total	64,000	52,569
Commercial | Commercial mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	215,295	418,587
Year two, originated, fiscal year before current fiscal year	687,332	286,698
Year three, originated, two years before current fiscal year	584,758	221,100
Year four, originated, three years before current fiscal year	574,966	137,452
Year five, originated, four years before current fiscal year	288,233	243,705
Prior	765,542	383,997
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	205,528	189,971
Total	3,321,654	1,881,510	2,024,684
Commercial | Commercial mortgages | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	208,322	416,149
Year two, originated, fiscal year before current fiscal year	680,573	280,889
Year three, originated, two years before current fiscal year	556,456	217,311
Year four, originated, three years before current fiscal year	565,068	134,477
Year five, originated, four years before current fiscal year	280,557	229,863
Prior	711,412	368,527
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	201,214	187,396
Total	3,203,602	1,834,612
Commercial | Commercial mortgages | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	6,225	0
Year two, originated, fiscal year before current fiscal year	1,620	4,185
Year three, originated, two years before current fiscal year	14,750	0
Year four, originated, three years before current fiscal year	6,281	861
Year five, originated, four years before current fiscal year	3,527	11,588
Prior	37,184	1,385
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	4,057	2,097
Total	73,644	20,116
Commercial | Commercial mortgages | Substandard or Lower
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	748	2,438
Year two, originated, fiscal year before current fiscal year	5,139	1,624
Year three, originated, two years before current fiscal year	13,552	3,789
Year four, originated, three years before current fiscal year	3,617	2,114
Year five, originated, four years before current fiscal year	4,149	2,254
Prior	16,946	14,085
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	257	478
Total	44,408	26,782
Commercial | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	197,994	260,975
Year two, originated, fiscal year before current fiscal year	354,716	195,269
Year three, originated, two years before current fiscal year	208,881	87,290
Year four, originated, three years before current fiscal year	20,967	39,585
Year five, originated, four years before current fiscal year	45,782	2,313
Prior	9,586	11,297
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	96,398	90,484
Total	934,324	687,213	779,601
Commercial | Construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	195,969	248,053
Year two, originated, fiscal year before current fiscal year	349,705	195,269
Year three, originated, two years before current fiscal year	208,881	84,868
Year four, originated, three years before current fiscal year	20,770	39,585
Year five, originated, four years before current fiscal year	45,782	2,223
Prior	9,586	11,297
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	95,611	88,839
Total	926,304	670,134
Commercial | Construction | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0
Year two, originated, fiscal year before current fiscal year	603
Year three, originated, two years before current fiscal year	0
Year four, originated, three years before current fiscal year	0
Year five, originated, four years before current fiscal year	0
Prior	0
Revolving loans amortized cost basis	0
Revolving loans converted to term	0
Total	603
Commercial | Construction | Substandard or Lower
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	2,025	12,922
Year two, originated, fiscal year before current fiscal year	4,408	0
Year three, originated, two years before current fiscal year	0	2,422
Year four, originated, three years before current fiscal year	197	0
Year five, originated, four years before current fiscal year	0	90
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	787	1,645
Total	7,417	17,079
Commercial | PPP loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	5,200	31,500
Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	24,777	59,977
Year two, originated, fiscal year before current fiscal year	118,096	28,538
Year three, originated, two years before current fiscal year	62,730	13,570
Year four, originated, three years before current fiscal year	40,905	32,871
Year five, originated, four years before current fiscal year	53,079	45,032
Prior	470,988	362,745
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Total	770,575	542,733	606,058
Residential | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	24,777	59,977
Year two, originated, fiscal year before current fiscal year	117,528	28,426
Year three, originated, two years before current fiscal year	62,225	12,526
Year four, originated, three years before current fiscal year	39,318	32,871
Year five, originated, four years before current fiscal year	52,955	44,969
Prior	467,969	358,964
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Total	764,772	537,733
Residential | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	0
Year two, originated, fiscal year before current fiscal year	568	112
Year three, originated, two years before current fiscal year	505	1,044
Year four, originated, three years before current fiscal year	1,587	0
Year five, originated, four years before current fiscal year	124	63
Prior	3,019	3,781
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Total	5,803	5,000
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	258,696	219,918
Year two, originated, fiscal year before current fiscal year	222,594	170,069
Year three, originated, two years before current fiscal year	141,667	74,048
Year four, originated, three years before current fiscal year	61,751	204,119
Year five, originated, four years before current fiscal year	209,250	39,184
Prior	84,737	60,952
Revolving loans amortized cost basis	538,479	384,373
Revolving loans converted to term	5,422	5,910
Total	1,522,596	1,158,573	$ 1,105,169
Consumer | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	258,696	219,918
Year two, originated, fiscal year before current fiscal year	222,594	169,922
Year three, originated, two years before current fiscal year	141,316	74,048
Year four, originated, three years before current fiscal year	61,751	203,519
Year five, originated, four years before current fiscal year	208,705	39,113
Prior	84,737	60,952
Revolving loans amortized cost basis	537,619	382,718
Revolving loans converted to term	5,150	5,364
Total	1,520,568	1,155,554
Consumer | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	0
Year two, originated, fiscal year before current fiscal year	0	147
Year three, originated, two years before current fiscal year	351	0
Year four, originated, three years before current fiscal year	0	600
Year five, originated, four years before current fiscal year	545	71
Prior	0	0
Revolving loans amortized cost basis	860	1,655
Revolving loans converted to term	272	546
Total	$ 2,028	$ 3,019