CREDIT QUALITY ASSESSMENT - Information about Credit Quality Indicator by Year of Origination (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	$ 423,944		$ 3,120,897
Year one	2,989,944		2,647,414
Year two	2,575,626		1,339,364
Year three	1,297,604		1,039,363
Year four	1,014,618		649,024
Prior	2,094,716		1,559,209
Revolving Loans	998,789		1,041,435
Total loans	11,395,241		11,396,706
Current period gross charge-offs, Total	171	$ 306	1,105
Commercial investor real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	178,124		1,543,664
Year one	1,423,085		1,216,546
Year two	1,257,753		695,224
Year three	689,500		567,341
Year four	559,727		343,815
Prior	1,030,923		748,262
Revolving Loans	28,344		15,242
Total loans	5,167,456		5,130,094
Current period gross charge-offs, current year	0		0
Current period gross charge-offs, year one	0		0
Current period gross charge-offs, year two	0		0
Current period gross charge-offs, year three	0		0
Current period gross charge-offs, year four	0		0
Current period gross charge-offs, prior	0		0
Current period gross charge-offs, revolving	0		0
Current period gross charge-offs, Total	0		0
Commercial investor real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	173,232		1,510,446
Year one	1,412,186		1,197,504
Year two	1,239,661		694,756
Year three	689,500		567,247
Year four	558,229		335,103
Prior	1,024,028		742,405
Revolving Loans	28,344		15,242
Total loans	5,125,180		5,062,703
Commercial investor real estate | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	4,619		32,661
Year one	10,349		17,146
Year two	4,587		468
Year three	0		94
Year four	93		473
Prior	3,253		4,814
Revolving Loans	0		0
Total loans	22,901		55,656
Commercial investor real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	273		557
Year one	550		1,896
Year two	13,505		0
Year three	0		0
Year four	1,405		8,239
Prior	3,642		1,043
Revolving Loans	0		0
Total loans	19,375		11,735
Commercial investor real estate | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		0
Year one	0		0
Year two	0		0
Year three	0		0
Year four	0		0
Prior	0		0
Revolving Loans	0		0
Total loans	0		0
Commercial owner-occupied real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	51,969		399,126
Year one	381,280		328,817
Year two	324,370		242,172
Year three	238,609		267,964
Year four	261,590		144,917
Prior	511,072		390,874
Revolving Loans	1,038		1,167
Total loans	1,769,928		1,775,037
Current period gross charge-offs, current year	0		0
Current period gross charge-offs, year one	0		0
Current period gross charge-offs, year two	0		0
Current period gross charge-offs, year three	0		0
Current period gross charge-offs, year four	0		0
Current period gross charge-offs, prior	0		0
Current period gross charge-offs, revolving	0		0
Current period gross charge-offs, Total	0		0
Commercial owner-occupied real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	49,900		391,340
Year one	373,223		328,657
Year two	324,299		240,738
Year three	236,977		260,114
Year four	253,818		140,841
Prior	498,559		381,386
Revolving Loans	1,038		1,167
Total loans	1,737,814		1,744,243
Commercial owner-occupied real estate | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	731		4,567
Year one	1,530		0
Year two	0		1,301
Year three	1,277		1,740
Year four	1,716		2,066
Prior	8,682		7,323
Revolving Loans	0		0
Total loans	13,936		16,997
Commercial owner-occupied real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	1,338		3,219
Year one	6,527		160
Year two	71		133
Year three	355		6,110
Year four	6,056		2,010
Prior	3,831		2,165
Revolving Loans	0		0
Total loans	18,178		13,797
Commercial owner-occupied real estate | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		0
Year one	0		0
Year two	0		0
Year three	0		0
Year four	0		0
Prior	0		0
Revolving Loans	0		0
Total loans	0		0
Commercial AD&C
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	126,933		367,169
Year one	336,371		439,468
Year two	325,527		113,713
Year three	94,337		34,340
Year four	32,053		14,816
Prior	14,932		0
Revolving Loans	116,512		120,522
Total loans	1,046,665		1,090,028
Current period gross charge-offs, current year	0		0
Current period gross charge-offs, year one	0		0
Current period gross charge-offs, year two	0		0
Current period gross charge-offs, year three	0		0
Current period gross charge-offs, year four	0		0
Current period gross charge-offs, prior	0		0
Current period gross charge-offs, revolving	0		0
Current period gross charge-offs, Total	0		0
Commercial AD&C | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	126,933		366,096
Year one	334,502		439,468
Year two	325,527		113,713
Year three	94,337		34,340
Year four	32,053		14,816
Prior	14,932		0
Revolving Loans	116,512		119,727
Total loans	1,044,796		1,088,160
Commercial AD&C | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		1,073
Year one	1,073		0
Year two	0		0
Year three	0		0
Year four	0		0
Prior	0		0
Revolving Loans	0		795
Total loans	1,073		1,868
Commercial AD&C | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		0
Year one	796		0
Year two	0		0
Year three	0		0
Year four	0		0
Prior	0		0
Revolving Loans	0		0
Total loans	796		0
Commercial AD&C | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		0
Year one	0		0
Year two	0		0
Year three	0		0
Year four	0		0
Prior	0		0
Revolving Loans	0		0
Total loans	0		0
Residential mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	15,813		336,909
Year one	346,107		357,307
Year two	389,628		176,834
Year three	178,248		50,886
Year four	49,937		61,970
Prior	348,791		304,027
Revolving Loans	0		0
Total loans	1,328,524		1,287,933
Current period gross charge-offs, current year	0		0
Current period gross charge-offs, year one	0		0
Current period gross charge-offs, year two	0		0
Current period gross charge-offs, year three	0		0
Current period gross charge-offs, year four	0		24
Current period gross charge-offs, prior	23		131
Current period gross charge-offs, revolving	0		0
Current period gross charge-offs, Total	23		155
Residential mortgage | 660-850
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	15,508		330,109
Year one	336,165		344,062
Year two	369,442		171,330
Year three	170,124		41,883
Year four	41,488		51,651
Prior	293,891		262,570
Revolving Loans	0		0
Total loans	1,226,618		1,201,605
Residential mortgage | 600-659
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		4,571
Year one	6,648		6,196
Year two	13,800		1,173
Year three	4,119		3,925
Year four	3,885		6,041
Prior	30,112		24,006
Revolving Loans	0		0
Total loans	58,564		45,912
Residential mortgage | 540-599
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	305		369
Year one	2,929		4,013
Year two	3,361		1,439
Year three	526		1,256
Year four	1,517		1,931
Prior	8,986		6,945
Revolving Loans	0		0
Total loans	17,624		15,953
Residential mortgage | less than 540
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		1,860
Year one	365		3,036
Year two	3,025		2,892
Year three	3,479		3,822
Year four	3,047		2,347
Prior	15,802		10,506
Revolving Loans	0		0
Total loans	25,718		24,463
Residential construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	4,482		132,776
Year one	154,506		77,036
Year two	52,845		12,133
Year three	8,596		150
Year four	150		1,432
Prior	2,877		1,245
Revolving Loans	0		0
Total loans	223,456		224,772
Current period gross charge-offs, current year	0		0
Current period gross charge-offs, year one	0		0
Current period gross charge-offs, year two	0		0
Current period gross charge-offs, year three	0		0
Current period gross charge-offs, year four	0		0
Current period gross charge-offs, prior	0		0
Current period gross charge-offs, revolving	0		0
Current period gross charge-offs, Total	0		0
Residential construction | 660-850
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	4,482		131,259
Year one	152,343		75,844
Year two	50,886		12,133
Year three	8,596		150
Year four	150		1,432
Prior	2,877		1,245
Revolving Loans	0		0
Total loans	219,334		222,063
Residential construction | 600-659
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		908
Year one	2,163		373
Year two	739		0
Year three	0		0
Year four	0		0
Prior	0		0
Revolving Loans	0		0
Total loans	2,902		1,281
Residential construction | 540-599
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		609
Year one	0		0
Year two	401		0
Year three	0		0
Year four	0		0
Prior	0		0
Revolving Loans	0		0
Total loans	401		609
Residential construction | less than 540
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		0
Year one	0		819
Year two	819		0
Year three	0		0
Year four	0		0
Prior	0		0
Revolving Loans	0		0
Total loans	819		819
Commercial Business
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	9,421,527		9,451,044
Commercial Business | Commercial business
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	43,548		333,627
Year one	340,858		225,314
Year two	222,709		97,988
Year three	87,078		115,739
Year four	108,377		78,838
Prior	150,613		80,452
Revolving Loans	484,295		523,927
Total loans	1,437,478		1,455,885
Current period gross charge-offs, current year	0		174
Current period gross charge-offs, year one	0		0
Current period gross charge-offs, year two	0		0
Current period gross charge-offs, year three	0		0
Current period gross charge-offs, year four	0		138
Current period gross charge-offs, prior	29		404
Current period gross charge-offs, revolving	25		0
Current period gross charge-offs, Total	54		716
Commercial Business | Commercial business | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	43,548		330,598
Year one	337,157		223,245
Year two	219,980		95,787
Year three	85,098		105,922
Year four	99,564		77,891
Prior	147,806		78,009
Revolving Loans	467,480		508,839
Total loans	1,400,633		1,420,291
Commercial Business | Commercial business | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		127
Year one	330		458
Year two	650		1,107
Year three	1,024		7,787
Year four	6,818		498
Prior	564		322
Revolving Loans	12,977		13,225
Total loans	22,363		23,524
Commercial Business | Commercial business | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		2,902
Year one	3,371		1,611
Year two	2,079		1,094
Year three	956		2,030
Year four	1,995		449
Prior	2,243		2,121
Revolving Loans	3,838		1,863
Total loans	14,482		12,070
Commercial Business | Commercial business | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		0
Year one	0		0
Year two	0		0
Year three	0		0
Year four	0		0
Prior	0		0
Revolving Loans	0		0
Total loans	0		0
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	3,075		7,626
Year one	7,737		2,926
Year two	2,794		1,300
Year three	1,236		2,943
Year four	2,784		3,236
Prior	35,508		34,349
Revolving Loans	368,600		380,577
Total loans	421,734		432,957
Current period gross charge-offs, current year	0		0
Current period gross charge-offs, year one	0		5
Current period gross charge-offs, year two	0		15
Current period gross charge-offs, year three	0		0
Current period gross charge-offs, year four	0		13
Current period gross charge-offs, prior	49		20
Current period gross charge-offs, revolving	45		181
Current period gross charge-offs, Total	94		234
Consumer | 660-850
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	2,976		6,689
Year one	6,559		2,346
Year two	2,608		1,201
Year three	1,133		2,147
Year four	2,084		2,047
Prior	23,941		23,170
Revolving Loans	343,677		359,468
Total loans	382,978		397,068
Consumer | 600-659
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	47		658
Year one	554		467
Year two	31		59
Year three	34		198
Year four	112		664
Prior	5,949		5,459
Revolving Loans	12,384		11,269
Total loans	19,111		18,774
Consumer | 540-599
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	12		123
Year one	396		56
Year two	84		0
Year three	39		465
Year four	129		316
Prior	2,299		2,802
Revolving Loans	5,519		3,824
Total loans	8,478		7,586
Consumer | less than 540
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	40		156
Year one	228		57
Year two	71		40
Year three	30		133
Year four	459		209
Prior	3,319		2,918
Revolving Loans	7,020		6,016
Total loans	$ 11,167		$ 9,529