CREDIT QUALITY ASSESSMENT - Information about Credit Quality Indicator by Year of Origination (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	$ 990,390		$ 1,245,085
Year one	931,399		2,958,596
Year two	2,880,790		2,375,873
Year three	2,232,924		1,175,656
Year four	1,048,879		870,390
Prior	2,361,522		1,776,440
Revolving Loans	1,046,017		964,949
Total loans	11,491,921		11,366,989
Current period gross charge-offs, Total	2,810	$ 2,518	2,614
Commercial investor real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	260,574		445,782
Year one	298,081		1,396,438
Year two	1,324,875		1,226,951
Year three	1,157,854		634,361
Year four	572,435		511,146
Prior	1,231,279		865,346
Revolving Loans	23,369		24,401
Total loans	4,868,467		5,104,425
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	357		0
Current period gross charge-offs, year four	0		0
Current period gross charge-offs, prior	44		0
Current period gross charge-offs, revolving	0		0
Current period gross charge-offs, Total	401		0
Commercial investor real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	260,574		405,740
Year one	298,081		1,395,973
Year two	1,320,775		1,195,708
Year three	1,124,987		634,361
Year four	547,597		511,146
Prior	1,135,568		848,958
Revolving Loans	23,369		23,653
Total loans	4,710,951		5,015,539
Commercial investor real estate | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		9,250
Year one	0		0
Year two	4,100		316
Year three	0		0
Year four	18,957		0
Prior	37,849		1,978
Revolving Loans	0		0
Total loans	60,906		11,544
Commercial investor real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		30,792
Year one	0		465
Year two	0		30,927
Year three	32,867		0
Year four	5,881		0
Prior	57,862		14,410
Revolving Loans	0		748
Total loans	96,610		77,342
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	138,665		139,040
Year one	110,890		364,951
Year two	341,942		321,310
Year three	310,090		239,979
Year four	226,305		243,278
Prior	603,609		441,056
Revolving Loans	5,826		5,621
Total loans	1,737,327		1,755,235
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	138,665		136,072
Year one	107,779		361,247
Year two	337,859		318,269
Year three	307,138		238,761
Year four	225,020		235,145
Prior	573,158		428,846
Revolving Loans	5,826		5,621
Total loans	1,695,445		1,723,961
Commercial owner-occupied real estate | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		406
Year one	3,111		70
Year two	1,787		2,240
Year three	57		875
Year four	953		2,267
Prior	9,795		8,616
Revolving Loans	0		0
Total loans	15,703		14,474
Commercial owner-occupied real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		2,562
Year one	0		3,634
Year two	2,296		801
Year three	2,895		343
Year four	332		5,866
Prior	20,656		3,594
Revolving Loans	0		0
Total loans	26,179		16,800
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	271,589		335,934
Year one	283,455		289,301
Year two	352,064		178,889
Year three	155,905		28,954
Year four	1,571		0
Prior	1,358		0
Revolving Loans	189,667		155,889
Total loans	1,255,609		988,967
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	135		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	135		0
Commercial AD&C | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	271,589		334,918
Year one	281,782		288,732
Year two	324,070		178,889
Year three	132,419		28,954
Year four	0		0
Prior	0		0
Revolving Loans	189,667		155,889
Total loans	1,199,527		987,382
Commercial AD&C | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		0
Year one	1,673		0
Year two	0		0
Year three	22,593		0
Year four	0		0
Prior	0		0
Revolving Loans	0		0
Total loans	24,266		0
Commercial AD&C | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		1,016
Year one	0		569
Year two	27,994		0
Year three	893		0
Year four	1,571		0
Prior	1,358		0
Revolving Loans	0		0
Total loans	31,816		1,585
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	25,087		32,863
Year one	47,018		487,240
Year two	535,060		418,747
Year three	423,182		173,191
Year four	168,328		47,779
Prior	331,111		314,701
Revolving Loans	0		0
Total loans	1,529,786		1,474,521
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		43
Current period gross charge-offs, year three	50		0
Current period gross charge-offs, year four	0		10
Current period gross charge-offs, prior	0		107
Current period gross charge-offs, revolving	0		0
Current period gross charge-offs, Total	50		160
Residential mortgage | 660-850
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	24,440		31,853
Year one	43,161		476,631
Year two	520,653		394,414
Year three	398,546		166,387
Year four	160,929		41,473
Prior	277,431		266,927
Revolving Loans	0		0
Total loans	1,425,160		1,377,685
Residential mortgage | 600-659
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	647		781
Year one	1,629		7,022
Year two	8,990		18,284
Year three	15,456		2,009
Year four	2,409		1,882
Prior	24,345		24,040
Revolving Loans	0		0
Total loans	53,476		54,018
Residential mortgage | 540-599
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		0
Year one	1,497		1,545
Year two	3,237		2,698
Year three	2,897		2,371
Year four	3,126		1,891
Prior	10,994		9,377
Revolving Loans	0		0
Total loans	21,751		17,882
Residential mortgage | less than 540
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		229
Year one	731		2,042
Year two	2,180		3,351
Year three	6,283		2,424
Year four	1,864		2,533
Prior	18,341		14,357
Revolving Loans	0		0
Total loans	29,399		24,936
Residential construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	8,325		24,059
Year one	18,354		68,773
Year two	16,639		23,216
Year three	6,614		3,978
Year four	2,249		150
Prior	1,458		1,243
Revolving Loans	0		0
Total loans	53,639		121,419
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	7,686		21,975
Year one	18,354		68,273
Year two	15,032		21,897
Year three	6,614		2,478
Year four	749		150
Prior	150		0
Revolving Loans	0		0
Total loans	48,585		114,773
Residential construction | 600-659
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0		1,641
Year one	0		500
Year two	1,107		1,319
Year three	0		1,500
Year four	0		0
Prior	1,308		1,243
Revolving Loans	0		0
Total loans	2,415		6,203
Residential construction | 540-599
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	539		443
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	539		443
Residential construction | less than 540
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	100		0
Year one	0		0
Year two	500		0
Year three	0		0
Year four	1,500		0
Prior	0		0
Revolving Loans	0		0
Total loans	2,100		0
Commercial Business
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	9,482,329		9,353,507
Commercial Business | Commercial business
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	273,471		254,338
Year one	162,552		346,152
Year two	304,980		204,481
Year three	177,336		94,152
Year four	77,006		65,378
Prior	159,313		119,926
Revolving Loans	466,268		420,453
Total loans	1,620,926		1,504,880
Current period gross charge-offs, current year	0		0
Current period gross charge-offs, year one	0		9
Current period gross charge-offs, year two	212		324
Current period gross charge-offs, year three	231		0
Current period gross charge-offs, year four	0		0
Current period gross charge-offs, prior	1,360		116
Current period gross charge-offs, revolving	0		0
Current period gross charge-offs, Total	1,803		449
Commercial Business | Commercial business | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	272,957		247,081
Year one	158,931		344,034
Year two	297,879		202,020
Year three	173,027		92,198
Year four	76,056		62,413
Prior	152,933		118,061
Revolving Loans	441,806		410,856
Total loans	1,573,589		1,476,663
Commercial Business | Commercial business | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	364		532
Year one	448		45
Year two	5,800		180
Year three	2,794		1,037
Year four	269		1,040
Prior	895		294
Revolving Loans	18,557		3,635
Total loans	29,127		6,763
Commercial Business | Commercial business | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	150		6,725
Year one	3,173		2,073
Year two	1,301		2,281
Year three	1,515		917
Year four	681		1,925
Prior	5,485		1,571
Revolving Loans	5,905		5,962
Total loans	18,210		21,454
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	12,679		13,069
Year one	11,049		5,741
Year two	5,230		2,279
Year three	1,943		1,041
Year four	985		2,659
Prior	33,394		34,168
Revolving Loans	360,887		358,585
Total loans	426,167		417,542
Current period gross charge-offs, current year	0		0
Current period gross charge-offs, year one	4		20
Current period gross charge-offs, year two	0		28
Current period gross charge-offs, year three	5		0
Current period gross charge-offs, year four	0		15
Current period gross charge-offs, prior	16		1,735
Current period gross charge-offs, revolving	396		207
Current period gross charge-offs, Total	421		2,005
Consumer | 660-850
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	12,252		11,452
Year one	8,048		4,960
Year two	3,801		1,823
Year three	1,520		519
Year four	722		1,662
Prior	26,061		24,543
Revolving Loans	332,190		333,382
Total loans	384,594		378,341
Consumer | 600-659
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	276		1,209
Year one	2,069		192
Year two	295		237
Year three	16		425
Year four	36		209
Prior	2,201		3,954
Revolving Loans	16,692		12,668
Total loans	21,585		18,894
Consumer | 540-599
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	62		24
Year one	160		374
Year two	801		87
Year three	154		47
Year four	50		500
Prior	2,048		2,868
Revolving Loans	4,191		5,920
Total loans	7,466		9,820
Consumer | less than 540
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	89		384
Year one	772		215
Year two	333		132
Year three	253		50
Year four	177		288
Prior	3,084		2,803
Revolving Loans	7,814		6,615
Total loans	$ 12,522		$ 10,487