LOANS AND ALLOWANCE FOR CREDIT LOSSES - Risk Rating (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) grade	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Loans by risk rating
Number of grades utilized in internal loan rating system | grade			10
Year one, originated current fiscal year	$ 120,424		$ 120,424		$ 407,241
Year two, originated fiscal year before current fiscal year	420,301		420,301		1,443,688
Year three, originated two years before current fiscal year	1,466,854		1,466,854		1,092,960
Year four, originated three years before current fiscal year	1,078,644		1,078,644		513,582
Year five, originated four years before current fiscal year	500,588		500,588		308,448
Prior	997,038		997,038		739,967
Revolving Loans Amortized Cost	254,663		254,663		242,063
Revolving Loans Converted to Term Loans	1,453		1,453		1,469
Total loans before basis adjustment	4,839,965		4,839,965		4,749,418
YTD gross charge-offs, originated current fiscal year					31
YTD gross charge-offs, originated fiscal year before current fiscal year			47		129
YTD gross charge-offs, originated two years before current fiscal year			257		18
YTD gross charge-offs, originated three years before current fiscal year			97		20
YTD gross charge-offs, originated four years before current fiscal year			57		26
YTD gross charge-offs, prior			20		4,202
YTD gross charge-offs	201	$ 2,988	478	$ 3,002	4,426
Commercial | Commercial real estate
Loans by risk rating
Year one, originated current fiscal year	29,650		29,650		152,047
Year two, originated fiscal year before current fiscal year	148,027		148,027		839,306
Year three, originated two years before current fiscal year	881,237		881,237		455,996
Year four, originated three years before current fiscal year	453,903		453,903		238,885
Year five, originated four years before current fiscal year	235,731		235,731		242,690
Prior	632,333		632,333		414,751
Total loans before basis adjustment	2,380,881		2,380,881		2,343,675
YTD gross charge-offs, originated current fiscal year					4,171
YTD gross charge-offs		2,918		2,918	4,171
Commercial | Commercial real estate | Pass
Loans by risk rating
Year one, originated current fiscal year	29,650		29,650		152,047
Year two, originated fiscal year before current fiscal year	146,426		146,426		828,335
Year three, originated two years before current fiscal year	839,118		839,118		455,996
Year four, originated three years before current fiscal year	453,903		453,903		234,585
Year five, originated four years before current fiscal year	231,444		231,444		233,713
Prior	609,795		609,795		405,103
Total loans before basis adjustment	2,310,336		2,310,336		2,309,779
Commercial | Commercial real estate | Special mention
Loans by risk rating
Year two, originated fiscal year before current fiscal year	1,601		1,601		10,971
Year three, originated two years before current fiscal year	42,119		42,119
Year four, originated three years before current fiscal year					4,300
Year five, originated four years before current fiscal year	4,287		4,287		8,977
Prior	22,538		22,538		2,232
Total loans before basis adjustment	70,545		70,545		26,480
Commercial | Commercial real estate | Substandard
Loans by risk rating
Prior					1,670
Total loans before basis adjustment					1,670
Commercial | Commercial real estate | Doubtful
Loans by risk rating
Prior					5,746
Total loans before basis adjustment					5,746
Commercial | Commercial and industrial
Loans by risk rating
Year one, originated current fiscal year	36,438		36,438		73,240
Year two, originated fiscal year before current fiscal year	72,054		72,054		52,696
Year three, originated two years before current fiscal year	54,303		54,303		94,582
Year four, originated three years before current fiscal year	89,678		89,678		70,588
Year five, originated four years before current fiscal year	67,336		67,336		22,990
Prior	93,041		93,041		78,105
Revolving Loans Amortized Cost	86,193		86,193		74,242
Total loans before basis adjustment	499,043		499,043		466,443
YTD gross charge-offs, originated current fiscal year					24
YTD gross charge-offs, originated fiscal year before current fiscal year			22		113
YTD gross charge-offs, originated two years before current fiscal year			252		14
YTD gross charge-offs, originated three years before current fiscal year			78		5
YTD gross charge-offs, originated four years before current fiscal year			53		8
YTD gross charge-offs, prior			7		2
YTD gross charge-offs	184	28	412	35	166
Commercial | Commercial and industrial | Pass
Loans by risk rating
Year one, originated current fiscal year	36,438		36,438		73,240
Year two, originated fiscal year before current fiscal year	71,938		71,938		52,190
Year three, originated two years before current fiscal year	54,003		54,003		94,570
Year four, originated three years before current fiscal year	89,518		89,518		70,565
Year five, originated four years before current fiscal year	67,315		67,315		22,988
Prior	90,537		90,537		75,493
Revolving Loans Amortized Cost	86,090		86,090		74,125
Total loans before basis adjustment	495,839		495,839		463,171
Commercial | Commercial and industrial | Special mention
Loans by risk rating
Year two, originated fiscal year before current fiscal year	92		92		454
Year three, originated two years before current fiscal year	298		298		4
Year four, originated three years before current fiscal year	160		160		23
Year five, originated four years before current fiscal year	21		21		2
Prior	914		914		948
Revolving Loans Amortized Cost					50
Total loans before basis adjustment	1,485		1,485		1,481
Commercial | Commercial and industrial | Substandard
Loans by risk rating
Year two, originated fiscal year before current fiscal year	24		24		52
Year three, originated two years before current fiscal year	2		2		8
Prior	341		341		367
Revolving Loans Amortized Cost	54		54		18
Total loans before basis adjustment	421		421		445
Commercial | Commercial and industrial | Doubtful
Loans by risk rating
Prior	1,249		1,249		1,297
Revolving Loans Amortized Cost	49		49		49
Total loans before basis adjustment	1,298		1,298		1,346
Commercial | Commercial construction
Loans by risk rating
Year one, originated current fiscal year	643		643		35,181
Year two, originated fiscal year before current fiscal year	62,502		62,502		111,881
Year three, originated two years before current fiscal year	100,917		100,917		60,113
Year four, originated three years before current fiscal year	68,810		68,810		843
Revolving Loans Amortized Cost	1,054		1,054		425
Total loans before basis adjustment	233,926		233,926		208,443
Commercial | Commercial construction | Pass
Loans by risk rating
Year one, originated current fiscal year	643		643		35,181
Year two, originated fiscal year before current fiscal year	56,527		56,527		109,291
Year three, originated two years before current fiscal year	91,176		91,176		60,113
Year four, originated three years before current fiscal year	68,810		68,810		843
Revolving Loans Amortized Cost	1,054		1,054		425
Total loans before basis adjustment	218,210		218,210		205,853
Commercial | Commercial construction | Special mention
Loans by risk rating
Year two, originated fiscal year before current fiscal year	5,975		5,975		2,590
Year three, originated two years before current fiscal year	9,741		9,741
Total loans before basis adjustment	15,716		15,716		2,590
Residential
Loans by risk rating
Year one, originated current fiscal year	49,456		49,456		138,541
Year two, originated fiscal year before current fiscal year	132,666		132,666		434,421
Year three, originated two years before current fiscal year	426,068		426,068		480,010
Year four, originated three years before current fiscal year	464,590		464,590		202,245
Year five, originated four years before current fiscal year	196,912		196,912		39,631
Prior	269,830		269,830		246,144
Revolving Loans Amortized Cost	166,436		166,436		166,360
Revolving Loans Converted to Term Loans	1,453		1,453		1,469
Total loans before basis adjustment	1,707,411		1,707,411		1,708,821
Residential | Accrual
Loans by risk rating
Year one, originated current fiscal year	49,341		49,341		138,541
Year two, originated fiscal year before current fiscal year	132,666		132,666		434,421
Year three, originated two years before current fiscal year	426,068		426,068		480,010
Year four, originated three years before current fiscal year	464,100		464,100		202,118
Year five, originated four years before current fiscal year	196,785		196,785		38,675
Prior	263,245		263,245		239,185
Revolving Loans Amortized Cost	165,811		165,811		166,144
Revolving Loans Converted to Term Loans	1,446		1,446		1,469
Total loans before basis adjustment	1,699,462		1,699,462		1,700,563
Residential | Non-accrual
Loans by risk rating
Year one, originated current fiscal year	115		115
Year four, originated three years before current fiscal year	490		490		127
Year five, originated four years before current fiscal year	127		127		956
Prior	6,585		6,585		6,959
Revolving Loans Amortized Cost	625		625		216
Revolving Loans Converted to Term Loans	7		7
Total loans before basis adjustment	7,949		7,949		8,258
Consumer loans
Loans by risk rating
Year one, originated current fiscal year	4,237		4,237		8,232
Year two, originated fiscal year before current fiscal year	5,052		5,052		5,384
Year three, originated two years before current fiscal year	4,329		4,329		2,259
Year four, originated three years before current fiscal year	1,663		1,663		1,021
Year five, originated four years before current fiscal year	609		609		3,137
Prior	1,834		1,834		967
Revolving Loans Amortized Cost	980		980		1,036
Total loans before basis adjustment	18,704		18,704		22,036
YTD gross charge-offs, originated current fiscal year					7
YTD gross charge-offs, originated fiscal year before current fiscal year			25		16
YTD gross charge-offs, originated two years before current fiscal year			5		4
YTD gross charge-offs, originated three years before current fiscal year			19		15
YTD gross charge-offs, originated four years before current fiscal year			4		18
YTD gross charge-offs, prior			13		29
YTD gross charge-offs	17	$ 42	66	$ 49	89
Consumer loans | Accrual
Loans by risk rating
Year one, originated current fiscal year	4,237		4,237		8,218
Year two, originated fiscal year before current fiscal year	5,026		5,026		5,366
Year three, originated two years before current fiscal year	4,317		4,317		2,254
Year four, originated three years before current fiscal year	1,663		1,663		1,021
Year five, originated four years before current fiscal year	605		605		3,135
Prior	1,833		1,833		963
Revolving Loans Amortized Cost	979		979		1,031
Total loans before basis adjustment	18,660		18,660		21,988
Consumer loans | Non-accrual
Loans by risk rating
Year one, originated current fiscal year					14
Year two, originated fiscal year before current fiscal year	26		26		18
Year three, originated two years before current fiscal year	12		12		5
Year five, originated four years before current fiscal year	4		4		2
Prior	1		1		4
Revolving Loans Amortized Cost	1		1		5
Total loans before basis adjustment	$ 44		$ 44		$ 48