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LOANS AND ALLOWANCE FOR CREDIT LOSSES - Summary of Total Loans (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2026	Dec. 31, 2025	Dec. 31, 2026	Mar. 31, 2026	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024
LOANS AND ALLOWANCE FOR CREDIT LOSSES
Total loans	$ 3,614,180	$ 3,605,859
Allowance for credit losses	32,231	34,052	$ 34,052	$ 34,315	$ 28,885	$ 28,614	$ 28,744
Net loans	3,581,949	3,571,807
Accrued interest receivable for loans	12,400	11,500
Municipal and other
LOANS AND ALLOWANCE FOR CREDIT LOSSES
Total loans	36,798	43,106
Allowance for credit losses	95		119	111	110	112	128
Home equity
LOANS AND ALLOWANCE FOR CREDIT LOSSES
Total loans	120,612	114,484
Allowance for credit losses	778		814	777	786	744	741
Total commercial loans \| Commercial construction
LOANS AND ALLOWANCE FOR CREDIT LOSSES
Total loans	248,821	213,779
Allowance for credit losses	4,877		4,371	4,328	2,032	2,065	2,096
Total commercial real estate \| Commercial real estate owner occupied
LOANS AND ALLOWANCE FOR CREDIT LOSSES
Total loans	352,692	385,843
Allowance for credit losses	3,459		4,045	3,627	2,823	2,830	2,794
Total commercial real estate \| Commercial real estate non-owner occupied
LOANS AND ALLOWANCE FOR CREDIT LOSSES
Total loans	1,432,262	1,450,597
Allowance for credit losses	11,512		12,837	13,809	10,980	10,923	11,104
Total commercial and industrial \| Commercial and industrial
LOANS AND ALLOWANCE FOR CREDIT LOSSES
Total loans	360,268	315,370
Allowance for credit losses	5,729		5,378	5,549	5,664	5,414	5,064
Total residential real estate \| Residential real estate
LOANS AND ALLOWANCE FOR CREDIT LOSSES
Total loans	1,050,059	1,068,413
Allowance for credit losses	5,640		6,350	5,972	6,406	6,447	6,732
Total consumer \| Consumer other
LOANS AND ALLOWANCE FOR CREDIT LOSSES
Total loans	12,668	$ 14,267
Allowance for credit losses	$ 141		$ 138	$ 142	$ 84	$ 79	$ 85