FAIR VALUE MEASUREMENTS - FV of Financial instruments, Nonrecurring (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2026	Dec. 31, 2025
FINANCIAL LIABILITIES:
Accrued interest payable	$ 2,680	$ 2,735
Estimate of Fair Value Measurement | Fair Value Measurements, Nonrecurring | Fair Value, Inputs, Level 1, Level 2, and Level 3
FINANCIAL ASSETS:
Cash and due from banks	9,007	8,755
Interest-bearing deposits in other banks	127,832	112,494
Restricted investment in bank stocks	8,944	8,944
Net loans	924,603	945,462
Mortgage servicing rights	192	196
Accrued interest receivable	4,844	4,997
FINANCIAL LIABILITIES:
Demand, savings and other deposits	647,198	633,448
Time deposits	483,063	503,245
Short-term borrowings	136,860	137,887
Long-term borrowings	106,827	107,124
Subordinated debentures	21,702	21,706
Accrued interest payable	2,680	2,735
Estimate of Fair Value Measurement | Fair Value Measurements, Nonrecurring | Fair Value, Inputs, Level 1
FINANCIAL ASSETS:
Cash and due from banks	9,007	8,755
Interest-bearing deposits in other banks	0	0
Restricted investment in bank stocks	0	0
Net loans	0	0
Mortgage servicing rights	0	0
Accrued interest receivable	0	0
FINANCIAL LIABILITIES:
Demand, savings and other deposits	0	0
Time deposits	0	0
Short-term borrowings	0	0
Long-term borrowings	0	0
Subordinated debentures	0	0
Accrued interest payable	0	0
Estimate of Fair Value Measurement | Fair Value Measurements, Nonrecurring | Fair Value, Inputs, Level 2
FINANCIAL ASSETS:
Cash and due from banks	0	0
Interest-bearing deposits in other banks	127,832	112,494
Restricted investment in bank stocks	8,944	8,944
Net loans	0	0
Mortgage servicing rights	0	0
Accrued interest receivable	4,844	4,997
FINANCIAL LIABILITIES:
Demand, savings and other deposits	647,198	633,448
Time deposits	483,063	503,245
Short-term borrowings	136,860	137,887
Long-term borrowings	106,827	107,124
Subordinated debentures	21,702	21,706
Accrued interest payable	2,680	2,735
Estimate of Fair Value Measurement | Fair Value Measurements, Nonrecurring | Fair Value, Inputs, Level 3
FINANCIAL ASSETS:
Cash and due from banks	0	0
Interest-bearing deposits in other banks	0	0
Restricted investment in bank stocks	0	0
Net loans	924,603	945,462
Mortgage servicing rights	192	196
Accrued interest receivable	0	0
FINANCIAL LIABILITIES:
Demand, savings and other deposits	0	0
Time deposits	0	0
Short-term borrowings	0	0
Long-term borrowings	0	0
Subordinated debentures	0	0
Accrued interest payable	0	0
Carrying Amount | Fair Value Measurements, Nonrecurring
FINANCIAL ASSETS:
Cash and due from banks	9,007	8,755
Interest-bearing deposits in other banks	127,832	112,494
Restricted investment in bank stocks	8,944	8,944
Net loans	923,577	939,013
Mortgage servicing rights	192	196
Accrued interest receivable	4,844	4,997
FINANCIAL LIABILITIES:
Demand, savings and other deposits	647,198	633,448
Time deposits	484,091	503,988
Short-term borrowings	136,084	136,845
Long-term borrowings	106,000	106,000
Subordinated debentures	25,000	25,000
Accrued interest payable	$ 2,680	$ 2,735