FAIR VALUE MEASUREMENTS - FV of Financial instruments., nonrecurring (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2025	Dec. 31, 2024
FINANCIAL LIABILITIES:
Accrued interest payable	$ 3,175	$ 2,152
Derivative liabilities	4,409	1,463
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	13,016	9,933
Interest-bearing deposits in other banks	134,239	7,321
Restricted investment in bank stocks	8,944	8,984
Net loans	955,958	929,302
Mortgage servicing rights	199	218
Accrued interest receivable	5,075	4,993
FINANCIAL LIABILITIES:
Demand, savings and other deposits	677,320	677,762
Time deposits	514,494	366,772
Short-term borrowings	134,139	134,541
Long-term borrowings	107,367	107,728
Subordinated debentures	21,629	20,618
Accrued interest payable	3,175	2,152
Derivative liabilities	4,409	1,463
Estimate of Fair Value Measurement | Fair Value Measurements, Nonrecurring | Fair Value, Inputs, Level 1
FINANCIAL ASSETS:
Cash and due from banks	13,016	9,933
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
Derivative liabilities	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	134,239	7,321
Restricted investment in bank stocks	8,944	8,984
Net loans	0	0
Mortgage servicing rights	0	0
Accrued interest receivable	5,075	4,993
FINANCIAL LIABILITIES:
Demand, savings and other deposits	677,320	677,762
Time deposits	514,494	366,772
Short-term borrowings	134,139	134,541
Long-term borrowings	107,367	107,728
Subordinated debentures	21,629	20,618
Accrued interest payable	3,175	2,152
Derivative liabilities	4,409	1,463
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	955,958	929,302
Mortgage servicing rights	199	218
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
Derivative liabilities	0	0
Reported Value Measurement | Fair Value Measurements, Nonrecurring
FINANCIAL ASSETS:
Cash and due from banks	13,016	9,933
Interest-bearing deposits in other banks	134,239	7,321
Restricted investment in bank stocks	8,944	8,984
Net loans	949,733	940,779
Mortgage servicing rights	199	218
Accrued interest receivable	5,075	4,993
FINANCIAL LIABILITIES:
Demand, savings and other deposits	677,320	677,762
Time deposits	515,174	368,118
Short-term borrowings	132,856	134,426
Long-term borrowings	106,000	106,000
Subordinated debentures	25,000	25,000
Accrued interest payable	3,175	2,152
Derivative liabilities	$ 4,409	$ 1,463