FAIR VALUE MEASUREMENTS - Carrying value and estimated fair values of financial instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Carrying value
Financial Assets
Cash and cash equivalents	$ 62,118	$ 36,105
Securities available-for-sale	76,694	91,312
Federal Home Loan Bank stock	3,176	3,515
Loans held-for-sale	763	568
Loans receivable, net	699,018	673,330
Accrued interest receivable	2,307	2,334
Cash surrender value of life insurance	13,685	13,314
Financial Liabilities
Demand (non-interest-bearing)	201,340	161,386
Demand (interest-bearing)	125,465	117,169
Money market	183,783	174,274
Savings and other	119,651	121,387
Certificates of deposit	124,294	141,210
Deposits	754,533	715,426
Repurchase agreements	3,914	4,163
FHLBB advances	26,979	28,813
Subordinated debt	9,764
Note payable	376
Capital lease liability	422	424
Accrued interest payable	150	166
Estimated fair value
Financial Assets
Cash and cash equivalents	62,118	36,105
Securities available-for-sale	76,694	91,312
Federal Home Loan Bank stock	3,176	3,515
Loans held-for-sale	778	572
Loans receivable, net	707,154	683,845
Accrued interest receivable	2,307	2,334
Cash surrender value of life insurance	13,685	13,314
Financial Liabilities
Demand (non-interest-bearing)	201,340	161,386
Demand (interest-bearing)	125,465	117,169
Money market	183,783	174,274
Savings and other	119,651	121,387
Certificates of deposit	125,437	142,261
Deposits	755,676	716,477
Repurchase agreements	3,914	4,163
FHLBB advances	28,559	30,626
Subordinated debt	9,764
Note payable	405
Capital lease liability	870	929
Accrued interest payable	150	166
Fair Value Measurements Using - Level 1
Financial Assets
Cash and cash equivalents	62,118	36,105
Securities available-for-sale	$ 246	$ 246
Federal Home Loan Bank stock
Loans held-for-sale
Loans receivable, net
Accrued interest receivable
Cash surrender value of life insurance	$ 13,685	$ 13,314
Financial Liabilities
Demand (non-interest-bearing)
Demand (interest-bearing)
Money market
Savings and other
Certificates of deposit
Deposits
Repurchase agreements
FHLBB advances
Subordinated debt
Note payable
Capital lease liability
Accrued interest payable
Fair Value Measurements Using - Level 2
Financial Assets
Cash and cash equivalents
Securities available-for-sale	$ 76,448	$ 76,448
Federal Home Loan Bank stock	$ 3,176	$ 3,515
Loans held-for-sale
Loans receivable, net
Accrued interest receivable
Cash surrender value of life insurance
Financial Liabilities
Demand (non-interest-bearing)
Demand (interest-bearing)
Money market
Savings and other
Certificates of deposit
Deposits
Repurchase agreements
FHLBB advances
Subordinated debt
Note payable
Capital lease liability
Accrued interest payable
Fair Value Measurements Using - Level 3
Financial Assets
Cash and cash equivalents
Securities available-for-sale
Federal Home Loan Bank stock
Loans held-for-sale	$ 788	$ 572
Loans receivable, net	707,154	683,845
Accrued interest receivable	$ 2,307	$ 2,334
Cash surrender value of life insurance
Financial Liabilities
Demand (non-interest-bearing)	$ 201,340	$ 161,386
Demand (interest-bearing)	125,465	117,169
Money market	183,783	174,274
Savings and other	119,651	121,387
Certificates of deposit	125,437	142,261
Deposits	755,676	716,477
Repurchase agreements	3,914	4,163
FHLBB advances	28,559	30,626
Subordinated debt	9,764
Note payable	405
Capital lease liability	870	929
Accrued interest payable	$ 150	$ 166