LOANS AND ALLOWANCE FOR LOAN LOSSES - Allowance (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016 USD ($) item	Mar. 31, 2015 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2015 USD ($)
Changes in the allowance for loan losses
Balance at beginning of period	$ 8,006	$ 6,223
Charge-offs	(191)	(423)
Recoveries	7	22
Provision	625	659
Balance at end of period	8,447	6,481
Individually evaluated for impairment	1,369	868
Collectively evaluated for impairment	7,078	5,613
Net deferred fees and costs	$ 1,000	1,400
Number of rolling quarters utilized by Commercial, Residential, Home Equity, Installment and Credit Card pools | item	12
Unfunded commitment liability	$ 224	108
Commercial
Changes in the allowance for loan losses
Balance at beginning of period	6,066	4,363
Charge-offs	(102)	(409)
Recoveries		21
Provision	257	672
Balance at end of period	6,221	4,647
Individually evaluated for impairment	946	554
Collectively evaluated for impairment	5,275	4,093
Loans acquired, purchase price			$ 74,300
Premium on loans acquired, ratio			1.024
Loans acquired, premium paid			$ 1,800
Loans acquired, outstanding balance	33,100			$ 46,800
Loans acquired, outstanding balance, decrease	41,200
Loans acquired, refinanced	17,200
Loans acquired, sold in participation	2,900
Loans acquired, sold back to institution	$ 9,700
Loans acquired, remaining portfolio, weighted average yield	5.02%
Residential
Changes in the allowance for loan losses
Balance at beginning of period	$ 1,095	962
Charge-offs	(67)	(14)
Provision	129	9
Balance at end of period	1,157	957
Individually evaluated for impairment	212	284
Collectively evaluated for impairment	945	673
Home Equity
Changes in the allowance for loan losses
Balance at beginning of period	715	691
Recoveries		1
Provision	32	(12)
Balance at end of period	747	680
Individually evaluated for impairment		28
Collectively evaluated for impairment	747	652
Consumer
Changes in the allowance for loan losses
Balance at beginning of period	130	207
Charge-offs	(22)
Recoveries	7
Provision	207	(10)
Balance at end of period	322	197
Individually evaluated for impairment	211	2
Collectively evaluated for impairment	$ 111	$ 195