COMMITMENTS, CONTINGENCIES AND DERIVATIVES (Narrative) (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2018 USD ($) derivative swap	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($) derivative
Other Commitments [Line Items]
Loss Contingency Accrual	$ 0		$ 0
Loss on Cash Flow Hedge Ineffectiveness	$ 0		0
Derivative, Number of Instruments Held | derivative	2
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred	$ 693,000
Unrealized Gain (Loss) on Derivatives	(12,000)	$ (12,000)
Interest rate swaps
Other Commitments [Line Items]
Derivative Instrument Payment Of Interest Rate Swaps Designated As Cash Flow Hedges	275,000	346,000
Notional amount of derivative	43,000,000		43,000,000
Cash held as collateral	6,000,000
Forward-Starting Interest Rate Swap
Other Commitments [Line Items]
Derivative Instrument Payment Of Interest Rate Swaps Designated As Cash Flow Hedges	9,000	109,000
Notional amount of derivative	25,000,000		50,000,000
Cash held as collateral	10,400,000
Forward Contracts [Member]
Other Commitments [Line Items]
Notional amount of derivative	9,502,000		$ 8,065,000
Unrealized Gain (Loss) on Derivatives	$ 19,000	$ 118,000
Federal home loan bank 30-day | Interest rate swaps
Other Commitments [Line Items]
Derivative, Number of Instruments Held | derivative	6		23
Notional amount of derivative	$ 19,763,000		$ 124,784,000
Commercial and Industrial Sector [Member] | Interest rate swaps
Other Commitments [Line Items]
Derivative, Number of Instruments Held | derivative	69		65
Notional amount of derivative	$ 354,158,000		$ 351,668,000
Contract One [Member] | Interest rate swaps
Other Commitments [Line Items]
Notional amount of derivative	$ 10,000,000
Contract One [Member] | Forward-Starting Interest Rate Swap
Other Commitments [Line Items]
Number of interest rate swap agreements | swap	1
Notional amount of derivative	$ 25,000,000