COMMITMENTS, CONTINGENCIES AND DERIVATIVES (Narrative) (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2019 USD ($) derivative swap	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($) derivative
Other Commitments [Line Items]
Loss Contingency Accrual	$ 0		$ 0
Loss on Cash Flow Hedge Ineffectiveness	0		0
Unrealized Gain (Loss) on Derivatives	$ (181,000)	$ (12,000)
Derivative, Number of Interest Rate Swap Agreements | swap	2
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred	$ 715,000
Customer Loan Swaps
Other Commitments [Line Items]
Notional amount of derivative	802,580,000		833,030,000
Cash held as collateral	6,200,000
Interest rate swaps
Other Commitments [Line Items]
Notional amount of derivative	43,000,000		43,000,000
Cash held as collateral	7,100,000
Derivative Instrument Payment Of Interest Rate Swaps Designated As Cash Flow Hedges	152,000	275,000
Forward-Starting Interest Rate Swap
Other Commitments [Line Items]
Notional amount of derivative	0		25,000,000
Derivative Instrument Payment Of Interest Rate Swaps Designated As Cash Flow Hedges	32,000	(9,000)
Forward Contracts [Member]
Other Commitments [Line Items]
Notional amount of derivative	8,711,000		4,315,000
Unrealized Gain (Loss) on Derivatives	83,000	$ 19,000
Cancellable Commitment
Other Commitments [Line Items]
Contractual Amounts Of Financial Instrument	274,500,000		270,800,000
Federal home loan bank 30-day | Interest rate swaps
Other Commitments [Line Items]
Notional amount of derivative	$ 251,477,000		$ 118,891,000
Derivative, Number of Instruments Held | derivative	46		25
Commercial and Industrial Sector [Member] | Interest rate swaps
Other Commitments [Line Items]
Notional amount of derivative	$ 401,290,000		$ 416,515,000
Derivative, Number of Instruments Held | derivative	82		82
Contract Two [Member] | Interest rate swaps
Other Commitments [Line Items]
Notional amount of derivative	$ 10,000,000		$ 10,000,000
Contract Two [Member] | Forward-Starting Interest Rate Swap
Other Commitments [Line Items]
Notional amount of derivative	0		25,000,000
Contract One [Member] | Interest rate swaps
Other Commitments [Line Items]
Notional amount of derivative	$ 10,000,000		$ 10,000,000