DERIVATIVE FINANCIAL INSTRUMENTS - Narrative (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Derivative [Line Items]
Ineffectiveness included in net income	$ 0		$ 0
Interest expense	3,666,000	$ 2,895,000
Unrealized loss to be reclassified as a reduction of interest expense	0
Designated as Hedging Instrument | Cash Flow Hedging | Interest Rate Swap
Derivative [Line Items]
Notional amount	5,000,000		$ 5,000,000
Interest expense	$ 167,000	$ 207,000