DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Narrative) (Details) $ in Thousands	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2019 USD ($) derivative_instrument	Jun. 30, 2019 USD ($) settled_derivative derivative_instrument	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($) settled_derivative
Derivative [Line Items]
Payment received from derivative settlement		$ 0	$ 9,390
Derivative liability fair value gross	$ 40,848	$ 40,848		$ 16,517
Interest Rate Cap
Derivative [Line Items]
Interest rate swap agreements settled | settled_derivative		1
Interest rate derivatives
Derivative [Line Items]
Interest rate swap agreements settled | settled_derivative				4
Reduction in interest expense	900	$ 2,000
Credit Risk Contract
Derivative [Line Items]
Derivative liability fair value gross	43,800	43,800		$ 18,200
Designated as Hedging Instrument | Interest Rate Cap
Derivative [Line Items]
Notional amount	$ 230,000	230,000
Payment received from derivative settlement		$ 200
Designated as Hedging Instrument | Interest rate derivatives
Derivative [Line Items]
Notional amount				250,000
Payment received from derivative settlement				15,800
Termination fee				300
Derivatives deferred effective portion of fair value change | derivative_instrument	3	3
Derivative change in fair value recognition period		8 years 6 months
Gain on derivative expected amount to be reclassified	$ 3,600	$ 3,600
Fixed Interest Rate 2.96%, Maturing October 2019 | Designated as Hedging Instrument | Interest rate derivatives
Derivative [Line Items]
Notional amount				18,900
Fixed Interest Rate 1.66%, Maturing May 2020 | Designated as Hedging Instrument | Interest rate derivatives
Derivative [Line Items]
Notional amount				40,000
Derivative change in fair value recognition period		2 years 2 months 12 days
Fixed Interest Rate 1.14%, Maturing September 2021 | Designated as Hedging Instrument | Interest rate derivatives
Derivative [Line Items]
Notional amount				$ 119,400
Derivative change in fair value recognition period		9 months 18 days