DERIVATIVE INSTRUMENTS - Schedule of Derivatives (Details) - Cash Flow Hedging - Designated as Hedging Instrument	Sep. 30, 2018 USD ($)
Derivative [Line Items]
Current Notional Amount	$ 1,050,000,000
Estimated Fair Value, Assets (Liabilities)	26,929,000
3-Month USD LIBOR | Interest Rate Swap Designated June 22, 2016 Tranche 1
Derivative [Line Items]
Current Notional Amount	$ 50,000,000
Fixed Interest Rate	1.062%
Estimated Fair Value, Assets (Liabilities)	$ 588,000
3-Month USD LIBOR | Interest Rate Swap Designated June 22, 2016 Tranche 2
Derivative [Line Items]
Current Notional Amount	$ 50,000,000
Fixed Interest Rate	1.062%
Estimated Fair Value, Assets (Liabilities)	$ 924,000
3-Month USD LIBOR | Interest Rate Swap Designated February 6, 2017 Tranche 1
Derivative [Line Items]
Current Notional Amount	$ 50,000,000
Fixed Interest Rate	1.834%
Estimated Fair Value, Assets (Liabilities)	$ 590,000
1-Month USD LIBOR | Interest Rate Swap Designated July 12, 2016
Derivative [Line Items]
Current Notional Amount	$ 50,000,000
Fixed Interest Rate	0.825%
Estimated Fair Value, Assets (Liabilities)	$ 637,000
1-Month USD LIBOR | Interest Rate Swap Designated February 6, 2017 Tranche 2
Derivative [Line Items]
Current Notional Amount	$ 100,000,000
Fixed Interest Rate	1.652%
Estimated Fair Value, Assets (Liabilities)	$ 1,950,000
1-Month USD LIBOR | Interest Rate Swap Designated March 27, 2017
Derivative [Line Items]
Current Notional Amount	$ 100,000,000
Fixed Interest Rate	1.971%
Estimated Fair Value, Assets (Liabilities)	$ 2,342,000
1-Month USD LIBOR | Interest Rate Swap Designated December 13, 2017 Tranche 1
Derivative [Line Items]
Current Notional Amount	$ 150,000,000
Fixed Interest Rate	2.201%
Estimated Fair Value, Assets (Liabilities)	$ 4,322,000
1-Month USD LIBOR | Interest Rate Swap Designated December 13, 2017 Tranche 2
Derivative [Line Items]
Current Notional Amount	$ 150,000,000
Fixed Interest Rate	2.201%
Estimated Fair Value, Assets (Liabilities)	$ 4,277,000
1-Month USD LIBOR | Interest Rate Swap Designated December 13, 2017 Tranche 3
Derivative [Line Items]
Current Notional Amount	$ 100,000,000
Fixed Interest Rate	2.423%
Estimated Fair Value, Assets (Liabilities)	$ 2,786,000
1-Month USD LIBOR | Interest Rate Swap Designated December 13, 2017 Tranche 4
Derivative [Line Items]
Current Notional Amount	$ 50,000,000
Fixed Interest Rate	2.423%
Estimated Fair Value, Assets (Liabilities)	$ 1,339,000
1-Month USD LIBOR | Interest Rate Swap Designated December 13, 2017 Tranche 5
Derivative [Line Items]
Current Notional Amount	$ 200,000,000
Fixed Interest Rate	2.313%
Estimated Fair Value, Assets (Liabilities)	$ 7,174,000