DERIVATIVES - Narrative (Details) - Designated as Hedging Instrument - Cash Flow Hedging $ in Millions	Dec. 31, 2017 USD ($)	Dec. 31, 2017 CAD ($)	Dec. 31, 2016 USD ($)
Interest rate swap
Derivative [Line Items]
Notional amount of cash flow hedge instruments	$ 150,000,000
Fixed-rate payments	1.50%	1.50%
Foreign currency contracts | June 2016
Derivative [Line Items]
Notional amount of cash flow hedge instruments		$ 6.0
Foreign currency contracts exchange rate	1.268	1.268
Foreign currency contracts | June 2017
Derivative [Line Items]
Notional amount of cash flow hedge instruments		$ 12.0
Foreign currency contracts exchange rate	1.2855	1.2855
Foreign currency contracts | Other Current Liabilities
Derivative [Line Items]
Fair value of derivatives	$ 0		$ 200,000