DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Fair Value of Derivative Financial Instruments (Details) (Interest Rate Swap [Member], Designated as Hedging Instrument [Member], Accounts Payable and Accrued Liabilities [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member] | Accounts Payable and Accrued Liabilities [Member]
Fair value of derivative instruments
Derivative liabilities	$ 3,307	$ 3,144