DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES
Total outstanding notional amount of cash flow hedges	$ 143,000,000
Amount to be reclassified from AOCI to interest expense in next 12 months	3,900,000
Derivatives designated as hedging instruments
Derivative instruments and hedging activities
Hedge ineffectiveness recognized	0
Fair Value, liability derivatives	10,075,000	11,142,000
Interest rate swaps | Derivatives designated as hedging instruments
Derivative instruments and hedging activities
Fair Value, liability derivatives	$ 10,075,000	$ 11,142,000