FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accumulated other comprehensive income - unrealized loss on valuation of swap agreements	$ 3,900,000	$ 2,800,000
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	1,500,000
Asset Impairment Charges	6,925,000	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	3,518,000	2,800,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	0
Cash Flow Hedging [Member] | Variable-Rate Derivatives, Maturing in October 2012 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, Cap Interest Rate	3.00%
Cash Flow Hedging [Member] | Variable-Rate Derivatives, Maturing in April 2013 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, Cap Interest Rate	6.00%
Cash Flow Hedging [Member] | Variable-Rate Derivatives, Maturing in August 2013 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, Cap Interest Rate	3.50%
Cash Flow Hedging [Member] | Interest Rate Swap [Member] | Fixed-Rate Derivatives, Maturing between March 2012 and December 2022 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional Amount of Interest Rate Cash Flow Hedge Derivatives	57,000,000
Cash Flow Hedging [Member] | Interest Rate Swap [Member] | Fixed-Rate Derivatives, Maturing between March 2012 and December 2022 [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, Fixed Interest Rate	2.70%
Cash Flow Hedging [Member] | Interest Rate Swap [Member] | Fixed-Rate Derivatives, Maturing between March 2012 and December 2022 [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, Fixed Interest Rate	5.10%
Cash Flow Hedging [Member] | Interest Rate Swap [Member] | Variable-Rate Derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional Amount of Interest Rate Cash Flow Hedge Derivatives	75,000,000
Fund I [Member] | Granville Centre [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges	$ 6,900,000