Investment in Unconsolidated Ventures (Summary of Results of Operations of Unconsolidated Real Estate Ventures) (Details) (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Summary of results of operations of Real Estate Ventures
Company's share of income (Company's basis)	$ 44,000	$ 1,233,000
Unconsolidated real estate ventures [Member]
Summary of results of operations of Real Estate Ventures
Revenue	38,593,000	36,434,000
Operating expenses	16,815,000	15,705,000
Interest expense, net	11,249,000	11,207,000
Depreciation and amortization	11,471,000	10,126,000
Net income	(942,000)	(604,000)
Guaranteed repayment of loans on behalf of a certain Real Estate Venture	$ 700,000