Investment in Unconsolidated Ventures (Summary of Results of Operations of Unconsolidated Real Estate Ventures) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Summary of results of operations of Real Estate Ventures
Company's share of income (Company's basis)	$ 838,000	$ 1,088,000	$ 882,000	$ 2,321,000
Unconsolidated real estate ventures [Member]
Summary of results of operations of Real Estate Ventures
Revenue	39,008,000	32,722,000	77,601,000	72,398,000
Operating expenses	11,000,000	14,370,000	27,815,000	30,544,000
Interest expense, net	9,840,000	9,550,000	21,089,000	21,673,000
Depreciation and amortization	13,887,000	8,487,000	25,358,000	18,968,000
Net income	4,281,000	315,000	3,339,000	1,213,000
Guaranteed repayment of loans on behalf of a certain Real Estate Venture	$ 700,000		$ 700,000