Summary of Significant Accounting Policies and Procedures and Recent Accounting Pronouncements (Details) (USD $)	Jun. 30, 2011	Dec. 31, 2010
Summary of Significant Accounting Policies and Procedures and Recent Accounting Pronouncements [Abstract]
Allowance for doubtful accounts	$ 1,100,000	$ 1,100,000
Other assets [Abstract]
Value of in-place and above market leases, net	106,551,000	26,221,000
Deferred bond financing costs, net	23,224,000	14,203,000
Notes receivable issued in connection with Crest property sales	22,002,000	22,075,000
Prepaid expenses	8,926,000	8,431,000
Restricted escrow deposits	5,999,000	6,361,000
Credit facility origination costs, net	3,874,000	4,619,000
Corporate assets, net of accumulated depreciation and amortization	767,000	827,000
Deferred financing costs on assumed mortgages payable, net	583,000	0
Other items	2,288,000	1,861,000
Other assets	174,214,000	84,598,000
Distributions payable [Abstract]
Distributions payable	20,401,000	19,051,000
Accounts payable and accrued expenses [Abstract]
Bond interest payable	32,943,000	33,240,000
Other items	19,020,000	13,779,000
Accounts payable and accrued expenses	51,963,000	47,019,000
Other liabilities disclosure [Abstract]
Rent received in advance	8,595,000	14,564,000
Security deposits	4,370,000	4,539,000
Value of in-place below-market leases, net	5,125,000	3,452,000
Other liabilities	18,090,000	22,555,000
Common Stock [Member]
Distributions payable [Abstract]
Distributions payable	18,380,000	17,030,000
Preferred Stock [Member]
Distributions payable [Abstract]
Distributions payable	$ 2,021,000	$ 2,021,000