Investments in and Advances to Other Real Estate Partnerships (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Condensed Combined Statements of Operations
Total Revenues	$ 73,562	$ 70,400	$ 146,019	$ 141,368
Property Expenses	(24,203)	(23,960)	(48,800)	(50,035)
Impairment of Real Estate		5,335	(7)	6,999
Depreciation and Other Amortization	(26,898)	(25,310)	(55,374)	(49,558)
Interest Income	697	908	1,643	1,898
Interest Expense	(19,695)	(24,534)	(40,904)	(50,333)
Amortization of Deferred Financing Costs	(799)	(1,034)	(1,622)	(2,085)
Loss from Retirement of Debt	(6,223)	(3,233)	(6,222)	(4,099)
Discontinued Operations:
Income Attributable to Discontinued Operations	994	1,229	986	417
Gain on Sale of Real Estate	1,415	3,537	7,614	6,279
Income from Discontinued Operations	2,409	3,234	8,600	4,657
Net Loss	(10,344)	(88)	(9,240)	(4,489)
Other Real Estate Partnership [Member]
Condensed Combined Statements of Operations
Total Revenues	10,258	10,005	20,294	20,285
Property Expenses	(2,913)	(2,915)	(5,910)	(6,119)
Impairment of Real Estate			172	881
Depreciation and Other Amortization	(3,350)	(2,972)	(7,635)	(6,011)
Interest Income	2,243	3,111	4,386	6,688
Interest Expense	(1,477)	(1,212)	(2,961)	(2,152)
Amortization of Deferred Financing Costs	(51)	(43)	(103)	(77)
Loss from Retirement of Debt				(160)
Income from Continuing Operations	4,710	5,974	8,243	13,335
Discontinued Operations:
Income Attributable to Discontinued Operations	65	25	(199)	73
Gain on Sale of Real Estate	(29)		(29)	1,062
Income from Discontinued Operations	36	25	(228)	1,135
Net Loss	$ 4,746	$ 5,999	$ 8,015	$ 14,470