Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011
ASSETS
Property	$ 4,263,222		$ 4,688,526
Accumulated Depreciation	(981,443)		(1,059,531)
Property Held for Sale, net	414,413		73,241
Property, net	3,696,192	[1]	3,702,236	[1]
Investment in Real Estate Joint Ventures and Partnerships, net	338,332		341,608
Total	4,034,524		4,043,844
Notes Receivable from Real Estate Joint Ventures and Partnerships	92,216		149,204
Unamortized Debt and Lease Costs, net	117,346		115,191
Accrued Rent and Accounts Receivable (net of allowance for doubtful accounts of $12,244 in 2012 and $11,301 in 2011)	69,702	[1]	86,530	[1]
Cash and Cash Equivalents	18,024	[1]	13,642	[1]
Restricted Deposits and Mortgage Escrows	9,834		11,144
Other, net	170,895		168,671
Total Assets	4,512,541		4,588,226
LIABILITIES AND EQUITY
Debt, net	2,497,561	[1]	2,531,837	[1]
Accounts Payable and Accrued Expenses	95,436		124,888
Other, net	115,285		107,919
Total Liabilities	2,708,282		2,764,644
Commitments and Contingencies
Shareholders' Equity:
Common Shares of Beneficial Interest - par value, $.03 per share; shares authorized: 275,000; shares issued and outstanding: 121,113 in 2012 and 120,844 in 2011	3,649		3,641
Additional Paid-In Capital	1,989,198		1,983,978
Net Income Less Than Accumulated Dividends	(327,296)		(304,504)
Accumulated Other Comprehensive Loss	(27,068)		(27,743)
Total Shareholders' Equity	1,638,491		1,655,380
Noncontrolling Interests	165,768		168,202
Total Equity	1,804,259		1,823,582
Total Liabilities and Equity	4,512,541		4,588,226
* Consolidated Variable Interest Entities' Assets and Liabilities included in the above balances (See Note 17):
Property, net	227,743		230,159
Accrued Rent and Accounts Receivable, net	6,997		8,564
Cash and Cash Equivalents	12,148		11,382
Debt, net	278,594		279,301
6.75% Series D Preferred Shares [Member]
Shareholders' Equity:
Cumulative redeemable preferred shares of beneficial interest, value	3		3
6.95% Series E Preferred Shares [Member]
Shareholders' Equity:
Cumulative redeemable preferred shares of beneficial interest, value	1		1
6.5% Series F Preferred Shares [Member]
Shareholders' Equity:
Cumulative redeemable preferred shares of beneficial interest, value	$ 4		$ 4

[1] Consolidated Variable Interest Entities' Assets and Liabilities included in the above balances (See Note 17):