Consolidated Balance Sheets (Parentheticals) (USD $) In Thousands, except Share data	Jun. 30, 2011	Dec. 31, 2010
ASSETS
Accounts receivable, allowance for doubtful accounts	$ 71,939	$ 62,979
Receivable arising from the straight-lining of rents, allowance	8,148	7,323
Deferred leasing and financing costs, accumulated amortization	236,577	223,131
Identified intangible assets (included in other assets): Accumulated amortization	$ 363,341	$ 338,508
LIABILITIES, REDEEMABLE NONCONTROLLING INTERESTS AND EQUITY
Preferred shares of beneficial interest: authorized shares	110,000,000	110,000,000
Preferred shares of beneficial interest: issued shares	41,188,509	32,340,009
Preferred shares of beneficial interest: outstanding shares	41,188,509	32,340,009
Common shares of beneficial interest: par value per share	$ 0.04	$ 0.04
Common shares of beneficial interest: authorized shares	250,000,000	250,000,000
Common shares of beneficial interest: issued shares	184,427,825	183,661,875
Common shares of beneficial interest: outstanding shares	184,427,825	183,661,875
Common Class A [Member]
LIABILITIES, REDEEMABLE NONCONTROLLING INTERESTS AND EQUITY
Redeemable noncontrolling interests units outstanding	12,561,359	12,804,202
Cumulative Redeemable Preferred Unit [Member]
LIABILITIES, REDEEMABLE NONCONTROLLING INTERESTS AND EQUITY
Redeemable noncontrolling interests units outstanding	10,000,001	10,400,001