Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Cash Flows from Operating Activities:
Net Income	$ 152,421		$ 16,739		$ 51,238
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	148,413		157,290		151,107
Amortization of deferred financing costs, net	(1,162)		5,215		5,017
Impairment loss	15,436		75,874		33,317
Equity in losses (earnings) of real estate joint ventures and partnerships, net	1,558		(7,834)		(12,889)
Gain on acquisition	(1,869)		(4,559)		0
Gain on sale of real estate joint venture and partnership interests	(14,203)		0		0
Gain on sale of property	(69,623)		(11,952)		(3,098)
Loss on redemption of convertible senior unsecured notes	0		0		135
Distributions of income from real estate joint ventures and partnerships, net	3,141		2,186		1,733
Changes in accrued rent and accounts receivable, net	82		6,662		(2,898)
Changes in other assets, net	(19,008)		(22,482)		(16,225)
Changes in accounts payable, accrued expenses and other liabilities, net	(878)		(13,525)		(3,875)
Other, net	13,022		11,117		11,063
Net cash provided by operating activities	227,330		214,731		214,625
Cash Flows from Investing Activities:
Acquisition of real estate and land	(198,171)		(49,880)		(62,102)
Development and capital improvements	(95,743)		(94,108)		(80,870)
Proceeds from sale of property and real estate equity investments, net	591,091		113,043		29,064
Change in restricted deposits and mortgage escrows	(30,520)		(794)		2,175
Notes receivable from real estate joint ventures and partnerships and other receivables:
Advances	(6,614)		(2,926)		(9,145)
Collections	75,081		15,687		20,010
Real estate joint ventures and partnerships:
Investments	(9,792)		(18,583)		(37,738)
Distributions of capital	44,976		17,271		15,663
Proceeds from tax increment revenue bonds	0		16,545		0
Other, net	0		0		1,522
Net cash provided by (used in) investing activities	370,308		(3,745)		(121,421)
Cash Flows from Financing Activities:
Proceeds from issuance of debt	300,098		215,750		336
Proceeds from issuance of common shares of beneficial interest, net	8,267		3,999		3,122
Repurchase of preferred shares of beneficial interest	(72,500)		0		0
Principal payments of debt	(538,438)		(336,760)		(139,722)
Changes in unsecured credit facilities	(100,500)		86,500		80,000
Common and preferred dividends paid	(173,202)		(165,721)		(158,012)
Debt issuance costs paid	(4,250)		(4,002)		(6,622)
Distributions to noncontrolling interests	(12,770)		(23,560)		(13,014)
Contributions from noncontrolling interests	2,123		3,717		2,686
Other, net	(504)		(1,126)		8,297
Net cash used in financing activities	(591,676)		(221,203)		(222,929)
Net increase (decrease) in cash and cash equivalents	5,962		(10,217)		(129,725)
Cash and cash equivalents at January 1	13,642	[1]	23,859		153,584
Cash and cash equivalents at December 31	19,604	[1]	13,642	[1]	23,859
Interest paid during the period (net of amount capitalized of $3,125, $2,329 and $3,405, respectively)	117,085		137,758		140,335
Income taxes paid during the period	$ 1,548		$ 1,578		$ 2,116

[1] * Consolidated Variable Interest Entities' Assets and Liabilities included in the above balances (See Note 22):