Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Cash Flows from Operating Activities:
Net Income	$ 307,579		$ 265,156		$ 152,421
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	150,616		157,665		148,413
Amortization of debt deferred costs and intangibles, net	3,641		(7,518)		(1,162)
Impairment loss	1,024		2,815		15,436
Equity in (earnings) losses of real estate joint ventures and partnerships, net	(22,317)		(35,112)		1,558
Gain on acquisition	0		0		(1,869)
Gain on sale and acquisition of real estate joint venture and partnership interests	(1,718)		(33,670)		(14,203)
Gain on sale of property	(190,872)		(119,965)		(69,623)
Distributions of income from real estate joint ventures and partnerships, net	4,058		3,498		3,141
Changes in accrued rent and accounts receivable, net	(3,494)		(4,606)		82
Changes in unamortized debt and lease costs and other assets, net	(16,299)		(19,587)		(19,008)
Changes in accounts payable, accrued expenses and other liabilities, net	2,890		18,420		(878)
Other, net	5,661		6,896		13,022
Net cash provided by operating activities	240,769		233,992		227,330
Cash Flows from Investing Activities:
Acquisition of real estate and land	(43,587)		(105,765)		(198,171)
Development and capital improvements	(100,926)		(76,992)		(95,743)
Proceeds from sale of property and real estate equity investments, net	351,224		282,705		591,091
Change in restricted deposits and mortgage escrows	(75,299)		39,505		(30,520)
Notes receivable from real estate joint ventures and partnerships and other receivables - Advances	0		(289)		(6,614)
Notes receivable from real estate joint ventures and partnerships and other receivables - Collections	10,336		19,411		75,081
Real estate joint ventures and partnerships - Investments	(5,223)		(26,241)		(9,792)
Real estate joint ventures and partnerships - Distributions of capital	31,260		59,932		44,976
Purchase of investments	(3,000)		(58,836)		0
Proceeds from investments	51,788		0		0
Other, net	1,504		1,224		0
Net cash provided by investing activities	218,077		134,654		370,308
Cash Flows from Financing Activities:
Proceeds from issuance of debt	4,500		573,542		300,098
Principal payments of debt	(508,997)		(449,629)		(538,438)
Changes in unsecured credit facilities	189,000		(66,000)		(100,500)
Proceeds from issuance of common shares of beneficial interest, net	7,987		5,968		8,267
Repurchase of preferred shares of beneficial interest	0		(275,000)		(72,500)
Common and preferred dividends paid	(199,343)		(165,900)		(173,202)
Debt issuance costs paid	(463)		(6,716)		(4,250)
Distributions to noncontrolling interests	(21,055)		(20,151)		(12,770)
Contributions from noncontrolling interests	980		106,613		2,123
Other, net	158		599		(504)
Net cash used in financing activities	(527,233)		(296,674)		(591,676)
Net (decrease) increase in cash and cash equivalents	(68,387)		71,972		5,962
Cash and cash equivalents at January 1	91,576	[1]	19,604		13,642
Cash and cash equivalents at December 31	23,189	[1]	91,576	[1]	19,604
Interest paid during the period (net of amount capitalized of $3,302, $2,403 and $3,125, respectively)	91,277		106,918		117,085
Income taxes paid during the period	$ 1,705		$ 1,860		$ 1,548

[1] * Consolidated variable interest entities' assets held as collateral and debt included in the above balances (see Note 22):