Consolidated Statements of Operations and Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Revenues:
Rental and related revenue	$ 203,432	$ 190,986
General contractor and service fee revenue	68,968	146,547
Revenues, total	272,400	337,533
Expenses:
Rental expenses	37,342	40,699
Real estate taxes	28,671	27,471
General contractor and other services expenses	63,921	135,664
Depreciation and amortization	91,613	77,822
Costs and expenses, total	221,547	281,656
Other operating activities:
Equity in earnings of unconsolidated companies	1,509	1,073
Gain on sale of properties	(277)	67,856
Undeveloped land carrying costs	(2,298)	(2,309)
Other operating expenses	(265)	(85)
General and administrative expenses	(11,839)	(11,197)
Other operation transactions, total	(13,170)	55,338
Operating income	37,683	111,215
Other income (expenses):
Interest and other income, net	146	87
Interest expense	(61,086)	(52,124)
Acquisition-related activity	(580)	(589)
Income (loss) from continuing operations	(23,837)	58,589
Discontinued operations:
Loss before gain on sales	(749)	(5,403)
Gain on sale of depreciable properties	6,476	11,603
Income from discontinued operations	5,727	6,200
Net income (loss)	(18,110)	64,789
Distributions on Preferred Units	(13,193)	(15,974)
Adjustments for redemption/repurchase of Preferred Units	(5,730)	(163)
Net (income) loss attributable to noncontrolling interests	(168)	122
Net income (loss) attributable to common unitholders	(37,201)	48,774
Basic net income (loss) per Common Unit:
Continuing operations attributable to common unitholders	$ (0.16)	$ 0.16
Discontinued operations attributable to common unitholders	$ 0.02	$ 0.03
Total	$ (0.14)	$ 0.19
Diluted net income (loss) per Common Unit:
Continuing operations attributable to common unitholders	$ (0.16)	$ 0.16
Discontinued operations attributable to common unitholders	$ 0.02	$ 0.03
Total	$ (0.14)	$ 0.19
Weighted average number of Common Units outstanding	264,114	258,790
Weighted average number of Common Units and potential dilutive securities	264,114	258,837
Comprehensive income (loss):
Net income (loss)	(18,110)	64,789
Other comprehensive income:
Derivative instrument activity	519	771
Other comprehensive income	519	771
Comprehensive income (loss)	$ (17,591)	$ 65,560