Consolidated Statements of Operations and Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenues:
Rental and related revenue	$ 221,264	$ 196,693
General contractor and service fee revenue	47,404	68,968
Revenues, total	268,668	265,661
Expenses:
Rental expenses	41,713	35,758
Real estate taxes	30,487	27,849
General contractor and other services expenses	38,341	63,921
Depreciation and amortization	97,115	88,090
Costs and expenses, total	207,656	215,618
Other operating activities:
Equity in earnings of unconsolidated companies	49,378	1,509
Gain on sale of properties	168	(277)
Undeveloped land carrying costs	(2,198)	(2,298)
Other operating expenses	(68)	(265)
General and administrative expenses	(13,145)	(11,839)
Other operation transactions, total	34,135	(13,170)
Operating income	95,147	36,873
Other income (expenses):
Interest and other income, net	153	146
Interest expense	(60,075)	(59,299)
Acquisition-related activity	643	(580)
Income (loss) from continuing operations	35,868	(22,860)
Discontinued operations:
Income (loss) before gain on sales	(699)	(1,726)
Gain on sale of depreciable properties	8,954	6,476
Income (loss) from discontinued operations	8,255	4,750
Net income (loss)	44,123	(18,110)
Dividends on preferred shares/units	(9,550)	(13,193)
Adjustments for redemption of preferred shares/units	(5,932)	(5,730)
Net (income) loss attributable to noncontrolling interests - consolidated entities not wholly owned by the Partnership	(206)	(168)
Net (income) loss attributable to noncontrolling interests	(598)	643
Net income (loss) attributable to common shareholders/unitholders	28,043	(36,390)
Basic net income (loss) per common share/unit:
Continuing operations attributable to common shareholders/unitholders	$ 0.06	$ (0.16)
Discontinued operations attributable to common shareholders/unitholders	$ 0.03	$ 0.02
Total	$ 0.09	$ (0.14)
Diluted net income (loss) per common share/unit:
Continuing operations attributable to common shareholders/unitholders	$ 0.06	$ (0.16)
Discontinued operations attributable to common shareholders/unitholders	$ 0.03	$ 0.02
Total	$ 0.09	$ (0.14)
Weighted average number of common shares/units outstanding	314,936	258,365
Weighted average number of common shares/units and potential dilutive securities	319,571	258,365
Comprehensive income (loss):
Net income (loss)	44,123	(18,110)
Other comprehensive income:
Amortization of interest contracts	457	457
Other	80	62
Total other comprehensive income	537	519
Comprehensive income (loss)	44,660	(17,591)
Subsidiary of Common Parent [Member]
Revenues:
Rental and related revenue	221,264	196,693
General contractor and service fee revenue	47,404	68,968
Revenues, total	268,668	265,661
Expenses:
Rental expenses	41,713	35,758
Real estate taxes	30,487	27,849
General contractor and other services expenses	38,341	63,921
Depreciation and amortization	97,115	88,090
Costs and expenses, total	207,656	215,618
Other operating activities:
Equity in earnings of unconsolidated companies	49,378	1,509
Gain on sale of properties	168	(277)
Undeveloped land carrying costs	(2,198)	(2,298)
Other operating expenses	(68)	(265)
General and administrative expenses	(13,145)	(11,839)
Other operation transactions, total	34,135	(13,170)
Operating income	95,147	36,873
Other income (expenses):
Interest and other income, net	153	146
Interest expense	(60,075)	(59,299)
Acquisition-related activity	643	(580)
Income (loss) from continuing operations	35,868	(22,860)
Discontinued operations:
Income (loss) before gain on sales	(699)	(1,726)
Gain on sale of depreciable properties	8,954	6,476
Income (loss) from discontinued operations	8,255	4,750
Net income (loss)	44,123	(18,110)
Dividends on preferred shares/units	(9,550)	(13,193)
Adjustments for redemption of preferred shares/units	(5,932)	(5,730)
Net (income) loss attributable to noncontrolling interests - consolidated entities not wholly owned by the Partnership	(206)	(168)
Net income (loss) attributable to common shareholders/unitholders	28,435	(37,201)
Basic net income (loss) per common share/unit:
Continuing operations attributable to common shareholders/unitholders	$ 0.06	$ (0.16)
Discontinued operations attributable to common shareholders/unitholders	$ 0.03	$ 0.02
Total	$ 0.09	$ (0.14)
Diluted net income (loss) per common share/unit:
Continuing operations attributable to common shareholders/unitholders	$ 0.06	$ (0.16)
Discontinued operations attributable to common shareholders/unitholders	$ 0.03	$ 0.02
Total	$ 0.09	$ (0.14)
Weighted average number of common shares/units outstanding	319,341	264,114
Weighted average number of common shares/units and potential dilutive securities	319,571	264,114
Comprehensive income (loss):
Net income (loss)	44,123	(18,110)
Other comprehensive income:
Amortization of interest contracts	457	457
Other	80	62
Total other comprehensive income	537	519
Comprehensive income (loss)	$ 44,660	$ (17,591)