Consolidated Statements of Operations and Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Revenues:
Rental and related revenue	$ 205,008	$ 180,009	$ 407,678	$ 370,438
General contractor and service fee revenue	63,607	135,362	132,575	281,909
Revenues, total	268,615	315,371	540,253	652,347
Expenses:
Rental expenses	34,795	32,712	71,846	73,136
Real estate taxes	28,071	26,147	56,608	53,540
General contractor and other services expenses	57,879	122,969	121,800	258,633
Depreciation and amortization	92,721	83,351	184,084	161,057
Costs and expenses, total	213,466	265,179	434,338	546,366
Other operating activities:
Equity in earnings of unconsolidated companies	267	1,713	1,776	2,786
Gain on sale of properties	119	492	(158)	68,348
Undeveloped land carrying costs	(2,168)	(2,453)	(4,466)	(4,762)
Other operating expenses	(196)	(26)	(461)	(111)
General and administrative expenses	(11,594)	(8,541)	(23,433)	(19,738)
Other operation transactions, total	(13,572)	(8,815)	(26,742)	46,523
Operating income	41,577	41,377	79,173	152,504
Other income (expenses):
Interest and other income, net	98	284	244	371
Interest expense	(61,220)	(53,814)	(122,138)	(106,461)
Acquisition-related activity	(1,029)	(594)	(1,609)	(1,183)
Income (loss) from continuing operations	(20,574)	(12,747)	(44,330)	45,231
Discontinued operations:
Income (loss) before gain on sales	(249)	(3,824)	(1,079)	(8,616)
Gain on sale of depreciable properties	3,095	2,713	9,571	14,316
Income (Loss) from discontinued operations	2,846	(1,111)	8,492	5,700
Net income (loss)	(17,728)	(13,858)	(35,838)	50,931
Dividends on preferred shares	(11,082)	(15,974)	(24,275)	(31,948)
Adjustments for redemption/repurchase of preferred shares	0	0	(5,730)	(163)
Net (Income) Loss Attributable to Noncontrolling Interests - consolidated entities not wholly owned by the Partnership	(138)	84	(306)	206
Net (income) loss attributable to noncontrolling interests	328	790	971	(293)
Net income (loss) attributable to common shareholders	(28,482)	(29,042)	(64,872)	18,527
Net income (loss) attributable to common unitholders	(28,948)	(29,748)	(66,149)	19,026
Basic net income (loss) per common share/unit:
Continuing operations attributable to common shareholders	$ (0.12)	$ (0.11)	$ (0.28)	$ 0.05
Discontinued operations attributable to common shareholders	$ 0.01	$ (0.01)	$ 0.03	$ 0.02
Total	$ (0.11)	$ (0.12)	$ (0.25)	$ 0.07
Diluted net income (loss) per common share/unit:
Continuing operations attributable to common shareholders	$ (0.12)	$ (0.11)	$ (0.28)	$ 0.05
Discontinued operations attributable to common shareholders	$ 0.01	$ (0.01)	$ 0.03	$ 0.02
Total	$ (0.11)	$ (0.12)	$ (0.25)	$ 0.07
Weighted average number of common shares outstanding	266,748	252,640	262,556	252,524
Weighted average number of common shares and potential dilutive securities	266,748	252,640	262,556	259,390
Comprehensive income (loss):
Net income (loss)	(17,728)	(13,858)	(35,838)	50,931
Other comprehensive income:
Derivative instrument activity	261	717	780	1,488
Other comprehensive income	261	717	780	1,488
Comprehensive income (loss)	(17,467)	(13,141)	(35,058)	52,419
Subsidiary of Common Parent [Member]
Revenues:
Rental and related revenue	205,008	180,009	407,678	370,438
General contractor and service fee revenue	63,607	135,362	132,575	281,909
Revenues, total	268,615	315,371	540,253	652,347
Expenses:
Rental expenses	34,795	32,712	71,846	73,136
Real estate taxes	28,071	26,147	56,608	53,540
General contractor and other services expenses	57,879	122,969	121,800	258,633
Depreciation and amortization	92,721	83,351	184,084	161,057
Costs and expenses, total	213,466	265,179	434,338	546,366
Other operating activities:
Equity in earnings of unconsolidated companies	267	1,713	1,776	2,786
Gain on sale of properties	119	492	(158)	68,348
Undeveloped land carrying costs	(2,168)	(2,453)	(4,466)	(4,762)
Other operating expenses	(196)	(26)	(461)	(111)
General and administrative expenses	(11,594)	(8,541)	(23,433)	(19,738)
Other operation transactions, total	(13,572)	(8,815)	(26,742)	46,523
Operating income	41,577	41,377	79,173	152,504
Other income (expenses):
Interest and other income, net	98	284	244	371
Interest expense	(61,220)	(53,814)	(122,138)	(106,461)
Acquisition-related activity	(1,029)	(594)	(1,609)	(1,183)
Income (loss) from continuing operations	(20,574)	(12,747)	(44,330)	45,231
Discontinued operations:
Income (loss) before gain on sales	(249)	(3,824)	(1,079)	(8,616)
Gain on sale of depreciable properties	3,095	2,713	9,571	14,316
Income (Loss) from discontinued operations	2,846	(1,111)	8,492	5,700
Net income (loss)	(17,728)	(13,858)	(35,838)	50,931
Distributions on Preferred Units	(11,082)	(15,974)	(24,275)	(31,948)
Adjustments for redemption/repurchase of Preferred Units	0	0	(5,730)	(163)
Net (Income) Loss Attributable to Noncontrolling Interests - consolidated entities not wholly owned by the Partnership	(138)	84	(306)	206
Net income (loss) attributable to common unitholders	(28,948)	(29,748)	(66,149)	19,026
Basic net income (loss) per common share/unit:
Continuing operations attributable to common unitholders	$ (0.12)	$ (0.11)	$ (0.28)	$ 0.05
Discontinued operations attributable to common unitholders	$ 0.01	$ (0.01)	$ 0.03	$ 0.02
Total	$ (0.11)	$ (0.12)	$ (0.25)	$ 0.07
Diluted net income (loss) per common share/unit:
Continuing operations attributable to common unitholders	$ (0.12)	$ (0.11)	$ (0.28)	$ 0.05
Discontinued operations attributable to common unitholders	$ 0.01	$ (0.01)	$ 0.03	$ 0.02
Total	$ (0.11)	$ (0.12)	$ (0.25)	$ 0.07
Weighted average number of Common Units outstanding	271,317	259,849	267,716	259,322
Weighted average number of Common Units and potential dilutive securities	271,317	259,849	267,716	259,390
Comprehensive income (loss):
Net income (loss)	(17,728)	(13,858)	(35,838)	50,931
Other comprehensive income:
Derivative instrument activity	261	717	780	1,488
Other comprehensive income	261	717	780	1,488
Comprehensive income (loss)	$ (17,467)	$ (13,141)	$ (35,058)	$ 52,419