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, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Revenues:
Rental and related revenue	$ 224,665	$ 197,213	$ 443,977	$ 392,312
General contractor and service fee revenue	50,793	63,607	98,197	132,575
Revenues, total	275,458	260,820	542,174	524,887
Expenses:
Rental expenses	39,977	33,099	81,180	68,444
Real estate taxes	30,782	27,260	61,081	55,003
General contractor and other services expenses	45,192	57,879	83,533	121,800
Depreciation and amortization	98,545	88,667	194,801	175,953
Costs and expenses, total	214,496	206,905	420,595	421,200
Other operating activities:
Equity in earnings of unconsolidated companies	1,091	267	50,469	1,776
Gain on sale of properties	940	119	1,108	(158)
Undeveloped land carrying costs	(2,531)	(2,168)	(4,729)	(4,466)
Asset Impairment Charges	(3,777)	0	(3,777)	0
Other operating expenses	(35)	(196)	(103)	(461)
General and administrative expenses	(9,707)	(11,594)	(22,852)	(23,433)
Other operation transactions, total	(14,019)	(13,572)	20,116	(26,742)
Operating income	46,943	40,343	141,695	76,945
Other income (expenses):
Interest and other income, net	921	98	1,074	244
Interest expense	(59,296)	(59,146)	(118,945)	(118,025)
Acquisition-related activity	(2,423)	(1,029)	(1,780)	(1,609)
Income (loss) from continuing operations	(13,855)	(19,734)	22,044	(42,445)
Discontinued operations:
Income (loss) before gain on sales	30	(1,089)	(700)	(2,964)
Gain on sale of depreciable properties	83,657	3,095	92,611	9,571
Income (loss) from discontinued operations	83,687	2,006	91,911	6,607
Net income (loss)	69,832	(17,728)	113,955	(35,838)
Dividends on preferred shares/units	(7,355)	(11,082)	(16,905)	(24,275)
Adjustments for redemption of preferred shares/units	0	0	(5,932)	(5,730)
Net (income) loss attributable to noncontrolling interests	(983)	328	(1,581)	971
Net income (loss) attributable to common shareholders/unitholders	61,494	(28,482)	89,537	(64,872)
Basic net income (loss) per common share/unit:
Continuing operations attributable to common shareholders/unitholders	$ (0.07)	$ (0.12)	$ (0.01)	$ (0.28)
Discontinued operations attributable to common shareholders/unitholders	$ 0.26	$ 0.01	$ 0.29	$ 0.03
Total	$ 0.19	$ (0.11)	$ 0.28	$ (0.25)
Diluted net income (loss) per common share/unit:
Continuing operations attributable to common shareholders/unitholders	$ (0.07)	$ (0.12)	$ (0.01)	$ (0.28)
Discontinued operations attributable to common shareholders/unitholders	$ 0.26	$ 0.01	$ 0.29	$ 0.03
Total	$ 0.19	$ (0.11)	$ 0.28	$ (0.25)
Weighted average number of common shares/units outstanding	322,489	266,748	318,733	262,556
Weighted average number of common shares/units and potential dilutive securities	327,098	266,748	323,350	262,556
Comprehensive income (loss):
Net income (loss)	69,832	(17,728)	113,955	(35,838)
Other comprehensive income:
Amortization of interest contracts	226	457	683	914
Other	496	(196)	576	(134)
Total other comprehensive income	722	261	1,259	780
Comprehensive income (loss)	70,554	(17,467)	115,214	(35,058)
Subsidiary of Common Parent [Member]
Revenues:
Rental and related revenue	224,665	197,213	443,977	392,312
General contractor and service fee revenue	50,793	63,607	98,197	132,575
Revenues, total	275,458	260,820	542,174	524,887
Expenses:
Rental expenses	39,977	33,099	81,180	68,444
Real estate taxes	30,782	27,260	61,081	55,003
General contractor and other services expenses	45,192	57,879	83,533	121,800
Depreciation and amortization	98,545	88,667	194,801	175,953
Costs and expenses, total	214,496	206,905	420,595	421,200
Other operating activities:
Equity in earnings of unconsolidated companies	1,091	267	50,469	1,776
Gain on sale of properties	940	119	1,108	(158)
Undeveloped land carrying costs	(2,531)	(2,168)	(4,729)	(4,466)
Asset Impairment Charges	(3,777)	0	(3,777)	0
Other operating expenses	(35)	(196)	(103)	(461)
General and administrative expenses	(9,707)	(11,594)	(22,852)	(23,433)
Other operation transactions, total	(14,019)	(13,572)	20,116	(26,742)
Operating income	46,943	40,343	141,695	76,945
Other income (expenses):
Interest and other income, net	921	98	1,074	244
Interest expense	(59,296)	(59,146)	(118,945)	(118,025)
Acquisition-related activity	(2,423)	(1,029)	(1,780)	(1,609)
Income (loss) from continuing operations	(13,855)	(19,734)	22,044	(42,445)
Discontinued operations:
Income (loss) before gain on sales	30	(1,089)	(700)	(2,964)
Gain on sale of depreciable properties	83,657	3,095	92,611	9,571
Income (loss) from discontinued operations	83,687	2,006	91,911	6,607
Net income (loss)	69,832	(17,728)	113,955	(35,838)
Dividends on preferred shares/units	(7,355)	(11,082)	(16,905)	(24,275)
Adjustments for redemption of preferred shares/units	0	0	(5,932)	(5,730)
Noncontrolling Interest in Net Income (Loss) Joint Venture Partners, NonRedeemable	(141)	(138)	(347)	(306)
Net income (loss) attributable to common shareholders/unitholders	62,336	(28,948)	90,771	(66,149)
Basic net income (loss) per common share/unit:
Continuing operations attributable to common shareholders/unitholders	$ (0.07)	$ (0.12)	$ (0.01)	$ (0.28)
Discontinued operations attributable to common shareholders/unitholders	$ 0.26	$ 0.01	$ 0.29	$ 0.03
Total	$ 0.19	$ (0.11)	$ 0.28	$ (0.25)
Diluted net income (loss) per common share/unit:
Continuing operations attributable to common shareholders/unitholders	$ (0.07)	$ (0.12)	$ (0.01)	$ (0.28)
Discontinued operations attributable to common shareholders/unitholders	$ 0.26	$ 0.01	$ 0.29	$ 0.03
Total	$ 0.19	$ (0.11)	$ 0.28	$ (0.25)
Weighted average number of common shares/units outstanding	326,877	271,317	323,130	267,716
Weighted average number of common shares/units and potential dilutive securities	327,098	271,317	323,350	267,716
Comprehensive income (loss):
Net income (loss)	69,832	(17,728)	113,955	(35,838)
Other comprehensive income:
Amortization of interest contracts	226	457	683	914
Other	496	(196)	576	(134)
Total other comprehensive income	722	261	1,259	780
Comprehensive income (loss)	$ 70,554	$ (17,467)	$ 115,214	$ (35,058)