Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenues:
Rental and related revenue	$ 752,478	$ 678,795	$ 634,455
General contractor and service fee revenue	521,796	515,361	449,509
Revenues, total	1,274,274	1,194,156	1,083,964
Expenses:
Rental expenses	147,173	137,348	130,811
Real estate taxes	103,724	89,718	83,471
General contractor and other services expenses	480,480	486,865	427,666
Depreciation and amortization	330,450	279,606	245,456
Costs and expenses, total	1,061,827	993,537	887,404
Other operating activities:
Equity in earnings of unconsolidated companies	4,565	7,980	9,896
Gain on sale of properties	68,549	39,662	12,337
Earnings from sales of land	0	0	357
Undeveloped land carrying costs	(8,934)	(9,203)	(10,403)
Impairment charges	(12,931)	(9,834)	(275,360)
Other operating expenses	(1,237)	(1,231)	(1,017)
General and administrative expenses	(43,107)	(41,329)	(47,937)
Other operation transactions, total	6,905	(13,955)	(312,127)
Operating income (loss)	219,352	186,664	(115,567)
Other income (expenses):
Interest and other income, net	658	534	1,229
Interest expense	(223,053)	(189,094)	(151,605)
Gain (loss) on debt transactions	0	(16,349)	20,700
Acquisition-related activity	(1,188)	55,820	(1,062)
Income (loss) from continuing operations before income taxes	(4,231)	37,575	(246,305)
Income tax benefit	194	1,126	6,070
Income (loss) from continuing operations	(4,037)	38,701	(240,235)
Discontinued operations:
Loss before impairment charges and gain on sales	(536)	(6,493)	(10,835)
Impairment charges	0	0	(27,206)
Gain on sale of depreciable properties	100,882	33,054	6,786
Income (loss) from discontinued operations	100,346	26,561	(31,255)
Net income (loss)	96,309	65,262	(271,490)
Distributions on Preferred Units	(60,353)	(69,468)	(73,451)
Adjustments for redemption/repurchase of Preferred Units	(3,796)	(10,438)	0
Net loss attributable to noncontrolling interests	115	185	241
Net income (loss) attributable to common unitholders	$ 32,275	$ (14,459)	$ (344,700)
Basic net income (loss) per Common Unit:
Continuing operations attributable to common unitholders	$ (0.28)	$ (0.18)	$ (1.52)
Discontinued operations attributable to common unitholders	$ 0.39	$ 0.11	$ (0.15)
Total	$ 0.11	$ (0.07)	$ (1.67)
Diluted net income (loss) per Common Unit:
Continuing operations attributable to common unitholders	$ (0.28)	$ (0.18)	$ (1.52)
Discontinued operations attributable to common unitholders	$ 0.39	$ 0.11	$ (0.15)
Total	$ 0.11	$ (0.07)	$ (1.67)
Weighted average number of Common Units outstanding	259,598	244,870	207,893
Weighted average number of Common Units and potential dilutive securities	259,598	244,870	207,893