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 income	$ 1,980,437	$ 1,763,792	$ 1,629,878
Fee and asset management	9,026	9,476	10,346
Total revenues	1,989,463	1,773,268	1,640,224
EXPENSES
Property and maintenance	416,723	402,078	369,731
Real estate taxes and insurance	222,427	211,621	190,374
Property management	82,133	80,087	71,300
Fee and asset management	4,279	4,998	7,345
Depreciation	646,963	613,146	518,726
General and administrative	43,606	39,881	38,985
Impairment	0	45,380	11,124
Total expenses	1,416,131	1,397,191	1,207,585
Operating income	573,332	376,077	432,639
Interest and other income	7,977	5,166	16,578
Other expenses	(14,557)	(11,928)	(6,477)
Interest:
Expense incurred, net	(469,237)	(468,306)	(493,278)
Amortization of deferred financing costs	(17,006)	(10,114)	(12,327)
Income (loss) before income and other taxes, (loss) from investments in unconsolidated entities, net gain (loss) on sales of unconsolidated entities and land parcels and discontinued operations	80,509	(109,105)	(62,865)
Income and other tax (expense) benefit	(728)	(292)	(2,716)
(Loss) from investments in unconsolidated entities	0	(735)	(2,815)
Net gain on sales of unconsolidated entities	0	28,101	10,689
Net (loss) gain on sales of land parcels	4,217	(1,395)	0
(Loss) income from continuing operations	83,998	(83,426)	(57,707)
Discontinued operations, net	851,199	379,409	439,736
Net income	935,197	295,983	382,029
Net (income) loss attributable to Noncontrolling Interests:
Operating Partnership	(40,780)	(13,099)	(20,305)
Preference Interests and Units	0	0	(9)
Partially Owned Properties	(832)	726	558
Net income attributable to controlling interests	893,585	283,610	362,273
Preferred distributions	(13,865)	(14,368)	(14,479)
Net income available to Common Shares	$ 879,720	$ 269,242	$ 347,794
Earnings per share - basic:
(Loss) from continuing operations available to Common Shares	$ 0.225	$ (0.327)	$ (0.247)
Net income available to Common Shares	$ 2.984	$ 0.952	$ 1.271
Weighted average Common Shares outstanding	294,856	282,888	273,609
Earnings per share - diluted:
(Loss) from continuing operations available to Common Shares	$ 0.222	$ (0.327)	$ (0.247)
Net income available to Common Shares	$ 2.950	$ 0.952	$ 1.271
Weighted average Common Shares outstanding	312,065	282,888	273,609