Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Operating Activities
Consolidated net loss	$ (27,533)	$ (77,271)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	276,008	225,246
Net gain on sale of marketable securities	(3,123)
Net gain on sale of cost investments	(2,550)
Net gain on the sale of depreciable property	(56,063)	(4,034)
Other Debt charges	4,052	1,121
Write off of bad debt	2,322	2,036
Loss from unconsolidated entities	4,260	2,757
Amortization of deferred financing costs and other	6,401	5,861
Amortization of deferred compensation	7,650	9,079
Amortization of convertible debt discount	1,077	2,754
Changes in income tax accruals	1,011	(2,702)
Changes in operating assets and liabilities:
Increase in operating assets	(30,395)	(10,364)
(Increase)/decrease in operating liabilities	(196)	3,006
Net cash provided by operating activities	182,921	157,489
Investing Activities
Proceeds from sales of real estate investments, net	77,130	20,688
Proceeds from sale of marketable securities	4,541
Payments related to the buyout of joint venture partner		(16,141)
Acquisition of real estate assets (net of liabilities assumed) and initial capital expenditures	(943,045)	(342,697)
Cash paid in nonmonetary asset exchange.	(28,124)
Development of real estate assets	(70,574)	(79,718)
Capital expenditures and other major improvements - real estate assets, net of escrow reimbursement	(68,125)	(52,681)
Capital expenditures - non-real estate assets	(12,260)	(3,332)
Investment in unconsolidated joint ventures	(47,509)	(5,697)
Distributions received from unconsolidated joint venture	4,592	730
Purchase deposits on pending real estate acquisitions	(3,410)
Net cash used in investing activities	(1,086,784)	(478,848)
Financing Activities
Payments on secured debt	(222,767)	(99,745)
Proceeds from the issuance of secured debt	30,542	62,833
Proceeds from the issuance of unsecured debt	296,964	149,190
Payments on unsecured debt	(264,829)	(79,488)
Net proceeds/(repayment) of revolving bank debt	330,250	(76,700)
Payment of financing costs	(4,192)	(5,040)
Issuance of common and restricted stock, net	3,832	4,680
Proceeds from the issuance of common shares through public offering, net	864,310	467,783
Payments from the repurchase of Series G preferred stock, net	(3,597)	(637)
Distributions paid to non-controlling interests	(8,717)	(3,069)
Distributions paid to preferred stockholders	(7,003)	(7,119)
Distributions paid to common stockholders	(106,934)	(87,207)
Net cash provided by/(used in) financing activities	907,859	325,481
Net increase in cash and cash equivalents	3,996	4,122
Cash and cash equivalents, beginning of period	9,486	5,985
Cash and cash equivalents, end of period	13,482	10,107
Supplemental Information:
Interest paid during the period, net of amounts capitalized	128,021	120,424
Non-cash transactions:
Real estate acquired in asset exchange	268,853
Real estate disposed in asset exchange	192,576
Contingent consideration accrued in business combination	3,000
OP Units issued in partial consideration for property acquisition	111,034
Secured debt assumed in the acquisitions of properties, including asset exchange	247,805	91,442
Secured debt transferred in asset exchange	55,356
Fair market value of secured debt assumed in acquisitions of properties, including asset exchange	26,880	1,820
Non-cash consideration to acquire non-real estate asset	6,864
Issuance of restricted stock awards	6	16
Fair market value of land contributed by non-controlling interest	4,078
Conversion of operating partnership non-controlling interests to common stock (4,453 shares in 2011 and 445,560 shares in 2010)	109	8,320
Retirement of fully depreciated assets		$ 8,680