Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 36,551	$ 63,908
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	63,273	68,067
Net amortization of deferred finance costs and debt premiums	2,071	2,200
Net amortization of intangible lease assets and liabilities	272	(253)
Gain on sales of real estate assets	(587)	(809)
Gain on sale of discontinued operations	(911)	(14)
Write-off of development projects	(124)	0
Share-based compensation expense	1,275	1,073
Net realized loss on sale of available-for-sale securities	0	22
Write down of mortgage and other notes receivable	0	1,500
Loss on impairment of real estate from discontinued operations	293	2,746
Gain on extinguishment of debt	0	(581)
Gain on extinguishment of debt from discontinued operations	0	(31,434)
Equity in earnings of unconsolidated affiliates	(1,266)	(1,778)
Distributions of earnings from unconsolidated affiliates	3,167	1,459
Provision for doubtful accounts	668	1,422
Change in deferred tax accounts	2,823	(258)
Changes in:
Tenant and other receivables	8,236	6,041
Other assets	756	(1,319)
Accounts payable and accrued liabilities	(24,675)	(33,178)
Net cash provided by operating activities	91,822	78,814
CASH FLOWS FROM INVESTING ACTIVITIES:
Additions to real estate assets	(42,862)	(31,292)
(Additions) reductions to restricted cash	15,067	(5,076)
Proceeds from sales of real estate assets	35,547	10,322
Payments received on mortgage and other notes receivable	599	206
Additional investments in and advances to unconsolidated affiliates	(3,908)	(1,892)
Distributions in excess of equity in earnings of unconsolidated affiliates	3,741	2,500
Changes in other assets	(746)	(1,634)
Net cash used in investing activities	7,438	(26,866)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from mortgage and other indebtedness	581,791	626,353
Principal payments on mortgage and other indebtedness	(611,382)	(619,234)
Additions to deferred financing costs	(1,105)	(3,003)
Proceeds from issuances of common stock	42	48
Proceeds from exercises of stock options	1,334	1,310
Purchase of noncontrolling interest in the Operating Partnership	6,359	0
Contributions from noncontrolling interests	285	0
Distributions to noncontrolling interests	(16,539)	(18,799)
Dividends paid to holders of preferred stock	(10,594)	(10,594)
Dividends paid to common shareholders	(31,156)	(29,585)
Net cash used in financing activities	(93,683)	(53,504)
NET CHANGE IN CASH AND CASH EQUIVALENTS	5,577	(1,556)
CASH AND CASH EQUIVALENTS, beginning of period	56,092	50,896
CASH AND CASH EQUIVALENTS, end of period	61,669	49,340
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	$ 57,054	$ 66,027