Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 39,885	$ 36,551
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	71,662	63,273
Net amortization of deferred finance costs and debt premiums	1,586	2,071
Net amortization of intangible lease assets and liabilities	(314)	272
Gain on sales of real estate assets	(543)	(587)
Gain on sale of discontinued operations	(781)	(911)
Write-off of development projects	2	(124)
Share-based compensation expense	1,464	1,275
Loss on impairment of real estate from discontinued operations	0	293
Equity in earnings of unconsolidated affiliates	(2,619)	(1,266)
Distributions of earnings from unconsolidated affiliates	4,465	3,167
Provision for doubtful accounts	698	668
Change in deferred tax accounts	2,661	2,823
Changes in:
Tenant and other receivables	102	8,236
Other assets	0	756
Accounts payable and accrued liabilities	(50,763)	(24,675)
Net cash provided by operating activities	67,505	91,822
CASH FLOWS FROM INVESTING ACTIVITIES:
Additions to real estate assets	(42,567)	(42,862)
Reductions to restricted cash	1,697	15,067
Proceeds from sales of real estate assets	44,328	35,547
Payments received on mortgage and other notes receivable	3,630	599
Proceeds from sales of available-for-sale securities	(11,002)
Additional investments in and advances to unconsolidated affiliates	(20,588)	(3,908)
Distributions in excess of equity in earnings of unconsolidated affiliates	4,343	3,741
Changes in other assets	(1,816)	(746)
Net cash provided by investing activities	29	7,438
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from mortgage and other indebtedness	247,209	581,791
Principal payments on mortgage and other indebtedness	(307,697)	(611,382)
Additions to deferred financing costs	(651)	(1,105)
Proceeds from issuances of common stock	43,869	42
Proceeds from exercises of stock options	0	1,334
Purchase of noncontrolling interest in the Operating Partnership	0	(6,359)
Contributions from noncontrolling interests	0	285
Distributions to noncontrolling interests	(15,224)	(16,539)
Dividends paid to holders of preferred stock	(11,223)	(10,594)
Dividends paid to common shareholders	(35,485)	(31,156)
Net cash used in financing activities	(79,202)	(93,683)
NET CHANGE IN CASH AND CASH EQUIVALENTS	(11,668)	5,577
CASH AND CASH EQUIVALENTS, beginning of period	78,248	56,092
CASH AND CASH EQUIVALENTS, end of period	66,580	61,669
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	$ 57,775	$ 57,054