Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
OPERATING ACTIVITIES
Net income	$ 138,005	$ 117,374
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization, including discontinued operations	119,885	106,702
Gain on sale of real estate	(28,855)	(11,860)
Income from real estate partnerships	(1,065)	(1,229)
Other, net	2,578	4,236
Changes in assets and liabilities, net of effects of acquisitions and dispositions
Increase in accounts receivable	(10,182)	(2,419)
Increase in prepaid expenses and other assets	(949)	(7,393)
Increase in accounts payable and accrued expenses	4,906	5,217
Increase (decrease) in security deposits and other liabilities	2,405	(1,473)
Net cash provided by operating activities	226,728	209,155
INVESTING ACTIVITIES
Acquisition of real estate	(47,202)	(8,927)
Capital expenditures - development and redevelopment	(156,651)	(92,316)
Capital expenditures - other	(32,200)	(33,700)
Proceeds from sale of real estate	42,866	0
Distribution from real estate partnership in excess of earnings	93	420
Leasing costs	(9,088)	(9,003)
Repayment of mortgage and other notes receivable, net	695	91
Net cash used in investing activities	(201,487)	(143,435)
FINANCING ACTIVITIES
Costs to upsize and extend revolving credit facility	(1,929)	0
Issuance of Senior Notes, net of costs	269,347	244,807
Redemption and retirement of senior notes	(135,000)	(175,000)
Issuance of mortgages, capital leases and notes payable, net of costs	0	5,399
Repayment of mortgages, capital leases and notes payable	(37,375)	(16,312)
Issuance of common shares	118,087	93,668
Dividends paid to common and preferred shareholders	(141,849)	(131,172)
Distributions to and redemptions of noncontrolling interests	(5,679)	(7,236)
Net cash provided by financing activities	65,602	14,154
Increase in cash and cash equivalents	90,843	79,874
Cash and cash equivalents at beginning of year	36,988	67,806
Cash and cash equivalents at end of period	$ 127,831	$ 147,680