Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
OPERATING ACTIVITIES
Net income	$ 167,608	$ 156,232	$ 149,612
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization, including discontinued operations	161,099	142,039	126,568
Gain on sale of real estate	(28,855)	(11,860)	(15,075)
Gain on deconsolidation of VIE	0	0	(2,026)
Early extinguishment of debt	13,304	0	(296)
Income from real estate partnerships	(1,498)	(1,757)	(1,808)
Other, net	2,704	4,348	3,871
Changes in assets and liabilities, net of effects of acquisitions and dispositions
Increase (decrease) in accounts receivable	(6,321)	7,332	1,888
Decrease (increase) in prepaid expenses and other assets	69	(7,793)	2,613
Increase (decrease) in accounts payable and accrued expenses	5,325	3,259	(14,994)
Increase (decrease) in security deposits and other liabilities	1,063	4,833	(5,642)
Net cash provided by operating activities	314,498	296,633	244,711
INVESTING ACTIVITIES
Acquisition of real estate	(87,276)	(80,865)	(103,557)
Capital expenditures - development and redevelopment	(243,073)	(129,346)	(91,922)
Capital expenditures - other	(47,069)	(51,325)	(50,540)
Proceeds from sale of real estate	42,866	0	23,695
Investment in real estate partnerships	0	0	(6,947)
Distribution from real estate partnership in excess of earnings	790	1,116	1,070
Distribution from sale of real estate partnership properties	0	0	34,617
Leasing costs	(12,393)	(14,233)	(12,415)
Repayment of mortgage and other notes receivable, net	957	1,095	9,630
Net cash used in investing activities	(345,198)	(273,558)	(196,369)
FINANCING ACTIVITIES
Net repayments under revolving credit facility, net of costs	(1,929)	0	(81,159)
Issuance of senior notes, net of costs	564,389	244,807	0
Purchase and retirement of senior notes/debentures	(293,360)	(175,000)	(75,000)
Issuance of mortgages, capital leases and notes payable, net of costs	860	5,399	272,193
Repayment of mortgages, capital leases and notes payable	(173,735)	(53,414)	(91,952)
Issuance of common shares	186,548	112,270	154,921
Dividends paid to common and preferred shareholders	(193,016)	(178,020)	(167,313)
Distributions to and redemptions of noncontrolling interests	(7,118)	(9,935)	(8,023)
Net cash provided by (used in) financing activities	82,639	(53,893)	3,667
Increase (decrease) in cash and cash equivalents	51,939	(30,818)	52,009
Cash and cash equivalents at beginning of year	36,988	67,806	15,797
Cash and cash equivalents at end of period	$ 88,927	$ 36,988	$ 67,806