Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
OPERATING ACTIVITIES
Net income	$ 258,883	$ 218,424	$ 172,289
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	193,585	174,796	170,814
Gain on sale of real estate and change in control of interests	32,458	28,330	4,401
Early extinguishment of debt	0	19,072	10,545
Income from real estate partnerships	50	1,416	1,243
Other, net	(89)	177	733
Changes in assets and liabilities, net of effects of acquisitions and dispositions:
Decrease (increase) in accounts receivable, net	1,868	(9,200)	(3,063)
Increase in prepaid expenses and other assets	(5,241)	(7,422)	(4,222)
Increase (decrease) in accounts payable and accrued expenses	4,759	(9,995)	4,253
(Decrease) increase in security deposits and other liabilities	(2,003)	3,729	425
Net cash provided by operating activities	419,254	359,835	346,130
INVESTING ACTIVITIES
Acquisition of real estate	(142,958)	(154,313)	(9,154)
Capital expenditures - development and redevelopment	(379,720)	(236,437)	(314,654)
Capital expenditures - other	(57,560)	(46,096)	(46,304)
Proceeds from sale of real estate	0	97,422	10,406
Investment in real estate partnerships	(7,220)	(2,802)	(6,731)
Distribution from real estate partnership in excess of earnings	3,910	512	565
Leasing costs	(18,299)	(22,382)	(35,286)
Repayment of mortgage and other notes receivable, net	11,626	10,333	5,008
Net cash used in investing activities	(590,221)	(353,763)	(396,150)
FINANCING ACTIVITIES
Net (repayments) borrowings under revolving credit facility, net of costs	(56,916)	53,500	0
Issuance of senior notes, net of costs	241,795	456,151	244,579
Redemption and retirement of senior notes	0	(219,228)	(134,240)
Repayment of mortgages, capital leases, notes, and other payables	(49,559)	(181,315)	(94,422)
Issuance of common shares, net of costs	329,103	110,855	216,155
Dividends paid to common and preferred shareholders	(267,694)	(243,314)	(215,216)
Distributions to and redemptions of noncontrolling interests	(10,422)	(9,626)	(7,812)
Redemption of redeemable noncontrolling interests	13,018	0	0
Net cash provided by (used in) financing activities	173,289	(32,977)	9,044
Increase (decrease) in cash and cash equivalents	2,322	(26,905)	(40,976)
Cash and cash equivalents at beginning of year	21,046	47,951	88,927
Cash and cash equivalents at end of year	$ 23,368	$ 21,046	$ 47,951