Earnings Per Share (Schedule Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
INCOME FROM CONTINUING OPERATIONS	$ 57,111	$ 34,164	$ 110,448	$ 82,367
Less: Preferred share dividends	(135)	(135)	(271)	(271)
Less: Net income attributable to noncontrolling interests	1,871	2,041	3,979	4,058
Less: Earnings allocated to unvested shares	(156)	(207)	(364)	(417)
Income from continuing operations available for common shareholders	54,949	31,781	105,834	77,621
Gain on change in control of interests and sale of real estate, net	701	11,509	26,427	11,509
Net income available for common shareholders, basic and diluted	$ 55,650	$ 43,290	$ 132,261	$ 89,130
Weighted average common shares outstanding—basic	70,797	68,531	70,270	68,449
Stock options	177	182	181	189
Weighted average common shares outstanding—diluted	70,974	68,713	70,451	68,638
Continuing operations	$ 0.78	$ 0.46	$ 1.50	$ 1.13
Gain on change in control of interests and sale of real estate, net	0.01	0.17	0.38	0.17
Earnings per common share, basic	0.79	0.63	1.88	1.30
Continuing operations	0.77	0.46	1.50	1.13
Gain on change in control of interests and sale of real estate, net	0.01	0.17	0.38	0.17
Earnings per common share, diluted	$ 0.78	$ 0.63	$ 1.88	$ 1.30
Income from continuing operations attributable to the Trust	$ 55,240	$ 32,123	$ 106,469	$ 78,309