Earnings Per Share (Components Of Earnings Per Common Share - Basic And Diluted) (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Continuing Operations:
Income from continuing operations	$ 36,969	$ 36,618	$ 57,602	$ 100,128
Gain on Sale of Property	32,224	1,033	47,987	46,190
Net income attributable to noncontrolling interests	(5,341)	(1,835)	(10,911)	(3,428)
Net income attributable to common shareholders - basic	63,852	35,816	94,678	142,890
Income attributable to operating partnership units	526	0	0	998
Net income attributable to common shareholders - diluted	$ 64,378	$ 35,816	$ 94,678	$ 143,888
Denominator:
Weighted average shares outstanding – basic (in shares)	127,788	125,791	127,700	124,692
Effect of dilutive securities:
Share options and awards (in shares)	848	1,053	894	1,136
Operating partnership units (in shares)	1,459	0	0	1,462
Weighted average shares outstanding – diluted (in shares)	130,095	126,844	128,594	127,290