Earnings Per Share (Components Of Earnings Per Common Share - Basic And Diluted) (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Continuing Operations:
Income from continuing operations	$ 36,195	$ 35,894	$ 109,037	$ 93,496
Gain on Sale of Property	17,079	38,579	173,077	86,566
Net income attributable to noncontrolling interests	(10,293)	(1,844)	(14,020)	(12,755)
Net income attributable to common shareholders - basic	42,981	72,629	268,094	167,307
Income attributable to operating partnership units	0	515	1,584	1,567
Net income attributable to common shareholders - diluted	$ 42,981	$ 73,144	$ 269,678	$ 168,874
Denominator:
Weighted average shares outstanding – basic (in shares)	127,525	127,801	127,651	127,734
Effect of dilutive securities:
Share options and awards (in shares)	792	844	809	877
Operating partnership units (in shares)	0	1,432	1,432	1,450
Weighted average shares outstanding – diluted (in shares)	128,317	130,077	129,892	130,061