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, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Continuing Operations:
Income from continuing operations	$ 36,618	$ 29,623	$ 100,128	$ 56,323
Gain on dispositions	1,033	8,163	46,190	30,685
Net income attributable to noncontrolling interests	(1,835)	(1,757)	(3,428)	(3,332)
Dividends on preferred shares	0	(1,120)	0	(3,830)
Redemption costs of preferred shares	0	9,687	0	9,687
Net income attributable to common shareholders - basic	35,816	25,222	142,890	70,159
Income attributable to operating partnership units	0	0	998	0
Net income attributable to common shareholders - diluted	$ 35,816	$ 25,222	$ 143,888	$ 70,159
Denominator:
Weighted average shares outstanding – basic (in shares)	125,791	123,298	124,692	122,715
Effect of dilutive securities:
Share options and awards (in shares)	1,053	1,252	1,136	1,344
Operating partnership units (in shares)	0	0	1,462	0
Weighted average shares outstanding – diluted (in shares)	126,844	124,550	127,290	124,059