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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Continuing Operations:
Income from continuing operations	$ 39,229	$ 31,956	$ 139,357	$ 88,279
Gain on dispositions	22,108	13,232	68,298	43,917
Net income attributable to noncontrolling interests	(9,436)	(1,787)	(12,864)	(5,119)
Dividends on preferred shares	0	0	0	(3,830)
Redemption costs of preferred shares	0	0	0	9,687
Net income attributable to common shareholders - basic	51,901	43,401	194,791	113,560
Income attributable to operating partnership units	499	472	1,497	0
Net income attributable to common shareholders - diluted	$ 52,400	$ 43,873	$ 196,288	$ 113,560
Denominator:
Weighted average shares outstanding – basic (in shares)	127,304	123,349	125,569	122,929
Effect of dilutive securities:
Share options and awards (in shares)	1,022	1,222	1,100	1,303
Operating partnership units (in shares)	1,462	1,462	1,462	0
Weighted average shares outstanding – diluted (in shares)	129,788	126,033	128,131	124,232