Earnings Per Share (Components Of Earnings Per Common Share - Basic And Diluted) (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Continuing Operations:
Income from continuing operations	$ 20,633	$ 63,510
Gain on dispositions	15,763	45,157
Net income attributable to noncontrolling interests	(5,570)	(1,593)
Net income attributable to common shareholders - basic	30,826	107,074
Income attributable to operating partnership units	0	499
Net income attributable to common shareholders - diluted	$ 30,826	$ 107,573
Denominator:
Weighted average shares outstanding – basic (in shares)	127,610	123,593
Effect of dilutive securities:
Share options and awards (in shares)	938	1,216
Operating partnership units (in shares)	0	1,462
Weighted average shares outstanding – diluted (in shares)	128,548	126,271