Earnings Per Share (Components Of Earnings Per Common Share - Basic And Diluted) (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Numerator:
Net income	$ 345,343	$ 350,715	$ 276,831
Net income attributable to noncontrolling interests	(17,742)	(15,441)	(37,898)
Net income attributable to common shareholders – basic	327,601	335,274	238,933
Income attributable to operating partnership units	0	3,084	1,996
Net income attributable to common shareholders – diluted	$ 327,601	$ 338,358	$ 240,929
Denominator:
Weighted average shares outstanding – basic (in shares)	127,651	127,755	126,048
Effect of dilutive securities:
Share options and awards (in shares)	790	870	1,059
Operating partnership units (in shares)	0	1,446	1,462
Weighted average shares outstanding - diluted (in shares)	128,441	130,071	128,569