Earnings Per Share (Components Of Earnings Per Common Share - Basic And Diluted) (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator:
Net income	$ 322,575	$ 345,343	$ 350,715
Net income attributable to noncontrolling interests	(7,140)	(17,742)	(15,441)
Net income attributable to common shareholders – basic	315,435	327,601	335,274
Income attributable to operating partnership units	2,112	0	3,084
Net income attributable to common shareholders – diluted	$ 317,547	$ 327,601	$ 338,358
Denominator:
Weighted average shares outstanding – basic (in shares)	127,842	127,651	127,755
Effect of dilutive securities:
Share options and awards (in shares)	842	790	870
Operating partnership units (in shares)	1,432	0	1,446
Weighted average shares outstanding - diluted (in shares)	130,116	128,441	130,071