Earnings Per Share (Schedule Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended													12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	[1]	Jun. 30, 2016	[1]	Mar. 31, 2016	[1]	Dec. 31, 2015	[1]	Sep. 30, 2015	Jun. 30, 2015	[1]	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Income from continuing operations														$ 226,425	$ 190,094	$ 167,888
Less: Preferred share dividends														(541)	(541)	(541)
Less: Income from continuing operations attributable to noncontrolling interests														7,648	8,205	7,754
Less: Earnings allocated to unvested shares														(702)	(797)	(1,003)
Income from continuing operations available for common shareholders														217,534	180,551	158,590
Gain on sale of real estate and change in control of interests, net														31,133	28,330	4,401
Net income available for common shareholders, basic and diluted														$ 248,667	$ 208,881	$ 162,991
Weighted average common shares outstanding—basic														70,877	68,797	67,322
Stock options														172	184	170
Weighted average common shares outstanding—diluted														71,049	68,981	67,492
Continuing operations														$ 3.07	$ 2.63	$ 2.35
Gain on sale of real estate and change in control of interests, net														0.44	0.41	0.07
EARNINGS PER COMMON SHARE, BASIC	$ 0.81	$ 0.82		$ 0.79		$ 1.10		$ 0.98		$ 0.75	$ 0.63		$ 0.67	3.51	3.04	2.42
Continuing operations														3.06	2.62	2.34
Gain on sale of real estate and change in control of interests, net														0.44	0.41	0.07
EARNINGS PER COMMON SHARE, DILUTED	$ 0.80	$ 0.82		$ 0.78		$ 1.10		$ 0.97		$ 0.75	$ 0.63		$ 0.67	$ 3.50	$ 3.03	$ 2.41
Income from continuing operations attributable to the Trust														$ 218,777	$ 181,889	$ 160,134

[1] (1)First quarter 2016 includes a $25.7 million gain on change in control of interests from our Clarion Partners acquisition as further discussed in Note 3. Third quarter 2016 includes a $4.9 million gain on sale from the reversal of our warranty reserve on condominiums sold at Santana Row as further discussed in Note 9. Second and fourth quarter 2015 include an $11.5 million and $16.8 million gain on sale, respectively, from our Houston Street and Courtyard Shops properties as further discussed in Note 3.