Condensed Consolidated Statements Of Equity (USD $)		Total	Preferred Shares Of Beneficial Interest [Member]	Common Shares Of Beneficial Interest [Member]	Additional Paid-In Capital [Member]	Net Income Less Than Accumulated Dividends [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2012		$ 1,740,155,000	$ 7,000	$ 3,663,000	$ 1,934,183,000	$ (335,980,000)	$ (24,743,000)	$ 163,025,000
Increase (Decrease) in Equity [Roll Forward]
Net Income		211,384,000				170,328,000		41,056,000
Redemption of preferred shares		(275,000,000)	(5,000)		(257,051,000)	(17,944,000)
Shares issued under benefit plans		12,493,000		20,000	12,473,000
Dividends declared - common shares	[1]	(111,509,000)				(111,509,000)
Dividends declared - preferred shares	[2]	(14,760,000)				(14,760,000)
Distributions to noncontrolling interests		(13,455,000)						(13,455,000)
Contributions from noncontrolling interests		33,884,000						33,884,000
Other comprehensive income		9,596,000					9,596,000
Other, net		1,501,000			1,082,000	(703,000)		1,122,000
Balance at Sep. 30, 2013		1,594,289,000	2,000	3,683,000	1,690,687,000	(310,568,000)	(15,147,000)	225,632,000
Balance at Dec. 31, 2013		1,687,978,000	2,000	3,683,000	1,679,229,000	(300,537,000)	(4,202,000)	309,803,000
Increase (Decrease) in Equity [Roll Forward]
Net Income		203,964,000				199,028,000		4,936,000
Shares issued under benefit plans		9,687,000		10,000	9,677,000
Dividends declared - common shares	[1]	(119,163,000)				(119,163,000)
Dividends declared - preferred shares	[2]	(7,314,000)				(7,314,000)
Distributions to noncontrolling interests		(5,939,000)						(5,939,000)
Contributions from noncontrolling interests		980,000						980,000
Acquisition of noncontrolling interests		0			11,015,000			(11,015,000)
Disposition of noncontrolling interests		(144,263,000)						(144,263,000)
Other comprehensive income		1,824,000					1,824,000
Other, net		(506,000)			499,000	(816,000)		(189,000)
Balance at Sep. 30, 2014		$ 1,627,248,000	$ 2,000	$ 3,693,000	$ 1,700,420,000	$ (228,802,000)	$ (2,378,000)	$ 154,313,000

[1] Common dividend per share was $.98 and $.92 for the nine months ended September 30, 2014 and 2013, respectively.

[2] Series D preferred dividend per share was $13.08 for the nine months ended September 30, 2013. Series F preferred dividend per share was $121.88 and $119.62 for the nine months ended September 30, 2014 and 2013, respectively.