Consolidated Statements Of Equity And Perpetual Preferred Units Consolidated Statements Of Equity and Perpetual Preferred Units (Parentheticals) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Common shares issued	1,751	4,868
Common share options exercised	(504,838)	(141,213)
Conversions and redemptions of operating partnership units	66	279
Cash distributions declared to equity holders per share	$ 1.96	$ 1.80
Additional Paid-In Capital
Common share options exercised	68	41