Consolidated Statements of Equity (Parenthetical) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Dividends paid or accrued on Common Shares of Beneficial Interest	$ 0.4875	$ 0.4875
Dividends paid or accrued on Series D Preferred Share	$ 1.7344	$ 1.15625
Accumulated Distributions in Excess of Net Income [Member]
Dividends paid or accrued on Common Shares of Beneficial Interest	$ 0.4875	$ 0.4875
Dividends paid or accrued on Series D Preferred Share	$ 1.7344	$ 1.15625