CONSOLIDATED BALANCE SHEETS (Parenthetical) (Unaudited) - $ / shares	Jun. 30, 2015	Dec. 31, 2014
Shareholders' equity:
Preferred Shares of beneficial interest, par value	$ 0.01	$ 0.01
Preferred Shares of beneficial interest, shares authorized	100,000,000	100,000,000
Preferred Shares of beneficial interest, shares issued	803,600	1,000,000
Preferred Shares of beneficial interest, shares outstanding	803,600	1,000,000
Common Shares of beneficial interest, par value	$ 0.01	$ 0.01
Common Shares of beneficial interest, shares authorized	1,000,000,000	1,000,000,000
Common Shares of beneficial interest, shares issued	364,050,890	362,855,454
Common Shares of beneficial interest, shares outstanding	364,050,890	362,855,454