Quarterly report pursuant to Section 13 or 15(d)

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)

v3.7.0.1
CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares
Mar. 31, 2017
Dec. 31, 2016
Statement of Financial Position [Abstract]    
Common shares of beneficial interest, par value (in dollars per share) $ 0.01 $ 0.01
Common shares of beneficial interest, authorized (in shares) 250,000,000 250,000,000
Common shares of beneficial interest, issued (in shares) 44,202,780 43,110,362
Common shares of beneficial interest, outstanding (in shares) 44,202,780 43,110,362