Consolidated Statements of Equity (Parenthetical)	1 Months Ended		12 Months Ended			0 Months Ended
	Nov. 30, 2014	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jul. 16, 2013	Dec. 31, 2011
Balance (in units/ shares)			93,255,284	87,394,512	80,952,986		72,011,324
Conversion of common units to common shares (in shares/units)			140,149	311,343	234,246
Shares issued to the public (in units/shares)	5,520,000	4,485,000
Exercise of share options (in units/shares)			62,888	39,331	61,624
Restricted common units/shares redemptions			57,537	78,440	139,851
Preferred Shares
Shares issued to the public (in units/shares)					6,900,000
Stock redeemed or called during period (in units/ shares)			(2,000,000)	(3,390,000)	(2,200,000)
Common Shares
Shares issued to the public (in units/shares)			5,520,000	4,485,000	8,625,000
Common Stock Issued to Public Under At-the-Market Program
Shares issued to the public (in units/shares)				1,500,000		1,500,000