Consolidated Statements of Equity (Parenthetical)	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Consolidated Statements of Equity
Balance (in shares)	66,931,582	58,342,673
Conversion of common units to common shares	83,506	620,598
Common shares issued to the public (in shares)	4,600,000
Exercise of share options	185,714	271,242
Restricted common share redemptions	112,683	103,721
Balance (in shares)	71,986,936	59,406,247