CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2012	Dec. 31, 2011
EQUITY
Preferred Shares, par value (in dollars per share)	$ 0	$ 0
Preferred Shares, authorized (in shares)	1,000,000	1,000,000
Preferred Shares, issued (in shares)	0	0
Common shares, par value (in dollars per share)	$ 0	$ 0
Common shares, authorized (in shares)	75,000,000	75,000,000
Common shares, issued (in shares)	51,183,318	50,321,962
Common shares, outstanding (in shares)	49,383,209	49,035,788
Treasury stock (in shares)	1,800,109	1,286,174