Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2013	Dec. 31, 2012
Condensed Consolidated Balance Sheets
Preferred shares, authorized	50,000,000	50,000,000
Preferred shares, issued	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, Authorized	200,000,000	200,000,000
Common stock, issued	33,613,832	33,567,730
Common stock, outstanding	33,613,832	33,567,730