Consolidated Balance Sheets (Parenthetical) (USD $)
Mar. 31, 2012
Dec. 31, 2011
Stockholders equity:    
Preferred stock, par value $ 0.0001 $ 0.0001
Preferred stock, authorized shares 5,000,000 5,000,000
Preferred stock, issued shares 0 0
Preferred stock, outstanding shares 0 0
Common stock, par value $ 0.0001 $ 0.0001
Common stock, authorized shares 100,000,000 100,000,000
Common stock, issued shares 77,086,189 76,102,582
Common stock, outstanding shares 77,086,189 76,102,582