CONSOLIDATED BALANCE SHEETS [Parenthetical] (USD $)
Mar. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Common stock, par value (in dollars per share) $ 0.00005 $ 0.00005 $ 0.00005
Common stock, shares Authorized 800,000,000 800,000,000 800,000,000
Common stock, shares Issued 151,854,176 150,085,035 126,444,309
Common stock, shares outstanding 151,854,176 150,085,035 126,444,309