Subsequent Events (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2012 2010 Non-Employee Directors' Stock Option Plan	Dec. 31, 2012 2010 Employee Stock Purchase Plan	Feb. 04, 2013 Follow-on Offering
Subsequent Events
FInancing proceeds				$ 49.0
Financing shares				4,600,000
Financing price per share				$ 11.40
Current Common Stock Authorized	38,833,334
Pending Common Stock Authorized	75,000,000
Current Shares Reserved		238,095	214,285
Pending Shares Reserved		400,000	400,000