Common Stock - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended
	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2010	Jan. 23, 2013 Archer Daniels Midland Company Subsequent Event	Jun. 02, 2011 IPO	Jun. 02, 2011 Redeemable convertible preferred stock	Jun. 02, 2011 Series B preferred stock
Common Stock Disclosure [Line Items]
Shares issued for initial public offering, net of offering costs	12,021,250
Common stock issuance price					$ 18.00
Proceeds from the issuance of common stock in initial public offering	$ 201,236,000
Underwriting discounts and commissions	15,100,000
Initial public offering costs	$ 4,295,000
Conversion of redeemable convertible preferred stock at initial public offering, shares						34,534,125	303,855
Common stock, shares authorized	150,000,000	150,000,000	60,000,000
Common stock, par value	$ 0.001	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Percentage of stockholder vote required for adoption, amendment or repeal	66.6667%
Common stock issued pursuant to collaboration agreement				347,483