Collaborative Research and Development Agreements, Government Programs and Licenses - Additional Information (Detail) (USD $)	1 Months Ended				1 Months Ended						12 Months Ended			1 Months Ended		12 Months Ended			12 Months Ended
	Nov. 30, 2011 gal	Nov. 30, 2011 l	Dec. 31, 2012	Dec. 31, 2011	Jan. 31, 2013 Archer Daniels Midland Company Subsequent Event	Nov. 30, 2012 Collaboration Agreement Mg	Jul. 31, 2011 Unilever	Mar. 31, 2011 Unilever	Sep. 30, 2011 Department of defense Phase 1 gal	Sep. 30, 2011 Department of defense Phase 1 l	Dec. 31, 2012 Department of defense Phase 1	Dec. 31, 2011 Department of defense Phase 1	Sep. 30, 2010 Department of defense Phase 1	Aug. 31, 2011 Department of defense Phase 2 gal	Aug. 31, 2011 Department of defense Phase 2 l	Dec. 31, 2012 Department of defense Phase 2	Dec. 31, 2011 Department of defense Phase 2	Sep. 30, 2010 Department of defense Phase 2	Dec. 31, 2012 Department of energy	Dec. 31, 2011 Department of energy	Dec. 31, 2009 Department of energy
Collaboration Agreements [Line Items]
Proceeds from collaborative R & D agreement							$ 750,000	$ 750,000
Research and Development Contract Price							1,500,000						5,600,000					4,600,000
Delivered diesel fuel under contract									75,000	283,906				75,000	283,906
Current DoD contract, revenues											0	1,100,000				700,000	3,900,000
Unbilled revenue			3,150,000	3,889,000							0	0				0	2,200,000		2,100,000	1,700,000
Deferred revenue balances											0	0				0	0		0	0
Funds awarded to partially fund an integrated biorefinery																					21,800,000
Company recognized revenues																			$ 9,200,000	$ 7,000,000
Renewable fuels	450,000	1,703,000
Jet fuel	100,000	379,000
Marine distillate fuel	350,000	1,325,000
Warrants to purchase number of common stock					500,000
Warrant vesting period					5 years
Initial production capacity per year						20,000
Initial expansion production capacity per year						40,000
Expanded production capacity per year						100,000