Significant Agreements - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended								3 Months Ended		12 Months Ended	1 Months Ended			3 Months Ended
	Dec. 31, 2013 Boe	Sep. 30, 2013 Boe	May 31, 2013 Boe	Mar. 31, 2013 Boe	Sep. 30, 2012 Boe	Sep. 30, 2011 Boe	Aug. 31, 2011	Mar. 31, 2010	Mar. 31, 2014 Installment	Mar. 31, 2013	Dec. 31, 2009	Jul. 31, 2011 Sasol	Aug. 31, 2011 Mansfield	Aug. 31, 2011 C And N	Mar. 31, 2014 Ethanol Marketing Agreement with Subsidiary of Mansfield Oil Company	Mar. 31, 2014 Development and Commercialization Agreements with ICM Inc	Mar. 31, 2014 Cargill License Agreement
Parties To Contract [Line Items]
Agreement term												3 years	5 years	3 years
Terms of agreement															The ethanol purchase and marketing agreement with C&N was entered into on April 1, 2009 and automatically renews for subsequent one-year terms unless either party terminates the agreement 60 days before the end of a term.	In December 2011, the development agreement was amended to extend the term indefinitely. The development agreement, as amended, may be cancelled by either party with 30 days’ prior written notice.	The Company may terminate the license agreement at any time upon 90 days’ prior written notice. Unless terminated earlier, the license agreement remains in effect until the later of December 31, 2025 and the date that no licensed patent rights remain.
Production, barrels of oil Equivalents	10,000	20,000	12,500	3,650	45,000	11,000
Revenue from contract									$ 0.4	$ 0.4
Commercialization Agreement Period							2018-10
Revenue recognized under agreement									0	0.3
Milestone payment									5
Royalty expense								2.0	4.3		0.9
Present value of license fee								1.6
Royalty fee payable									1.0
Royalty fee payable, due date									2015-12
License fees									0.5
Common stock shares issued	68,492,894			250,000					68,858,219	250,000
Amount received for pilot plant									1.0
Amount refund from pilot plant									1.0
Refund amount as component of other long term liabilities									$ 1.0