Significant Agreements - Additional Information (Detail) gal in Thousands		1 Months Ended								3 Months Ended		6 Months Ended		12 Months Ended
	Aug. 22, 2015 Boe	Jan. 31, 2016 Boe Plant	Jun. 30, 2015 USD ($) bu	Sep. 30, 2013 Boe	May 31, 2013 Boe	Mar. 31, 2013 Boe	Sep. 30, 2012 Boe	Nov. 30, 2011 USD ($)	Sep. 30, 2011 Boe	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) gal	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	May 31, 2014 USD ($)
Parties To Contract [Line Items]
Production, barrels of oil equivalents | Boe				20,000		3,650
Hydrocarbon revenue										$ 713,000	$ 740,000	$ 1,011,000	$ 1,257,000
Increase decrease in production barrels of oil equivalents | Boe					12,500
Minimum | BCD Chemie
Parties To Contract [Line Items]
Value of purchase orders										1,000,000		$ 1,000,000
Maximum
Parties To Contract [Line Items]
Production, barrels of oil equivalents | Boe							45,000		11,000
Ethanol Marketing Agreement with Subsidiary of Mansfield Oil Company
Parties To Contract [Line Items]
Terms of agreement												The ethanol purchase and marketing agreement with C&N was entered into in April 2009 and automatically renews for subsequent one-year terms unless either party terminates the agreement 60 days before the end of a term.
Supply Agreement with Musket Corporation | Minimum
Parties To Contract [Line Items]
Railcar capacity of isobutanol | gal												28
Supply Agreement with Musket Corporation | Maximum
Parties To Contract [Line Items]
Railcar capacity of isobutanol | gal												29
ATJ Fuel
Parties To Contract [Line Items]
Hydrocarbon revenue												$ 0		$ 1,000,000	$ 2,000,000	$ 1,900,000	$ 600,000
Joint Research Development License and Commercialization Agreement with Coca-Cola Company
Parties To Contract [Line Items]
Agreement term								3 years
Revenue recognized under agreement								$ 2,600,000
Licensing Agreement with Porta
Parties To Contract [Line Items]
Number of additional isobutanol plants | Plant		3
Licensing Agreement with Porta | Maximum
Parties To Contract [Line Items]
Expected production capacity | Boe		5,000,000
Patent Cross-License Agreement with Butamax Advanced Biofuels, LLC
Parties To Contract [Line Items]
Production and sale, barrels of oil equivalents | Boe	30,000,000
Negotiation to sell, barrels of oil equivalents | Boe	15,000,000
Toray Industries
Parties To Contract [Line Items]
Amount received for Pilot Plant										$ 1,000,000		$ 1,000,000
Amount refund from Pilot Plant																		$ 1,000,000
Origination Agreement
Parties To Contract [Line Items]
Agreement term			1 year
Storage bins to store corn grains, bu | bu			700,000
Automatic renewal term			18 months
Agreement to pay to agri energy, per year			$ 175,000								$ 175,000		$ 175,000