Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred tax assets:
Accrued bonuses	$ 39	$ 315
Accrued payroll	49	11
Stock-based compensation	125	14
Federal net operating loss carryover	55,622	62,575
State net operating loss carryover	1,161	1,161
Basis in partnerships	24,773	26,123
Warranty accrual	166	161
Historical BioFuel capitalized start-up costs	24	24
Historical BioFuel - other	16	16
Deferred tax assets, gross	81,975	90,400
Valuation allowance	(1,161)	(1,161)	$ 0
Deferred tax assets, net	80,814	89,239
Deferred tax liabilities:
Prepaid insurance	(34)	(11)
Noncontrolling interests impact of M-1s	(117)	(31)
Deferred tax liabilities, net	$ (151)	$ (42)