Note 15 - Fair Value Measurements and Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Fair Value Measurements, Recurring and Nonrecurring [Table Text Block]

			Fair Value Measurements at December 31, 201 9
	Fair Value at December 31, 201 9		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Recurring
Derivative Warrant Liability	$	8	$	—	$	—	$	8
Nonrecurring
Corn and finished goods inventory	$	940	$	267	$	673	$	—

			Fair Value Measurements at December 31, 201 8
	Fair Value at December 31, 201 8		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Recurring
Derivative Warrant Liability	$	22	$	—	$	—	$	22
2020 Notes Embedded Derivative Liability		394		—		—		394
Total Recurring Fair Value Measurements	$	416	$	—	$	—	$	416
Nonrecurring
Corn and finished goods inventory	$	1,047	$	29	$	1,018	$	—

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

	Fair Value Measurements Using Significant Unobservable Inputs (Level 3) (in thousands)
	Derivative Warrant Liability			2020 Embedded Derivative Liability
Balance, December 31, 2018	$	22		$	394
Total (gains) or losses for the period included in earnings		(14	)		(394	)
Purchases		—			—
Balance, December 31, 2019	$	8		$	—