Note 7 - Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2019

Notes Tables

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

	Derivatives at Fair Value as of March 31, 2018
(in thousands)	Level 1		Level 2		Level 3			Total
Warrant derivative liabilities		-		-	$	(1,871	)	$	(1,871	)
Total warrant derivative liabilities	$	-	$	-	$	(1,871	)	$	(1,871	)

	Derivatives at Fair Value as of March 31, 201 9
(in thousands)	Level 1		Level 2		Level 3		Total
Warrant derivative liabilities		-		-		-		-
Total warrant derivative liabilities	$	-	$	-	$	-	$	-

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

	Level 3 Liabilities
(in thousands)	Warrant Derivative Liabilities
Balance at December 31, 2018	$	865
Reclassification of warrant liability to additional paid-in capital upon adoption of ASU 2017-11		(865	)
Balance at March 31, 2019	$	-