Note 6 - Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2018

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	)

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, 2017	$	2,387
Unrealized Gains, net		(516	)
Balance at March 31, 2018	$	1,871