Note 6 - Fair Value of Financial Measurements (Tables)

3 Months Ended

Mar. 31, 2017

Notes Tables

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

	Fair Value		Fair value measurement using
	March 31,
(in thousands)	2017		Level 1		Level 2		Level 3
Assets:
Cash and cash equivalents	$	8,022	$	8,022	$	-	$	-
Certificate of deposit		225		225		-		-
Total Assets	$	8,247	$	8,247	$	-	$	-

	Fair Value		Fair value measurement using
	December 31,
(in thousands)	2016		Level 1		Level 2		Level 3
Assets:
Cash and cash equivalents	$	5,588	$	5,588	$	-	$	-
Certificate of deposit		225		225		-		-
Total Assets	$	5,813	$	5,813	$	-	$	-

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

(in thousands)
Balance at January 1, 2016	$	223
Change in fair value of common stock warrant liability		(223	)
Balance at March 31, 2016	$	-