Note 9 - Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

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

	Balance as of		Fair value measurements
Description	December 31, 201 9		Level 1		Level 2		Level 3
Assets
Cash equivalents
Money market mutual funds	$	11,635	$	11,635	$	-	$	-
Short-term marketable securities and time deposits
U.S. GSE securities	$	752	$	-	$	752	$	-
Corporate debt securities	$	23,322	$	-	$	23,322	$	-
Long-term marketable securities
U.S. GSE securities	$	3,710	$	-	$	3,710	$	-
Corporate debt securities	$	59,174	$	-	$	59,174	$	-

	Balance as of		Fair value measurements
Description	December 31, 201 8		Level 1		Level 2		Level 3
Assets
Cash equivalents
Money market mutual funds	$	773	$	773	$	-	$	-
Short-term marketable securities and time deposits
U.S. GSE securities	$	1,785	$	-	$	1,785	$	-
Corporate debt securities	$	25,579	$	-	$	25,579	$	-
Long-term marketable securities
U.S. GSE securities	$	19,512	$	-	$	19,512	$	-
Corporate debt securities	$	50,896	$	-	$	50,896	$	-
Derivative liabilities	$	3	$	-	$	3	$	-