Note 8 - Stockholders' Equity and Stock-based Compensation Expense (Tables)

3 Months Ended

Mar. 31, 2020

Notes Tables

Share-based Payment Arrangement, Option, Activity [Table Text Block]

			Options Outstanding
	Shares Available for Grant		Number of Stock Options Outstanding		Weighted- Average Exercise Price
Balance, December 31, 201 9		761,705		295,699	$	25.52
Stock awards granted		(434,797)		-		-
Options exercised		-		(22,291)		8.98
Options canceled		19,560		(19,560)		43.91
Stock awards canceled		343,911		-		-
Balance, March 31, 20 20		690,379		253,848	$	25.55

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Three Months Ended
	March 31,
	20 20		201 9
Cost of revenue	$	290	$	269
Sales and marketing		719		718
Research and development		321		263
General and administrative		650		57
Total stock-based compensation expense	$	1,980	$	1,307