Note 5 - Investments, Available-for-sale (Tables)

12 Months Ended

Dec. 31, 2021

Notes Tables

Debt Securities, Available-for-sale [Table Text Block]

	December 31, 2021
	(in thousands)
	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value		Short-term investments		Long-term investments
Commerical Paper	$	50,705	$	-	$	(46	)	$	50,659	$	50,660	$	-
Corporate Bonds		67,239		1		(202	)		67,038		29,602		37,435
Total Investments	$	117,944	$	1	$	(248	)	$	117,697	$	80,262	$	37,435

	Amortized Cost		Fair Value
Mature in less than one year	$	80,336	$	80,262
Mature in one to two years		37,608		37,435
Total	$	117,944	$	117,697