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

9 Months Ended

Sep. 30, 2022

Notes Tables

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

	September 30, 2022
	(in thousands)
	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value		Short-term investments		Long-term investments
Commercial Paper	$	18,869	$	-	$	(85	)	$	18,784	$	18,784	$	-
Corporate Bonds		55,407		-		(768	)		54,639		53,697		942
U.S. Government Agencies		999		-		(4	)		995		-		995
Total Investments	$	75,275	$	-	$	(857	)	$	74,418	$	72,481	$	1,937

	December 31, 2021
	(in thousands)
	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value		Short-term investments		Long-term investments
Commercial 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

Investments Classified by Contractual Maturity Date [Table Text Block]

	September 30, 2022
	(in thousands)
	Amortized Cost		Fair Value
Mature in less than one year	$	73,303	$	72,481
Mature in one to two years		1,972		1,937
Total	$	75,275	$	74,418