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

6 Months Ended

Jun. 30, 2022

Notes Tables

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

	June 30, 2022
	(in thousands)
	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value		Short-term investments		Long-term investments
Commercial Paper	$	35,643	$	-	$	(191	)	$	35,452	$	35,452	$	-
Corporate Bonds		58,242		-		(753	)		57,489		47,908		9,581
Total Investments	$	93,885	$	-	$	(944	)	$	92,941	$	83,360	$	9,581

	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]

	June 30, 2022
	(in thousands)
	Amortized Cost		Fair Value
Mature in less than one year	$	84,173	$	83,360
Mature in one to two years		9,712		9,581
Total	$	93,885	$	92,941