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

3 Months Ended

Mar. 31, 2023

Notes Tables

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

	March 31, 2023
	(in thousands)
	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value		Short-term investments		Long-term investments
Commercial Paper	$	5,442	$	-	$	(16	)	$	5,426	$	5,426	$	-
Corporate Bonds		29,459		2		(178	)		29,283		28,325		958
U.S. Treasuries		2,953		-		(1	)		2,952		2,952		-
U.S. Government Agencies		999		-		(5	)		994		994		-
Total Investments	$	38,853	$	2	$	(200	)	$	38,655	$	37,697	$	958

	December 31, 2022
	(in thousands)
	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value		Short-term investments		Long-term investments
Commercial Paper	$	12,364	$	-	$	(49	)	$	12,315	$	12,315	$	-
Corporate Bonds		55,201		-		(447	)		54,754		50,889		3,865
U.S. Government Agencies		999		-		(8	)		991		991		-
Total Investments	$	68,564	$	-	$	(504	)	$	68,060	$	64,195	$	3,865

Investments Classified by Contractual Maturity Date [Table Text Block]

	March 31, 2023
	(in thousands)
	Amortized Cost		Fair Value
Mature in less than one year	$	37,897	$	37,697
Mature in one to two years		956		958
Total	$	38,853	$	38,655