Note 3 - Investments (Tables)

6 Months Ended

Jun. 30, 2022

Notes Tables

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

	June 30, 2022
	Amortized		Gross unrealized				Estimated
(In thousands)	Cost		Gains		Losses		Fair Value
Available-for-sale securities, current portion
U.S. government securities	$	10,361	$	-	$	26	$	10,335
Corporate debt securities		11,524		-		8		11,516
Other debt securities		699		-		4		695
Total short-term		22,584		-		38		22,546
Available-for-sale securities, long-term
Other debt securities		491		-		2		489
Total marketable securities	$	23,075	$	-	$	40	$	23,035

	Amortized		Estimated
(In thousands)	Cost		Fair Value
Due in one year or less	$	22,584	$	22,546
Due after one year through five years		491		489
Total	$	23,075	$	23,035