Note 8 - Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2022

Notes Tables

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

	December 31, 2022
(in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
U.S. government agency securities	$	25,275	$	-	$	(750	)	$	24,525
Corporate debt securities		9,578		-		(205	)		9,373
U.S. municipal securities		15,574		-		(417	)		15,157
Certificates of deposit/time deposits		939		-		(7	)		932
Total marketable securities	$	51,366	$	-	$	(1,379	)	$	49,987

	December 31, 2021
(in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
U.S. government agency securities	$	2,500	$	-	$	(12	)	$	2,488
Corporate debt securities		9,303		-		(44	)		9,259
U.S. municipal securities		12,549		-		(70	)		12,479
Certificates of deposit/time deposits		1,687		7		-			1,694
Total marketable securities	$	26,039	$	7	$	(126	)	$	25,920

Investments Classified by Contractual Maturity Date [Table Text Block]

	December 31,
(in thousands)	2022
Due in one year or less	$	23,568
Due after one year through five years		26,419
Total marketable securities	$	49,987