Note 8 - Marketable Securities (Tables)

9 Months Ended

Sep. 30, 2022

Notes Tables

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

	September 30, 2022
(in thousands)	Cost		Unrealized Gains		Unrealized Losses			Fair Value
U.S. municipal securities	$	17,991	$	-	$	(494	)	$	17,497
Corporate debt securities		9,602		-		(259	)		9,343
U.S. government agency securities		25,780		-		(787	)		24,993
Certificates of deposit/time deposits		1,189		-		(11	)		1,178
Commercial paper		1,500		-		(1	)		1,499
Total marketable securities	$	56,062	$	-	$	(1,552	)	$	54,510

Debt Securities, Held-to-Maturity [Table Text Block]

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

Investments Classified by Contractual Maturity Date [Table Text Block]

	September 30,
(in thousands)	2022
Due in one year or less	$	25,253
Due after one year through five years		29,257
Total marketable securities	$	54,510