Note 8 - Marketable Securities (Tables)

9 Months Ended

Sep. 30, 2023

Notes Tables

Marketable Securities [Table Text Block]

	September 30, 2023
(In thousands)	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
Marketable securities
Corporate, municipal debt and treasury securities	$	5,109	$	56	$	(18	)	$	5,147

Investments Classified by Contractual Maturity Date [Table Text Block]

	September 30, 2023				December 31, 2022
(In thousands)	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due within one year	$	2,012	$	2,048	$	1,594	$	1,602
Due after one year through three years		3,097		3,099		3,356		3,371
Total	$	5,109	$	5,147	$	4,950	$	4,973