Note 4 - Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2023

Notes Tables

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

		September 30, 2023							December 31, 2022
	Fair Value Level1	Adjusted Cost		Gross Unrealized Losses			Fair Value		Adjusted Cost		Gross Unrealized Losses			Fair Value
Money market funds	Level 1	$	19,102	$	—		$	19,102	$	2,143	$	—		$	2,143
Government and municipal debt securities	Level 2		5,625		—			5,625		6,759		—			6,759
Corporate debt securities	Level 2		24,144		(7	)		24,137		47,947		(16	)		47,931
Total investments		$	48,871	$	(7	)	$	48,864	$	56,849	$	(16	)	$	56,833