Note 4 - Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2023

Notes Tables

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

		March 31, 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	$	7,622	$	—		$	7,622	$	2,143	$	—		$	2,143
Government and municipal debt securities	Level 2		—		—			—		6,759		—			6,759
Corporate debt securities	Level 2		47,547		(19	)		47,528		47,947		(16	)		47,931
Total investments		$	55,169	$	(19	)	$	55,150	$	56,849	$	(16	)	$	56,833