Note 4 - Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2022

Notes Tables

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

		September 30, 2022							December 31, 2021
	Fair Value Level1	Adjusted Cost		Gross Unrealized Losses			Fair Value		Adjusted Cost		Gross Unrealized Losses			Fair Value
Money market funds	Level 1	$	10,956	$	—		$	10,956	$	20,711	$	—		$	20,711
Government and municipal debt securities	Level 2		10,658		(2	)		10,656		14,006		(2	)		14,004
Corporate debt securities	Level 2		37,008		(37	)		36,971		31,863		(16	)		31,847
Total investments		$	58,622	$	(39	)	$	58,583	$	66,580	$	(18	)	$	66,562