Note 5 - Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2021

Notes Tables

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

		December 31, 2021							December 31, 2020
	Fair Value Level1	Adjusted Cost		Gross Unrealized Losses			Fair Value		Adjusted Cost		Gross Unrealized Losses			Fair Value
Money market funds	Level 1	$	20,711	$	—		$	20,711	$	21,042	$	—		$	21,042
Time deposits	Level 2		—		—			—		5,458		—			5,458
Government and municipal debt securities	Level 2		14,006		(2	)		14,004		30,280		(5	)		30,275
Corporate debt securities	Level 2		31,863		(16	)		31,847		11,621		(6	)		11,615
Total investments		$	66,580	$	(18	)	$	66,562	$	68,401	$	(11	)	$	68,390