Note 10 - Interest and Other Income, Net (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Schedule of Other Nonoperating Income (Expense) [Table Text Block]

	Year Ended December 31,
	2019			2018			2017
Interest income	$	7,305		$	6,321		$	5,353
Amortization of premium on available-for-sale securities		(729	)		(1,353	)		(1,976	)
Gain (loss) on deferred compensation plan investments		3,806			(1,022	)		2,531
Foreign currency exchange gain (loss)		(310	)		953			(550	)
Other		486			95			162
Total	$	10,558		$	4,994		$	5,520