Note 13 - Stock-based Compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Allocated share-based compensation expense	$ 19,095	$ 14,673	$ 10,781
Cost of Sales [Member]
Allocated share-based compensation expense	2,595	2,451	2,056
Selling and Marketing Expense [Member]
Allocated share-based compensation expense	3,736	3,121	2,632
Research and Development Expense [Member]
Allocated share-based compensation expense	2,833	2,440	1,851
General and Administrative Expense [Member]
Allocated share-based compensation expense	9,931	6,661	4,242
Stock Options, Restricted Stock, and Other [Member]
Allocated share-based compensation expense	17,553	13,327	9,591
ESPP [Member]
Allocated share-based compensation expense	$ 1,542	$ 1,346	$ 1,190