Note 12 - Income Taxes - Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
U.S. statutory federal tax rate	21.00%	21.00%	21.00%
Foreign income at lower rates	(23.20%)	(15.20%)	(20.70%)
GILTI	11.40%	11.10%	11.00%
Changes in valuation allowance	0.50%	1.60%	2.10%
Stock-based compensation	1.60%	(11.20%)	(1.50%)
Tax credits, net of reserves	(1.10%)	(3.80%)	(6.20%)
State income taxes	(0.50%)	(1.60%)	(0.70%)
Other adjustments	1.40%	1.00%	(1.20%)
Effective tax rate	11.10%	2.90%	3.80%