Note 4 - Balance Sheet Components - Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
RSU tax withholding proceeds receivable	$ 16,075	$ 12,504
Prepaid expense	10,638	5,032
Accrued interest receivable	4,094	1,914
Assets for product returns	2,059	1,684
Other	1,669	1,846
Total	$ 34,535	$ 22,980