Note 4 - Balance Sheet Detail - Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Accrued payroll and related expenses	$ 11,842	$ 14,341
Sales and marketing accruals	1,581	2,527
Warranty liability	3,398	4,401
Sales tax	1,443	3,922
Other	5,399	5,116
Total	$ 23,663	$ 30,307