Note 3 - Balance Sheet Detail - Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accrued payroll and related expenses	$ 9,377	$ 12,567
Sales and marketing accruals	2,379	3,710
Accrued sales tax	2,935	2,920
Warranty liability	4,666	3,508
Other accrued liabilities	3,943	4,143
Total	$ 23,300	$ 26,848