Note 3 - Balance Sheet Detail - Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accrued payroll and related expenses	$ 9,036	$ 7,726
Accrued sales tax	2,373	1,935
Warranty liability	2,461	1,819
Other accrued liabilities	3,527	2,354
Total	$ 17,397	$ 13,834