Note 3 - Revenue by Product Group, by Significant Customer and by Geographic Region; Geographic Information - Net Tangible Long-lived Assets by Principal Geographic Areas (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property and equipment, net	$ 54,111	$ 56,183
UNITED STATES
Property and equipment, net	51,385	52,828
ITALY
Property and equipment, net	$ 2,726	$ 3,355