Note 7 - Segment, Significant Customers and Geographic Information - Long Lived Assets by Geographic Region (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Long lived assets by region	$ 236,807	$ 228,315
CHINA
Long lived assets by region	119,904	113,888
UNITED STATES
Long lived assets by region	96,982	94,671
TAIWAN, PROVINCE OF CHINA
Long lived assets by region	17,341	17,652
Other Region [Member]
Long lived assets by region	$ 2,580	$ 2,104