Note 6 - Revenue by Region (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
CHINA
Region	$ 60,928	$ 53,450	$ 113,316	$ 99,252
TAIWAN, PROVINCE OF CHINA
Region	10,160	10,143	19,015	21,172
Europe [Member]
Region	7,054	5,317	14,039	10,432
KOREA, REPUBLIC OF
Region	7,024	5,109	14,117	9,354
South East Asia [Member]
Region	3,501	3,336	7,840	7,075
JAPAN
Region	3,037	2,412	5,687	4,297
UNITED STATES
Region	2,303	1,566	4,449	3,259
Other Region [Member]
Region	72	83	128	113
Region	$ 94,079	$ 81,416	$ 178,591	$ 154,954