Note 6 - Segment and Geographic Information - Revenue by Region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
CHINA
Region	$ 67,372	$ 58,716	$ 180,689	$ 157,968
TAIWAN, PROVINCE OF CHINA
Region	12,786	10,352	31,801	31,524
KOREA, REPUBLIC OF
Region	7,405	6,019	21,522	15,373
Europe [Member]
Region	7,193	5,956	21,232	16,388
South East Asia [Member]
Region	5,370	5,764	13,210	12,839
JAPAN
Region	4,084	2,633	9,771	6,930
UNITED STATES
Region	2,164	1,673	6,613	4,932
Other Region [Member]
Region	82	81	209	194
Region	$ 106,456	$ 91,194	$ 285,047	$ 246,148