Note 6 - Segment and Geographic Information - Revenue by Region (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenue	$ 112,198	$ 94,079	$ 212,560	$ 178,591
CHINA
Revenue	62,325	60,928	118,409	113,316
TAIWAN, PROVINCE OF CHINA
Revenue	17,286	10,160	32,161	19,015
Europe [Member]
Revenue	9,593	7,054	17,501	14,039
KOREA, REPUBLIC OF
Revenue	8,154	7,024	16,315	14,117
South East Asia [Member]
Revenue	6,925	3,501	13,297	7,840
JAPAN
Revenue	4,945	3,037	9,771	5,687
UNITED STATES
Revenue	2,888	2,303	4,930	4,449
Other Region [Member]
Revenue	$ 82	$ 72	$ 176	$ 128