Note 6 - Revenue by Region (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
CHINA
Region	$ 52,388	$ 45,802
TAIWAN, PROVINCE OF CHINA
Region	8,855	11,029
KOREA, REPUBLIC OF
Region	7,093	4,245
Europe [Member]
Region	6,985	5,115
South East Asia [Member]
Region	4,338	3,739
JAPAN
Region	2,650	1,885
UNITED STATES
Region	2,146	1,693
Other Region [Member]
Region	57	30
Region	$ 84,512	$ 73,538

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration