SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES Geograpic Net Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue by Geography
Total net revenues	$ 102,865	$ 109,482	$ 192,053	$ 212,563
United States of America
Revenue by Geography
Total net revenues	2,612	3,729	5,284	7,596
Hong Kong/China
Revenue by Geography
Total net revenues	59,355	58,614	106,584	109,971
Taiwan
Revenue by Geography
Total net revenues	10,164	12,914	16,836	24,800
Korea
Revenue by Geography
Total net revenues	6,902	8,229	15,444	17,878
Western Europe (excluding Germany)
Revenue by Geography
Total net revenues	8,625	11,476	19,526	25,068
Japan
Revenue by Geography
Total net revenues	2,909	5,647	6,559	10,198
Germany
Revenue by Geography
Total net revenues	3,813	3,705	8,740	7,009
Other
Revenue by Geography
Total net revenues	$ 8,485	$ 5,168	$ 13,080	$ 10,043