SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES Geograpic Net Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue by Geography
Total net revenues	$ 89,188	$ 103,081
United States of America
Revenue by Geography
Total net revenues	2,672	3,867
Hong Kong/China
Revenue by Geography
Total net revenues	47,229	51,357
Taiwan
Revenue by Geography
Total net revenues	6,672	11,886
Korea
Revenue by Geography
Total net revenues	8,542	9,649
Western Europe (excluding Germany)
Revenue by Geography
Total net revenues	10,901	13,592
Japan
Revenue by Geography
Total net revenues	3,650	4,551
Germany
Revenue by Geography
Total net revenues	4,927	3,304
Other
Revenue by Geography
Total net revenues	$ 4,595	$ 4,875