SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES Geograpic Net Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue by Geography
Total net revenues	$ 106,832	$ 102,865	$ 216,496	$ 192,053
United States of America
Revenue by Geography
Total net revenues	2,935	2,612	5,648	5,284
Hong Kong/China
Revenue by Geography
Total net revenues	65,680	59,355	126,093	106,584
Taiwan
Revenue by Geography
Total net revenues	7,199	10,164	13,678	16,836
Korea
Revenue by Geography
Total net revenues	7,284	6,902	17,641	15,444
Western Europe (excluding Germany)
Revenue by Geography
Total net revenues	7,995	8,625	18,030	19,526
Japan
Revenue by Geography
Total net revenues	4,398	2,909	8,303	6,559
Germany
Revenue by Geography
Total net revenues	5,847	3,813	11,414	8,740
Other
Revenue by Geography
Total net revenues	$ 5,494	$ 8,485	$ 15,689	$ 13,080