SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES Geograpic Net Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue by Geography
Total net revenues	$ 121,129	$ 114,159	$ 337,625	$ 306,212
United States of America
Revenue by Geography
Total net revenues	2,380	2,878	8,028	8,162
Hong Kong/China
Revenue by Geography
Total net revenues	76,549	64,526	202,642	171,110
Taiwan
Revenue by Geography
Total net revenues	4,133	10,410	17,811	27,246
Korea
Revenue by Geography
Total net revenues	12,121	7,177	29,762	22,621
Western Europe (excluding Germany)
Revenue by Geography
Total net revenues	7,535	9,220	25,565	28,746
Japan
Revenue by Geography
Total net revenues	4,303	4,753	12,606	11,312
Germany
Revenue by Geography
Total net revenues	5,755	4,921	17,169	13,661
Other
Revenue by Geography
Total net revenues	$ 8,353	$ 10,274	$ 24,042	$ 23,354