SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES Geograpic Net Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue by Geography
Total net revenues	$ 114,159	$ 110,085	$ 306,212	$ 322,648
United States of America
Revenue by Geography
Total net revenues	2,878	4,460	8,162	12,056
Hong Kong/China
Revenue by Geography
Total net revenues	64,526	59,178	171,110	169,149
Taiwan
Revenue by Geography
Total net revenues	10,410	11,210	27,246	36,010
Korea
Revenue by Geography
Total net revenues	7,177	8,087	22,621	25,965
Western Europe (excluding Germany)
Revenue by Geography
Total net revenues	9,220	12,842	28,746	37,910
Japan
Revenue by Geography
Total net revenues	4,753	5,040	11,312	15,238
Germany
Revenue by Geography
Total net revenues	4,921	3,873	13,661	10,882
Other
Revenue by Geography
Total net revenues	$ 10,274	$ 5,395	$ 23,354	$ 15,438