Segment Reporting and Geographic Information - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Revenues	$ 61,511	$ 77,476	$ 122,403	$ 150,572
United States [Member]
Segment Reporting Information [Line Items]
Revenues	8,932	8,800	18,063	17,868
Taiwan [Member]
Segment Reporting Information [Line Items]
Revenues	7,111	10,943	18,142	25,410
Japan [Member]
Segment Reporting Information [Line Items]
Revenues	3,427	5,818	7,367	9,948
China [Member]
Segment Reporting Information [Line Items]
Revenues	24,177	23,347	40,221	41,318
South Korea [Member]
Segment Reporting Information [Line Items]
Revenues	10,775	16,374	21,546	33,604
Singapore [Member]
Segment Reporting Information [Line Items]
Revenues	1,596	3,059	3,612	7,341
Other Asia [Member]
Segment Reporting Information [Line Items]
Revenues	1,047	501	2,039	2,418
Germany [Member]
Segment Reporting Information [Line Items]
Revenues	674	3,818	2,524	5,142
Other Europe [Member]
Segment Reporting Information [Line Items]
Revenues	$ 3,772	$ 4,816	$ 8,889	$ 7,523