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		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Revenues	$ 66,920	$ 61,641	$ 195,017	$ 178,704
United States [Member]
Segment Reporting Information [Line Items]
Revenues	7,666	10,750	25,856	23,784
Taiwan [Member]
Segment Reporting Information [Line Items]
Revenues	17,300	18,535	49,960	55,105
Japan [Member]
Segment Reporting Information [Line Items]
Revenues	6,268	2,970	12,944	9,071
China [Member]
Segment Reporting Information [Line Items]
Revenues	4,151	5,942	24,156	25,591
South Korea [Member]
Segment Reporting Information [Line Items]
Revenues	10,852	6,342	36,099	10,191
Singapore [Member]
Segment Reporting Information [Line Items]
Revenues	4,664	7,415	9,875	29,341
Other Asia [Member]
Segment Reporting Information [Line Items]
Revenues	1,690	1,079	3,249	3,625
Germany [Member]
Segment Reporting Information [Line Items]
Revenues	4,488	1,400	12,357	6,331
Other Europe [Member]
Segment Reporting Information [Line Items]
Revenues	$ 9,841	$ 7,208	$ 20,521	$ 15,665