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								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total revenue	$ 120,558	$ 62,935	$ 61,511	$ 60,892	$ 62,780	$ 60,432	$ 77,476	$ 73,096	$ 305,896	$ 273,784	$ 255,098
United States [Member]
Segment Reporting Information [Line Items]
Total revenue									46,717	43,944	36,104
Taiwan [Member]
Segment Reporting Information [Line Items]
Total revenue									66,601	45,312	63,079
South Korea [Member]
Segment Reporting Information [Line Items]
Total revenue									43,997	51,750	44,180
Singapore [Member]
Segment Reporting Information [Line Items]
Total revenue									10,699	14,371	12,775
Japan [Member]
Segment Reporting Information [Line Items]
Total revenue									29,816	22,361	18,943
Germany [Member]
Segment Reporting Information [Line Items]
Total revenue									4,899	14,913	15,580
China [Member]
Segment Reporting Information [Line Items]
Total revenue									80,017	63,243	35,925
Other Europe [Member]
Segment Reporting Information [Line Items]
Total revenue									18,124	12,260	23,768
Other Asia [Member]
Segment Reporting Information [Line Items]
Total revenue									$ 5,026	$ 5,630	$ 4,744