Schedule of Geographic Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenue	$ 614,337	$ 521,290	$ 384,758
Geographic Concentration Risk | Revenue from Contract with Customer
Segment Reporting Information [Line Items]
Percentage of Total	100.00%	100.00%	100.00%
United States
Segment Reporting Information [Line Items]
Revenue	$ 242,243	$ 220,583	$ 154,756
United States | Geographic Concentration Risk | Revenue from Contract with Customer
Segment Reporting Information [Line Items]
Percentage of Total	39.40%	42.30%	40.20%
Germany
Segment Reporting Information [Line Items]
Revenue	$ 88,027	$ 68,003	$ 55,940
Germany | Geographic Concentration Risk | Revenue from Contract with Customer
Segment Reporting Information [Line Items]
Percentage of Total	14.30%	13.00%	14.50%
Rest of Europe
Segment Reporting Information [Line Items]
Revenue	$ 105,608	$ 81,001	$ 51,705
Rest of Europe | Geographic Concentration Risk | Revenue from Contract with Customer
Segment Reporting Information [Line Items]
Percentage of Total	17.20%	15.50%	13.40%
China
Segment Reporting Information [Line Items]
Revenue	$ 66,414	$ 56,128	$ 44,225
China | Geographic Concentration Risk | Revenue from Contract with Customer
Segment Reporting Information [Line Items]
Percentage of Total	10.80%	10.80%	11.50%
Rest of Asia-Pacific
Segment Reporting Information [Line Items]
Revenue	$ 104,300	$ 84,727	$ 60,104
Rest of Asia-Pacific | Geographic Concentration Risk | Revenue from Contract with Customer
Segment Reporting Information [Line Items]
Percentage of Total	17.00%	16.30%	15.60%
Other Countries
Segment Reporting Information [Line Items]
Revenue	$ 7,745	$ 10,848	$ 18,028
Other Countries | Geographic Concentration Risk | Revenue from Contract with Customer
Segment Reporting Information [Line Items]
Percentage of Total	1.30%	2.10%	4.80%