Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 73,941	$ 50,070	$ 203,092	$ 137,175
Sales Channel Concentration Risk | Revenue
Disaggregation of Revenue [Line Items]
Percentage of Revenue	100.00%	100.00%	100.00%	100.00%
Geographic Concentration Risk | Revenue
Disaggregation of Revenue [Line Items]
Percentage of Revenue	100.00%	100.00%	100.00%	100.00%
Channel partners
Disaggregation of Revenue [Line Items]
Revenue	$ 6,554	$ 3,367	$ 18,413	$ 9,085
Channel partners | Sales Channel Concentration Risk | Revenue
Disaggregation of Revenue [Line Items]
Percentage of Revenue	9.00%	7.00%	9.00%	7.00%
Direct customers
Disaggregation of Revenue [Line Items]
Revenue	$ 67,387	$ 46,703	$ 184,679	$ 128,090
Direct customers | Sales Channel Concentration Risk | Revenue
Disaggregation of Revenue [Line Items]
Percentage of Revenue	91.00%	93.00%	91.00%	93.00%
United States
Disaggregation of Revenue [Line Items]
Revenue	$ 37,605	$ 23,914	$ 101,571	$ 64,874
United States | Geographic Concentration Risk | Revenue
Disaggregation of Revenue [Line Items]
Percentage of Revenue	51.00%	48.00%	50.00%	47.00%
Europe, Middle East, and Africa
Disaggregation of Revenue [Line Items]
Revenue	$ 17,652	$ 12,648	$ 48,275	$ 35,375
Europe, Middle East, and Africa | Geographic Concentration Risk | Revenue
Disaggregation of Revenue [Line Items]
Percentage of Revenue	24.00%	25.00%	24.00%	26.00%
Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue	$ 13,993	$ 10,223	$ 39,782	$ 27,989
Asia Pacific | Geographic Concentration Risk | Revenue
Disaggregation of Revenue [Line Items]
Percentage of Revenue	19.00%	20.00%	20.00%	20.00%
Other
Disaggregation of Revenue [Line Items]
Revenue	$ 4,691	$ 3,285	$ 13,464	$ 8,937
Other | Geographic Concentration Risk | Revenue
Disaggregation of Revenue [Line Items]
Percentage of Revenue	6.00%	7.00%	6.00%	7.00%