Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Total revenue	$ 129,717	$ 103,397	$ 334,781	$ 261,460
United States
Disaggregation of Revenue [Line Items]
Total revenue	81,065	74,710	227,569	185,388
International
Disaggregation of Revenue [Line Items]
Total revenue	$ 48,652	$ 28,687	$ 107,212	$ 76,072
Geographic Concentration Risk | Revenue from Contract with Customer | United Kingdom
Disaggregation of Revenue [Line Items]
Concentration risk, percent		12.30%		10.50%