Share-based compensation - Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 15,836	$ 2,328	$ 22,774	$ 3,903
Cost of revenues | Subscription
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	1,716	314	2,384	390
Cost of revenues | Services
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	229	62	381	62
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	4,833	675	6,763	897
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	5,145	523	7,076	821
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 3,913	$ 754	$ 6,170	$ 1,733