Share-based compensation - Share Options (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Additional Information
Total share-based compensation expense	$ 5,368	$ 2,688	$ 21,239	$ 9,084
Stock option
Number of Shares
Outstanding number of shares at beginning			4,603,486
Granted			1,398,517
Exercised			(64,067)
Forfeited			(153,355)
Outstanding number of shares at end	5,784,581		5,784,581		4,603,486
Number of shares, vested and expected to vest	5,784,581		5,784,581
Number of shares, options exercisable	3,177,177		3,177,177
Weighted Average Exercise Price
Weighted average exercise price at beginning			$ 14.97
Granted			46.83
Exercised			12.55
Forfeited			25.86
Weighted average exercise price at ending	$ 22.41		22.41		$ 14.97
Weighted average exercise price, vested and expected to vest	22.41		22.41
Weighted average exercise price, options exercisable	$ 13.51		$ 13.51
Weighted Average Contractual Term
Weighted average contractual term, outstanding			7 years 9 months 25 days		8 years 1 month 17 days
Weighted average contractual term, vested and expected to vest			7 years 9 months 25 days
Weighted average contractual term ,options exercisable			7 years 21 days
Aggregate Intrinsic Value
Aggregate intrinsic value outstanding	$ 43,632		$ 43,632		$ 207,009
Aggregate intrinsic value, vested and expected to vest	43,632		43,632
Aggregate intrinsic value, options exercisable	35,164		$ 35,164
Additional Information
Granted			$ 32.91	$ 13.83
Exercised	100	5,700	$ 1,300	$ 9,400
Total share-based compensation expense	$ 4,700	$ 2,700	$ 17,100	$ 9,100