Share-based compensation - Schedule of Service Based Options Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares
Target-based stock options
Options
Outstanding, beginning of period (in shares) | shares	3,272,920
Granted (in shares) | shares	0
Exercised (in shares) | shares	(668,298)
Forfeitures (in shares) | shares	0
Outstanding, end of period (in shares) | shares	2,604,622	3,272,920
Options exercisable (in shares) | shares	2,604,622
Vested or expected to vest (in shares) | shares	2,604,622
Weighted‑ Average Exercise Price
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 6.75
Granted (in dollars per share) | $ / shares	0
Exercised (in dollars per share) | $ / shares	7.26
Forfeitures (in dollars per share) | $ / shares	0
Outstanding, end of period (in dollars per share) | $ / shares	6.62	$ 6.75
Options exercisable (in dollars per share) | $ / shares	6.62
Vested or expected to vest (in dollars per share) | $ / shares	$ 6.62
Weighted‑ Average Remaining Contractual Term (Years)
Remaining term, options outstanding	4 years 7 months 6 days	5 years 9 months 18 days
Remaining term, options exercisable	4 years 7 months 6 days
Remaining term, options vested or expected to vest	4 years 7 months 6 days
Aggregate Intrinsic Value (in thousands)
Outstanding | $	$ 28,762	$ 47,623
Exercised | $	9,174
Options exercisable | $	28,762
Vested or expected to vest | $	$ 28,762
Service-based stock option
Options
Outstanding, beginning of period (in shares) | shares	1,215,822
Granted (in shares) | shares	0
Exercised (in shares) | shares	(110,291)
Forfeitures (in shares) | shares	0
Outstanding, end of period (in shares) | shares	1,105,531	1,215,822
Options exercisable (in shares) | shares	1,092,239
Vested or expected to vest (in shares) | shares	1,105,531
Weighted‑ Average Exercise Price
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 5.70
Granted (in dollars per share) | $ / shares	0
Exercised (in dollars per share) | $ / shares	7.13
Forfeitures (in dollars per share) | $ / shares	0
Outstanding, end of period (in dollars per share) | $ / shares	5.56	$ 5.70
Options exercisable (in dollars per share) | $ / shares	5.52
Vested or expected to vest (in dollars per share) | $ / shares	$ 5.56
Weighted‑ Average Remaining Contractual Term (Years)
Remaining term, options outstanding	3 years 4 months 24 days	5 years 1 month 6 days
Remaining term, options exercisable	3 years 3 months 18 days
Remaining term, options vested or expected to vest	3 years 4 months 24 days
Aggregate Intrinsic Value (in thousands)
Outstanding | $	$ 13,381	$ 18,968
Exercised | $	1,490
Options exercisable | $	13,255
Vested or expected to vest | $	$ 13,381