Stock-based compensation - Schedule of option activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Price
Options expired (in dollars per share)	$ 19.74
Performance stock units
Shares
Options expired (in shares)	(44,205)
2018 Stock Plan
Shares
Options outstanding, balance beginning (in shares)	1,598,811	1,916,101	4,599,790
Options exercised (in shares)	(112,383)	(286,842)	(2,668,191)
Options forfeited (in shares)		(30,448)	(15,498)
Options outstanding, balance ending (in shares)	1,486,428	1,598,811	1,916,101
Options vested and exercisable (in shares)	1,486,428
Price
Options outstanding, beginning balance (in dollars per share)	$ 3.54	$ 3.54	$ 3.54
Options exercised (in dollars per share)	3.54	3.54	3.54
Options forfeited (in dollars per share)		3.54	3.54
Option outstanding, ending balance (in dollars per share)	3.54	$ 3.54	$ 3.54
Options vested and exercisable (in dollars per share)	$ 3.54
Additional Disclosures
Options outstanding, aggregate intrinsic value	$ 14,552	$ 12,279	$ 65,971	$ 41,674
Options vested and exercisable, aggregate intrinsic value	$ 14,552
Options outstanding, weighted average contractual term (in years)	5 years 14 days
Options vested and exercisable, weighted average contractual term (in years)	5 years 14 days
2020 Equity Incentive Plan
Shares
Options outstanding, balance beginning (in shares)	3,003,611	2,224,687	1,942,400
Options granted (in shares)	689,500	1,228,700	766,250
Options exercised (in shares)	(153,302)	(67,593)	(112,087)
Options forfeited (in shares)	(329,889)	(382,183)	(371,876)
Options outstanding, balance ending (in shares)	3,165,715	3,003,611	2,224,687
Options vested and exercisable (in shares)	1,646,249
Price
Options outstanding, beginning balance (in dollars per share)	$ 13.22	$ 12.86	$ 8.38
Options granted (in dollars per share)	11.49	14.67	21.61
Options exercised (in dollars per share)	8.67	9.69	8.20
Options forfeited (in dollars per share)	14.99	16.40	8.88
Option outstanding, ending balance (in dollars per share)	12.79	$ 13.22	$ 12.86
Options vested and exercisable (in dollars per share)	$ 11.68
Additional Disclosures
Options outstanding, aggregate intrinsic value	$ 7,197	$ 3,883	$ 55,856	$ 8,200
Options vested and exercisable, aggregate intrinsic value	$ 5,382
Options outstanding, weighted average contractual term (in years)	7 years 6 months 10 days
Options vested and exercisable, weighted average contractual term (in years)	6 years 6 months 25 days