Stock-based compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended	6 Months Ended
	Mar. 07, 2024	Jun. 30, 2024	Jun. 30, 2024
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted (in shares)			3,055,807
Stock options granted, weighted average exercise price (in dollars per share)			$ 6.95
Stock options granted, weighted average grant date fair value (in dollars per share)			$ 5.70
2020 Stock Option and Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted, weighted average exercise price (in dollars per share)	$ 22.00
New exercise price per share, tranche one (in dollars per share)	19.00
New exercise price per share, tranche two (in dollars per share)	$ 11.88
Share-based payment arrangement, plan modification, incremental cost		$ 0.4	$ 0.5
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs		50.1	$ 50.1
Expected to be recognized over a weighted average period			2 years 4 months 24 days
Performance-based RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs		$ 3.0	$ 3.0
Units vested (in shares)			0
Share-based compensation, number of common stock issuable per RSU vested (in shares)		1	1
Time-based RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs		$ 9.7	$ 9.7
Expected to be recognized over a weighted average period			3 years 3 months 18 days
Units vested (in shares)			136,837
Granted (in shares)			1,013,350
Number of shares retained to cover statutory minimum withholding taxes (in shares)			15,321