Stock-based compensation - Restricted stock units (Details) - Unvested restricted stock units - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Restricted stock (in units)
Outstanding, beginning of period (in shares)	8,417,357
Granted (in shares)	5,478,078		413,234
Vested (in shares)	(2,489,574)
Forfeited (in shares)	(854,182)
Outstanding, end of period (in shares)	10,551,679	8,417,357
Weighted-Average Grant Date Fair Value (per share)
Outstanding, beginning of period (in dollars per share)	$ 29.61
Granted (in dollars per share)	19.45	$ 27.50	$ 32.51
Vested (in dollars per share)	29.72
Forfeited (in dollars per share)	27.91
Outstanding, end of period (in dollars per share)	$ 24.49	$ 29.61