Share-based compensation and employee benefit plans - Options activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Number of options
Beginning of period (in shares)	8,255,810
Granted (in shares)	2,772,215	0	0
Forfeited (in shares)	(3,720,930)
Exercised (in shares)	(220,000)	0	(187,678)
End of period (in shares)	7,087,095	8,255,810
Weighted average exercise price
Beginning of period (in dollars per share)	$ 13.45
Granted (in dollars per share)	10.69
Forfeited (in dollars per share)	13.20
Exercised (in dollars per share)	10.00
End of period (in dollars per share)	$ 12.61	$ 13.45