Stockholders' equity - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2018
Options Outstanding
Outstanding, beginning balance (in shares)	20,342,259
Outstanding, ending balance (in shares)	10,728,915	20,342,259
2021 Stock incentive Plan
Options Outstanding
Outstanding, beginning balance (in shares)	19,942,259
Granted (in shares)	0
Exercised (in shares)	(1,273,968)
Exchanged in connection with the stock option exchange program (in shares)	(6,762,489)
Canceled (in shares)	(1,226,887)
Outstanding, ending balance (in shares)	10,678,915	19,942,259
Weighted Average Exercise Price
Outstanding, beginning balance (in USD per share)	$ 9.70
Granted (in USD per share)	0
Exercised (in USD per share)	4.44
Exchanged in connection with the stock option exchange program (in USD per share)	18.62
Canceled (in USD per share)	13.49
Outstanding, ending balance (in USD per share)	$ 4.25	$ 9.70
Outstanding, Weighted Average Remaining Contractual Term (in years)	6 years 7 months 17 days	8 years 1 month 20 days
Outstanding, Aggregate Intrinsic Value	$ 84,557	$ 226,350
Vested and Expected to Vest, Awards Outstanding (in shares)	10,678,915
Vested and Expected to Vest, Weighted Average Exercise Price (in USD per shares)	$ 4.25
Vested and Expected to Vest, Weighted Average Remaining Contractual Term (in years)	6 years 7 months 17 days
Vested and Expected to Vest, Aggregate Intrinsic Value	$ 84,557
Exercisable, Awards Outstanding (in shares)	8,388,865
Exercisable, Weighted Average Exercise Price (in USD per share)	$ 3.95
Exercisable, Weighted Average Remaining Contractual Term (in years)	6 years 5 months 26 days
Exercisable, Aggregate Intrinsic Value	$ 68,602
Performance-Based Awards
Options Outstanding
Granted (in shares)			350,000	50,000
Performance-Based Awards | Amended and Restated 2010 Equity Incentive Plan
Options Outstanding
Outstanding, beginning balance (in shares)	400,000
Granted (in shares)	0
Exercised (in shares)	0
Canceled (in shares)	(350,000)
Outstanding, ending balance (in shares)	50,000	400,000
Weighted Average Exercise Price
Outstanding, beginning balance (in USD per share)	$ 10.12
Granted (in USD per share)
Exercised (in USD per share)
Canceled (in USD per share)	11.13
Outstanding, ending balance (in USD per share)	$ 3.06	$ 10.12
Outstanding, Weighted Average Remaining Contractual Term (in years)	5 years 9 months 29 days	8 years 7 months 6 days
Outstanding, Aggregate Intrinsic Value	$ 452	$ 3,768
Vested and Expected to Vest, Awards Outstanding (in shares)	50,000
Vested and Expected to Vest, Weighted Average Exercise Price (in USD per shares)	$ 3.06
Vested and Expected to Vest, Weighted Average Remaining Contractual Term (in years)	5 years 9 months 29 days
Vested and Expected to Vest, Aggregate Intrinsic Value	$ 452
Exercisable, Awards Outstanding (in shares)	10,416
Exercisable, Weighted Average Exercise Price (in USD per share)	$ 3.06
Exercisable, Weighted Average Remaining Contractual Term (in years)	5 years 9 months 29 days
Exercisable, Aggregate Intrinsic Value	$ 94