Stockholders' equity - SARs Activity (Details) - Stock Appreciation Rights - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
RSUs Outstanding
Outstanding, beginning balance (in shares)	106,155
Granted (in shares)	0
Exercised (in shares)	(743)
Canceled in connection with the Equity Exchange (in shares)	(21,055)
Canceled (in shares)	(1,566)
Outstanding, ending balance (in shares)	82,791	106,155
Weighted Average Exercise Price
Outstanding, beginning balance (in USD per share)	$ 8.45
Granted (in USD per share)	0
Exercised (in USD per share)	3.63
Canceled in connection with the Equity Exchange (in USD per share)	19.19
Canceled (in USD per share)	18.95
Outstanding, ending balance (in USD per share)	$ 5.57	$ 8.45
Outstanding, Weighted Average Remaining Contractual Term (in years)	7 years 21 days	8 years 3 months
Outstanding, Aggregate Intrinsic Value	$ 546	$ 1,267
Vested and Expected to Vest, Awards Outstanding (in shares)	82,791
Vested and Expected to Vest, Weighted Average Exercise Price (in USD per shares)	$ 5.57
Vested and Expected to Vest, Weighted Average Remaining Contractual Term (in years)	7 years 21 days
Vested and Expected to Vest, Aggregate Intrinsic Value	$ 546
Exercisable, Awards Outstanding (in shares)	61,845
Exercisable, Weighted Average Exercise Price (in USD per share)	$ 5.36
Exercisable, Weighted Average Remaining Contractual Term (in years)	6 years 11 months 23 days
Exercisable, Aggregate Intrinsic Value	$ 423