Common stock and convertible preferred stock - Warrants (Details) - Warrants $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) $ / shares shares
Class of Warrant or Right [Line Items]
Warrants exercised, numbers	148,653
Exercise price | $ / shares	$ 9.00
Gross proceeds from issuance of warrants | $	$ 1.3
Exercise of common stock warrants (shares)	148,653
Additional warrants exercised on cashless	83,431
Additional warrants exercise price | $ / shares	$ 9.00
Shares issued in cashless exercise	52,326
Exercise Price $9.00
Class of Warrant or Right [Line Items]
Warrants outstanding	803,112
Exercise price | $ / shares	$ 9.00
Exercise Price $45.00
Class of Warrant or Right [Line Items]
Warrants outstanding	500,000
Exercise price | $ / shares	$ 45.00