Net loss per share - Anti-dilutive securities (Details) - shares shares in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Common stock equivalents outstanding excluded from the computation of diluted net loss per share attributable to common stockholders
Outstanding anti-dilutive securities excluded from computation of diluted net loss per share	12,167	9,540
Stock options
Common stock equivalents outstanding excluded from the computation of diluted net loss per share attributable to common stockholders
Outstanding anti-dilutive securities excluded from computation of diluted net loss per share	11,921	9,392
Warrants
Common stock equivalents outstanding excluded from the computation of diluted net loss per share attributable to common stockholders
Outstanding anti-dilutive securities excluded from computation of diluted net loss per share	246	148