Net Loss per Share - Basic and diluted net loss per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended		12 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Numerator:
Net loss	$ (8,671)	$ (14,346)	$ (13,859)	$ (20,156)	$ (20,437)	$ (18,973)	$ (36,876)	$ (59,566)	$ (77,300)
Net loss attributable to common stockholders	$ (8,671)			$ (20,156)			$ (36,876)	$ (59,566)
Denominator:
Weighted average common stock outstanding-basic (in shares)	32,399,855			32,055,551			32,389,771	31,707,068
Weighted average common stock outstanding-diluted (in shares)	32,399,855			32,055,551			32,389,771	31,707,068
Net loss per share attributable to common stockholders-basic (in dollars per share)	$ (0.27)			$ (0.63)			$ (1.14)	$ (1.88)
Net loss per share attributable to common stockholders-diluted (in dollars per share)	$ (0.27)			$ (0.63)			$ (1.14)	$ (1.88)