Stock-Based Compensation - Stock option activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024 USD ($) $ / shares shares	Dec. 31, 2023 $ / shares shares
Options Outstanding
Outstanding at beginning of period (in shares)	7,455,795
Granted (in shares)	2,085,853
Exercised (in shares)	(7,215)
Cancelled/forfeited (in shares)	(1,528,062)
Outstanding at end of period (in shares)	8,006,371	7,455,795
Exercisable at end of period (in shares)	3,964,796
Weighted Average Exercise Price
Outstanding (in dollars per share) | $ / shares	$ 4.35	$ 5.52
Granted (in dollars per share) | $ / shares	0.89
Exercised (in dollars per share) | $ / shares	0.55
Cancelled/forfeited (in dollars per share) | $ / shares	5.36
Exercisable at end of period (in dollars per share) | $ / shares	$ 5.92
Weighted Average Remaining Contractual Term (In years)
Outstanding (in years)	8 years	8 years
Exercisable at end of period (in years)	7 years
Aggregate Intrinsic Value
Outstanding (in dollars) | $	$ 99
Exercisable (in dollars) | $	$ 17