Stock-Based Compensation - Summary of stock option activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Number of shares
Outstanding at the beginning (in shares)	2,548,849
Outstanding at the end (in shares)	2,548,849	2,548,849
Options vested and exercisable (in shares)	2,022,085
Weighted average exercise price
Outstanding at the beginning (in dollars per share)	$ 3.32
Outstanding at the end (in dollars per share)	3.32	$ 3.32
Options vested and exercisable (in dollars per share)	$ 3.68
Weighted average remaining remaining term (in years)
Outstanding (in years)	7 years 7 months 6 days	8 years 4 months 24 days
Options vested and exercisable (in years)	7 years 3 months 18 days
Aggregate intrinsic value
Outstanding at the beginning (in dollars)	$ 618
Outstanding at the end (in dollars)	10	$ 618
Options vested and exercisable	$ 10