Stock-Based Compensation - Summary of Stock Option Activity (Detail) - 2006 and 2014 Stock Option Plans and Inducement Plan [Member] - Stock Options [Member] - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Share-Based Compensation
Number of Shares Outstanding, beginning of the period	1,674
Number of Shares, Granted	404
Number of Shares, Exercised	0	0
Number of Shares, Forfeited	(303)
Number of Shares, Cancelled	(202)
Number of Shares Outstanding, end of the period	1,573		1,674
Number of Shares, Exercisable	1,183
Number of Shares, Vested or expected to vest	1,490
Weighted-Average Exercise Price Per Share Outstanding, beginning of the period	$ 13,855.94
Weighted-Average Exercise Price Per Share, Granted	30.84
Weighted-Average Exercise Price Per Share, Forfeited	1,245.82
Weighted-Average Exercise Price Per Share, Cancelled	13,738.32
Weighted-Average Exercise Price Per Share Outstanding, end of the period	12,749.32		$ 13,855.94
Weighted-Average Exercise Price Per Share, Exercisable	16,274.86
Weighted-Average Exercise Price Per Share, Vested or expected to vest	$ 13,386.78
Weighted-Average Remaining Contractual Term, Outstanding	6 years 1 month 17 days		5 years 11 months 4 days
Weighted-Average Remaining Contractual Term, Exercisable	5 years 3 months 10 days
Weighted-Average Remaining Contractual Term, Vested or expected to vest	5 years 11 months 15 days
Aggregate Intrinsic Value, Outstanding	$ 3
Aggregate Intrinsic Value, Vested or expected to vest	$ 2