Nature of Business - Additional Information (Detail)				1 Months Ended	9 Months Ended
	Nov. 14, 2022	Oct. 12, 2022	Oct. 11, 2022	Feb. 28, 2022	Sep. 30, 2022 USD ($) $ / shares	Aug. 24, 2022 USD ($)	Jul. 22, 2022 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Nov. 05, 2021 $ / shares	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Nature Of Business [Line Items]
Cash, cash equivalents, and restricted cash					$ 21,500,000
Accumulated deficit					524,120,000					$ 472,216,000
Stockholders' deficit					$ 31,669,000			$ 37,519,000	$ 25,651,000	$ 12,903,000		$ 2,463,000	$ (9,009,000)	$ 566,000	$ (8,726,000)
Bid price of common stock | $ / shares											$ 1.00
Stock split, conversion ratio					0.02
Reverse stock split description					the changes in the number of shares resulting from the 50 to 1 reverse stock split that was approved by shareholders on October 11, 2022 and became effective as of October 12, 2022.
Minimum market value of listed securities						$ 35,000,000	$ 35,000,000
Maximum [Member]
Nature Of Business [Line Items]
Stock trading price | $ / shares					$ 1.00
Minimum [Member]
Nature Of Business [Line Items]
Regain compliance by increasing the stock price | $ / shares					$ 1.00
Term Loan Agreement [Member] | CRG [Member]
Nature Of Business [Line Items]
Minimum cash balance					$ 5,000,000.0
Debt maturity date				Dec. 30, 2023
Subsequent Event [Member]
Nature Of Business [Line Items]
Stock split, conversion ratio		0.02	0.02
Reverse stock split description		On October 12, 2022, we effected a reverse stock split at the ratio of 1 post-split share for every 50 pre-split shares. All common stock amounts and references have been retroactively adjusted for all figures presented to reflect this split unless specifically stated otherwise	On October 11, 2022, at the Company’s annual meeting of stockholders, the Company’s stockholders approved an amendment to the Company’s restated certificate of incorporation to effect a reverse stock split of the Company’s common stock. Following the receipt of the stockholders’ approval, the Company’s board of directors approved the reverse stock split at the ratio of 1 post-split share for every 50 pre-split shares, which was effective as of October 12, 2022. On October 31, 2022, the Company received a letter from Nasdaq informing the Company that it has regained compliance with the Bid Price Rule.
Subsequent Event [Member] | Term Loan Agreement [Member] | CRG [Member]
Nature Of Business [Line Items]
Debt maturity date	Dec. 30, 2024