Description of Business and Basis of Preparation - Additional Information (Detail)	Jan. 08, 2021 USD ($)	Jan. 01, 2021 USD ($)	Oct. 01, 2020 USD ($)	Jul. 17, 2020 shares	Jul. 16, 2020 shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($) shares	Dec. 31, 2019 shares	Jun. 18, 2019 shares	Jun. 17, 2019 shares
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Accumulated deficit | $						$ 359,479,000	$ 326,613,000
Cash and cash equivalents | $						$ 104,484,000	$ 93,041,000
Shelf registration maximum equity initial offering price | $			$ 200,000,000.0
Reverse stock split, ratio					0.1
Common stock, shares authorized (in shares) | shares				100,000,000	250,000,000	100,000,000	100,000,000		250,000,000	125,000,000
Common stock, shares issued (in shares) | shares				10,508,302	105,083,291	28,705,334	19,663,698
Common stock, shares outstanding (in shares) | shares				10,508,302	105,083,291	28,705,334	19,663,698
Stock issued during period as result of reverse stock splits | shares				0	0
Common Stock
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Common stock, shares outstanding (in shares) | shares						28,705,334	19,663,698	9,741,372
Sales Agreement | Common Stock
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Shelf registration maximum equity initial offering price | $		$ 50,000,000.0
January 2021 Shelf Registration
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Shelf registration maximum equity initial offering price | $	$ 200,000,000.0