The Company and Basis of Presentation - Additional Information (Detail) - USD ($)				1 Months Ended	12 Months Ended
	Jan. 22, 2020	Nov. 13, 2019	Mar. 06, 2018	Jan. 31, 2021	Dec. 31, 2020	Dec. 31, 2018	Feb. 28, 2021	Aug. 31, 2020	Jan. 29, 2020	Dec. 31, 2019
Cash and cash equivalents					$ 104,055,000					$ 147,528,000
Description of reverse stock split	1-for-40
Issuance of common stock					$ 8,901,000	$ 45,996,000
Follow on Offering [Member]
Issuance of common stock, Shares			546,250
Share issued price per share			$ 90.00
Proceeds from issuance of common stock, net of deferred financing costs			$ 46,000,000
Underwriting discounts and commissions and offering expenses			$ 3,200,000
ATM Program [Member]
Issuance of common stock, Shares					732,752
Issuance of common stock					$ 8,900,000
ATM Program [Member] | Subsequent Event [Member]
Issuance of common stock, Shares				450,000
ATM Program [Member] | Maximum [Member]
Common stock reserved for issuance								$ 20,000,000
ATM Program [Member] | Maximum [Member] | Subsequent Event [Member]
Common stock reserved for issuance							$ 30,000,000
Series A Warrants [Member] | Underwritten Public Offering [Member]
Number of securitites called by warrants and rights		7,802,241
Excercise price of warrants or rights		$ 13.20
Series B Warrants [Member] | Underwritten Public Offering [Member]
Number of securitites called by warrants and rights		2,574,727
Excercise price of warrants or rights		$ 13.20
Series A Convertible Voting Preferred Stock and Warrants [Member] | Underwritten Public Offering [Member]
Issuance of common stock, Shares		103,000
Share issued price per share		$ 1,000
Proceeds from issuance of convertible preferred stock and warrants net of issuance cost		$ 97,700,000
Stock issuance costs		$ 5,300,000
Preferred Stock converted into of the Company's common stock									7,803,273