Warrants - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended	12 Months Ended
	Jun. 14, 2017	Apr. 13, 2016	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Apr. 13, 2021	Jan. 16, 2018
Class of Warrant or Right [Line Items]
Issuance of shares of common stock		7,500,000	0	0	0	0	0
Warrants sold		7,500,000
Common stock, price per share		$ 1.25
Exercise price of warrant		1.50
Warrants expiry date			Apr. 13, 2021
Public offering price per warrant		$ 0.01
Class of warrants or rights expired								29,101
Securities Purchase Agreement [Member]
Class of Warrant or Right [Line Items]
Warrants sold			14,587
Warrants exercised			472,500
Public offering price per share and per warrant	$ 1.15
Unexercised warrants									1,987,337
Loan and Security Agreement [Member] | Minimum [Member]
Class of Warrant or Right [Line Items]
Beneficial ownership of company's common stock		49.90%
Ligand [Member] | Loan and Security Agreement [Member]
Class of Warrant or Right [Line Items]
Warrants sold		960,000
Exercise price of warrant		$ 1.50
Warrants expiry date			Apr. 13, 2021
Repayments of notes payable in stock		$ 1.2
Over-Allotment Option [Member]
Class of Warrant or Right [Line Items]
Warrants sold		1,125,000
Private Placement and Registered Direct Offering [Member] | Securities Purchase Agreement [Member]
Class of Warrant or Right [Line Items]
Exercise price of warrant	$ 1.30
Warrants expiry date			Dec. 19, 2022
Number of warrants issued for common stock	0.75
Warrants exercisable date			Dec. 19, 2017
Percentage of warrant exercise beneficial ownership limitation of common stock outstanding minimum	4.99%
Prior notice period of increase beneficial ownership limitation	61 days
Percentage of minimum beneficial ownership limitation	9.99%
Description of beneficial ownership limitation			Each holder of a Warrant does not have the right to exercise any portion of its Warrant if the holder, together with its affiliates, would beneficially own in excess of 4.99% of the number of shares of common stock outstanding immediately after giving effect to such exercise (the “Beneficial Ownership Limitation”); provided, however, that upon 61 days’ prior notice to the Company, the holder may increase the Beneficial Ownership Limitation; however, in no event shall the Beneficial Ownership Limitation exceed 9.99%.
Private Placement and Registered Direct Offering [Member] | Common Stock [Member] | Securities Purchase Agreement [Member]
Class of Warrant or Right [Line Items]
Issuance of shares of common stock	3,749,783
Private Placement and Registered Direct Offering [Member] | Maximum [Member] | Common Stock [Member] | Securities Purchase Agreement [Member]
Class of Warrant or Right [Line Items]
Warrants sold	2,812,337