Preferred Stock and Stockholders' Equity (Deficit) - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended	12 Months Ended
	Feb. 05, 2020	Nov. 11, 2018	Jun. 30, 2019	Dec. 31, 2021	Dec. 31, 2020
Equity [Line Items]
Common stock, shares authorized				350,000,000	250,000,000
Initial Public Offering of Common Stock				$ 0.001	$ 0.001
Net Proceeds from Underwriting					$ 13,016
Issuance of common stock in connection with a public offering, net				$ 0	$ 88,661
Common stock, shares outstanding				216,127,443	214,591,906
Common Stock [Member]
Equity [Line Items]
Common stock, shares authorized				350,000,000
Net Proceeds from Underwriting					$ 3
Common stock, shares outstanding				216,127,443
Common Stock, shares reserved for future issuance				33,620,711
Maximum [Member] | At The Market Offering [Member]
Equity [Line Items]
Net Proceeds from Underwriting			$ 100,000
Underwriting Agreement [Member]
Equity [Line Items]
Issuance of common stock in connection with a public offering, net	$ 84,800
Issuance & sale of common stock in public offering price per share	$ 3.25
Underwriting Agreement [Member] | At The Market Offering [Member]
Equity [Line Items]
Issuance of common stock in connection with a public offering, net					$ 13,000
Securities Purchase Agreement [Member]
Equity [Line Items]
Net Proceeds from Underwriting		$ 47,100