Common Stock and Preferred Stock - Additional Information (Detail) $ / shares in Units, $ in Thousands	1 Months Ended				12 Months Ended
	Oct. 31, 2020 USD ($) shares	Mar. 31, 2019 USD ($) shares	Jul. 31, 2018 USD ($) shares	Jan. 31, 2018 USD ($) shares	Dec. 31, 2020 USD ($) Vote $ / shares shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018 USD ($)
Subsidiary, Sale of Stock [Line Items]
Proceeds from sale of common stock, net | $					$ 215,765	$ 68,273	$ 53,829
Preferred stock, shares issued (in shares)					0	0
Each share of common stock is entitled to vote | Vote					1
Preferred stock, shares authorized (in shares)					15,000,000	15,000,000
Preferred stock warrants were converted into warrants to purchase common stock (in shares)					470,510
Exercise price of common stock warrants (in dollars per share) | $ / shares					$ 24.70
Overallotment option
Subsidiary, Sale of Stock [Line Items]
Sale of Stock, Number of Shares Issued in Transaction	750,000	675,000	600,000
Selling Stockholder
Subsidiary, Sale of Stock [Line Items]
Sale of Stock, Number of Shares Issued in Transaction		2,000,000
At the market equity offering
Subsidiary, Sale of Stock [Line Items]
Proceeds from sale of common stock, net | $				$ 40,000
Sale of Stock, Number of Shares Issued in Transaction				0
Public Stock Offering
Subsidiary, Sale of Stock [Line Items]
Proceeds from underwritten public offering after fees and commissions | $	$ 215,800	$ 68,300	$ 53,800
Sale of Stock, Number of Shares Issued in Transaction		3,175,000	4,600,000
Sale Of Stock, Gross Consideration Received On Transaction | $		$ 73,000	$ 57,500
IPO
Subsidiary, Sale of Stock [Line Items]
Sale of Stock, Number of Shares Issued in Transaction	5,750,000
Sale Of Stock, Gross Consideration Received On Transaction | $	$ 230,000