Common Stock and Preferred Stock - Additional Information (Detail) $ / shares in Units, $ in Thousands	1 Months Ended				12 Months Ended
	Mar. 31, 2019 USD ($) shares	Jul. 31, 2018 USD ($) shares	Jan. 31, 2018 USD ($) shares	Jun. 30, 2017 USD ($) shares	Dec. 31, 2019 USD ($) Vote $ / shares shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($)
Subsidiary, Sale of Stock [Line Items]
Preferred Stock, Shares Outstanding					0
Proceeds from sale of common stock, net | $					$ 68,273	$ 53,829	$ 56,486
Proceeds from underwritten public offering after fees and commissions | $				$ 56,500
Sale of Stock, Number of Shares Issued in Transaction				3,450,000
Subsidiary or Equity Method Investee, Cumulative Proceeds Received on All Transactions | $				$ 57,800
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, shares issued (in shares)					0	0
Preferred stock warrants were converted into warrants to purchase common stock (in shares)					1,368,772
Exercise price of common stock warrants (in dollars per share) | $ / shares					$ 19.47
Overallotment option
Subsidiary, Sale of Stock [Line Items]
Sale of Stock, Number of Shares Issued in Transaction	700,000	600,000		450,000
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 | $	$ 68,300	$ 53,800
Sale of Stock, Number of Shares Issued in Transaction	3,200,000	4,600,000
Sale Of Stock, Gross Consideration Received On Transaction | $	$ 73,000	$ 57,500