Stockholders' Equity - 2019 Equity Financing - Additional Information (Detail) - Underwritten Public Offering [Member] - 2019 Equity Financing [Member] $ / shares in Units, $ in Millions	Apr. 01, 2019 USD ($) $ / shares shares
Class of Stock [Line Items]
Common stock issued | shares	10,526,500
Price per share | $ / shares	$ 1.90
Gross proceeds from issuance of common stock	$ 20.0
Underwriter discounts and commissions and other share issue costs	$ 1.7