Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended
	May 08, 2018	Apr. 05, 2018	Oct. 23, 2017	Mar. 31, 2018
Subsequent Event [Line Items]
Amount of net proceeds from issuance of securities				$ 634
Common Stock
Subsequent Event [Line Items]
Number of shares sold in underwritten public offering			973,236
Subsequent Event | Cipla Ltd
Subsequent Event [Line Items]
Marketing and distribution agreement date	May 08, 2018
Upfront payment received	$ 2,200
Subsequent Event | Purchase Agreements
Subsequent Event [Line Items]
Stock purchase agreements date		Apr. 05, 2018
Subsequent Event | Purchase Agreements | Common Stock
Subsequent Event [Line Items]
Number of shares sold in underwritten public offering		14,000,000
Amount of net proceeds from issuance of securities		$ 26,300
Exchange price per share		$ 2.00
Subsequent Event | Purchase Agreements | Warrants
Subsequent Event [Line Items]
Warrants to purchase of common stock		14,000,000
Exercise price of warrants		$ 2.38