Stockholders' Equity - Additional Information (Detail) - USD ($)		1 Months Ended	9 Months Ended
	Aug. 16, 2016	Apr. 30, 2014	Mar. 31, 2017
Class of Stock [Line Items]
Aggregate value of securities available under shelf registration statement			$ 104,000,000
Shelf registration expiration date			2017-04
Helsinn Investment Fund SA | Helsinn Equity Agreement
Class of Stock [Line Items]
Sale of stock, number of common stock issued	2,616,431
Rights Offering
Class of Stock [Line Items]
Warrants outstanding			315,484
Exercise price			$ 7.14
Warrants expiration date			2017-05
Maximum
Class of Stock [Line Items]
Sale of shares and warrants under agreement		$ 150,000,000
December 2012 Private Placement
Class of Stock [Line Items]
Warrants outstanding			3,230,202
Exercise price			$ 3.12
Warrants expiration date			2017-12