Subsequent Events - Additional Information (Detail) $ in Thousands	1 Months Ended
Jul. 31, 2017 USD ($)
Subsequent Event [Member] \| Phase 3 Clinical Trials [Member]
Subsequent Event [Line Items]
Revenue recorded upon achievement of related milestone	$ 20,000

The amount of consideration recognized during the period for the milestone or milestones.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 28
-Section 50
-Paragraph 2
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=68058744&loc=SL6892177-166501

Name:	us-gaap_RevenueRecognitionMilestoneMethodRevenueRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration