Net Loss Per Share - Additional Information (Detail)	6 Months Ended
Jun. 30, 2015
Earnings Per Share [Abstract]
Warrant exercise date	Jul. 31, 2014

Date the warrants or rights are exercisable, in CCYY-MM-DD format.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(i)(3))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Name:	us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration