Common Stock - Summary of Outstanding Warrants (Parenthetical) (Detail)

v2.4.1.9

Common Stock - Summary of Outstanding Warrants (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2014
Series A Warrants [Member]
Class of Warrant or Right [Line Items]
Warrants issued date	2014-07
Series B Warrants [Member]
Class of Warrant or Right [Line Items]
Warrants issued date	2014-07
Warrant [Member]
Class of Warrant or Right [Line Items]
Warrants issued date	2010-10
Pre-Funded Series B Warrants [Member]
Class of Warrant or Right [Line Items]
Warrants issued date	2014-07