Stockholders' Equity (Deficit) - Summary of Common Stock Issued (Detail)	9 Months Ended
	Sep. 30, 2015 shares
Class Of Stock [Line Items]
Balance at December 31, 2014	403,539
Debt conversion, converted instrument, shares issued	3,532,756
Issuance of shares in connection with the Merger	6,939,282
Issuance of shares for banker fees	78,213
Issuance of shares in connection with the Private Placement	2,542,365
Issuance of shares at-the-market	1,141,970
Issuance of shares from options exercised	32,874
Balance at September 30, 2015	18,809,993
Series A and B Preferred Stock [Member]
Class Of Stock [Line Items]
Conversion of preferred stock	3,916,772
Series F Preferred Stock [Member]
Class Of Stock [Line Items]
Conversion of preferred stock	222,222