Stockholders' Equity (Detail)	Jun. 30, 2017 shares
Shares Of Common Stock Reserved For Future Issuance [Line Items]
Options to purchase common stock	487,528
Shares reserved for issuance	21,528,369
Warrants
Shares Of Common Stock Reserved For Future Issuance [Line Items]
Shares reserved for issuance	11,615,849
2014 Stock Plan
Shares Of Common Stock Reserved For Future Issuance [Line Items]
Shares reserved for issuance	202,290
Series C Convertible Preferred Stock [Member]
Shares Of Common Stock Reserved For Future Issuance [Line Items]
Convertible preferred stock	3,335
Series D Convertible Preferred Stock [Member]
Shares Of Common Stock Reserved For Future Issuance [Line Items]
Convertible preferred stock	186,367
Series E Convertible Preferred Stock [Member]
Shares Of Common Stock Reserved For Future Issuance [Line Items]
Convertible preferred stock	9,033,000