Shares of Common Stock Reserved for Future Issuance (Detail)	Mar. 31, 2015
Shares Of Common Stock Reserved For Future Issuance [Line Items]
Options to purchase common stock	2,798,480
Shares reserved for issuance	6,396,836
Warrants
Shares Of Common Stock Reserved For Future Issuance [Line Items]
Shares reserved for issuance	1,691,639
2014 Stock Plan
Shares Of Common Stock Reserved For Future Issuance [Line Items]
Shares reserved for issuance	274,009
Series A Convertible Preferred Stock [Member]
Shares Of Common Stock Reserved For Future Issuance [Line Items]
Convertible preferred stock	666,041
Series B Convertible Preferred Stock [Member]
Shares Of Common Stock Reserved For Future Issuance [Line Items]
Convertible preferred stock	966,667