Stockholders' Equity - Schedule of Common Stock Reserved for Future Issuance (Detail)	Dec. 31, 2015 shares
Class Of Stock [Line Items]
Total reserved shares of common stock	4,349,260
2014 Equity Incentive Plan
Class Of Stock [Line Items]
Total reserved shares of common stock	3,916,362
2014 Employee Stock Purchase Plan
Class Of Stock [Line Items]
Total reserved shares of common stock	432,898