Convertible Preferred Stock, Common Stock and Stockholders' Equity (Deficit) - Summary of Stock Option Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares, Outstanding beginning balance	123,250
Shares, Granted	501,500	0
Shares, Exercised
Shares, Canceled/Forfeited
Shares, Outstanding ending balance	624,750	123,250
Shares, Exercisable at December 31, 2013	90,540
Shares, Vested or expected to vest at December 31, 2013	624,750
Weighted Average Exercise Price, Outstanding beginning balance	$ 0.40
Weighted Average Exercise Price, Granted	$ 9.39
Weighted Average Exercise Price, Exercised
Weighted Average Exercise Price, Canceled/Forfeited
Weighted Average Exercise Price, ending balance	$ 7.61	$ 0.40
Weighted Average Exercise Price, Exercisable at December 31, 2013	$ 0.39
Weighted Average Exercise Price, Vested or expected to vest at December 31, 2013	$ 7.61
Weighted Average Remaining Contractual Term (Years), Granted	9 years 10 months 17 days
Weighted Average Remaining Contractual Term (Years), Exercised
Weighted Average Remaining Contractual Term (Years), Canceled/Forfeited
Weighted Average Remaining Contractual Term (Years), Outstanding	8 years 4 months 28 days	7 years 10 months 2 days
Weighted Average Remaining Contractual Term (Years), Exercisable at December 31, 2013	5 years 4 days
Weighted Average Remaining Contractual Term (Years), Vested or expected to vest at December 31, 2013	8 years 4 months 28 days
Aggregate Intrinsic Value, Outstanding beginning balance	$ 578
Aggregate Intrinsic Value, Granted
Aggregate Intrinsic Value, Exercised
Aggregate Intrinsic Value, Canceled/Forfeited
Aggregate Intrinsic Value, Outstanding ending balance	869,490	578
Aggregate Intrinsic Value, Exercisable at December 31, 2013	638,881
Aggregate Intrinsic Value, Vested or expected to vest at December 31, 2013	$ 869,490