Share-Based Payments - Summary of Stock Option Activity and Related Information (Detail) (USD $)	6 Months Ended		12 Months Ended
	Jun. 30, 2014		Dec. 31, 2013
Number of Shares
Outstanding at beginning of period	1,346,238
Granted	186,115
Exercised	(36,612)
Cancelled or forfeited	(4,762)
Outstanding at end of period	1,490,979		1,346,238
Exercisable at end of period	470,531
Vested and expected to vest at end of period	1,126,768	[1]
Weighted-Average Exercise Price
Outstanding at beginning of period	$ 3.39
Granted	$ 14.66
Exercised	$ 0.49
Canceled or forfeited	$ 7.37
Outstanding at end of period	$ 4.86		$ 3.39
Exercisable at end of period	$ 2.20
Vested and expected to vest at end of period	$ 5.35	[1]
Remaining Contractual Life (in years)
Outstanding at beginning of period	8 years 3 months 29 days		8 years 7 months 2 days
Exercisable at end of period	7 years 7 months 28 days
Vested and expected to vest at end of period	8 years 6 months	[1]

[1] Represents the number of vested options, plus the number of unvested options expected to vest.