Stockholders' Equity - Summary of Stock Option Activity Under the 2010 Stock Plan and 2013 Stock Plan (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Shares, Outstanding, beginning balance	2,792,021
Number of Shares, Granted	160,600
Number of Shares, Exercised	(927,588)
Number of Shares, Cancelled	(62,194)
Number of Shares, Outstanding, ending balance	1,962,839	2,792,021
Number of Shares, Exercisable as of June 30, 2015	696,585
Weighted-Average Exercise Price, Outstanding, beginning balance	$ 10.82
Weighted-Average Exercise Price, Granted	45.51
Weighted-Average Exercise Price, Exercised	4.55
Weighted-Average Exercise Price, Cancelled	21.61
Weighted- Average Exercise Price, Outstanding, ending balance	16.29	$ 10.82
Weighted- Average Exercise Price, Exercisable as of June 30, 2015	$ 10.40
Weighted-Average Remaining Contractual Term, Outstanding, beginning balance	8 years 1 month 6 days	8 years 3 months 18 days
Weighted-Average Remaining Contractual Term, Exercisable as of June 30, 2015	7 years 7 months 6 days
Aggregate Intrinsic Value, Outstanding, beginning balance	$ 35,390
Aggregate Intrinsic Value, Outstanding, ending balance	36,566	$ 35,390
Aggregate Intrinsic Value, Exercisable as of June 30, 2015	$ 16,358