Equity Awards - Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2017
Number of Shares
Number of shares, outstanding, beginning balance	5,649,375	5,818,435	5,818,435
Number of shares, granted	50,000	566,720
Number of shares, exercised	(705,807)	(697,446)
Number of shares, canceled	(1,174)	(38,334)
Number of shares, outstanding, ending balance	4,992,394	5,649,375	4,992,394
Number of shares, vested and expected to vest	4,919,086		4,919,086
Number of shares, vested and exercisable	3,772,067		3,772,067
Weighted- Average Exercise Price
Weighted-average exercise price, outstanding, beginning balance (in USD per share)	$ 27.26	$ 20.57	$ 20.57
Weighted-average exercise price, granted (in USD per share)	103.60	84.81
Weighted-average exercise price, exercised (in USD per share)	8.62	15.77
Weighted-average exercise price canceled (in USD per share)	57.78	71.68
Weighted-average exercise price, outstanding, ending balance (in USD per share)	30.65	$ 27.26	30.65
Weighted-average exercise price, vested and expected to vest (in USD per share)	29.99		29.99
Weighted-average exercise price, vested and exercisable (in USD per share)	$ 15.16		$ 15.16
Weighted-average remaining contractual term, outstanding			5 years 6 months 25 days
Weighted-average remaining contractual term, vested and expected to vest			5 years 6 months 7 days
Weighted-average remaining contractual term, vested and exercisable			4 years 5 months 1 day
Aggregate intrinsic value, exercised	$ 62,617	$ 51,560
Aggregate intrinsic value, outstanding	376,150		$ 376,150
Aggregate intrinsic value, vested and expected to vest	373,914		373,914
Aggregate intrinsic value, vested and exercisable	$ 342,656		$ 342,656