Stock-based Compensation - Schedule of Stock Options Activity (Detail) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) $ / shares shares
NUMBER OF SHARES
Beginning balance (in shares) | shares	5,255,930
Granted (in shares) | shares	643,059
Exercised (in shares) | shares	(173,203)
Canceled (in shares) | shares	(17,571)
Ending balance (in shares) | shares	5,708,215
Options exercisable (in shares) | shares	3,406,018
WEIGHTED AVERAGE EXERCISE PRICE
Beginning balance (in dollars per share) | $ / shares	$ 14.34
Granted (in dollars per share) | $ / shares	43.71
Exercised (in dollars per share) | $ / shares	9.75
Cancelled (in dollars per share) | $ / shares	34.34
Ending balance (in dollars per share) | $ / shares	17.73
Options exercisable (in dollars per share) | $ / shares	$ 11.32
WEIGHTED AVERAGE REMAINING CONTRACTUAL LIFE (YEARS)
Options outstanding, weighted average remaining contractual life (in years)	7 years 6 months 6 days
Options exercisable (in years)	6 years 8 months 17 days
AGGREGATE INTRINSIC VALUE
Options outstanding | $	$ 157,690
Options exercisable | $	$ 115,894