Summary of Option Activity (Detail) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) $ / shares shares
Options Outstanding
Options outstanding at December 31, 2019 | shares	957,559
Granted | shares	25,836
Exercised | shares	(67,877)
Options outstanding at March 31, 2020 | shares	915,518
Options exercisable at March 31, 2020 | shares	555,159
Vested and expected to vest at March 31, 2020 | shares	885,461	[1]
Weighted-Average Exercise Price Per Share
Options outstanding at December 31, 2019 | $ / shares	$ 30.81
Granted | $ / shares	86.10
Exercised | $ / shares	23.56
Options outstanding at March 31, 2020 | $ / shares	32.91
Options exercisable at March 31, 2020 | $ / shares	$ 26.77
Weighted-Average Remaining Contractual Term (in years)
Options outstanding at March 31, 2020	6 years 7 months 20 days
Options exercisable at March 31, 2020	5 years 7 months 24 days
Vested and expected to vest at March 31, 2020	6 years 7 months 2 days	[1]
Aggregate Intrinsic Value
Options outstanding at March 31, 2020 | $	$ 58,257
Options exercisable at March 31, 2020 | $	38,734
Vested and expectd to vest at March 31, 2020 | $	$ 56,522	[1]

[1] Represents the number of vested options as of March 31, 2020 plus the number of unvested options expected to vest as of March 31, 2020 based on the unvested outstanding options at March 31, 2020 adjusted for estimated forfeiture rates of 8% for awards granted to non-executive level employees and 3% for awards granted to executive level employees.