Summary of Restricted Stock Unit Activity (Detail) - Restricted Stock Units and Performance Stock Units $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) shares
Options Outstanding
Unvested at December 31, 2019	734,984
Awarded	127,286
Vested	(132,053)
Forfeited/expired/cancelled	(13,587)
Unvested at March 31, 2020	716,630
Vested and expected to vest at March 31, 2020	656,225	[1]
Weighted-Average Remaining Contractual Term (in years)
Unvested at March 31, 2020	3 years 8 months 8 days
Vested and expected to vest at March 31, 2020	3 years 5 months 4 days	[1]
Aggregate Intrinsic Value
Unvested at March 31, 2020 | $	$ 69,183
Vested and expected to vest at March 31, 2020 | $	$ 63,352	[1]

[1] Represents the number of vested stock units as of March 31, 2020 plus the number of unvested stock units expected to vest as of December 31, 2019 based on the unvested outstanding stock units at December 31, 2019 adjusted for estimated forfeiture rates of 8% for awards granted to non-executive level employees and 3% for awards granted to executive level employees.