Summary of Information Regarding Option Activity (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares
Options Outstanding
Options outstanding at December 31, 2014 | shares	1,225,117
Granted | shares	310,857
Exercised | shares	(177,693)
Forfeited/cancelled | shares	(117,346)
Options outstanding at December 31, 2015 | shares	1,240,935
Options exercisable at December 31, 2015 | shares	559,922
Vested and expected to vest at December 31, 2015 | shares	1,183,574	[1]
Weighted-Average Exercise Price Per Share
Options outstanding at December 31, 2014 | $ / shares	$ 8.31
Granted | $ / shares	15.23
Exercised | $ / shares	5.22
Forfeited/cancelled | $ / shares	8.81
Options outstanding at December 31, 2015 | $ / shares	10.44
Options exercisable at December 31, 2015 | $ / shares	6.77
Vested and expected to vest at December 31, 2015 | $ / shares	$ 10.42	[1]
Weighted-Average Remaining Contractual Term (in years)
Options outstanding at December 31, 2015	6 years 5 months 1 day
Options exercisable at December 31, 2015	3 years 10 months 21 days
Vested and expected to vest at December 31, 2015	6 years 4 months 10 days	[1]
Aggregate Intrinsic Value
Options outstanding at December 31, 2015 | $	$ 22,653
Options exercisable at December 31, 2015 | $	12,048
Vested and expected to vest at December 31, 2015 | $	$ 21,652	[1]

[1] This represents the number of vested options as of December 31, 2015 plus the number of unvested options expected to vest as of December 31, 2015 based on the unvested outstanding options at December 31, 2015 adjusted for estimated forfeiture rates of 8% for awards granted to non-executive level employees and 3% for awards granted to executive level employees.