Stock-Based Compensation - Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Options Outstanding
Beginning balance (in shares)	1,097,323
Granted (in shares)	93,765
Exercised (in shares)	(21,565)
Canceled (in shares)	(4,471)
Ending balance (in shares)	1,165,052	1,097,323
Exercisable at period end (in shares)	942,015
Weighted-Average Exercise Price per Share
Beginning balance (in dollars per share)	$ 32.70
Granted (in dollars per share)	61.33
Exercised (in dollars per share)	23.90
Canceled (in dollars per share)	68.03
Ending balance (in dollars per share)	35.04	$ 32.70
Exercisable (in dollars per share)	$ 27.17
Weighted-Average Remaining Contractual Life
Outstanding, weighted average remaining contractual life	5 years	4 years 9 months 18 days
Exercisable weighted average remaining contractual life	4 years 2 months 12 days
Aggregate Intrinsic Value
Beginning balance	$ 42,154
Granted	1,779
Exercised	1,216
Canceled	55
Ending balance	52,735	$ 42,154
Exercisable	$ 50,051