Stock-based Compensation - Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares, Beginning Balance	507,084
Granted, Shares	103,709
Exercised, Shares	(167,675)	(45,289)	(67,029)
Forfeited, Shares	(6,992)
Shares, Ending Balance	436,126	507,084
Vested or expected to vest, Shares	432,181
Exercisable, Shares	258,093
Weighted Average Exercise Price, Beginning Balance	$ 36.57
Granted, Weighted Average Exercise Price	44.03
Exercised, Weighted Average Exercise Price	23.95
Forfeited, Weighted Average Exercise Price	45.36
Weighted Average Exercise Price, Ending Balance	42.99	$ 36.57
Vested or expected to vest, Weighted Average Exercise Price	42.68
Exercisable, Weighted Average Exercise Price	$ 43.12
Weighted Average Remaining Contractual Term, Ending Balance	5 years 9 months 18 days
Vested or expected to vest, Weighted Average Remaining Contractual Term	5 years 10 months 10 days
Exercisable, Weighted Average Remaining Contractual Term	3 years 9 months 26 days
Aggregate Intrinsic Value, Ending Balance	$ 16,785
Vested or expected to vest, Aggregate Intrinsic Value	13,022
Exercisable, Aggregate Intrinsic Value	$ 9,900