Stock-Based Compensation - Summary of Stock Option Activity (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Beginning balance, options	353,525
Granted, options	209,310
Exercised, options	(124,065)
Expired, options	(11,400)
Ending balance, options	427,370
Exercisable options, ending balance	24,600
Beginning balance, weighted average exercise price | $ / shares	$ 31.63
Ending balance, weighted average exercise price | $ / shares	32.15
Exercisable, weighted average exercisable price | $ / shares	$ 27.28
Outstanding, weighted average remaining contractual life (years)	5 years 3 months 18 days
Exercisable, weighted average remaining contractual life (years)	3 years 3 months 18 days
Outstanding, aggregate intrinsic value | $	$ 5,128
Exercisable, aggregate intrinsic value | $	$ 415