Stock-Based Compensation - Summary of Stock Option Transactions and Related Information (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options Outstanding, Beginning Balance (in shares) | shares	1,089,538
Options, Granted (in shares) | shares	155,100
Options, Exercised (in shares) | shares	(487,203)
Options, Forfeited (in shares) | shares	(9,064)
Options Outstanding, Ending Balance (in shares) | shares	748,371
Options Exercisable, Ending Balance (in shares) | shares	384,679
Weighted Average Exercise Price, Outstanding Beginning Balance (in dollars per share) | $ / shares	$ 44.95
Weighted Average Exercise Price, Granted (in dollars per share) | $ / shares	68.73
Weighted Average Exercise Price, Exercised (in dollars per share) | $ / shares	39.44
Weighted Average Exercise Price, Forfeited (in dollars per share) | $ / shares	64.20
Weighted Average Exercise Price, Outstanding Ending Balance (in dollars per share) | $ / shares	53.24
Weighted Average Exercise Price, Exercisable Ending Balance (in dollars per share) | $ / shares	$ 45.82
Weighted Average Remaining Contractual Life - Years, Outstanding Ending Balance	7 years 1 month 17 days
Weighted Average Remaining Contractual Life - Years, Exercisable Ending Balance	5 years 7 months 2 days
Aggregate Intrinsic Value, Outstanding Ending Balance | $	$ 37,523
Aggregate Intrinsic Value, Exercisable Ending Balance | $	$ 22,142