Stock-based Compensation - Summary of Status and Activity of Stock Options (Detail) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2021 USD ($) $ / shares shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Options, Outstanding at December 31, 2020 | shares	1,120,254
Options, Granted | shares	90,879
Options, Exercised | shares	(71,785)
Options, Expired | shares	(25,402)
Options, Outstanding at September 30, 2021 | shares	1,113,946
Options, Exercisable at September 30, 2021 | shares	797,911
Weighted Average Exercise Price per Option, Outstanding at December 31, 2020 | $ / shares	$ 26.89
Weighted Average Exercise Price per Option, Granted | $ / shares	29.84
Weighted Average Exercise Price per Option, Exercised | $ / shares	17.74
Weighted Average Exercise Price per Option, Expired | $ / shares	40.26
Weighted Average Exercise Price per Option, Outstanding at September 30, 2021 | $ / shares	27.41
Weighted Average Exercise Price per Option, Exercisable at September 30, 2021 | $ / shares	$ 28.16
Weighted Average Remaining Contractual Term, Outstanding at September 30, 2021	5 years 2 months 15 days
Weighted Average Remaining Contractual Term, Exercisable at September 30, 2021	4 years 29 days
Aggregate Intrinsic Value, Outstanding at September 30, 2021 | $	$ 7.8
Aggregate Intrinsic Value, Exercisable at September 30, 2021 | $	$ 5.7