Summary of Activity Under Stock Plans (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Intrinsic value of options exercised	$ 25.4	$ 26.9	$ 31.9
Cash received from stock option exercises	38.4	53.8	60.9
Tax benefit related to stock award exercises	4.9	3.8	3.8
Stock-based compensation	14.7	13.0	15.1
Tax benefit related to stock-based compensation	$ 1.6	$ 1.6	$ 1.9

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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