Share-Based Compensation Plans - Stock Options Granted, Vested, and Exercised (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-Based Payment Arrangement [Abstract]
Grant-Date Fair Value of Stock Options Vested	$ 0.0	$ 0.0	$ 2.2
Stock Options Exercised
Intrinsic Value as of Exercise Date	1.6	3.6	41.3
Cash Received	2.3	3.9	53.8
Tax Deduction Benefits Realized	$ 1.6	$ 3.5	$ 41.3

Employee Service Share Based Compensation Tax Benefit Realized From Exercise Of Stock Option

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- Definition

Share Based Compensation Arrangement by Share Based Payment Award, Options, Exercises in Period [Abstract]

+ References

No definition available.

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- References

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- Definition

Amount of cash inflow from exercise of option under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 14
-Subparagraph (a)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-14

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2A
-Subparagraph (a)
-SubTopic 10
-Topic 718
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2A

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- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

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- Definition

Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

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