Shareholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Equity, Class of Treasury Stock [Line Items]
Repurchase and retirement of common stock	$ 58.3	$ 206.2	$ 159.4	$ 378.5
Number of shares authorized to be repurchased (in shares)	204.0		204.0
Cash dividend paid during period, per share (in dollars per share)	$ 0.65	$ 0.64	$ 1.95	$ 1.92
Common stock excluded from calculation of diluted earnings per share (shares)	1.0	1.4	1.4	1.6
Common Stock
Equity, Class of Treasury Stock [Line Items]
Repurchase and retirement of common stock (shares)	0.5	1.7	1.4	3.2

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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Aggregate dividends paid during the period for each share of common stock outstanding.

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The number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

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Number of shares that have been repurchased and retired during the period.

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Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital).

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