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Employee Benefit Plans (Principal Components of Employee Benefit Costs) (Detail) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Employee Benefit Plan Disclosure [Line Items] |  |  |
Pension and Other Postretirement Benefits Cost (Reversal of Cost) | $ 98.9 | $ 73.6 | $ 34.8
Savings Plan |  |  |
Employee Benefit Plan Disclosure [Line Items] |  |  |
Savings plan | 60.5 | 34.5 | 37.3
Unfunded Supplemental Benefit Plans |  |  |
Employee Benefit Plan Disclosure [Line Items] |  |  |
Employee benefit plan expenses | 12.0 | 12.3 | 12.2
Other Plans, Net |  |  |
Employee Benefit Plan Disclosure [Line Items] |  |  |
Other plans, net | $ 26.4 | $ 26.8 | $ (14.7)

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- Definition Employee benefit plan disclosure line items. + References No definition available. + Details
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- Definition Savings and deferred compensation plans expense. + References No definition available. + Details
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- Definition Amount of cost for defined contribution plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 70 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480794/715-70-50-1 + Details
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- Definition Amount of cost (reversal of cost) for pension benefits. Excludes other postretirement benefits. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 48 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482785/280-10-55-48 + Details
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- Details
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- Details
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