Other–Net, (Income) Expense (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Nonoperating Income (Expense) [Abstract]
Interest expense	$ 192.7	$ 124.6	$ 555.9	$ 347.7
Interest income	(47.8)	(48.9)	(130.9)	(129.1)
Net investment (gains) losses on equity securities (Note 7)	(112.4)	62.9	29.5	141.5
Retirement benefit plans	(115.4)	(115.5)	(345.9)	(346.9)
Other (income) expense	20.9	0.1	(0.1)	11.1
Other–net, (income) expense	$ (62.0)	$ 23.2	$ 108.5	$ 24.3

Amount of unrealized and realized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of interest expense classified as nonoperating.

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Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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Amount of expense (reversal of expense) for net periodic benefit cost components, excluding service cost component, of defined benefit plan. Amount includes, but is not limited to, interest cost, expected (return) loss on plan asset, amortization of prior service cost (credit), amortization of (gain) loss, amortization of transition (asset) obligation, settlement (gain) loss, curtailment (gain) loss and certain termination benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).

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Amount of income (expense) related to nonoperating activities, classified as other.

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