Supplemental Financial Information Supplemental Financial Information (Other Income) (Details) - USD ($) $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
Apr. 30, 2021	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022
Supplemental Financial Information [Abstract]
Loss on extinguishment of debt	$ 0.0	$ 0.0	$ (29.2)	$ 0.0
Gain (Loss) on Sale of Properties	6.0	21.2	28.6	141.2
Net foreign currency exchange gains (losses)	13.4	8.1	(3.5)	12.2
Net periodic pension and retiree medical income	(5.4)	8.7	0.9	16.4
Other Nonoperating Expense	1.1	0.1	1.4	0.1
Other, net	$ 25.9	$ 38.1	$ (1.8)	$ 169.9
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]			Other, net

Indicates line item in statement of income or comprehensive income that includes components of net periodic benefit cost (credit), excluding service cost component, for defined benefit plan.

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Amount, before tax, of realized and unrealized gain (loss) from foreign currency transaction.

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The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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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.

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

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

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Supplemental Financial Information [Abstract]

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No definition available.

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