Segments - Restructuring and Related Costs (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment Reporting, Asset Reconciling Item [Line Items]
Restructuring costs	$ 8.0	$ 18.8	$ 45.9	$ 64.6
Other items, net	1.9	(5.0)	(3.3)	19.5
Foreign currency exchange gain (loss)	2.0	(0.3)	(1.4)	29.3
Nonoperating Income (Expense), Net Of Adjustments	(1.9)	0.6	3.0	(2.9)
Other items, net	1.3	1.6	4.8	4.9
Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment
Segment Reporting, Asset Reconciling Item [Line Items]
Restructuring costs	8.0	18.8	45.9	64.6
Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment \| Business Combination, Integration Related Costs
Segment Reporting, Asset Reconciling Item [Line Items]
Nonoperating Income (Expense), Adjustment	0.0	0.0	0.0	(1.0)
Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment \| Restructuring Costs
Segment Reporting, Asset Reconciling Item [Line Items]
Nonoperating Income (Expense), Adjustment	0.0	(4.4)	(0.3)	(4.4)
Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment \| Gain (Loss), Foreign Currency Transaction, Before Tax
Segment Reporting, Asset Reconciling Item [Line Items]
Nonoperating Income (Expense), Adjustment	0.0	0.0	0.0	22.0
ARGENTINA
Segment Reporting, Asset Reconciling Item [Line Items]
Foreign currency exchange gain (loss)			22.0	22.0
Cost of Sales
Segment Reporting, Asset Reconciling Item [Line Items]
Other items, net	0.0	0.2	0.0	3.1
Cost of Sales \| Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment
Segment Reporting, Asset Reconciling Item [Line Items]
Restructuring costs	2.9	13.4	21.0	41.7
Selling, general and administrate expense
Segment Reporting, Asset Reconciling Item [Line Items]
Other items, net	1.3	1.4	4.8	2.8
Selling, general and administrate expense \| Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment
Segment Reporting, Asset Reconciling Item [Line Items]
Restructuring costs	3.4	7.0	12.0	17.3
Selling, general and administrate expense \| IT enablement
Segment Reporting, Asset Reconciling Item [Line Items]
Restructuring costs	1.7	2.8	13.2	10.0
Selling, general and administrate expense \| IT enablement \| Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment
Segment Reporting, Asset Reconciling Item [Line Items]
Restructuring costs	$ 1.7	$ 2.8	13.2	$ 10.0
Nonoperating Income (Expense) \| ARGENTINA
Segment Reporting, Asset Reconciling Item [Line Items]
Foreign currency exchange gain (loss)			$ 21.0

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