Segments - Restructuring and Related Costs (Details) - USD ($) $ in Millions	3 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Segment Reporting, Asset Reconciling Item [Line Items]
Restructuring costs	$ 20.3	$ 22.4
Other items, net	(5.0)	19.0
Foreign currency exchange gain (loss)	(3.8)	23.7
Nonoperating Income (Expense), Net Of Adjustments	5.0	1.0
APS Battery Manufacturing Assets
Segment Reporting, Asset Reconciling Item [Line Items]
Acquisition and integration costs	(1.2)	(2.6)
ARGENTINA
Segment Reporting, Asset Reconciling Item [Line Items]
Foreign currency exchange gain (loss)	21.0	(21.0)
Cost of Sales
Segment Reporting, Asset Reconciling Item [Line Items]
Restructuring costs	9.4	12.8
Cost of Sales \| APS Battery Manufacturing Assets
Segment Reporting, Asset Reconciling Item [Line Items]
Acquisition and integration costs, operating costs	0.0	2.9
Selling, general and administrate expense
Segment Reporting, Asset Reconciling Item [Line Items]
Restructuring costs	4.8	5.7
Selling, general and administrate expense \| APS Battery Manufacturing Assets
Segment Reporting, Asset Reconciling Item [Line Items]
Legal and diligence fees	1.2	0.7
Selling, general and administrate expense \| IT enablement
Segment Reporting, Asset Reconciling Item [Line Items]
Restructuring costs	6.1	3.9
Nonoperating Income (Expense)
Segment Reporting, Asset Reconciling Item [Line Items]
Foreign currency exchange gain (loss)	0.0	$ 21.0
Nonoperating Income (Expense) \| ARGENTINA
Segment Reporting, Asset Reconciling Item [Line Items]
Foreign currency exchange gain (loss)	$ 21.0

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