Goodwill and intangible assets - Narrative (Details) - USD ($) $ in Millions |
Jun. 30, 2026 |
Sep. 30, 2025 |
Jun. 30, 2025 |
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| Intangible Asset, Finite-Lived [Line Items] | |||
| Indefinite-lived intangible assets | $ 641.1 | $ 640.8 | |
| Intangible asset, book value | 325.6 | 364.7 | |
| Trade names | |||
| Intangible Asset, Finite-Lived [Line Items] | |||
| Intangible asset, book value | $ 102.1 | $ 108.6 | |
| Trade names | Rayovac | |||
| Intangible Asset, Finite-Lived [Line Items] | |||
| Intangible asset, definite life (in years) | 30 years | ||
| Intangible asset, book value | $ 337.0 |
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- Definition Useful life of finite-lived intangible asset, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Excludes goodwill and capitalized cost for software to be sold, leased, or marketed. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount, after accumulated amortization, of finite-lived intangible asset. Excludes goodwill and capitalized cost for software to be sold, leased, or marketed. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount of indefinite-lived intangible asset. Excludes goodwill. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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