Fair value measurements - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt at fair value	$ 3,538.9	$ 3,793.5
Level 3 \| Fair value, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	12,691.2	12,878.0
Goodwill at fair value	9,085.4	9,022.1
Net intangible assets at fair value	$ 3,605.8	$ 3,855.9

Fair value portion of asset recognized for present right to economic benefit.

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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.

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Fair value portion of assets, excluding financial assets, that lack physical substance, having a limited useful life.

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Fair value portion of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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