Fair value disclosures - Schedule of fair value, assets and liabilities measured on recurring basis (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Fair value hierarchy level 2 \| Carrying amount
Assets
Derivative instruments	$ 39.9	$ 3.8
Liabilities
Debt	2,611.3	2,658.8
Derivative instruments	49.0	7.9
Fair value hierarchy level 2 \| Fair value
Assets
Derivative instruments	39.9	3.8
Liabilities
Debt	2,552.8	2,699.7
Derivative instruments	49.0	7.9
Fair value hierarchy level 3 \| Carrying amount
Liabilities
Contingent consideration	1.0	2.7
Fair value hierarchy level 3 \| Fair value
Liabilities
Contingent consideration	$ 1.0	$ 2.7

Amount of liability recognized arising from contingent consideration in a business combination.

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Name:	us-gaap_BusinessCombinationContingentConsiderationLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant