Goodwill and other intangible assets - Schedule of Other intangibles (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Finite-lived
Gross value	$ 5,865.5	$ 5,923.4
Accumulated amortization and impairment	2,943.6	2,821.9
Carrying value	2,921.9	3,101.5
Indefinite-lived	92.3	92.3
Total	3,014.2	3,193.8
Accumulated asset impairment charge	106.4	106.4
Customer relationships
Finite-lived
Gross value	4,864.4	4,915.0
Accumulated amortization and impairment	2,273.8	2,172.7
Carrying value	2,590.6	2,742.3
Accumulated asset impairment charge	65.9	65.9
Trade names
Finite-lived
Gross value	363.4	366.8
Accumulated amortization and impairment	279.5	272.9
Carrying value	83.9	93.9
Other
Finite-lived
Gross value	637.7	641.6
Accumulated amortization and impairment	390.3	376.3
Carrying value	247.4	265.3
Accumulated asset impairment charge	$ 40.5	$ 40.5

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