Commitments and contingencies - Changes in Accrued Environmental Remediation and Related Costs (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2025	Dec. 31, 2024
Environmental Remediation Obligations
Balance at the beginning of the period	$ 74.6
Additions charged to expense, net	2.2
Payments, net	(58.2)
Balance at the end of the period	18.6
Amounts recognized in the Consolidated Balance Sheet at the end of the period:
Current liabilities	4.3	$ 59.7
Noncurrent liabilities	14.3	14.9
Total	$ 18.6	$ 74.6

Total costs accrued as of the balance sheet date for environmental loss contingencies.

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Amount of cash outflow to settle environmental loss contingencies.

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Carrying value of the obligation (known or estimated) arising from requirements to perform activities to remediate one or more sites, payable in twelve months or in the next operating cycle if longer.

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Accrued environmental loss contingencies.

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