Summary of significant accounting policies - Cash and cash equivalents (Details) - USD ($) $ in Millions |
Dec. 31, 2025 |
Dec. 31, 2024 |
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| Summary of significant accounting policies | ||
| Cash equivalents | $ 364.2 | $ 664.9 |
| Collateral restricted cash | $ 0.5 | $ 0.5 |
| Restricted Cash, Statement of Financial Position [Extensible Enumeration] | Other Assets, Noncurrent, Prepaid Expense and Other Assets, Current | Other Assets, Noncurrent, Prepaid Expense and Other Assets, Current |
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- References No definition available.
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- Definition Amount of short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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| X | ||||||||||
- Definition Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Indicates line item in statement of financial position that includes cash restricted to withdrawal or usage. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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