Fair value of financial assets and liabilities - Financial assets and liabilities measured at fair value (Details) - USD ($) $ in Millions |
Sep. 30, 2026 |
Dec. 31, 2025 |
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| Fair value of financial assets and liabilities | ||
| Collateral restricted cash | $ 0.5 | |
| Restricted Cash, Statement of Financial Position [Extensible Enumeration] | Prepaid Expense and Other Assets, Current | |
| Recurring | ||
| Fair value of financial assets and liabilities | ||
| Liabilities at fair value | $ 0.0 | $ 0.0 |
| Assets at fair value | 0.0 | 0.0 |
| Level 1 | Recurring | Cash equivalents | ||
| Fair value of financial assets and liabilities | ||
| Market funds | $ 325.4 | $ 364.2 |
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- Definition Fair value portion of asset recognized for present right to economic benefit. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition 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. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Investment in short-term money-market instruments (such as commercial paper, banker's acceptances, repurchase agreements, government securities, certificates of deposit, and so forth) which are highly liquid (that is, readily convertible to known amounts of cash) and so near their maturity that they present an insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify as cash equivalents by definition. Original maturity means an original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- 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/2003/role/disclosureRef
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