Income taxes - Uncertain tax positions (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
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| Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] | |||
| Balance, January 1 | $ 85 | $ 82 | $ 82 |
| Additions based on tax positions related to the current year | 2 | 3 | 3 |
| Additions for tax positions of prior years | 0 | 0 | 0 |
| Reductions for tax positions of prior years | 0 | 0 | (3) |
| Balance, December 31 | 87 | 85 | 82 |
| Interest income (expense) recognized in the year ended December 31 | 9 | (5) | (9) |
| Interest payable as of December 31 | $ 22 | $ 15 | $ 10 |
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- Definition Amount of interest benefit (expense) for an overpayment or underpayment of income taxes. No definition available.
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- Definition Amount of interest benefit (expense) accrued for an overpayment or underpayment of income taxes. No definition available.
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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- Definition Amount of unrecognized tax benefits. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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