Income Taxes - Schedule of Reconciliation of Income Tax Expense (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
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| Income Tax Disclosure [Abstract] | ||
| Net loss before taxes | $ (285,556) | $ (219,134) |
| U.K. statutory tax rate | 25.00% | 25.00% |
| Income tax benefit at U.K. statutory tax rate | $ 71,389 | $ 54,783 |
| Tax-exempt reimbursable tax credits included within research and development expense | 0 | 4,934 |
| Non-deductible expenses | (17,505) | (26,757) |
| Adjustments in respect of prior years | 19,745 | 2,363 |
| Valuation allowance changes affecting the provision for income taxes | (74,571) | (36,022) |
| Other, net | (198) | 71 |
| Other foreign jurisdictions | (832) | (900) |
| Income tax expense | (1,972) | (1,528) |
| Current income tax expense | (2,603) | (1,703) |
| Deferred income tax benefit | $ 631 | $ 175 |
| Effective rate of income tax | 0.70% | 0.70% |
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- Definition Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Percentage of domestic federal statutory tax rate applicable to pretax income (loss). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- References No definition available.
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- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to foreign income tax expense (benefit). Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to nondeductible expenses. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other adjustments. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to revisions of previously reported income tax expense (benefit). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax credits. Including, but not limited to, research credit, foreign tax credit, investment tax credit, and other tax credits. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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