v3.26.1
Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Amount    
Pretax loss $ (290,335) $ (153,528)
UK Federal Statutory Tax Rate (72,584) (38,382)
State and local income taxes, net of federal benefit   57
Other   (129)
Change in valuation allowance   25,410
Nontaxable or nondeductible items    
R&D deduction (64)  
R&D deductions surrendered 138 14,375
R&D credit included in profit before tax 3,305  
Change in fair value warrant liabilities 42,572  
Group relief 1,705  
Other 3,965  
Total provision for income taxes $ (2,473) $ 1,594
Rate    
UK Federal Statutory Tax Rate 25.00%  
Nontaxable or nondeductible items    
R&D deduction 0.00%  
R&D deductions surrendered 0.00%  
R&D credit included in profit before tax (1.10%)  
Change in fair value warrant liabilities (14.70%)  
Group relief (0.006)  
Other (1.40%)  
Effective income tax rate 0.90%  
United States    
Amount    
Foreign rate differential $ (144)  
Foreign-derived intangible income (FDII) deduction (2,772)  
Tax credits - federal research and development credit (1,478)  
State and local income taxes, net of federal benefit 19  
Other 1,005  
Change in valuation allowance $ 21,860  
Rate    
Foreign rate differential 0.00%  
Foreign-derived intangible income (FDII) deduction 1.00%  
Tax credits - federal research and development credit 0.50%  
State and local income taxes, net of federal benefit 0.00%  
Other (0.30%)  
Change in valuation allowance (7.50%)