v3.26.1
Income Taxes - Reconciliation of Income Tax Benefit with Amounts at U.K. Statutory Income Tax Rate (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Reconciliation, amount:    
Statutory rate $ (26,827) $ (36,948)
Tax Credits (3,539) 6,476
Nontaxable or Nondeductible Items    
Nondeductible interest   (4,105)
Disallowed interest 837 1,456
Actual income tax benefit effective tax rate $ 0 $ 0
Tax Jurisdiction of Domicile [Extensible Enumeration] United Kingdom United Kingdom
Reconciliation, percent:    
Statutory rate 25.00% 25.00%
Tax Credits 3.30% (4.38%)
Nontaxable or Nondeductible Items    
Nondeductible interest 0.00% 2.78%
Other (0.78%) (0.99%)
Actual income tax benefit effective tax rate 0.00% 0.00%
United Kingdom    
Reconciliation, amount:    
Change in valuation allowance $ 4,395 $ 9,344
Nontaxable or Nondeductible Items    
Other Adjustments $ 621 $ 2,520
Reconciliation, percent:    
Change in valuation allowance (4.10%) (6.32%)
Nontaxable or Nondeductible Items    
Permanent differences - other (0.58%) 1.70%
United States    
Reconciliation, amount:    
Statutory tax rate difference between United States and United Kingdom $ 1,945 $ 1,621
State and Local Income Taxes, Net of Federal Income Tax Effect (188) (634)
RTP and other adjustment (4,253) (3,352)
Section 162(m) Adj. (2,226) (1,568)
Share based compensation shortfall 1,467 2,221
U.S. state rate change 1,832 (309)
Change in valuation allowance 12,694 11,405
Nontaxable or Nondeductible Items    
Other Adjustments $ 660 $ 1,875
Reconciliation, percent:    
Statutory tax rate difference between United States or Other Foreign Countries and United Kingdom (1.81%) (1.10%)
State and local rate, net of federal tax 0.18% 0.43%
Research and development tax credits 3.96% 2.27%
Section 162(m) Adj. 2.07% 1.06%
Share based compensation shortfall (1.37%) (1.50%)
U.S. state rate change (1.71%) 0.21%
Change in valuation allowance (11.83%) (7.72%)
Nontaxable or Nondeductible Items    
Permanent differences - other 0.62% 1.27%
Ireland    
Reconciliation, amount:    
Statutory rate $ 3,265 $ 3,134
Change in valuation allowance 3,265 3,134
Nontaxable or Nondeductible Items    
Other Adjustments $ 1,018 $ 172
Reconciliation, percent:    
Statutory tax rate difference between United States or Other Foreign Countries and United Kingdom (3.04%) (2.12%)
Change in valuation allowance (3.04%) (2.12%)
Nontaxable or Nondeductible Items    
Permanent differences - other (0.95%) (0.12%)
Other    
Reconciliation, amount:    
Statutory tax rate difference between United States and United Kingdom $ 1 $ (5)
Change in valuation allowance 938 155
Nontaxable or Nondeductible Items    
Other Adjustments $ (357) $ 272
Reconciliation, percent:    
Statutory tax rate difference between United States or Other Foreign Countries and United Kingdom 0.00% 0.00%
Change in valuation allowance (0.87%) (0.11%)
Nontaxable or Nondeductible Items    
Permanent differences - other 0.33% (0.18%)