Annual report pursuant to Section 13 and 15(d)

Income taxes - Change in Tax Rate (Details)

v3.22.0.1
Income taxes - Change in Tax Rate (Details)
12 Months Ended
Apr. 01, 2023
Dec. 31, 2021
USD ($)
Dec. 31, 2021
GBP (£)
Dec. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Income taxes          
Net operating loss   $ (162,246,000)   $ (133,405,000) $ (139,770,000)
Annual allowance | £     £ 5,000,000    
Percentage on taxable profit   50.00%      
U.K. | Forecast          
Income taxes          
Tax rate, deferred taxes (as a percent) 25.00%        
Her Majesty's Revenue and Customs (HMRC)          
Income taxes          
Tax rate (as a percent) 19.00% 19.00% 19.00% 19.00% 19.00%
Operating Loss Carryforwards   $ 423,572,000      
Expenditure credit carryforward   762,000      
Increase in net deferred tax asset and corresponding valuation allowance   $ 28,420,000      
Her Majesty's Revenue and Customs (HMRC) | U.K.          
Income taxes          
Tax rate, deferred taxes (as a percent)   25.00% 25.00% 19.00%  
Her Majesty's Revenue and Customs (HMRC) | U.S.          
Income taxes          
Tax rate, deferred taxes (as a percent)   21.00% 21.00%    
Internal Revenue Service (IRS)          
Income taxes          
Tax rate, deferred taxes (as a percent)   21.00% 21.00% 21.00% 21.00%
Tax credit carryforwards   $ 8,316,000      
Tax credit carried forward period   20 years 20 years