v3.26.1
STOCK-BASED COMPENSATION - Quantinuum 2023 Equity Incentive Plan (Details) - USD ($)
$ in Thousands
1 Months Ended 3 Months Ended 6 Months Ended
Jun. 05, 2026
Dec. 20, 2023
Jun. 30, 2026
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Jun. 04, 2026
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]                
Stock compensation expense     $ 6,900 $ 447,460 $ 0 $ 447,460 $ 0  
Restricted shares                
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]                
Shares with not grant date (in shares)     400,791 400,791   400,791    
RSUs                
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]                
Award service period 4 years              
Shares with not grant date (in shares)     151,562 151,562   151,562    
2023 Plan                
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]                
Award service period   4 years            
Stock compensation expense $ 103,800              
2023 Plan | Restricted Stock Units (RSUs) And Restricted Shares                
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]                
Unrecognized stock-based compensation expense     $ 38,700 $ 38,700   $ 38,700    
Weighted-average period of recognition           1 year 3 months 18 days    
2023 Plan | Class C                
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]                
Awards available for grant (in shares) 3,845,117             6,443,305
2023 Plan | Class C | RSUs                
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]                
Awards available for grant (in shares) 757,816              
2023 Plan | Class A | Restricted shares                
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]                
Awards available for grant (in shares) 2,898,904