v3.26.3
Income Taxes- Additional Information (Details) - USD ($)
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Income taxes [Line Items]              
Tax (benefit) provision $ 4,500,000 $ 5,200,000 $ 1,300,000 $ 10,400,000      
Effective tax rate 47.30% 34.60% 666.30% 40.00%      
Pre-IPO stock-based compensation expense $ 22,500,000   $ 22,500,000        
IPO related transaction costs included in tax expense     $ 500,000        
TRA liability 3,800,000            
Tax impact of reorganization $ 2,800,000            
HMH Holding BV And Subsidiaries [Member]              
Income taxes [Line Items]              
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount         $ 5,100,000 $ 2,800,000  
Addition In Valuation Allowance Deferred Tax Asset Change In Amount         3,600,000 3,400,000  
Deferred Tax Assets Valuation Allowance Reversal         900,000 900,000  
Deferred Tax Assets Operating Loss Reduction In Carryforwards         8,100,000 7,500,000  
Foreign Currency Translation Adjustments         400,000 1,900,000  
Addition In Valuation Allowance Defered Tax Assets           4,100,000  
Unrecognized Tax Benefits Favorable Rate Amount         800,000    
Deferred Tax Assets, Operating Loss Carryforwards         9,330 11,144  
Deferred Tax Asset, Interest Carryforward         10,885 18,713  
Undistributed Earnings of Foreign Subsidiaries         114,500,000    
Unrecognized Tax Benefits         771 771 $ 0
Income Tax Examination, Penalties and Interest Expense         300,000    
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense         1,900,000    
HMH Holding BV And Subsidiaries [Member] | Deferred Income Tax Charge [Member]              
Income taxes [Line Items]              
Deferred Tax Assets Interest Carryforward Subject To Expiration         10,600,000 19,600,000  
Deferred Tax Assets, Operating Loss Carryforwards         42,600,000 42,500,000  
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration         19,000,000 18,100,000  
Deferred Tax Asset, Interest Carryforward         43,800,000 $ 75,400,000  
Unrecognized Tax Benefits         $ 800,000