v3.26.1
Equity - Change in Ownership of HMH B.V (Details) - HMH Holding B.V. And Subsidiaries
 3 Months Ended
Jun. 30, 2026
shares
Ownership  
Beginning balance (in shares) 86,194,992
Purchase of HMH B.V. Shares (in shares) 0
Partial Exercise of Underwriters Purchase Option (in shares) 0
Issuance under the Equity Based Compensation Plan (in shares) 1,673,568
Ending balance (in shares) 87,868,560
Ownership Percentage  
Beginning balance 100.00%
Purchase of HMH B.V. Shares 0.00%
Partial Exercise of Underwriters Purchase Option 0.00%
Issuance under the Equity Based Compensation Plan 0.00%
Ending balance 100.00%
HMH Holdings Inc.  
Ownership  
Beginning balance (in shares) 16,840,000
Purchase of HMH B.V. Shares (in shares) 4,200,000
Partial Exercise of Underwriters Purchase Option (in shares) 1,371,688
Issuance under the Equity Based Compensation Plan (in shares) 1,673,568
Ending balance (in shares) 24,085,256
Ownership Percentage  
Beginning balance 19.50%
Purchase of HMH B.V. Shares 4.90%
Partial Exercise of Underwriters Purchase Option 1.60%
Issuance under the Equity Based Compensation Plan 1.40%
Ending balance 27.40%
Noncontrolling Interests  
Ownership  
Beginning balance (in shares) 69,354,992
Purchase of HMH B.V. Shares (in shares) (4,200,000)
Partial Exercise of Underwriters Purchase Option (in shares) (1,371,688)
Issuance under the Equity Based Compensation Plan (in shares) 0
Ending balance (in shares) 63,783,304
Ownership Percentage  
Beginning balance 80.50%
Purchase of HMH B.V. Shares (4.90%)
Partial Exercise of Underwriters Purchase Option (1.60%)
Issuance under the Equity Based Compensation Plan (1.40%)
Ending balance 72.60%