v3.26.1
Financial Instruments and Financial Risk Management - Schedule of Fair Value and Fair Value Hierarchy of Tax Receivable Liability Carried at Amortized Cost (Details) - EUR (€)
€ in Thousands
Jun. 30, 2026
Sep. 30, 2025
Disclosure of fair value measurement of liabilities [line items]    
Tax receivable agreement liability € 299,215 € 302,400
Carrying Value | Level 3    
Disclosure of fair value measurement of liabilities [line items]    
Tax receivable agreement liability 361,259 356,764
Fair Value | Level 3    
Disclosure of fair value measurement of liabilities [line items]    
Tax receivable agreement liability € 365,202 € 370,080