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, 2025 |
Sep. 30, 2024 |
|---|---|---|
| Disclosure of fair value measurement of liabilities [line items] | ||
| Tax receivable agreement liability | € 330,776 | € 344,590 |
| Carrying Value | Level 3 | ||
| Disclosure of fair value measurement of liabilities [line items] | ||
| Tax receivable agreement liability | 364,217 | 359,890 |
| Fair Value | Level 3 | ||
| Disclosure of fair value measurement of liabilities [line items] | ||
| Tax receivable agreement liability | € 379,436 | € 382,619 |