Financial Instruments and Financial Risk Management - Schedule of Fair Values and Fair Value Hierarchy of Financial Instruments Carried at Fair Value on Recurring Basis (Details) - Recurring Fair Value Measurement - FVtPL - EUR (€) € in Thousands |
Jun. 30, 2026 |
Sep. 30, 2025 |
|---|---|---|
| Level 2 | ||
| Disclosure of detailed information about financial instruments [line items] | ||
| Currency derivative | € 2,174 | € 16,851 |
| Derivative liabilities | 9,307 | 347 |
| Level 3 | ||
| Disclosure of detailed information about financial instruments [line items] | ||
| Original Senior Notes - embedded derivative | 0 | 22,796 |
| New Senior Notes - embedded derivative | € 5,621 | € 0 |