Commitments and Contingencies - Schedule of Warranty Liabilities (Details) - USD ($) $ in Thousands |
9 Months Ended | 12 Months Ended |
|---|---|---|
Jun. 30, 2026 |
Sep. 30, 2025 |
|
| Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward] | ||
| Warranty balance, beginning | $ 51,807 | $ 40,242 |
| Warranties issued and assumed in period | 13,309 | 22,409 |
| Change in estimates | 0 | 3,173 |
| Net changes in liability for warranty expirations, costs incurred, and foreign exchange impact | (7,641) | (14,017) |
| Warranty balance, ending | 57,475 | 51,807 |
| Less: Recoverable warranty costs from suppliers | 28,138 | 23,578 |
| Warranty balance, net of recoverable warranty costs from suppliers, at end of period | $ 29,337 | $ 28,229 |