Contract Assets and Liabilities - Cost and Estimated Earnings Compared to Billings on Uncompleted Contracts (Details) - USD ($) $ in Thousands |
Jun. 30, 2026 |
Sep. 30, 2025 |
Jun. 30, 2025 |
Sep. 30, 2024 |
|---|---|---|---|---|
| Revenue from Contract with Customer [Abstract] | ||||
| Costs on uncompleted contracts | $ 3,069,358 | $ 2,899,250 | ||
| Estimated earnings to date on uncompleted contracts | 406,155 | 393,665 | ||
| Costs and estimated earnings to date on uncompleted contracts | 3,475,513 | 3,292,915 | ||
| Billings to date on uncompleted contracts | (3,564,001) | (3,376,875) | ||
| Net billings in excess of costs and estimated earnings on uncompleted contracts | $ (88,488) | $ (83,960) | $ (69,588) | $ (94,099) |