Note 9 - Asset Retirement Obligations - Estimated Amounts and Timing of Cash Flows and Assumptions Used for ARO Estimates (Details) $ in Thousands |
Apr. 30, 2026
USD ($)
|
Jul. 31, 2025
USD ($)
|
|---|---|---|
| Undiscounted amount of estimated cash flows | $ 88,900 | $ 88,669 |
| Minimum [Member] | Measurement Input, Expected Term [Member] | ||
| Asset retirement obligations, measurement input | 1 | 1 |
| Minimum [Member] | Measurement Input, Inflation Rate [Member] | ||
| Asset retirement obligations, measurement input | 0.0156 | 0.0156 |
| Minimum [Member] | Measurement Input, Discount Rate [Member] | ||
| Asset retirement obligations, measurement input | 0.0372 | 0.0372 |
| Maximum [Member] | Measurement Input, Expected Term [Member] | ||
| Asset retirement obligations, measurement input | 36 | 37 |
| Maximum [Member] | Measurement Input, Inflation Rate [Member] | ||
| Asset retirement obligations, measurement input | 0.0532 | 0.0532 |
| Maximum [Member] | Measurement Input, Discount Rate [Member] | ||
| Asset retirement obligations, measurement input | 0.0635 | 0.0635 |