Financial assets - Consolidated balance sheets classification of financial assets carried at fair value (Details) - USD ($) $ in Thousands |
Jun. 30, 2026 |
Jun. 30, 2025 |
|---|---|---|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Total financial assets | $ 0 | $ 211,617 |
| 2030 Prepaid forward contract | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Total financial assets | 0 | 83,117 |
| 2029 Prepaid forward contract | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Total financial assets | 0 | 128,500 |
| Electricity financial asset | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Total financial assets | $ 0 | $ 0 |