Significant Events - Summary of Provision for Samarco Dam Failure (Detail) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Jun. 30, 2021 |
Jun. 30, 2020 |
|
| Disclosure of other provisions [line items] | ||
| Current | $ 3,696 | $ 2,810 |
| Non-current | 13,799 | 11,185 |
| Samarco dam failure [member] | ||
| Disclosure of other provisions [line items] | ||
| At the beginning of the financial year | 2,051 | 1,914 |
| Movement in provisions | 741 | 137 |
| Utilised | (359) | (369) |
| Change in estimate - Samarco dam failure provision | 842 | 916 |
| Change in estimate - Samarco Germano dam decommissioning | (6) | 37 |
| Amortisation of discounting impacting net finance costs | 85 | 93 |
| Exchange translation | 179 | (540) |
| Current | 1,206 | 896 |
| Non-current | 1,586 | 1,155 |
| At the end of the financial year | 2,792 | 2,051 |
| Samarco dam failure provision | 2,560 | 1,824 |
| Samarco Germano dam decommissioning provision | $ 232 | $ 227 |