Impairment of Non-current Assets - Additional Information (Detail) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Jun. 30, 2021 |
Jun. 30, 2020 |
|
| Disclosure of detailed information about impairment of noncurrent assets [Line items] | ||
| Goodwill | $ 1,197 | $ 1,197 |
| Olympic Dam [member] | ||
| Disclosure of detailed information about impairment of noncurrent assets [Line items] | ||
| Discount rate applied | 6.00% | |
| Amount by which unit's recoverable amount exceeds its carrying amount | $ 1,800 | |
| Goodwill | $ 1,010 | 1,010 |
| Production volume decrease | 4.80% | |
| Other Cash Generating Units [Member] | ||
| Disclosure of detailed information about impairment of noncurrent assets [Line items] | ||
| Goodwill | $ 187 | 187 |
| Goodwill impairment loss | $ 0 | $ 0 |
| Other Cash Generating Units [Member] | Top of range [member] | ||
| Disclosure of detailed information about impairment of noncurrent assets [Line items] | ||
| Percentage of goodwill included in net assets | 1.00% | 1.00% |