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v3.19.2

Segment Reporting - Additional Information (Detail) | 12 Months Ended
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Jun. 30, 2019 Segment
Disclosure of operating segments [abstract] |
Number of reportable segment | 4

X
- Definition Number of reportable segments. + References No definition available. + Details
Name: | bhp_NumberOfReportableSegments1
Namespace Prefix: | bhp_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

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- References No definition available. + Details
Name: | ifrs-full_DisclosureOfOperatingSegmentsAbstract
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration