XML 254 R193.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Standardised Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves (Standardised Measure) (Parenthetical) (Detail) - USD ($) $ in Millions | Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2016 | Jun. 30, 2015
--- | --- | --- | --- | ---
Discounted future net cash flows relating to proved oil and gas reserves [Line Items] |  |  |  |
Standardised measure | $ 10,240 | $ 8,242 | $ 8,987 | $ 17,244
United States [member] |  |  |  |
Discounted future net cash flows relating to proved oil and gas reserves [Line Items] |  |  |  |
Standardised measure | 5,257 | 3,466 | 3,477 |
United States [member] | Discontinued Operations - Onshore US Cash Generating Units [Member] |  |  |  |
Discounted future net cash flows relating to proved oil and gas reserves [Line Items] |  |  |  |
Standardised measure | $ 1,932 | $ 1,962 | $ 1,889 |

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of discounted future accumulated cash inflow relating to proved oil and gas reserves. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 30 -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62424-109447 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=34713648&loc=d3e63123-109448 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62479-109447 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 35 -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62500-109447 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 31 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62455-109447 + Details
Name: | us-gaap_StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_StatementGeographicalAxis=country_US
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ContinuingAndDiscontinuedOperationsAxis=bhp_DiscontinuedOperationsOnshoreUSCashGeneratingUnitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |