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Capitalised Costs Relating to Oil and Gas Production Activities (Detail) - USD ($) $ in Millions | Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2016
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Capitalized costs relating to oil and gas producing activities, by geographic area [Line Items] |  |  |
Unproved properties | $ 4,740 | $ 5,543 | $ 5,531
Proved properties | 62,567 | 60,431 | 58,824
Total costs | 67,307 | 65,974 | 64,355
Less: Accumulated depreciation, depletion, amortisation and valuation provisions | (45,486) | (42,038) | (38,966)
Net capitalised costs | 21,821 | 23,936 | 25,389
Australia [member] |  |  |
Capitalized costs relating to oil and gas producing activities, by geographic area [Line Items] |  |  |
Unproved properties | 10 | 94 | 338
Proved properties | 16,258 | 16,190 | 15,523
Total costs | 16,268 | 16,284 | 15,861
Less: Accumulated depreciation, depletion, amortisation and valuation provisions | (9,984) | (9,085) | (8,364)
Net capitalised costs | 6,284 | 7,199 | 7,497
United States [member] |  |  |
Capitalized costs relating to oil and gas producing activities, by geographic area [Line Items] |  |  |
Unproved properties | 4,528 | 5,284 | 5,074
Proved properties | 43,885 | 41,837 | 40,929
Total costs | 48,413 | 47,121 | 46,003
Less: Accumulated depreciation, depletion, amortisation and valuation provisions | (33,437) | (30,969) | (28,664)
Net capitalised costs | 14,976 | 16,152 | 17,339
Other countries [member] |  |  |
Capitalized costs relating to oil and gas producing activities, by geographic area [Line Items] |  |  |
Unproved properties | 202 | 165 | 119
Proved properties | 2,424 | 2,404 | 2,372
Total costs | 2,626 | 2,569 | 2,491
Less: Accumulated depreciation, depletion, amortisation and valuation provisions | (2,065) | (1,984) | (1,938)
Net capitalised costs | $ 561 | $ 585 | $ 553

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- Definition Amount of accumulated depreciation, depletion, amortization and valuation allowance relating to oil and gas producing activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61901-109447 + Details
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- Definition The sum of capitalized costs relating to oil and gas producing activities before accounting for accumulated depreciation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61901-109447 + Details
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- Definition Net amount of capitalized costs relating to oil and gas producing activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61901-109447 + Details
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- Definition Capitalized costs of proved properties incurred for any combination mineral interests acquisitions; wells and related equipment; support equipment and facilities; and uncompleted wells and equipment and other costs not previously disclosed within this table. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 360 -URI http://asc.fasb.org/subtopic&trid=2145654 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61901-109447 + Details
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- Definition Capitalized costs of unproved properties incurred for any combination mineral interests acquisitions and other costs not previously disclosed within this table. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -URI http://asc.fasb.org/topic&trid=2145477 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61901-109447 + Details
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