XML 125 R111.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Supplemental Oil and Gas Information (Narrative) (Details) MMBbls in Millions | 1 Months Ended | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Jan. 31, 2015 | Dec. 31, 2018 | Dec. 31, 2017 bbl | Dec. 31, 2017 MMcf | Dec. 31, 2017 ft³ | Dec. 31, 2017 MMBbls | Dec. 31, 2017 $ / Mcf | Dec. 31, 2017 | Dec. 31, 2016 ft³ MMBbls | Dec. 31, 2015 ft³ MMBbls | Dec. 31, 2014 ft³ MMBbls
Reserve Quantities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Proved reserves |  |  |  |  |  |  | 328.1 |  |  | 329.0 | 456.2 | 441.8
Future net cash flows annual discount factor, percentage |  |  |  |  |  |  |  |  | 10.00% |  |  |
U.S. statutory rate |  |  |  | 35.00% |  |  |  |  |  |  |  |
Equity Method Investee [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Reserves attributable to investees accounted for my the equity method | bbl |  |  |  | 0 |  |  |  |  |  |  |  |
Scenario, Plan [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
U.S. statutory rate |  |  | 21.00% |  |  |  |  |  |  |  |  |
Oil Reserves [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Proved undeveloped reserve development window |  |  |  | 5 years |  |  |  |  |  |  |  |
Natural Gas Liquids Reserves [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Proved reserves |  |  |  |  |  |  | 48.9 |  |  | 42.5 | 36.4 | 30.6
Proved undeveloped reserve development window |  |  |  | 5 years |  |  |  |  |  |  |  |
Natural Gas Reserves [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Proved reserves | ft³ |  |  |  |  |  | 1,927,100,000,000 |  |  |  | 1,878,000,000,000 | 1,688,800,000,000 | 1,704,700,000,000
Proved undeveloped reserve development window |  |  |  | 5 years |  |  |  |  |  |  |  |
Alberta, Canada [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Working interest |  |  |  |  |  |  |  |  |  |  | 5.00% |
Malaysia [Member] | Oil Reserves [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Proved reserves |  |  |  |  |  |  | 52.2 |  |  |  |  |
Malaysia [Member] | Natural Gas Liquids Reserves [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Proved reserves |  |  |  |  |  |  | 0.3 |  |  | 0.5 | 0.6 | 0.8
Malaysia [Member] | Natural Gas Reserves [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Proved reserves |  |  |  |  | 491,300 | 491,400,000,000 |  |  |  | 539,700,000,000 | 546,800,000,000 | 635,600,000,000
Malaysia [Member] | Natural Gas Reserves [Member] | Held-for-sale [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Proved reserves | ft³ |  |  |  |  |  | 26,700 |  |  |  |  |  |
Expected sales proceeds | $ / Mcf |  |  |  |  |  |  |  | 0.24 |  |  |  |
Canada [Member] | Natural Gas Liquids Reserves [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Proved reserves |  |  |  |  |  |  | 5.6 |  |  | 5.6 | 0.4 | 0.7
Canada [Member] | Natural Gas Reserves [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Proved reserves | ft³ |  |  |  |  |  | 1,212,400,000,000 |  |  |  | 1,118,900,000,000 | 909,600,000,000 | 842,800,000,000
Canada [Member] | Synthetic Oil [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Proved reserves | [1] |  |  |  |  |  |  |  |  | 0.0 | 114.8 | 105.6
Malaysia [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Percentage of interest in oil and gas property sold during period |  | 10.00% |  |  |  |  |  |  |  |  |  |
[1] | All synthetic oil operations were sold in June 2016.

X
- Definition Discounted Cash Flow Method Percentage + References No definition available. + Details
Name: | mur_DiscountedCashFlowMethodPercentage
Namespace Prefix: | mur_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Oil And Gas Property, Working Interest + References No definition available. + Details
Name: | mur_OilAndGasPropertyWorkingInterest
Namespace Prefix: | mur_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage Of Interest In Oil AndGas Properties Sold During Period + References No definition available. + Details
Name: | mur_PercentageOfInterestInOilAndgasPropertiesSoldDuringPeriod
Namespace Prefix: | mur_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Proved Developed Reserves, Expected Sales Price By Volume + References No definition available. + Details
Name: | mur_ProvedDevelopedReservesExpectedSalesPriceByVolume
Namespace Prefix: | mur_
Data Type: | us-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition Proved Undeveloped Reserve Development Window + References No definition available. + Details
Name: | mur_ProvedUndevelopedReserveDevelopmentWindow
Namespace Prefix: | mur_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of domestic federal statutory tax rate applicable to pretax income (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 6.I) -URI http://asc.fasb.org/extlink&oid=34349781&loc=d3e330036-122817 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319 + Details
Name: | us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The net quantity of proved reserves as of the balance sheet date. Proved oil reserves are the estimated quantities of crude oil and natural gas liquids which geological and engineering data demonstrate with reasonable certainty to be recoverable. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61831-109447 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-10.(a)(2)) -URI http://asc.fasb.org/extlink&oid=82851474&loc=d3e511914-122862 + Details
Name: | us-gaap_ProvedDevelopedAndUndevelopedReservesNet
Namespace Prefix: | us-gaap_
Data Type: | num:volumeItemType
Balance Type: | na
Period Type: | instant

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_ReserveQuantitiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The proportional interest of net proved oil reserve quantities of equity investees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 8 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61872-109447 + Details
Name: | us-gaap_ReservesShareOfEquityMethodInvesteesNetProvedOilAndGasReserves
Namespace Prefix: | us-gaap_
Data Type: | num:volumeItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_EquityMethodInvesteeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_ScenarioPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ReserveQuantitiesByTypeOfReserveAxis=us-gaap_OilReservesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ReserveQuantitiesByTypeOfReserveAxis=us-gaap_NaturalGasLiquidsReservesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ReserveQuantitiesByTypeOfReserveAxis=us-gaap_NaturalGasReservesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

X
- Details
Name: | us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_ProductOrServiceAxis=us-gaap_SyntheticOilMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=country_MY
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |