XML 127 R113.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Supplemental Oil and Gas Information (Costs Incurred in Oil and Gas Property Acquisition, Exploration and Development Activities) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Property acquisition costs |  |  |
Unproved | $ 63.4 | $ 18.6 | $ 12.6
Proved | 7.7 | 206.7 |
Total acquisition costs | 71.1 | 225.3 | 12.6
Exploration costs | 79.2 | 70.1 | 371.9
Development costs | 819.0 | 508.0 | 1,819.4
Total costs incurred | 969.3 | 803.4 | 2,203.9
Charged to expense |  |  |
Dry hole expense | (4.2) | 15.1 | 296.8
Geophysical and other costs | 65.2 | 43.4 | 98.7
Total charged to expense | 61.0 | 58.5 | 395.5
Property additions | 908.3 | 744.9 | 1,808.4
United States [Member] |  |  |
Property acquisition costs |  |  |
Unproved | 50.4 | 18.6 | 10.1
Proved | 7.7 |  |
Total acquisition costs | 58.1 | 18.6 | 10.1
Exploration costs | 13.7 | 18.5 | 166.8
Development costs | 508.4 | 239.7 | 1,375.1
Total costs incurred | 580.2 | 276.8 | 1,552.0
Charged to expense |  |  |
Dry hole expense | (1.9) | 0.4 | 241.3
Geophysical and other costs | 9.7 | 5.7 | 16.9
Total charged to expense | 7.8 | 6.1 | 258.2
Property additions | 572.4 | 270.7 | 1,293.8
Canada [Member] |  |  |
Property acquisition costs |  |  |
Unproved |  |  | 2.5
Proved |  | 206.7 |
Total acquisition costs |  | 206.7 | 2.5
Exploration costs | 0.6 | 3.6 | 0.7
Development costs | 273.8 | 165.1 | 231.5
Total costs incurred | 274.4 | 375.4 | 234.7
Charged to expense |  |  |
Geophysical and other costs | 0.5 | 3.6 | 0.7
Total charged to expense | 0.5 | 3.6 | 0.7
Property additions | 273.9 | 371.8 | 234.0
Malaysia [Member] |  |  |
Property acquisition costs |  |  |
Exploration costs | (8.9) | 6.0 | 69.0
Development costs | 35.7 | 102.9 | 210.0
Total costs incurred | 26.8 | 108.9 | 279.0
Charged to expense |  |  |
Dry hole expense | 0.7 | 4.5 | 29.7
Geophysical and other costs | 1.7 | 0.7 | 7.9
Total charged to expense | 2.4 | 5.2 | 37.6
Property additions | 24.4 | 103.7 | 241.4
Other Regions [Member] |  |  |
Property acquisition costs |  |  |
Unproved | 13.0 |  |
Total acquisition costs | 13.0 |  |
Exploration costs | 73.8 | 42.0 | 135.4
Development costs | 1.1 | 0.3 | 2.8
Total costs incurred | 87.9 | 42.3 | 138.2
Charged to expense |  |  |
Dry hole expense | (3.0) | 10.2 | 25.8
Geophysical and other costs | 53.3 | 33.4 | 73.2
Total charged to expense | 50.3 | 43.6 | 99.0
Property additions | 37.6 | (1.3) | 39.2
Asset Retirement Obligation Costs [Member] |  |  |
Property acquisition costs |  |  |
Development costs | 52.3 | 13.7 | 76.8
Total costs incurred | 52.3 | 13.7 | 76.8
Asset Retirement Obligation Costs [Member] | United States [Member] |  |  |
Property acquisition costs |  |  |
Development costs | 37.6 | 0.9 | 30.7
Total costs incurred | 37.6 | 0.9 | 30.7
Asset Retirement Obligation Costs [Member] | Canada [Member] |  |  |
Property acquisition costs |  |  |
Development costs | 6.3 | 10.5 | 49.1
Total costs incurred | 6.3 | 10.5 | 49.1
Asset Retirement Obligation Costs [Member] | Malaysia [Member] |  |  |
Property acquisition costs |  |  |
Development costs | 8.4 | 2.3 | (3.0)
Total costs incurred | $ 8.4 | $ 2.3 | $ (3.0)

X
- Definition Results Of Operations, Dry Hole Costs, Including Discontinued Operations + References No definition available. + Details
Name: | mur_ResultsOfOperationsDryHoleCostsIncludingDiscontinuedOperations
Namespace Prefix: | mur_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Results of Operations, Exploration Expense [Abstract] + References No definition available. + Details
Name: | mur_ResultsOfOperationsExplorationExpenseAbstract
Namespace Prefix: | mur_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Results Of Operations, Geophysical And Other Costs + References No definition available. + Details
Name: | mur_ResultsOfOperationsGeophysicalAndOtherCosts
Namespace Prefix: | mur_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Cost incurred, including capitalized costs and costs charged to expense, in acquisition of oil and gas properties. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 18 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62014-109447 + Details
Name: | us-gaap_CostsIncurredAcquisitionOfOilAndGasProperties
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_CostsIncurredAcquisitionOfOilAndGasPropertiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Costs incurred, including capitalized costs and costs charged to expense, associated with the acquisition of oil and gas properties that have proved reserves. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 18 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62014-109447 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 19 -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62038-109447 + Details
Name: | us-gaap_CostsIncurredAcquisitionOfOilAndGasPropertiesWithProvedReserves
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Costs incurred, including capitalized costs and costs charged to expense, associated with the acquisition of oil and gas properties that have unproved reserves. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 19 -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62038-109447 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 18 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62014-109447 + Details
Name: | us-gaap_CostsIncurredAcquisitionOfUnprovedOilAndGasProperties
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Development costs incurred, including capitalized costs and costs charged to expense, in oil and gas activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 18 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62014-109447 + Details
Name: | us-gaap_CostsIncurredDevelopmentCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Exploration costs incurred, including capitalized costs and costs charged to expense, in oil and gas activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 18 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62014-109447 + Details
Name: | us-gaap_CostsIncurredExplorationCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of costs incurred related to oil and gas property acquisition, exploration and development activities, including capitalized costs and costs charged to expense. + References No definition available. + Details
Name: | us-gaap_CostsIncurredOilAndGasPropertyAcquisitionExplorationAndDevelopmentActivities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of increase (decrease) of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. + References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentGrossPeriodIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition Exploration costs from 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 23 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62136-109447 + Details
Name: | us-gaap_ResultsOfOperationsExplorationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

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

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_AssetRetirementObligationCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |