XML 1075 R50.htm IDEA: XBRL DOCUMENT
v3.20.4

Summary of Significant Accounting Policies Property, Plant and Equipment (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Property, Plant and Equipment [Line Items] |  |  |  |  |
Property, Plant and Equipment, Gross | $ 13,442.2 |  | $ 12,912.7 |  |
Accumulated Depreciation | 4,067.6 |  | 3,868.1 |  |
Net property, plant and equipment | 9,374.6 |  | 9,044.6 |  |
Public Utilities, Property, Plant and Equipment, Amount of Acquisition Adjustments, Related Accumulated Depreciation | $ 67.3 |  | $ 61.8 |  |
McClain Plant [Member] |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Jointly Owned Utility Plant, Proportionate Ownership Share | 77.00% | [1] | 77.00% | [2] |
Property, Plant and Equipment, Gross | $ 257.1 | [1] | $ 254.4 | [2] |
Accumulated Depreciation | 96.0 | [1] | 83.5 | [2] |
Net property, plant and equipment | 161.1 | [1] | 170.9 | [2] |
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress | $ 0.1 |  | $ 0.2 |  |
Redbud Plant [Member] |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Jointly Owned Utility Plant, Proportionate Ownership Share | 51.00% | [1],[3] | 51.00% | [2],[4] |
Property, Plant and Equipment, Gross | $ 531.8 | [1],[3] | $ 529.9 | [2],[4] |
Accumulated Depreciation | 181.9 | [1],[3] | 159.0 | [2],[4] |
Net property, plant and equipment | 349.9 | [1],[3] | 370.9 | [2],[4] |
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress | 1.8 |  | 1.4 |  |
Amount of Acquisition Adjustments | 148.3 |  | 148.3 |  |
OGE Energy [Member] |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Property, Plant and Equipment, Gross | 6.1 |  | 6.1 |  |
Accumulated Depreciation | 0.0 |  | 0.0 |  |
Net property, plant and equipment | 6.1 |  | 6.1 |  |
OG&E [Member] |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Property, Plant and Equipment, Gross | 13,436.1 |  | 12,906.6 |  |
Accumulated Depreciation | 4,067.6 |  | 3,868.1 |  |
Net property, plant and equipment | 9,368.5 |  | 9,038.5 |  |
Capitalized Computer Software, Gross | 89.7 |  | 71.3 |  |
Capitalized Computer Software, Amortization | 14.9 |  | 11.0 |  | $ 9.6
OG&E [Member] | Total Property Plant and Equipment [Member] |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Property, Plant and Equipment, Gross | 13,436.1 |  | 12,906.6 |  |
Accumulated Depreciation | 4,067.6 |  | 3,868.1 |  |
Net property, plant and equipment | 9,368.5 |  | 9,038.5 |  |
OG&E [Member] | Electric Transmission and Distribution [Member] |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Property, Plant and Equipment, Gross | 4,809.9 |  | 4,468.6 |  |
Accumulated Depreciation | 1,422.1 |  | 1,381.1 |  |
Net property, plant and equipment | 3,387.8 |  | 3,087.5 |  |
OG&E [Member] | Electric Generation Equipment [Member] |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Property, Plant and Equipment, Gross | 4,932.2 | [5] | 4,838.6 | [6] |
Accumulated Depreciation | 1,713.6 | [5] | 1,601.0 | [6] |
Net property, plant and equipment | 3,218.6 | [5] | 3,237.6 | [6] |
Amount of Acquisition Adjustments | 148.3 |  | 148.3 |  |
Public Utilities, Property, Plant and Equipment, Amount of Acquisition Adjustments, Related Accumulated Depreciation | 67.3 |  | 61.8 |  |
OG&E [Member] | Electric Transmission [Member] |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Property, Plant and Equipment, Gross | 2,944.6 | [7] | 2,901.1 | [8] |
Accumulated Depreciation | 591.7 | [7] | 565.5 | [8] |
Net property, plant and equipment | 2,352.9 | [7] | 2,335.6 | [8] |
Amount of Acquisition Adjustments | 3.3 |  | 3.3 |  |
Public Utilities, Property, Plant and Equipment, Amount of Acquisition Adjustments, Related Accumulated Depreciation | 0.9 |  | 0.8 |  |
OG&E [Member] | Finite-Lived Intangible Assets, Major Class Name [Member] |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Property, Plant and Equipment, Gross | 254.1 |  | 225.2 |  |
Accumulated Depreciation | 153.9 |  | 145.4 |  |
Net property, plant and equipment | 100.2 |  | 79.8 |  |
OG&E [Member] | Property, Plant and Equipment, Other Types [Member] |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Property, Plant and Equipment, Gross | 495.3 |  | 473.1 |  |
Accumulated Depreciation | 186.3 |  | 175.1 |  |
Net property, plant and equipment | $ 309.0 |  | $ 298.0 |  |
[1] | Construction work in progress was $0.1 million and $1.8 million for the McClain and Redbud Plants, respectively.
[2] | Construction work in progress was $0.2 million and $1.4 million for the McClain and Redbud Plants, respectively.
[3] | This amount includes a plant acquisition adjustment of $148.3 million and accumulated amortization of $67.3 million.
[4] | This amount includes a plant acquisition adjustment of $148.3 million and accumulated amortization of $61.8 million.
[5] | This amount includes a plant acquisition adjustment of $148.3 million and accumulated amortization of $67.3 million.
[6] | This amount includes a plant acquisition adjustment of $148.3 million and accumulated amortization of $61.8 million.
[7] | This amount includes a plant acquisition adjustment of $3.3 million and accumulated amortization of $0.9 million.
[8] | This amount includes a plant acquisition adjustment of $3.3 million and accumulated amortization of $0.8 million.

X
- Definition Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.14) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of expense for amortization of capitalized computer software costs. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 985 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 985 -SubTopic 20 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128487-111756 + Details
Name: | us-gaap_CapitalizedComputerSoftwareAmortization1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The carrying amount of capitalized computer software costs net of accumulated amortization as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 985 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756 + Details
Name: | us-gaap_CapitalizedComputerSoftwareNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The period end amount of construction work in progress at a jointly owned electricity generation plant. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 10.C) -URI http://asc.fasb.org/extlink&oid=115995737&loc=d3e659983-123033 + Details
Name: | us-gaap_JointlyOwnedUtilityPlantOwnershipAmountOfConstructionWorkInProgress
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The proportionate share of interest (percent) in a jointly owned utility plant. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 10.C) -URI http://asc.fasb.org/extlink&oid=115995737&loc=d3e659983-123033 + Details
Name: | us-gaap_JointlyOwnedUtilityPlantProportionateOwnershipShare
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount before accumulated depreciation, depletion and amortization of 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, and furniture and fixtures. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.13) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_PropertyPlantAndEquipmentGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(14)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(8)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(13)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_PropertyPlantAndEquipmentNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of acquisition adjustments included in property, plant and equipment (PPE) for utilities. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAmountOfAcquisitionAdjustments1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of increase (decrease) for acquisition adjustments on accumulated depreciation included in long-lived, physical assets used to produce goods and services and not intended for resale for utilities. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAmountOfAcquisitionAdjustmentsRelatedAccumulatedDepreciation1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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_PublicUtilityPropertyPlantAndEquipmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_JointlyOwnedUtilityPlantAxis=oge_McclainPlantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_JointlyOwnedUtilityPlantAxis=oge_RedbudPlantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=oge_OgeEnergyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=oge_OgAndEMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=oge_TotalPropertyPlantAndEquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_ElectricDistributionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_ElectricGenerationEquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_ElectricTransmissionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=oge_FiniteLivedIntangibleAssetsMajorClassNameMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_PropertyPlantAndEquipmentOtherTypesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |