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JOINTLY-OWNED ELECTRIC UTILITY PLANTS (Details) $ in Millions | Dec. 31, 2020 USD ($) | Dec. 31, 2020 Rate | Dec. 31, 2020 MW | Dec. 31, 2020 | Dec. 31, 2019 USD ($)
--- | --- | --- | --- | --- | ---
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Nuclear fuel, net | $ 155.9 |  |  |  | $ 128.5
Wolf Creek Unit |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Jointly owned utility plant, proportionate ownership share |  | 94.00% |  | 94.00% |
Electric plant in service | 4,059.1 |  |  |  |
Accumulated depreciation | 1,970.3 |  |  |  |
Nuclear fuel, net | 155.9 |  |  |  |
Construction work in progress | 183.5 |  |  |  |
Accredited capacity | MW |  |  | 1,108 |  |
La Cygne Units |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Jointly owned utility plant, proportionate ownership share | Rate |  | 100.00% |  |  |
Electric plant in service | 2,207.6 |  |  |  |
Accumulated depreciation | 779.4 |  |  |  |
Nuclear fuel, net | 0.0 |  |  |  |
Construction work in progress | 27.7 |  |  |  |
Accredited capacity | MW |  |  | 1,426 |  |
Iatan No. 1 Unit |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Jointly owned utility plant, proportionate ownership share | Rate |  | 88.00% |  |  |
Electric plant in service | 773.3 |  |  |  |
Accumulated depreciation | 265.7 |  |  |  |
Nuclear fuel, net | 0.0 |  |  |  |
Construction work in progress | 10.3 |  |  |  |
Accredited capacity | MW |  |  | 618 |  |
Iatan No. 2 Unit |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Jointly owned utility plant, proportionate ownership share | Rate |  | 73.00% |  |  |
Electric plant in service | 1,404.3 |  |  |  |
Accumulated depreciation | 459.3 |  |  |  |
Nuclear fuel, net | 0.0 |  |  |  |
Construction work in progress | 10.7 |  |  |  |
Accredited capacity | MW |  |  | 640 |  |
Iatan Common |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Jointly owned utility plant, proportionate ownership share | Rate |  | 79.00% |  |  |
Electric plant in service | 499.7 |  |  |  |
Accumulated depreciation | 127.8 |  |  |  |
Nuclear fuel, net | 0.0 |  |  |  |
Construction work in progress | 4.4 |  |  |  |
Jeffrey Energy Center |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Jointly owned utility plant, proportionate ownership share | Rate |  | 100.00% |  |  |
Electric plant in service | 2,435.4 |  |  |  |
Accumulated depreciation | 984.1 |  |  |  |
Nuclear fuel, net | 0.0 |  |  |  |
Construction work in progress | 84.1 |  |  |  |
Accredited capacity | MW |  |  | 2,012 |  |
State Line |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Jointly owned utility plant, proportionate ownership share | Rate |  | 40.00% |  |  |
Electric plant in service | 115.0 |  |  |  |
Accumulated depreciation | 80.6 |  |  |  |
Nuclear fuel, net | 0.0 |  |  |  |
Construction work in progress | 12.9 |  |  |  |
Accredited capacity | MW |  |  | 200 |  |
Evergy Kansas Central |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Nuclear fuel, net | 77.7 |  |  |  | 63.9
Evergy Kansas Central | Wolf Creek Unit |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Jointly owned utility plant, proportionate ownership share | Rate |  | 47.00% |  |  |
Electric plant in service | 1,995.2 |  |  |  |
Accumulated depreciation | 956.6 |  |  |  |
Nuclear fuel, net | 77.7 |  |  |  |
Construction work in progress | 77.2 |  |  |  |
Accredited capacity | MW |  |  | 554 |  |
Evergy Kansas Central | La Cygne Units |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Jointly owned utility plant, proportionate ownership share | Rate |  | 50.00% |  |  |
Electric plant in service | 1,046.5 |  |  |  |
Accumulated depreciation | 446.2 |  |  |  |
Nuclear fuel, net | 0.0 |  |  |  |
Construction work in progress | 10.6 |  |  |  |
Accredited capacity | MW |  |  | 713 |  |
Evergy Kansas Central | Jeffrey Energy Center |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Jointly owned utility plant, proportionate ownership share | Rate |  | 92.00% |  |  |
Electric plant in service | 2,229.5 |  |  |  |
Accumulated depreciation | 895.3 |  |  |  |
Nuclear fuel, net | 0.0 |  |  |  |
Construction work in progress | 77.3 |  |  |  |
Accredited capacity | MW |  |  | 1,837 |  |
Evergy Kansas Central | State Line |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Jointly owned utility plant, proportionate ownership share | Rate |  | 40.00% |  |  |
Electric plant in service | 115.0 |  |  |  |
Accumulated depreciation | 80.6 |  |  |  |
Nuclear fuel, net | 0.0 |  |  |  |
Construction work in progress | 12.9 |  |  |  |
Accredited capacity | MW |  |  | 200 |  |
Evergy Metro |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Nuclear fuel, net | 78.2 |  |  |  | $ 64.6
Evergy Metro | Wolf Creek Unit |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Jointly owned utility plant, proportionate ownership share |  | 47.00% |  | 47.00% |
Electric plant in service | 2,063.9 |  |  |  |
Accumulated depreciation | 1,013.7 |  |  |  |
Nuclear fuel, net | 78.2 |  |  |  |
Construction work in progress | 106.3 |  |  |  |
Accredited capacity | MW |  |  | 554 |  |
Evergy Metro | La Cygne Units |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Jointly owned utility plant, proportionate ownership share | Rate |  | 50.00% |  |  |
Electric plant in service | 1,161.1 |  |  |  |
Accumulated depreciation | 333.2 |  |  |  |
Nuclear fuel, net | 0.0 |  |  |  |
Construction work in progress | 17.1 |  |  |  |
Accredited capacity | MW |  |  | 713 |  |
Evergy Metro | Iatan No. 1 Unit |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Jointly owned utility plant, proportionate ownership share | Rate |  | 70.00% |  |  |
Electric plant in service | 600.2 |  |  |  |
Accumulated depreciation | 204.7 |  |  |  |
Nuclear fuel, net | 0.0 |  |  |  |
Construction work in progress | 8.3 |  |  |  |
Accredited capacity | MW |  |  | 492 |  |
Evergy Metro | Iatan No. 2 Unit |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Jointly owned utility plant, proportionate ownership share | Rate |  | 55.00% |  |  |
Electric plant in service | 1,065.3 |  |  |  |
Accumulated depreciation | 397.4 |  |  |  |
Nuclear fuel, net | 0.0 |  |  |  |
Construction work in progress | 8.0 |  |  |  |
Accredited capacity | MW |  |  | 482 |  |
Evergy Metro | Iatan Common |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Jointly owned utility plant, proportionate ownership share | Rate |  | 61.00% |  |  |
Electric plant in service | 396.5 |  |  |  |
Accumulated depreciation | 110.5 |  |  |  |
Nuclear fuel, net | 0.0 |  |  |  |
Construction work in progress | $ 3.1 |  |  |  |
Subsidiaries | La Cygne Unit 2 |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Leasehold interest percentage |  |  |  | 50.00% |
Subsidiaries | Evergy Kansas Central | La Cygne Unit 2 |  |  |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |  |  |
Leasehold interest percentage |  |  |  | 50.00% |

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- Definition The accredited capacity of the jointly owned electric utility plant, in megawatts. + References No definition available. + Details
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- Definition Leasehold Interest Percentage + References No definition available. + Details
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- Definition The period end amount owned by the reporting utility of a jointly owned utility plant in service. + 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
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- 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
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- 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
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- Definition The period end amount of accumulated depreciation in 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
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- 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
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- Definition The carrying amount as of the balance sheet of nuclear fuel held as property plant and equipment. This amount is net of amortization based on the energy produced over the life of the fuel. + 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 210.5-02.13(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
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