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Jointly-Owned Electric Utility Plant (Details) $ in Millions | Dec. 31, 2023 USD ($)
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Jointly Owned Electric Utility Plant [Line Items] |
Electric Plant | $ 2,570
Accumulated Provision for Depreciation | 952
Construction Work in Progress | 33
IPL [Member] |
Jointly Owned Electric Utility Plant [Line Items] |
Electric Plant | 1,053
Accumulated Provision for Depreciation | 478
Construction Work in Progress | 21
WPL [Member] |
Jointly Owned Electric Utility Plant [Line Items] |
Electric Plant | 1,517
Accumulated Provision for Depreciation | 474
Construction Work in Progress | $ 12
Ottumwa Unit 1 [Member] | IPL [Member] |
Jointly Owned Electric Utility Plant [Line Items] |
Ownership Interest % | 48.00%
Electric Plant | $ 632
Accumulated Provision for Depreciation | 264
Construction Work in Progress | $ 7
George Neal Unit 4 [Member] | IPL [Member] |
Jointly Owned Electric Utility Plant [Line Items] |
Ownership Interest % | 25.70%
Electric Plant | $ 196
Accumulated Provision for Depreciation | 107
Construction Work in Progress | $ 6
George Neal Unit 3 [Member] | IPL [Member] |
Jointly Owned Electric Utility Plant [Line Items] |
Ownership Interest % | 28.00%
Electric Plant | $ 181
Accumulated Provision for Depreciation | 85
Construction Work in Progress | $ 8
Louisa Unit 1 [Member] | IPL [Member] |
Jointly Owned Electric Utility Plant [Line Items] |
Ownership Interest % | 4.00%
Electric Plant | $ 44
Accumulated Provision for Depreciation | 22
Construction Work in Progress | $ 0
Columbia Units 1-2 [Member] | WPL [Member] |
Jointly Owned Electric Utility Plant [Line Items] |
Ownership Interest % | 53.50%
Electric Plant | $ 818
Accumulated Provision for Depreciation | 361
Construction Work in Progress | $ 6
West Riverside Energy Center and Solar Facility [Member] | WPL [Member] |
Jointly Owned Electric Utility Plant [Line Items] |
Ownership Interest % | 73.80%
Electric Plant | $ 581
Accumulated Provision for Depreciation | 60
Construction Work in Progress | $ 6
Forward Wind Energy Center [Member] | WPL [Member] |
Jointly Owned Electric Utility Plant [Line Items] |
Ownership Interest % | 42.60%
Electric Plant | $ 118
Accumulated Provision for Depreciation | 53
Construction Work in Progress | $ 0

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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 -Topic 980 -SubTopic 360 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 10.C) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479960/980-360-S99-1 + 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 -Topic 980 -SubTopic 360 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 10.C) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479960/980-360-S99-1 + 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 -Topic 980 -SubTopic 360 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 10.C) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479960/980-360-S99-1 + 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 -Topic 980 -SubTopic 360 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 10.C) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479960/980-360-S99-1 + Details
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