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Summary Of Significant Accounting Policies (Schedule Of Average Rates Of Depreciation) (Details) | 12 Months Ended
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Dec. 31, 2025 | Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Electric - generation [Member] | IPL [Member] |  |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |  |
Average rate of depreciation, percent |  | 3.30% | 3.30% | 3.40%
Electric - generation [Member] | IPL [Member] | Forecast [Member] |  |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |  |
Average rate of depreciation, percent | 3.80% |  |  |
Electric - generation [Member] | WPL [Member] |  |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |  |
Average rate of depreciation, percent |  | 3.40% | 3.00% | 3.40%
Electric - distribution [Member] | IPL [Member] |  |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |  |
Average rate of depreciation, percent |  | 2.80% | 2.80% | 2.80%
Electric - distribution [Member] | IPL [Member] | Forecast [Member] |  |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |  |
Average rate of depreciation, percent | 3.00% |  |  |
Electric - distribution [Member] | WPL [Member] |  |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |  |
Average rate of depreciation, percent |  | 2.70% | 2.70% | 2.50%
Electric - other [Member] | IPL [Member] |  |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |  |
Average rate of depreciation, percent |  | 5.20% | 5.60% | 5.70%
Electric - other [Member] | WPL [Member] |  |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |  |
Average rate of depreciation, percent |  | 6.10% | 6.30% | 6.80%
Gas [Member] | IPL [Member] |  |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |  |
Average rate of depreciation, percent |  | 3.30% | 3.30% | 3.30%
Gas [Member] | WPL [Member] |  |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |  |
Average rate of depreciation, percent |  | 2.50% | 2.50% | 2.40%
Other [Member] | IPL [Member] |  |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |  |
Average rate of depreciation, percent |  | 4.60% | 6.20% | 6.10%
Other [Member] | WPL [Member] |  |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |  |
Average rate of depreciation, percent |  | 4.40% | 4.60% | 4.90%

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