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Summary Of Significant Accounting Policies (Narrative) (Details) - USD ($)
$ in Millions
Jun. 30, 2024
Dec. 31, 2023
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Money market fund investments $ 73 $ 45
Money market fund investments weighted-average interest rate, percentage 5.00%  
IPL [Member]    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Money market fund investments $ 1 45
WPL [Member]    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Money market fund investments $ 72 $ 0
Money market fund investments weighted-average interest rate, percentage 5.00%