Summary Of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash equivalents	$ 803	$ 45
Cash equivalents weighted-average interest rate, percentage	5.00%
IPL [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash equivalents	$ 745	45
Cash equivalents weighted-average interest rate, percentage	5.00%
WPL [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash equivalents	$ 58	$ 0
Cash equivalents weighted-average interest rate, percentage	5.00%