Derivative Instruments (Fair Value Of Financial Instruments) (Details) - Commodity Contracts [Member] - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Derivatives, Fair Value [Line Items]
Current derivative assets	$ 16	$ 44
Non-current derivative assets	40	44
Current derivative liabilities	49	51
Non-current derivative liabilities	45	47
IPL [Member]
Derivatives, Fair Value [Line Items]
Current derivative assets	12	30
Non-current derivative assets	22	24
Current derivative liabilities	23	22
Non-current derivative liabilities	7	8
WPL [Member]
Derivatives, Fair Value [Line Items]
Current derivative assets	4	14
Non-current derivative assets	18	20
Current derivative liabilities	26	29
Non-current derivative liabilities	$ 38	$ 39

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483466/210-20-50-3

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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- Definition

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