The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 410
-SubTopic 20
-Name Accounting Standards Codification
-Section 25
-Paragraph 4
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 410
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481879/410-20-45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Amount of asset retirement obligations incurred during the period.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
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Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 410
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
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Amount of increase (decrease) in the asset retirement obligation from changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 410
-SubTopic 20
-Name Accounting Standards Codification
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-Paragraph 1
-Subparagraph (c)(4)
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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No definition available.

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- Definition

Amount of operating expense for routine plant maintenance, repairs and operations of regulated operation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
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Asset Retirement Obligations (Reconciliation Of Changes In Asset Retirement Obligations) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance, January 1			$ 246
Revisions in estimated cash flows			(2)
Liabilities settled			(1)
Liabilities incurred			355
Accretion expense			5
Balance, June 30	$ 603		603
Steam Plant
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligation charge for IPL's steam assets	20		20
IPL [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance, January 1			148
Revisions in estimated cash flows			0
Liabilities settled			0
Liabilities incurred			102
Accretion expense			3
Balance, June 30	253		253
Asset retirement obligation charge for IPL's steam assets	102	$ 85	187	$ 181
IPL [Member] \| Steam Plant
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligation charge for IPL's steam assets	20		20
WPL [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance, January 1			98
Revisions in estimated cash flows			(2)
Liabilities settled			(1)
Liabilities incurred			253
Accretion expense			2
Balance, June 30	350		350
Asset retirement obligation charge for IPL's steam assets	$ 67	$ 67	$ 128	$ 133