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Debt (Other Short-Term Borrowings) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Debt [Line Items]
Maximum amount outstanding (based on daily outstanding balances)	$ 449	$ 648	$ 577	$ 648
Average amount outstanding (based on daily outstanding balances)	$ 353	$ 560	$ 377	$ 479
Weighted average interest rates	2.40%	0.20%	1.20%	0.20%
IPL [Member]
Debt [Line Items]
Maximum amount outstanding (based on daily outstanding balances)	$ 0	$ 8	$ 0	$ 19
Average amount outstanding (based on daily outstanding balances)	$ 0	$ 0	$ 0	$ 0
Weighted average interest rates	0.00%	0.20%	0.00%	0.20%
WPL [Member]
Debt [Line Items]
Maximum amount outstanding (based on daily outstanding balances)	$ 251	$ 320	$ 252	$ 320
Average amount outstanding (based on daily outstanding balances)	$ 110	$ 221	$ 160	$ 196
Weighted average interest rates	2.00%	0.10%	0.90%	0.10%

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+ References

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- Definition

Weighted average interest rate of short-term debt outstanding calculated over time.

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- Definition

For the form of debt having an initial term of less than one year or less than the normal operating cycle, if longer, average borrowings during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1402
-Paragraph (a)

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1402
-Paragraph (b)
-Subparagraph (1)

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- Definition

For the form of debt having an initial term of less than one year or less than the normal operating cycle, if longer, the maximum amount borrowed at any time during the period.

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