Income tax

No definition available.

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- Definition

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

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-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-12

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- Definition

Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).

+ References

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- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

The increase (decrease) during the reporting period in the value of other assets that are created when regulatory agencies permits public utilities to defer costs to the balance sheet.

+ References

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Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Income Taxes (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax [Line Items]
Overall income tax rate			1.00%	3.00%	(12.00%)
State income tax rate, percent			2.00%	3.00%	2.00%
Reduction of tax-related regulatory assets			$ 24	$ (108)	$ 51
Income tax expense (benefit)			4	22	$ (74)
Tax-related [Member]
Income Tax [Line Items]
Reduction of tax-related regulatory assets			74	77
Income tax expense (benefit)			$ 10	$ 8
IPL [Member]
Income Tax [Line Items]
Overall income tax rate			(19.00%)	(16.00%)	(11.00%)
State income tax rate, percent			(2.00%)	(2.00%)	(1.00%)
Reduction of tax-related regulatory assets			$ 58	$ 56	$ 30
Income tax expense (benefit)			(58)	(50)	$ (36)
IPL [Member] \| Tax-related [Member]
Income Tax [Line Items]
Reduction of tax-related regulatory assets			$ 74	$ 77
WPL [Member]
Income Tax [Line Items]
Overall income tax rate			15.00%	17.00%	(24.00%)
State income tax rate, percent			5.00%	6.00%	6.00%
Reduction of tax-related regulatory assets			$ (34)	$ (163)	$ 21
Income tax expense (benefit)			$ 60	$ 66	$ (51)
State [Member]
Income Tax [Line Items]
Overall income tax rate					9.80%	12.00%
State income tax rate, percent			8.40%
State [Member] \| Forecast [Member]
Income Tax [Line Items]
State income tax rate, percent	5.50%	7.10%