XML 73 R53.htm IDEA: XBRL DOCUMENT v3.25.3

Income Taxes (Schedule Of Effective Income Tax Rates) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Effective Tax Rate [Line Items]
Overall income tax rate, percent	(7.00%)	(27.00%)	(19.00%)	(24.00%)
IPL [Member]
Effective Tax Rate [Line Items]
Overall income tax rate, percent	(15.00%)	(56.00%)	(36.00%)	(70.00%)
WPL [Member]
Effective Tax Rate [Line Items]
Overall income tax rate, percent	1.00%	3.00%	(3.00%)	5.00%

X

- Definition

Effective tax rate

+ References

No definition available.

+ Details

Name:	lnt_EffectiveTaxRateLineItems
Namespace Prefix:	lnt_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

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

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 231
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-231

+ Details

Name:	us-gaap_EffectiveIncomeTaxRateContinuingOperations
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	dei_LegalEntityAxis=lnt_IplMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=lnt_WplMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: