XML 62 R42.htm IDEA: XBRL DOCUMENT v3.25.3

Receivables (Receivables Sold Under The Agreement) (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Receivables [Line Items]
Fair value of deferred proceeds	$ 231	$ 163
IPL [Member]
Receivables [Line Items]
Fair value of deferred proceeds	231	163
Receivables Sold [Member] | IPL [Member]
Receivables [Line Items]
Customer accounts receivable	166	137
Unbilled utility revenues	79	108
Other receivables	1	0
Receivables sold to third party	246	245
Less: cash proceeds	1	70
Deferred proceeds	245	175
Less: allowance for expected credit losses	14	12
Fair value of deferred proceeds	$ 231	$ 163

X

- Definition

Allowance for Doubtful Accounts Receivable Sold

+ References

No definition available.

+ Details

Name:	lnt_AllowanceForDoubtfulAccountsReceivableSold
Namespace Prefix:	lnt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Cash Proceeds From Receivables Sold

+ References

No definition available.

+ Details

Name:	lnt_CashProceedsFromReceivablesSold
Namespace Prefix:	lnt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Customer Accounts Receivable Sold, Amount

+ References

No definition available.

+ Details

Name:	lnt_CustomerAccountsReceivableSoldAmount
Namespace Prefix:	lnt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Deferred proceeds of receivables sold

+ References

No definition available.

+ Details

Name:	lnt_DeferredProceedsOfReceivablesSold
Namespace Prefix:	lnt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Fair value of deferred proceeds of receivables sold

+ References

No definition available.

+ Details

Name:	lnt_FairValueOfDeferredProceedsOfReceivablesSold
Namespace Prefix:	lnt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Other Receivables Sold Amount

+ References

No definition available.

+ Details

Name:	lnt_OtherReceivablesSoldAmount
Namespace Prefix:	lnt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Receivables sold

+ References

No definition available.

+ Details

Name:	lnt_ReceivablesSold
Namespace Prefix:	lnt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Unbilled Utility Revenues Sold, Amount

+ References

No definition available.

+ Details

Name:	lnt_UnbilledUtilityRevenuesSoldAmount
Namespace Prefix:	lnt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 40
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481628/310-20-40-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-2

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_FinanceReceivablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: