XML 68 R34.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Receivables (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2023
Receivables [Line Items] |
Accounts Receivable Details | Details for accounts receivable included on the balance sheets as of December 31 were as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
| 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Customer | $121 |  |  | $114 |  |  | $— |  |  | $— |  |  | $110 |  |  | $102 |
Unbilled utility revenues | 93 |  |  | 115 |  |  | — |  |  | — |  |  | 93 |  |  | 115 |
Deferred proceeds | 216 |  |  | 185 |  |  | 216 |  |  | 185 |  |  | — |  |  | — |
Other | 53 |  |  | 109 |  |  | 26 |  |  | 74 |  |  | 24 |  |  | 34 |
Allowance for expected credit losses | (8) |  |  | (7) |  |  | — |  |  | — |  |  | (8) |  |  | (7) |
| $475 |  |  | $516 |  |  | $242 |  |  | $259 |  |  | $219 |  |  | $244 |
Gross Write-offs for Accounts Receivable | In 2023, gross write-offs for accounts receivable were as follows (in millions):
| Originated in 2022 |  | Originated in 2023
Alliant Energy | $12 |  | $13
IPL | 8 |  | 8
WPL | 4 |  | 5
Maximum And Average Outstanding Cash Proceeds | IPL’s maximum and average outstanding aggregate cash proceeds (based on daily outstanding balances) related to the sales of accounts receivable program were as follows (in millions):
| Maximum |  | Average
| 2023 |  | 2022 |  | 2021 |  | 2023 |  | 2022 |  | 2021
Outstanding aggregate cash proceeds | $110 |  | $80 |  | $110 |  | $51 |  | $14 |  | $46
Receivables Sold Under the Agreement | As of December 31, the attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions):
| 2023 |  | 2022
Customer accounts receivable | $130 |  | $145
Unbilled utility revenues | 98 |  | 132
Other receivables | 1 |  | —
Receivables sold to third party | 229 |  | 277
Less: cash proceeds | 1 |  | 80
Deferred proceeds | 228 |  | 197
Less: allowance for expected credit losses | 12 |  | 12
Fair value of deferred proceeds | $216 |  | $185
Outstanding receivables past due | $22 |  | $26
Additional Attributes Of Receivables Sold Under The Agreement | Additional attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions):
| 2023 |  | 2022 |  | 2021
Collections | $2,233 |  | $2,302 |  | $2,134 |
Write-offs, net of recoveries | 12 |  | 9 |  | 9 |
IPL [Member] |
Receivables [Line Items] |
Accounts Receivable Details | Details for accounts receivable included on the balance sheets as of December 31 were as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
| 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Customer | $121 |  |  | $114 |  |  | $— |  |  | $— |  |  | $110 |  |  | $102 |
Unbilled utility revenues | 93 |  |  | 115 |  |  | — |  |  | — |  |  | 93 |  |  | 115 |
Deferred proceeds | 216 |  |  | 185 |  |  | 216 |  |  | 185 |  |  | — |  |  | — |
Other | 53 |  |  | 109 |  |  | 26 |  |  | 74 |  |  | 24 |  |  | 34 |
Allowance for expected credit losses | (8) |  |  | (7) |  |  | — |  |  | — |  |  | (8) |  |  | (7) |
| $475 |  |  | $516 |  |  | $242 |  |  | $259 |  |  | $219 |  |  | $244 |
Gross Write-offs for Accounts Receivable | In 2023, gross write-offs for accounts receivable were as follows (in millions):
| Originated in 2022 |  | Originated in 2023
Alliant Energy | $12 |  | $13
IPL | 8 |  | 8
WPL | 4 |  | 5
Maximum And Average Outstanding Cash Proceeds | IPL’s maximum and average outstanding aggregate cash proceeds (based on daily outstanding balances) related to the sales of accounts receivable program were as follows (in millions):
| Maximum |  | Average
| 2023 |  | 2022 |  | 2021 |  | 2023 |  | 2022 |  | 2021
Outstanding aggregate cash proceeds | $110 |  | $80 |  | $110 |  | $51 |  | $14 |  | $46
Receivables Sold Under the Agreement | As of December 31, the attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions):
| 2023 |  | 2022
Customer accounts receivable | $130 |  | $145
Unbilled utility revenues | 98 |  | 132
Other receivables | 1 |  | —
Receivables sold to third party | 229 |  | 277
Less: cash proceeds | 1 |  | 80
Deferred proceeds | 228 |  | 197
Less: allowance for expected credit losses | 12 |  | 12
Fair value of deferred proceeds | $216 |  | $185
Outstanding receivables past due | $22 |  | $26
Additional Attributes Of Receivables Sold Under The Agreement | Additional attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions):
| 2023 |  | 2022 |  | 2021
Collections | $2,233 |  | $2,302 |  | $2,134 |
Write-offs, net of recoveries | 12 |  | 9 |  | 9 |
WPL [Member] |
Receivables [Line Items] |
Accounts Receivable Details | Details for accounts receivable included on the balance sheets as of December 31 were as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
| 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Customer | $121 |  |  | $114 |  |  | $— |  |  | $— |  |  | $110 |  |  | $102 |
Unbilled utility revenues | 93 |  |  | 115 |  |  | — |  |  | — |  |  | 93 |  |  | 115 |
Deferred proceeds | 216 |  |  | 185 |  |  | 216 |  |  | 185 |  |  | — |  |  | — |
Other | 53 |  |  | 109 |  |  | 26 |  |  | 74 |  |  | 24 |  |  | 34 |
Allowance for expected credit losses | (8) |  |  | (7) |  |  | — |  |  | — |  |  | (8) |  |  | (7) |
| $475 |  |  | $516 |  |  | $242 |  |  | $259 |  |  | $219 |  |  | $244 |
Gross Write-offs for Accounts Receivable | In 2023, gross write-offs for accounts receivable were as follows (in millions):
| Originated in 2022 |  | Originated in 2023
Alliant Energy | $12 |  | $13
IPL | 8 |  | 8
WPL | 4 |  | 5

X
- Definition Schedule of Additional Attributes of Receivables Sold Under the Agreement [Table Text Block] + References No definition available. + Details
Name: | lnt_ScheduleOfAdditionalAttributesOfReceivablesSoldUnderAgreementTableTextBlock
Namespace Prefix: | lnt_
Data Type: | dtr-types1:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule of maximum and average sales of accounts receivable cash proceeds and related costs. + References No definition available. + Details
Name: | lnt_ScheduleOfSalesOfAccountsReceivableCashProceedsAndRelatedCostsTableTextBlock
Namespace Prefix: | lnt_
Data Type: | dtr-types1:textBlockItemType
Balance Type: | na
Period Type: | duration

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 No definition available. + Details
Name: | us-gaap_AccountsNotesAndLoansReceivableLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of allowance for credit loss on financing receivable. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-11B + Details
Name: | us-gaap_AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of financing receivables by credit quality indicator. The credit quality indicator is a statistic about the credit quality of financing receivables. Examples include, but not limited to, consumer credit risk scores, credit-rating-agency ratings, an entity's internal credit risk grades, loan-to-value ratios, collateral, collection experience and other internal metrics. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-5 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 29 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-29 + Details
Name: | us-gaap_FinancingReceivableCreditQualityIndicatorsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the various types of trade accounts and notes receivable and for each the gross carrying value, allowance, and net carrying value as of the balance sheet date. Presentation is categorized by current, noncurrent and unclassified receivables. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.3,4) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
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: |