XML 146 R114.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Commitments And Contingencies (Other Purchase Commitments) (Details) $ in Millions | Dec. 31, 2021 USD ($)
--- | ---
Long-term Purchase Commitment [Line Items] |
Minimum future commitments, 2022 | $ 452
Minimum future commitments, 2023 | 256
Minimum future commitments, 2024 | 177
Minimum future commitments, 2025 | 110
Minimum future commitments, 2026 | 90
Minimum future commitments, Thereafter | 200
Minimum future commitments, Total | 1,285
Individual commitments incurred | 1
Natural Gas [Member] |
Long-term Purchase Commitment [Line Items] |
Minimum future commitments, 2022 | 307
Minimum future commitments, 2023 | 196
Minimum future commitments, 2024 | 144
Minimum future commitments, 2025 | 102
Minimum future commitments, 2026 | 88
Minimum future commitments, Thereafter | 175
Minimum future commitments, Total | 1,012
Coal [Member] |
Long-term Purchase Commitment [Line Items] |
Minimum future commitments, 2022 | 63
Minimum future commitments, 2023 | 46
Minimum future commitments, 2024 | 25
Minimum future commitments, 2025 | 3
Minimum future commitments, 2026 | 0
Minimum future commitments, Thereafter | 0
Minimum future commitments, Total | 137
Other [Member] |
Long-term Purchase Commitment [Line Items] |
Minimum future commitments, 2022 | 82
Minimum future commitments, 2023 | 14
Minimum future commitments, 2024 | 8
Minimum future commitments, 2025 | 5
Minimum future commitments, 2026 | 2
Minimum future commitments, Thereafter | 25
Minimum future commitments, Total | 136
IPL [Member] |
Long-term Purchase Commitment [Line Items] |
Minimum future commitments, 2022 | 214
Minimum future commitments, 2023 | 139
Minimum future commitments, 2024 | 103
Minimum future commitments, 2025 | 57
Minimum future commitments, 2026 | 44
Minimum future commitments, Thereafter | 88
Minimum future commitments, Total | 645
IPL [Member] | Natural Gas [Member] |
Long-term Purchase Commitment [Line Items] |
Minimum future commitments, 2022 | 148
Minimum future commitments, 2023 | 108
Minimum future commitments, 2024 | 84
Minimum future commitments, 2025 | 52
Minimum future commitments, 2026 | 42
Minimum future commitments, Thereafter | 65
Minimum future commitments, Total | 499
IPL [Member] | Coal [Member] |
Long-term Purchase Commitment [Line Items] |
Minimum future commitments, 2022 | 32
Minimum future commitments, 2023 | 27
Minimum future commitments, 2024 | 17
Minimum future commitments, 2025 | 3
Minimum future commitments, 2026 | 0
Minimum future commitments, Thereafter | 0
Minimum future commitments, Total | 79
IPL [Member] | Other [Member] |
Long-term Purchase Commitment [Line Items] |
Minimum future commitments, 2022 | 34
Minimum future commitments, 2023 | 4
Minimum future commitments, 2024 | 2
Minimum future commitments, 2025 | 2
Minimum future commitments, 2026 | 2
Minimum future commitments, Thereafter | 23
Minimum future commitments, Total | 67
WPL [Member] |
Long-term Purchase Commitment [Line Items] |
Minimum future commitments, 2022 | 223
Minimum future commitments, 2023 | 108
Minimum future commitments, 2024 | 69
Minimum future commitments, 2025 | 51
Minimum future commitments, 2026 | 47
Minimum future commitments, Thereafter | 110
Minimum future commitments, Total | 608
WPL [Member] | Natural Gas [Member] |
Long-term Purchase Commitment [Line Items] |
Minimum future commitments, 2022 | 159
Minimum future commitments, 2023 | 88
Minimum future commitments, 2024 | 60
Minimum future commitments, 2025 | 50
Minimum future commitments, 2026 | 46
Minimum future commitments, Thereafter | 110
Minimum future commitments, Total | 513
WPL [Member] | Coal [Member] |
Long-term Purchase Commitment [Line Items] |
Minimum future commitments, 2022 | 31
Minimum future commitments, 2023 | 19
Minimum future commitments, 2024 | 8
Minimum future commitments, 2025 | 0
Minimum future commitments, 2026 | 0
Minimum future commitments, Thereafter | 0
Minimum future commitments, Total | 58
WPL [Member] | Other [Member] |
Long-term Purchase Commitment [Line Items] |
Minimum future commitments, 2022 | 33
Minimum future commitments, 2023 | 1
Minimum future commitments, 2024 | 1
Minimum future commitments, 2025 | 1
Minimum future commitments, 2026 | 1
Minimum future commitments, Thereafter | 0
Minimum future commitments, Total | $ 37

X
- Definition Individual commitments incurred in excess of $1 million + References No definition available. + Details
Name: | lnt_IndividualCommitmentsIncurred
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 No definition available. + Details
Name: | us-gaap_LongTermPurchaseCommitmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Minimum amount of purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier. + References No definition available. + Details
Name: | us-gaap_PurchaseObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of purchase arrangement to be paid after fifth fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References No definition available. + Details
Name: | us-gaap_PurchaseObligationDueAfterFifthYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of purchase arrangement to be paid in fifth fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References No definition available. + Details
Name: | us-gaap_PurchaseObligationDueInFifthYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of purchase arrangement to be paid in fourth fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References No definition available. + Details
Name: | us-gaap_PurchaseObligationDueInFourthYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of purchase arrangement to be paid in next fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References No definition available. + Details
Name: | us-gaap_PurchaseObligationDueInNextTwelveMonths
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of purchase arrangement to be paid in second fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References No definition available. + Details
Name: | us-gaap_PurchaseObligationDueInSecondYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of purchase arrangement to be paid in third fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References No definition available. + Details
Name: | us-gaap_PurchaseObligationDueInThirdYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=us-gaap_PublicUtilitiesInventoryNaturalGasMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=us-gaap_CoalSupplyAgreementsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=lnt_LongTermPurchaseCommitmentsOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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: |