XML 110 R78.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Leases (Narrative) (Details) | 12 Months Ended
--- | ---
Dec. 31, 2021 lease_renewal_period_option
Sheboygan Falls Energy Facility [Member] | WPL [Member] |
Leases [Line Items] |
Finance lease, renewal options (in number of renewal periods) | 2

X
- Definition Capital Leases, Lease Renewal Period Options + References No definition available. + Details
Name: | lnt_CapitalLeasesLeaseRenewalPeriodOptions
Namespace Prefix: | lnt_
Data Type: | xbrli:integerItemType
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_LesseeLeaseDescriptionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=lnt_SheboyganFallsEnergyFacilityMember
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: |