XML 89 R68.htm IDEA: XBRL DOCUMENT
v3.22.2.2

Related Parties (Narrative) (Details) - USD ($) $ in Millions | Sep. 30, 2022 | Dec. 31, 2021
--- | --- | ---
WPL [Member] | WPL Owed ATC LLC [Member] |  |
Related Party Transactions [Line Items] |  |
Net amounts owed | $ 9 | $ 10

X
- Definition Receivables to be collected from (obligations owed to) related parties, net as of the balance sheet date where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(C)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(5)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(5)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(k)(1)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iv)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iv)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756 Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iii)(B)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756 + Details
Name: | us-gaap_RelatedPartyTransactionDueFromToRelatedParty
Namespace Prefix: | us-gaap_
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_RelatedPartyTransactionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=lnt_WplMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=lnt_WplOwedAtcMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |