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Commitments And Contingencies (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Mar. 31, 2023 | Jun. 30, 2021 | Jun. 30, 2020
Commitments and Contingencies [Line Items] |  |  |
Minimum future commitments | $ 1,568 |  |
IPL [Member] |  |  |
Commitments and Contingencies [Line Items] |  |  |
Minimum future commitments | 707 |  |
WPL [Member] |  |  |
Commitments and Contingencies [Line Items] |  |  |
Minimum future commitments | 827 |  |
Capital Purchase Commitment [Member] |  |  |
Commitments and Contingencies [Line Items] |  |  |
Minimum future commitments | 252 |  |
Capital Purchase Commitment [Member] | IPL [Member] |  |  |
Commitments and Contingencies [Line Items] |  |  |
Minimum future commitments | 40 |  |
Capital Purchase Commitment [Member] | WPL [Member] |  |  |
Commitments and Contingencies [Line Items] |  |  |
Minimum future commitments | 212 |  |
Indemnification Agreement [Member] |  |  |
Commitments and Contingencies [Line Items] |  |  |
Obligations, maximum | 59 |  |
Indemnification Agreement [Member] | Purchased Power [Member] |  |  |
Commitments and Contingencies [Line Items] |  |  |
Obligations, maximum | $ 17 |  |
Whiting Petroleum Affiliate [Member] |  |  |
Commitments and Contingencies [Line Items] |  |  |
Partnership share, percent | 6.00% |  |
Obligations, maximum | $ 58 |  |
Credit loss liability | $ 5 |  |
Federal Energy Regulatory Commission [Member] |  |  |
Commitments and Contingencies [Line Items] |  |  |
MISO base return on equity, percentage |  | 10.02% | 9.88%

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- Definition Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 460 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482425/460-10-50-4 + Details
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- Definition Percentage investment held by members or limited partners of limited liability company (LLC) or limited partnership (LP). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482987/272-10-50-3 + Details
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- Definition The minimum amount the entity agreed to spend under the long-term purchase commitment. + References No definition available. + Details
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- 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
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- Definition Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479344/326-20-45-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 460 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482454/460-10-45-1 + Details
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- Definition Percentage of public utility's approved return on equity. + References No definition available. + Details
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