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Income Taxes (Tables) | 3 Months Ended
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Mar. 31, 2023
Income Taxes [Line Items] |
Schedule Of Effective Income Tax Rates | Overall effective income tax rates, which were computed by dividing income tax expense (benefit) by income before income taxes, were as follows. The effective income tax rates were different than the federal statutory rate primarily due to state income taxes, production tax credits, amortization of excess deferred taxes and the effect of rate-making on property-related differences.
| Alliant Energy |  | IPL |  | WPL
| 2023 |  | 2022 |  |  |  |  |  | 2023 |  | 2022 |  |  |  |  |  | 2023 |  | 2022 |  |  |  |
Overall income tax rate | (1%) |  | 4% |  |  |  |  |  | (18%) |  | (14%) |  |  |  |  |  | 12% |  | 19% |  |  |  |
Summary Of Tax Credit Carryforwards | At March 31, 2023, the carryforwards and expiration dates were estimated as follows (in millions):
| Range of Expiration Dates |  | Alliant Energy |  | IPL |  | WPL
State net operating losses | 2025-2043 |  | $535 |  | $12 |  | $1
Federal tax credits | 2027-2043 |  | 698 |  | 468 |  | 218
IPL [Member] |
Income Taxes [Line Items] |
Schedule Of Effective Income Tax Rates | Overall effective income tax rates, which were computed by dividing income tax expense (benefit) by income before income taxes, were as follows. The effective income tax rates were different than the federal statutory rate primarily due to state income taxes, production tax credits, amortization of excess deferred taxes and the effect of rate-making on property-related differences.
| Alliant Energy |  | IPL |  | WPL
| 2023 |  | 2022 |  |  |  |  |  | 2023 |  | 2022 |  |  |  |  |  | 2023 |  | 2022 |  |  |  |
Overall income tax rate | (1%) |  | 4% |  |  |  |  |  | (18%) |  | (14%) |  |  |  |  |  | 12% |  | 19% |  |  |  |
Summary Of Tax Credit Carryforwards | At March 31, 2023, the carryforwards and expiration dates were estimated as follows (in millions):
| Range of Expiration Dates |  | Alliant Energy |  | IPL |  | WPL
State net operating losses | 2025-2043 |  | $535 |  | $12 |  | $1
Federal tax credits | 2027-2043 |  | 698 |  | 468 |  | 218
WPL [Member] |
Income Taxes [Line Items] |
Schedule Of Effective Income Tax Rates | Overall effective income tax rates, which were computed by dividing income tax expense (benefit) by income before income taxes, were as follows. The effective income tax rates were different than the federal statutory rate primarily due to state income taxes, production tax credits, amortization of excess deferred taxes and the effect of rate-making on property-related differences.
| Alliant Energy |  | IPL |  | WPL
| 2023 |  | 2022 |  |  |  |  |  | 2023 |  | 2022 |  |  |  |  |  | 2023 |  | 2022 |  |  |  |
Overall income tax rate | (1%) |  | 4% |  |  |  |  |  | (18%) |  | (14%) |  |  |  |  |  | 12% |  | 19% |  |  |  |
Summary Of Tax Credit Carryforwards | At March 31, 2023, the carryforwards and expiration dates were estimated as follows (in millions):
| Range of Expiration Dates |  | Alliant Energy |  | IPL |  | WPL
State net operating losses | 2025-2043 |  | $535 |  | $12 |  | $1
Federal tax credits | 2027-2043 |  | 698 |  | 468 |  | 218

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- Definition Tabular disclosure of the reconciliation using percentage or dollar amounts of the reported amount of income tax expense attributable to continuing operations for the year to the amount of income tax expense that would result from applying domestic federal statutory tax rates to pretax income from continuing operations. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Paragraph 12 -Section 50 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-12 + Details
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- Definition Tabular disclosure of tax credit carryforwards available to reduce future taxable income, including amounts, expiration dates, limitations on use and the related deferred tax assets and valuation allowances. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-3 + Details
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