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Income Taxes (Schedule Of Components Of Income Tax) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Current tax expense (benefit): |  |  |
Federal | $ 1 | $ (7) | $ (1)
State | 8 | 24 | (5)
Deferred tax expense (benefit): |  |  |
Federal | 22 | 70 | 68
State | 8 | 42 | 30
Production tax credits | (95) | (55) | (30)
Investment tax credits | (1) | (1) | (1)
Income tax expense (benefit) | (57) | 69 | 48
IPL's tax benefit riders [Member] |  |  |
Current tax expense (benefit): |  |  |
IPL's tax benefit riders | 0 | (4) | (13)
IPL [Member] |  |  |
Current tax expense (benefit): |  |  |
Federal | 6 | (11) | 15
State | (1) | 24 | (7)
Deferred tax expense (benefit): |  |  |
Federal | 30 | 26 | 10
State | (2) | 31 | 7
Production tax credits | (80) | (42) | (14)
Investment tax credits | 0 | 0 | (1)
Income tax expense (benefit) | (47) | 24 | (3)
IPL [Member] | IPL's tax benefit riders [Member] |  |  |
Current tax expense (benefit): |  |  |
IPL's tax benefit riders | 0 | (4) | (13)
WPL [Member] |  |  |
Current tax expense (benefit): |  |  |
Federal | (11) | 12 | (9)
State | 7 | 13 | (5)
Deferred tax expense (benefit): |  |  |
Federal | (9) | 31 | 44
State | 10 | 6 | 22
Production tax credits | (15) | (13) | (15)
Investment tax credits | (1) | 0 | (1)
Income tax expense (benefit) | $ (19) | $ 49 | $ 36

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