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Income Taxes (Schedule Of Components Of Income Tax) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Current tax expense (benefit): |  |  |
Federal | $ (41.0) | $ 1.8 | $ 2.0
State | 8.5 | 17.2 | 3.2
Deferred tax expense (benefit): |  |  |
Federal | 159.5 | 112.8 | 120.8
State | 12.3 | 4.9 | 27.9
Production tax credits | (31.1) | (31.8) | (33.1)
Investment tax credits | (1.1) | (1.3) | (1.4)
Income tax expense (benefit) | 66.7 | 59.4 | 70.4
IPL's tax benefit riders [Member] |  |  |
Current tax expense (benefit): |  |  |
IPL's tax benefit riders | (40.4) | (44.2) | (49.0)
IPL [Member] |  |  |
Current tax expense (benefit): |  |  |
Federal | (27.9) | (12.8) | (14.1)
State | 1.6 | 15.5 | 11.5
Deferred tax expense (benefit): |  |  |
Federal | 72.5 | 59.1 | 40.7
State | (2.2) | (9.0) | 3.3
Production tax credits | (14.1) | (14.0) | (14.5)
Investment tax credits | (0.4) | (0.5) | (0.6)
Income tax expense (benefit) | (10.9) | (5.9) | (22.7)
IPL [Member] | IPL's tax benefit riders [Member] |  |  |
Current tax expense (benefit): |  |  |
IPL's tax benefit riders | (40.4) | (44.2) | (49.0)
WPL [Member] |  |  |
Current tax expense (benefit): |  |  |
Federal | 5.5 | (22.3) | 4.7
State | 2.5 | 1.1 | 0.6
Deferred tax expense (benefit): |  |  |
Federal | 55.0 | 112.3 | 76.8
State | 16.6 | 20.8 | 20.2
Production tax credits | (17.0) | (17.8) | (18.6)
Investment tax credits | (0.7) | (0.8) | (0.8)
Income tax expense (benefit) | $ 61.9 | $ 93.3 | $ 82.9

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- Definition Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(h)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Current Tax Expense (or Benefit) -URI http://asc.fasb.org/extlink&oid=6509736 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 6.I.7) -URI http://asc.fasb.org/extlink&oid=34349781&loc=d3e330036-122817 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=65882285&loc=d3e32639-109319 + Details
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