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Income Taxes (Schedule Of Components Of Income Tax) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Current tax expense (benefit): |  |  |
Federal | $ 2.0 | $ 36.6 | $ 4.4
State | 3.2 | 9.3 | (3.6)
Deferred tax expense (benefit): |  |  |
Federal | 120.8 | 83.5 | 123.9
State | 27.9 | 4.6 | 15.6
Production tax credits | (33.1) | (31.3) | (31.0)
Investment tax credits | (1.4) | (1.6) | (1.6)
Provision recorded as a change in uncertain tax positions, deferred | 0.0 | 0.0 | (0.4)
Provision recorded as a change in accrued interest | 0.0 | (0.1) | (0.5)
Income tax expense (benefit) | 70.4 | 44.3 | 53.9
IPL's tax benefit riders [Member] |  |  |
Current tax expense (benefit): |  |  |
IPL's tax benefit riders | (49.0) | (56.7) | (52.9)
IPL [Member] |  |  |
Current tax expense (benefit): |  |  |
Federal | (14.1) | 8.9 | 10.2
State | 11.5 | 10.4 | 4.2
Deferred tax expense (benefit): |  |  |
Federal | 40.7 | 10.8 | 21.7
State | 3.3 | (7.9) | (4.0)
Production tax credits | (14.5) | (13.8) | (14.1)
Investment tax credits | (0.6) | (0.6) | (0.6)
Provision recorded as a change in uncertain tax positions, deferred | 0.0 | 0.0 | 0.0
Provision recorded as a change in accrued interest | 0.0 | 0.0 | (0.8)
Income tax expense (benefit) | (22.7) | (48.9) | (36.3)
IPL [Member] | IPL's tax benefit riders [Member] |  |  |
Current tax expense (benefit): |  |  |
IPL's tax benefit riders | (49.0) | (56.7) | (52.9)
WPL [Member] |  |  |
Current tax expense (benefit): |  |  |
Federal | 4.7 | 2.0 | (0.3)
State | 0.6 | 0.8 | (4.3)
Deferred tax expense (benefit): |  |  |
Federal | 76.8 | 81.1 | 84.0
State | 20.2 | 20.0 | 24.1
Production tax credits | (18.6) | (17.5) | (16.9)
Investment tax credits | (0.8) | (1.0) | (1.0)
Provision recorded as a change in uncertain tax positions, deferred | 0.0 | 0.0 | (0.4)
Provision recorded as a change in accrued interest | 0.0 | (0.1) | 0.4
Income tax expense (benefit) | $ 82.9 | $ 85.3 | $ 85.6

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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=6907707&loc=d3e32639-109319 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 6 -Section I -Paragraph Question 1-7 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Article 4 + Details
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