v2.4.0.6

Derivative Instruments (Notional Amounts Of Derivative Instruments) (Details) (Commodity [Member]) | Sep. 30, 2012 MWh
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Electricity (MWhs) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 8,134,000
Electricity (MWhs) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 3,130,000
Electricity (MWhs) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 5,004,000
FTRs (MWs) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 44,000
FTRs (MWs) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 23,000
FTRs (MWs) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 21,000
Natural Gas (Dths) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 77,379,000
Natural Gas (Dths) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 54,818,000
Natural Gas (Dths) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 22,561,000
Coal (Tons) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 2,498,000
Coal (Tons) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 2,498,000
2012 [Member] | Electricity (MWhs) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 1,280,000
2012 [Member] | Electricity (MWhs) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 786,000
2012 [Member] | Electricity (MWhs) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 494,000
2012 [Member] | FTRs (MWs) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 16,000
2012 [Member] | FTRs (MWs) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 8,000
2012 [Member] | FTRs (MWs) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 8,000
2012 [Member] | Natural Gas (Dths) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 26,070,000
2012 [Member] | Natural Gas (Dths) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 19,274,000
2012 [Member] | Natural Gas (Dths) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 6,796,000
2012 [Member] | Coal (Tons) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 0
2012 [Member] | Coal (Tons) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 0
2013 [Member] | Electricity (MWhs) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 3,860,000
2013 [Member] | Electricity (MWhs) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 1,978,000
2013 [Member] | Electricity (MWhs) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 1,882,000
2013 [Member] | FTRs (MWs) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 28,000
2013 [Member] | FTRs (MWs) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 15,000
2013 [Member] | FTRs (MWs) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 13,000
2013 [Member] | Natural Gas (Dths) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 44,899,000
2013 [Member] | Natural Gas (Dths) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 32,309,000
2013 [Member] | Natural Gas (Dths) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 12,590,000
2013 [Member] | Coal (Tons) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 956,000
2013 [Member] | Coal (Tons) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 956,000
2014 [Member] | Electricity (MWhs) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 2,118,000
2014 [Member] | Electricity (MWhs) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 366,000
2014 [Member] | Electricity (MWhs) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 1,752,000
2014 [Member] | FTRs (MWs) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 0
2014 [Member] | FTRs (MWs) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 0
2014 [Member] | FTRs (MWs) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 0
2014 [Member] | Natural Gas (Dths) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 6,410,000
2014 [Member] | Natural Gas (Dths) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 3,235,000
2014 [Member] | Natural Gas (Dths) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 3,175,000
2014 [Member] | Coal (Tons) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 981,000
2014 [Member] | Coal (Tons) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 981,000
2015 [Member] | Electricity (MWhs) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 876,000
2015 [Member] | Electricity (MWhs) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 0
2015 [Member] | Electricity (MWhs) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 876,000
2015 [Member] | FTRs (MWs) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 0
2015 [Member] | FTRs (MWs) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 0
2015 [Member] | FTRs (MWs) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 0
2015 [Member] | Natural Gas (Dths) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 0
2015 [Member] | Natural Gas (Dths) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 0
2015 [Member] | Natural Gas (Dths) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 0
2015 [Member] | Coal (Tons) [Member] | Alliant Energy [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 561,000
2015 [Member] | Coal (Tons) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional Unit Amount Of Derivatives (in MWhs/MWs/Dths/Tons) | 561,000

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- Definition Aggregate notional amount of derivative expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 + Details
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