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Debt (Schedule Of Debt Maturities) (Details) (USD $) In Millions, unless otherwise specified | Dec. 31, 2012 | Dec. 31, 2011
--- | --- | ---
2013 | $ 51 |  |  |
2014 | 358 |  |  |
2015 | 183 |  |  |
2016 | 3 |  |  |
2017 | 4 |  |  |
Commercial paper | 217.5 |  | 102.8 |
IPL [Member] |  |  |  |
2013 | 50 | [1] |  |
2014 | 38 | [1] |  |
2015 | 150 | [1] |  |
2016 | 0 | [1] |  |
2017 | 0 | [1] |  |
Commercial paper | 26.3 |  | 7.1 |
Resources [Member] |  |  |  |
2013 | 1 |  |  |
2014 | 62 |  |  |
2015 | 2 |  |  |
2016 | 3 |  |  |
2017 | 4 |  |  |
Parent Company [Member] |  |  |  |
2013 | 0 |  |  |
2014 | 250 |  |  |
2015 | 0 |  |  |
2016 | 0 |  |  |
2017 | 0 |  |  |
Commercial paper | 105.0 |  | 70.0 |
WPL [Member] |  |  |  |
2013 | 0 |  |  |
2014 | 8 |  |  |
2015 | 31 |  |  |
2016 | 0 |  |  |
2017 | 0 |  |  |
Commercial paper | 86.6 |  | 25.7 |
Long-term debt [Member] |  |  |  |
Commercial paper | 50.0 | [2] | 0 | [2]
Long-term debt [Member] | IPL [Member] |  |  |  |
Commercial paper | $ 50.0 | [2] | $ 0 | [2]
[1] | IPL’s amount for 2013 includes $50.0 million of commercial paper that was recorded in “Long-term debt, net” on Alliant Energy’s and IPL’s Consolidated Balance Sheets as described above.
[2] | As of December 31, 2012, $50.0 million of commercial paper was recorded in “Long-term debt, net” on Alliant Energy’s and IPL’s Consolidated Balance Sheets due to the existence of long-term credit facilities that back-stop this commercial paper balance, along with Alliant Energy’s and IPL’s intent and ability to refinance these balances on a long-term basis. As of December 31, 2012, this commercial paper balance had a remaining maturity of 8 days.

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