v2.4.0.6

Investments | 12 Months Ended
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Dec. 31, 2012
Schedule of Equity Method Investments [Line Items] |
Investments | INVESTMENTS (a) Unconsolidated Equity Investments - Alliant Energy’s and WPL’s unconsolidated investments accounted for under the equity method of accounting are as follows (in millions):
| Ownership |  | Carrying Value at |  |
| Interest at |  | December 31, |  | Equity (Income) / Loss
| December 31, 2012 |  | 2012 |  | 2011 |  | 2012 |  | 2011 |  | 2010
Alliant Energy |  |  |  |  |  |  |  |  |  |  |
ATC (a) | 16% |  |  | $257.0 |  |  |  | $238.8 |  |  |  | ($41.3 | ) |  |  | ($37.8 | ) |  |  | ($36.9 | )
Wisconsin River Power Company | 50% |  | 7.3 |  |  | 7.7 |  |  | (0.8 | ) |  | (0.9 | ) |  | (0.9 | )
Other | Various |  | 2.3 |  |  | 3.1 |  |  | 0.8 |  |  | (0.6 | ) |  | (0.3 | )
|  |  |  | $266.6 |  |  |  | $249.6 |  |  |  | ($41.3 | ) |  |  | ($39.3 | ) |  |  | ($38.1 | )
WPL |  |  |  |  |  |  |  |  |  |  |
ATC (a) | 16% |  |  | $257.0 |  |  |  | $238.8 |  |  |  | ($41.3 | ) |  |  | ($37.8 | ) |  |  | ($36.9 | )
Wisconsin River Power Company | 50% |  | 7.3 |  |  | 7.7 |  |  | (0.8 | ) |  | (0.9 | ) |  | (0.9 | )
|  |  |  | $264.3 |  |  |  | $246.5 |  |  |  | ($42.1 | ) |  |  | ($38.7 | ) |  |  | ($37.8 | )
(a) | Alliant Energy and WPL have the ability to exercise significant influence over ATC’s financial and operating policies through their participation on ATC’s Board of Directors. Refer to Note 19 for information regarding related party transactions with ATC.
Summary aggregate financial information from the financial statements of these investments is as follows (in millions):
| Alliant Energy |  | WPL
| 2012 |  | 2011 |  | 2010 |  | 2012 |  | 2011 |  | 2010
Operating revenues |  | $611 |  |  |  | $575 |  |  |  | $564 |  |  |  | $611 |  |  |  | $575 |  |  |  | $564 |
Operating income | 326 |  |  | 307 |  |  | 307 |  |  | 325 |  |  | 308 |  |  | 308 |
Net income | 234 |  |  | 218 |  |  | 226 |  |  | 239 |  |  | 226 |  |  | 221 |
As of December 31: |  |  |  |  |  |  |  |  |  |  |
Current assets | 67 |  |  | 62 |  |  |  |  | 66 |  |  | 61 |  |  |
Non-current assets | 3,321 |  |  | 3,100 |  |  |  |  | 3,292 |  |  | 3,071 |  |  |
Current liabilities | 252 |  |  | 299 |  |  |  |  | 252 |  |  | 299 |  |  |
Non-current liabilities | 1,652 |  |  | 1,490 |  |  |  |  | 1,651 |  |  | 1,487 |  |  |
(b) Cash Surrender Value of Life Insurance Policies - Alliant Energy, IPL and WPL have various life insurance policies that cover certain current and former employees and directors. At December 31, the cash surrender value of these investments was as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
| 2012 |  | 2011 |  | 2012 |  | 2011 |  | 2012 |  | 2011
Cash surrender value | $50.5 |  | $49.2 |  | $16.0 |  | $15.1 |  | $12.1 |  | $11.9
IPL [Member] |
Schedule of Equity Method Investments [Line Items] |
Investments | INVESTMENTS (b) Cash Surrender Value of Life Insurance Policies - Alliant Energy, IPL and WPL have various life insurance policies that cover certain current and former employees and directors. At December 31, the cash surrender value of these investments was as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
| 2012 |  | 2011 |  | 2012 |  | 2011 |  | 2012 |  | 2011
Cash surrender value | $50.5 |  | $49.2 |  | $16.0 |  | $15.1 |  | $12.1 |  | $11.9
WPL [Member] |
Schedule of Equity Method Investments [Line Items] |
Investments | INVESTMENTS (a) Unconsolidated Equity Investments - Alliant Energy’s and WPL’s unconsolidated investments accounted for under the equity method of accounting are as follows (in millions):
| Ownership |  | Carrying Value at |  |
| Interest at |  | December 31, |  | Equity (Income) / Loss
| December 31, 2012 |  | 2012 |  | 2011 |  | 2012 |  | 2011 |  | 2010
Alliant Energy |  |  |  |  |  |  |  |  |  |  |
ATC (a) | 16% |  |  | $257.0 |  |  |  | $238.8 |  |  |  | ($41.3 | ) |  |  | ($37.8 | ) |  |  | ($36.9 | )
Wisconsin River Power Company | 50% |  | 7.3 |  |  | 7.7 |  |  | (0.8 | ) |  | (0.9 | ) |  | (0.9 | )
Other | Various |  | 2.3 |  |  | 3.1 |  |  | 0.8 |  |  | (0.6 | ) |  | (0.3 | )
|  |  |  | $266.6 |  |  |  | $249.6 |  |  |  | ($41.3 | ) |  |  | ($39.3 | ) |  |  | ($38.1 | )
WPL |  |  |  |  |  |  |  |  |  |  |
ATC (a) | 16% |  |  | $257.0 |  |  |  | $238.8 |  |  |  | ($41.3 | ) |  |  | ($37.8 | ) |  |  | ($36.9 | )
Wisconsin River Power Company | 50% |  | 7.3 |  |  | 7.7 |  |  | (0.8 | ) |  | (0.9 | ) |  | (0.9 | )
|  |  |  | $264.3 |  |  |  | $246.5 |  |  |  | ($42.1 | ) |  |  | ($38.7 | ) |  |  | ($37.8 | )
(a) | Alliant Energy and WPL have the ability to exercise significant influence over ATC’s financial and operating policies through their participation on ATC’s Board of Directors. Refer to Note 19 for information regarding related party transactions with ATC.
Summary aggregate financial information from the financial statements of these investments is as follows (in millions):
| Alliant Energy |  | WPL
| 2012 |  | 2011 |  | 2010 |  | 2012 |  | 2011 |  | 2010
Operating revenues |  | $611 |  |  |  | $575 |  |  |  | $564 |  |  |  | $611 |  |  |  | $575 |  |  |  | $564 |
Operating income | 326 |  |  | 307 |  |  | 307 |  |  | 325 |  |  | 308 |  |  | 308 |
Net income | 234 |  |  | 218 |  |  | 226 |  |  | 239 |  |  | 226 |  |  | 221 |
As of December 31: |  |  |  |  |  |  |  |  |  |  |
Current assets | 67 |  |  | 62 |  |  |  |  | 66 |  |  | 61 |  |  |
Non-current assets | 3,321 |  |  | 3,100 |  |  |  |  | 3,292 |  |  | 3,071 |  |  |
Current liabilities | 252 |  |  | 299 |  |  |  |  | 252 |  |  | 299 |  |  |
Non-current liabilities | 1,652 |  |  | 1,490 |  |  |  |  | 1,651 |  |  | 1,487 |  |  |
(b) Cash Surrender Value of Life Insurance Policies - Alliant Energy, IPL and WPL have various life insurance policies that cover certain current and former employees and directors. At December 31, the cash surrender value of these investments was as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
| 2012 |  | 2011 |  | 2012 |  | 2011 |  | 2012 |  | 2011
Cash surrender value | $50.5 |  | $49.2 |  | $16.0 |  | $15.1 |  | $12.1 |  | $11.9

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- Definition The entire disclosure for investments, including all tables. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 6 -Section 10 -Paragraph (c) -Subparagraph (1) + Details
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