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Investment in ATC (Tables) | 9 Months Ended
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Sep. 30, 2015
Investment in ATC [Abstract] |
ALLETE's Investment in ATC [Table Text Block] |
ALLETE’s Investment in ATC |
Millions |
Equity Investment Balance as of December 31, 2014 |  | $121.1 |
Cash Investments | 1.2 |
Equity in ATC Earnings | 14.1 |
Distributed ATC Earnings | (10.4 | )
Equity Investment Balance as of September 30, 2015 |  | $126.0 |
NOTE 8. INVESTMENT IN ATC (Continued) ATC’s summarized financial data for the quarter and nine months ended September 30, 2015 and 2014, is as follows:
| Quarter Ended |  | Nine Months Ended
ATC Summarized Financial Data | September 30, |  | September 30,
Income Statement Data | 2015 |  | 2014 |  | 2015 |  | 2014
Millions |  |  |  |  |  |  |
Revenue |  | $164.5 |  |  |  | $163.6 |  |  |  | $482.0 |  |  |  | $487.0 |
Operating Expense | 78.0 |  |  | 76.6 |  |  | 238.3 |  |  | 229.6 |
Other Expense | 23.1 |  |  | 21.4 |  |  | 71.7 |  |  | 65.1 |
Net Income |  | $63.4 |  |  |  | $65.6 |  |  |  | $172.0 |  |  |  | $192.3 |
ALLETE’s Equity in Net Income |  | $5.5 |  |  |  | $5.3 |  |  |  | $14.1 |  |  |  | $15.6 |

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- Definition Investment in ATC [Abstract] + References No definition available. + Details
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- Definition Tabular disclosure of equity method investments including, but not limited to, name of each investee or group of investments, percentage ownership, difference between recorded amount of an investment and the value of the underlying equity in the net assets, and summarized financial information. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571 + Details
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