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v3.19.3.a.u2

Investments (Tables) | 12 Months Ended
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Dec. 31, 2019
Investment [Line Items] |
Unconsolidated Equity Investments | Alliant Energy’s unconsolidated investments accounted for under the equity method of accounting are as follows (in millions):
| Ownership Interest at |  | Carrying Value at December 31, |  | Equity (Income) / Loss
| December 31, 2019 |  | 2019 |  | 2018 |  | 2019 |  | 2018 |  | 2017
ATC Holdings | 16%, 20% |  |  | $320.1 |  |  |  | $293.6 |  |  |  | ($45.3 | ) |  |  | ($38.1 | ) |  |  | ($42.4 | )
Non-utility wind farm in Oklahoma | 50% |  | 105.3 |  |  | 105.1 |  |  | (5.2 | ) |  | (15.6 | ) |  | (1.8 | )
Other | Various |  | 32.9 |  |  | 22.6 |  |  | (2.5 | ) |  | (0.9 | ) |  | (0.6 | )
|  |  |  | $458.3 |  |  |  | $421.3 |  |  |  | ($53.0 | ) |  |  | ($54.6 | ) |  |  | ($44.8 | )

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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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 + Details
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