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Investments | 9 Months Ended
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Sep. 30, 2018
Schedule of Investments [Line Items] |
Investments | INVESTMENTS Unconsolidated Equity Investments - Alliant Energy’s equity (income) loss from unconsolidated investments accounted for under the equity method of accounting for the three and nine months ended September 30 was as follows (in millions):
| Three Months |  | Nine Months
| 2018 |  | 2017 |  | 2018 |  | 2017
ATC Holdings |  | ($8.9 | ) |  |  | ($10.1 | ) |  |  | ($25.4 | ) |  |  | ($32.7 | )
Non-utility wind farm in Oklahoma | 0.1 |  |  | 0.2 |  |  | (14.5 | ) |  | 0.2 |
Other | (1.0 | ) |  | (0.2 | ) |  | (1.7 | ) |  | (0.4 | )
|  | ($9.8 | ) |  |  | ($10.1 | ) |  |  | ($41.6 | ) |  |  | ($32.9 | )
Non-utility Wind Farm in Oklahoma - Alliant Energy’s interest in a non-utility wind farm in Oklahoma commenced in July 2017. As a result, there was no corresponding equity income recognized during the first half of 2017. The equity income recognized during the nine months ended September 30, 2018 was primarily related to the impacts of Federal Tax Reform. The liquidation method utilized to recognize Alliant Energy’s share of the wind farm’s earnings includes utilizing the federal income tax rate in effect as of the end of the measurement period. The lower federal income tax rate effective as of January 1, 2018 resulted in an acceleration of earnings attributable to Alliant Energy’s interest in the Oklahoma wind farm. This increase in earnings is expected to reverse over time.

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- Definition The entire disclosure for investment holdings. This includes the long positions of investments for the entity. It contains investments in affiliated and unaffiliated issuers. The investments include securities and non securities (i.e. commodities and futures contracts). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-12C) -URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611225-123010 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14) -URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611322-123010 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 5 -Subparagraph (SX 210.12-13) -URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611282-123010 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-12) -URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611133-123010 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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