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Segments Of Business (Tables) | 3 Months Ended
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Mar. 31, 2019
Segment Reporting Information [Line Items] |
Schedule Of Segments Of Business | Certain financial information relating to Alliant Energy’s business segments is as follows. Intersegment revenues were not material to Alliant Energy’s operations.
|  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Three Months Ended March 31, 2019 |  |  |  |  |  |  |  |  |  |  |
Revenues |  | $743.4 |  |  |  | $215.8 |  |  |  | $11.1 |  |  |  | $970.3 |  |  |  | $16.9 |  |  |  | $987.2 |
Operating income | 126.4 |  |  | 45.2 |  |  | — |  |  | 171.6 |  |  | 5.2 |  |  | 176.8 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 119.0 |  |  | 6.1 |  |  | 125.1 |
Three Months Ended March 31, 2018 |  |  |  |  |  |  |  |  |  |  |
Revenues |  | $708.7 |  |  |  | $185.6 |  |  |  | $13.2 |  |  |  | $907.5 |  |  |  | $8.8 |  |  |  | $916.3 |
Operating income | 126.7 |  |  | 31.5 |  |  | 1.4 |  |  | 159.6 |  |  | 6.1 |  |  | 165.7 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 100.7 |  |  | 20.2 |  |  | 120.9 |
IPL [Member] |
Segment Reporting Information [Line Items] |
Schedule Of Segments Of Business | Certain financial information relating to IPL’s business segments is as follows. Intersegment revenues were not material to IPL’s operations.
| Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended March 31, 2019 |  |  |  |  |  |  |
Revenues |  | $419.8 |  |  |  | $124.6 |  |  |  | $10.7 |  |  |  | $555.1 |
Operating income | 46.8 |  |  | 26.3 |  |  | 0.4 |  |  | 73.5 |
Earnings available for common stock |  |  |  |  |  |  | 53.3 |
Three Months Ended March 31, 2018 |  |  |  |  |  |  |
Revenues |  | $405.7 |  |  |  | $108.1 |  |  |  | $12.0 |  |  |  | $525.8 |
Operating income | 57.5 |  |  | 16.9 |  |  | 1.2 |  |  | 75.6 |
Earnings available for common stock |  |  |  |  |  |  | 46.7 |
WPL [Member] |
Segment Reporting Information [Line Items] |
Schedule Of Segments Of Business | Certain financial information relating to WPL’s business segments is as follows. Intersegment revenues were not material to WPL’s operations.
| Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended March 31, 2019 |  |  |  |  |  |  |
Revenues |  | $323.6 |  |  |  | $91.2 |  |  |  | $0.4 |  |  |  | $415.2 |
Operating income (loss) | 79.6 |  |  | 18.9 |  |  | (0.4 | ) |  | 98.1 |
Earnings available for common stock |  |  |  |  |  |  | 65.7 |
Three Months Ended March 31, 2018 |  |  |  |  |  |  |
Revenues |  | $303.0 |  |  |  | $77.5 |  |  |  | $1.2 |  |  |  | $381.7 |
Operating income | 69.2 |  |  | 14.6 |  |  | 0.2 |  |  | 84.0 |
Earnings available for common stock |  |  |  |  |  |  | 54.0 |

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- Definition Tabular disclosure of the profit or loss and total assets for each reportable segment. An entity discloses certain information on each reportable segment if the amounts (a) are included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) are otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -URI http://asc.fasb.org/extlink&oid=68060357&loc=d3e8906-108599 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 25 -URI http://asc.fasb.org/extlink&oid=68060357&loc=d3e8813-108599 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=68060357&loc=d3e8721-108599 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=68060357&loc=d3e8736-108599 + Details
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