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Segments Of Business | 9 Months Ended
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Sep. 30, 2015
Segment Reporting Information [Line Items] |
Segments Of Business | SEGMENTS OF BUSINESS Alliant Energy - Certain financial information relating to Alliant Energy’s business segments is as follows. Intersegment revenues were not material to Alliant Energy’s operations.
| Utility |  | Non-Regulated, |  | Alliant Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Three Months Ended September 30, 2015 |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  | $835.8 |  |  |  | $38.0 |  |  |  | $13.4 |  |  |  | $887.2 |  |  |  | $11.7 |  |  |  | $898.9 |
Operating income (loss) | 232.8 |  |  | (5.7 | ) |  | 0.2 |  |  | 227.3 |  |  | 8.6 |  |  | 235.9 |
Amounts attributable to Alliant Energy common shareowners: |  |  |  |  |  |  |  |  |  |  |
Income (loss) from continuing operations, net of tax |  |  |  |  |  |  | 184.9 |  |  | (4.9 | ) |  | 180.0 |
Loss from discontinued operations, net of tax |  |  |  |  |  |  | — |  |  | (0.1 | ) |  | (0.1 | )
Net income (loss) |  |  |  |  |  |  | 184.9 |  |  | (5.0 | ) |  | 179.9 |
Three Months Ended September 30, 2014 |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  | $771.2 |  |  |  | $47.2 |  |  |  | $12.2 |  |  |  | $830.6 |  |  |  | $12.5 |  |  |  | $843.1 |
Operating income (loss) | 190.8 |  |  | (4.4 | ) |  | 1.4 |  |  | 187.8 |  |  | 7.0 |  |  | 194.8 |
Amounts attributable to Alliant Energy common shareowners: |  |  |  |  |  |  |  |  |  |  |
Income (loss) from continuing operations, net of tax |  |  |  |  |  |  | 164.1 |  |  | (8.9 | ) |  | 155.2 |
Loss from discontinued operations, net of tax |  |  |  |  |  |  | — |  |  | (1.9 | ) |  | (1.9 | )
Net income (loss) |  |  |  |  |  |  | 164.1 |  |  | (10.8 | ) |  | 153.3 |
| Utility |  | Non-Regulated, |  | Alliant Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Nine Months Ended September 30, 2015 |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  | $2,147.5 |  |  |  | $288.1 |  |  |  | $44.6 |  |  |  | $2,480.2 |  |  |  | $33.3 |  |  |  | $2,513.5 |
Operating income | 438.4 |  |  | 28.6 |  |  | 8.7 |  |  | 475.7 |  |  | 22.1 |  |  | 497.8 |
Amounts attributable to Alliant Energy common shareowners: |  |  |  |  |  |  |  |  |  |  |  |
Income from continuing operations, net of tax |  |  |  |  |  |  | 333.0 |  |  | 12.5 |  |  | 345.5 |
Loss from discontinued operations, net of tax |  |  |  |  |  |  | — |  |  | (1.4 | ) |  | (1.4 | )
Net income |  |  |  |  |  |  | 333.0 |  |  | 11.1 |  |  | 344.1 |
Nine Months Ended September 30, 2014 |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  | $2,090.9 |  |  |  | $364.8 |  |  |  | $50.6 |  |  |  | $2,506.3 |  |  |  | $39.9 |  |  |  | $2,546.2 |
Operating income | 374.2 |  |  | 41.3 |  |  | 11.5 |  |  | 427.0 |  |  | 25.3 |  |  | 452.3 |
Amounts attributable to Alliant Energy common shareowners: |  |  |  |  |  |  |  |  |  |  |
Income from continuing operations, net of tax |  |  |  |  |  |  | 315.3 |  |  | 10.0 |  |  | 325.3 |
Loss from discontinued operations, net of tax |  |  |  |  |  |  | — |  |  | (2.2 | ) |  | (2.2 | )
Net income |  |  |  |  |  |  | 315.3 |  |  | 7.8 |  |  | 323.1 |
IPL - 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 September 30, 2015 |  |  |  |  |  |  |
Operating revenues |  | $468.6 |  |  |  | $23.1 |  |  |  | $12.9 |  |  |  | $504.6 |
Operating income (loss) | 119.4 |  |  | (2.9 | ) |  | 0.5 |  |  | 117.0 |
Earnings available for common stock |  |  |  |  |  |  | 117.4 |
Three Months Ended September 30, 2014 |  |  |  |  |  |  |
Operating revenues |  | $435.9 |  |  |  | $28.7 |  |  |  | $11.6 |  |  |  | $476.2 |
Operating income (loss) | 94.7 |  |  | (2.8 | ) |  | 2.0 |  |  | 93.9 |
Earnings available for common stock |  |  |  |  |  |  | 102.5 |
Nine Months Ended September 30, 2015 |  |  |  |  |  |  |
Operating revenues |  | $1,170.6 |  |  |  | $164.1 |  |  |  | $41.1 |  |  |  | $1,375.8 |
Operating income | 193.6 |  |  | 15.3 |  |  | 7.4 |  |  | 216.3 |
Earnings available for common stock |  |  |  |  |  |  | 181.9 |
Nine Months Ended September 30, 2014 |  |  |  |  |  |  |
Operating revenues |  | $1,164.7 |  |  |  | $208.1 |  |  |  | $44.2 |  |  |  | $1,417.0 |
Operating income | 150.2 |  |  | 22.1 |  |  | 13.1 |  |  | 185.4 |
Earnings available for common stock |  |  |  |  |  |  | 164.3 |
WPL - 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 September 30, 2015 |  |  |  |  |  |  |
Operating revenues |  | $367.2 |  |  |  | $14.9 |  |  |  | $0.5 |  |  |  | $382.6 |
Operating income (loss) | 113.4 |  |  | (2.8 | ) |  | (0.3 | ) |  | 110.3 |
Earnings available for common stock |  |  |  |  |  |  | 67.5 |
Three Months Ended September 30, 2014 |  |  |  |  |  |  |
Operating revenues |  | $335.3 |  |  |  | $18.5 |  |  |  | $0.6 |  |  |  | $354.4 |
Operating income (loss) | 96.1 |  |  | (1.6 | ) |  | (0.6 | ) |  | 93.9 |
Earnings available for common stock |  |  |  |  |  |  | 61.6 |
Nine Months Ended September 30, 2015 |  |  |  |  |  |  |
Operating revenues |  | $976.9 |  |  |  | $124.0 |  |  |  | $3.5 |  |  |  | $1,104.4 |
Operating income | 244.8 |  |  | 13.3 |  |  | 1.3 |  |  | 259.4 |
Earnings available for common stock |  |  |  |  |  |  | 151.1 |
Nine Months Ended September 30, 2014 |  |  |  |  |  |  |
Operating revenues |  | $926.2 |  |  |  | $156.7 |  |  |  | $6.4 |  |  |  | $1,089.3 |
Operating income (loss) | 224.0 |  |  | 19.2 |  |  | (1.6 | ) |  | 241.6 |
Earnings available for common stock |  |  |  |  |  |  | 151.0 |
IPL [Member] |
Segment Reporting Information [Line Items] |
Segments Of Business | SEGMENTS OF BUSINESS Alliant Energy - Certain financial information relating to Alliant Energy’s business segments is as follows. Intersegment revenues were not material to Alliant Energy’s operations.
| Utility |  | Non-Regulated, |  | Alliant Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Three Months Ended September 30, 2015 |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  | $835.8 |  |  |  | $38.0 |  |  |  | $13.4 |  |  |  | $887.2 |  |  |  | $11.7 |  |  |  | $898.9 |
Operating income (loss) | 232.8 |  |  | (5.7 | ) |  | 0.2 |  |  | 227.3 |  |  | 8.6 |  |  | 235.9 |
Amounts attributable to Alliant Energy common shareowners: |  |  |  |  |  |  |  |  |  |  |
Income (loss) from continuing operations, net of tax |  |  |  |  |  |  | 184.9 |  |  | (4.9 | ) |  | 180.0 |
Loss from discontinued operations, net of tax |  |  |  |  |  |  | — |  |  | (0.1 | ) |  | (0.1 | )
Net income (loss) |  |  |  |  |  |  | 184.9 |  |  | (5.0 | ) |  | 179.9 |
Three Months Ended September 30, 2014 |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  | $771.2 |  |  |  | $47.2 |  |  |  | $12.2 |  |  |  | $830.6 |  |  |  | $12.5 |  |  |  | $843.1 |
Operating income (loss) | 190.8 |  |  | (4.4 | ) |  | 1.4 |  |  | 187.8 |  |  | 7.0 |  |  | 194.8 |
Amounts attributable to Alliant Energy common shareowners: |  |  |  |  |  |  |  |  |  |  |
Income (loss) from continuing operations, net of tax |  |  |  |  |  |  | 164.1 |  |  | (8.9 | ) |  | 155.2 |
Loss from discontinued operations, net of tax |  |  |  |  |  |  | — |  |  | (1.9 | ) |  | (1.9 | )
Net income (loss) |  |  |  |  |  |  | 164.1 |  |  | (10.8 | ) |  | 153.3 |
| Utility |  | Non-Regulated, |  | Alliant Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Nine Months Ended September 30, 2015 |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  | $2,147.5 |  |  |  | $288.1 |  |  |  | $44.6 |  |  |  | $2,480.2 |  |  |  | $33.3 |  |  |  | $2,513.5 |
Operating income | 438.4 |  |  | 28.6 |  |  | 8.7 |  |  | 475.7 |  |  | 22.1 |  |  | 497.8 |
Amounts attributable to Alliant Energy common shareowners: |  |  |  |  |  |  |  |  |  |  |  |
Income from continuing operations, net of tax |  |  |  |  |  |  | 333.0 |  |  | 12.5 |  |  | 345.5 |
Loss from discontinued operations, net of tax |  |  |  |  |  |  | — |  |  | (1.4 | ) |  | (1.4 | )
Net income |  |  |  |  |  |  | 333.0 |  |  | 11.1 |  |  | 344.1 |
Nine Months Ended September 30, 2014 |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  | $2,090.9 |  |  |  | $364.8 |  |  |  | $50.6 |  |  |  | $2,506.3 |  |  |  | $39.9 |  |  |  | $2,546.2 |
Operating income | 374.2 |  |  | 41.3 |  |  | 11.5 |  |  | 427.0 |  |  | 25.3 |  |  | 452.3 |
Amounts attributable to Alliant Energy common shareowners: |  |  |  |  |  |  |  |  |  |  |
Income from continuing operations, net of tax |  |  |  |  |  |  | 315.3 |  |  | 10.0 |  |  | 325.3 |
Loss from discontinued operations, net of tax |  |  |  |  |  |  | — |  |  | (2.2 | ) |  | (2.2 | )
Net income |  |  |  |  |  |  | 315.3 |  |  | 7.8 |  |  | 323.1 |
IPL - 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 September 30, 2015 |  |  |  |  |  |  |
Operating revenues |  | $468.6 |  |  |  | $23.1 |  |  |  | $12.9 |  |  |  | $504.6 |
Operating income (loss) | 119.4 |  |  | (2.9 | ) |  | 0.5 |  |  | 117.0 |
Earnings available for common stock |  |  |  |  |  |  | 117.4 |
Three Months Ended September 30, 2014 |  |  |  |  |  |  |
Operating revenues |  | $435.9 |  |  |  | $28.7 |  |  |  | $11.6 |  |  |  | $476.2 |
Operating income (loss) | 94.7 |  |  | (2.8 | ) |  | 2.0 |  |  | 93.9 |
Earnings available for common stock |  |  |  |  |  |  | 102.5 |
Nine Months Ended September 30, 2015 |  |  |  |  |  |  |
Operating revenues |  | $1,170.6 |  |  |  | $164.1 |  |  |  | $41.1 |  |  |  | $1,375.8 |
Operating income | 193.6 |  |  | 15.3 |  |  | 7.4 |  |  | 216.3 |
Earnings available for common stock |  |  |  |  |  |  | 181.9 |
Nine Months Ended September 30, 2014 |  |  |  |  |  |  |
Operating revenues |  | $1,164.7 |  |  |  | $208.1 |  |  |  | $44.2 |  |  |  | $1,417.0 |
Operating income | 150.2 |  |  | 22.1 |  |  | 13.1 |  |  | 185.4 |
Earnings available for common stock |  |  |  |  |  |  | 164.3 |
WPL - 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 September 30, 2015 |  |  |  |  |  |  |
Operating revenues |  | $367.2 |  |  |  | $14.9 |  |  |  | $0.5 |  |  |  | $382.6 |
Operating income (loss) | 113.4 |  |  | (2.8 | ) |  | (0.3 | ) |  | 110.3 |
Earnings available for common stock |  |  |  |  |  |  | 67.5 |
Three Months Ended September 30, 2014 |  |  |  |  |  |  |
Operating revenues |  | $335.3 |  |  |  | $18.5 |  |  |  | $0.6 |  |  |  | $354.4 |
Operating income (loss) | 96.1 |  |  | (1.6 | ) |  | (0.6 | ) |  | 93.9 |
Earnings available for common stock |  |  |  |  |  |  | 61.6 |
Nine Months Ended September 30, 2015 |  |  |  |  |  |  |
Operating revenues |  | $976.9 |  |  |  | $124.0 |  |  |  | $3.5 |  |  |  | $1,104.4 |
Operating income | 244.8 |  |  | 13.3 |  |  | 1.3 |  |  | 259.4 |
Earnings available for common stock |  |  |  |  |  |  | 151.1 |
Nine Months Ended September 30, 2014 |  |  |  |  |  |  |
Operating revenues |  | $926.2 |  |  |  | $156.7 |  |  |  | $6.4 |  |  |  | $1,089.3 |
Operating income (loss) | 224.0 |  |  | 19.2 |  |  | (1.6 | ) |  | 241.6 |
Earnings available for common stock |  |  |  |  |  |  | 151.0 |
WPL [Member] |
Segment Reporting Information [Line Items] |
Segments Of Business | SEGMENTS OF BUSINESS Alliant Energy - Certain financial information relating to Alliant Energy’s business segments is as follows. Intersegment revenues were not material to Alliant Energy’s operations.
| Utility |  | Non-Regulated, |  | Alliant Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Three Months Ended September 30, 2015 |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  | $835.8 |  |  |  | $38.0 |  |  |  | $13.4 |  |  |  | $887.2 |  |  |  | $11.7 |  |  |  | $898.9 |
Operating income (loss) | 232.8 |  |  | (5.7 | ) |  | 0.2 |  |  | 227.3 |  |  | 8.6 |  |  | 235.9 |
Amounts attributable to Alliant Energy common shareowners: |  |  |  |  |  |  |  |  |  |  |
Income (loss) from continuing operations, net of tax |  |  |  |  |  |  | 184.9 |  |  | (4.9 | ) |  | 180.0 |
Loss from discontinued operations, net of tax |  |  |  |  |  |  | — |  |  | (0.1 | ) |  | (0.1 | )
Net income (loss) |  |  |  |  |  |  | 184.9 |  |  | (5.0 | ) |  | 179.9 |
Three Months Ended September 30, 2014 |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  | $771.2 |  |  |  | $47.2 |  |  |  | $12.2 |  |  |  | $830.6 |  |  |  | $12.5 |  |  |  | $843.1 |
Operating income (loss) | 190.8 |  |  | (4.4 | ) |  | 1.4 |  |  | 187.8 |  |  | 7.0 |  |  | 194.8 |
Amounts attributable to Alliant Energy common shareowners: |  |  |  |  |  |  |  |  |  |  |
Income (loss) from continuing operations, net of tax |  |  |  |  |  |  | 164.1 |  |  | (8.9 | ) |  | 155.2 |
Loss from discontinued operations, net of tax |  |  |  |  |  |  | — |  |  | (1.9 | ) |  | (1.9 | )
Net income (loss) |  |  |  |  |  |  | 164.1 |  |  | (10.8 | ) |  | 153.3 |
| Utility |  | Non-Regulated, |  | Alliant Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Nine Months Ended September 30, 2015 |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  | $2,147.5 |  |  |  | $288.1 |  |  |  | $44.6 |  |  |  | $2,480.2 |  |  |  | $33.3 |  |  |  | $2,513.5 |
Operating income | 438.4 |  |  | 28.6 |  |  | 8.7 |  |  | 475.7 |  |  | 22.1 |  |  | 497.8 |
Amounts attributable to Alliant Energy common shareowners: |  |  |  |  |  |  |  |  |  |  |  |
Income from continuing operations, net of tax |  |  |  |  |  |  | 333.0 |  |  | 12.5 |  |  | 345.5 |
Loss from discontinued operations, net of tax |  |  |  |  |  |  | — |  |  | (1.4 | ) |  | (1.4 | )
Net income |  |  |  |  |  |  | 333.0 |  |  | 11.1 |  |  | 344.1 |
Nine Months Ended September 30, 2014 |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  | $2,090.9 |  |  |  | $364.8 |  |  |  | $50.6 |  |  |  | $2,506.3 |  |  |  | $39.9 |  |  |  | $2,546.2 |
Operating income | 374.2 |  |  | 41.3 |  |  | 11.5 |  |  | 427.0 |  |  | 25.3 |  |  | 452.3 |
Amounts attributable to Alliant Energy common shareowners: |  |  |  |  |  |  |  |  |  |  |
Income from continuing operations, net of tax |  |  |  |  |  |  | 315.3 |  |  | 10.0 |  |  | 325.3 |
Loss from discontinued operations, net of tax |  |  |  |  |  |  | — |  |  | (2.2 | ) |  | (2.2 | )
Net income |  |  |  |  |  |  | 315.3 |  |  | 7.8 |  |  | 323.1 |
IPL - 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 September 30, 2015 |  |  |  |  |  |  |
Operating revenues |  | $468.6 |  |  |  | $23.1 |  |  |  | $12.9 |  |  |  | $504.6 |
Operating income (loss) | 119.4 |  |  | (2.9 | ) |  | 0.5 |  |  | 117.0 |
Earnings available for common stock |  |  |  |  |  |  | 117.4 |
Three Months Ended September 30, 2014 |  |  |  |  |  |  |
Operating revenues |  | $435.9 |  |  |  | $28.7 |  |  |  | $11.6 |  |  |  | $476.2 |
Operating income (loss) | 94.7 |  |  | (2.8 | ) |  | 2.0 |  |  | 93.9 |
Earnings available for common stock |  |  |  |  |  |  | 102.5 |
Nine Months Ended September 30, 2015 |  |  |  |  |  |  |
Operating revenues |  | $1,170.6 |  |  |  | $164.1 |  |  |  | $41.1 |  |  |  | $1,375.8 |
Operating income | 193.6 |  |  | 15.3 |  |  | 7.4 |  |  | 216.3 |
Earnings available for common stock |  |  |  |  |  |  | 181.9 |
Nine Months Ended September 30, 2014 |  |  |  |  |  |  |
Operating revenues |  | $1,164.7 |  |  |  | $208.1 |  |  |  | $44.2 |  |  |  | $1,417.0 |
Operating income | 150.2 |  |  | 22.1 |  |  | 13.1 |  |  | 185.4 |
Earnings available for common stock |  |  |  |  |  |  | 164.3 |
WPL - 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 September 30, 2015 |  |  |  |  |  |  |
Operating revenues |  | $367.2 |  |  |  | $14.9 |  |  |  | $0.5 |  |  |  | $382.6 |
Operating income (loss) | 113.4 |  |  | (2.8 | ) |  | (0.3 | ) |  | 110.3 |
Earnings available for common stock |  |  |  |  |  |  | 67.5 |
Three Months Ended September 30, 2014 |  |  |  |  |  |  |
Operating revenues |  | $335.3 |  |  |  | $18.5 |  |  |  | $0.6 |  |  |  | $354.4 |
Operating income (loss) | 96.1 |  |  | (1.6 | ) |  | (0.6 | ) |  | 93.9 |
Earnings available for common stock |  |  |  |  |  |  | 61.6 |
Nine Months Ended September 30, 2015 |  |  |  |  |  |  |
Operating revenues |  | $976.9 |  |  |  | $124.0 |  |  |  | $3.5 |  |  |  | $1,104.4 |
Operating income | 244.8 |  |  | 13.3 |  |  | 1.3 |  |  | 259.4 |
Earnings available for common stock |  |  |  |  |  |  | 151.1 |
Nine Months Ended September 30, 2014 |  |  |  |  |  |  |
Operating revenues |  | $926.2 |  |  |  | $156.7 |  |  |  | $6.4 |  |  |  | $1,089.3 |
Operating income (loss) | 224.0 |  |  | 19.2 |  |  | (1.6 | ) |  | 241.6 |
Earnings available for common stock |  |  |  |  |  |  | 151.0 |

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