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Segments Of Business | 12 Months Ended
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Dec. 31, 2015
Segment Reporting Information [Line Items] |
Segments Of Business | SEGMENTS OF BUSINESS Alliant Energy - Alliant Energy’s principal businesses as of December 31, 2015 are:
• | Utility - includes the operations of IPL and WPL, which primarily serve retail customers in Iowa and Wisconsin. The utility business has three reportable segments: a) utility electric operations; b) utility gas operations; and c) utility other, which includes steam operations and the unallocated portions of the utility business. Various line items in the following tables are not allocated to the electric and gas segments for management reporting purposes, and therefore, are included only in “Total Utility.”
• | Non-regulated, Parent and Other - includes the operations of Resources and its subsidiaries, Corporate Services, the Alliant Energy parent company, and any Alliant Energy parent company consolidating adjustments. Resources’ businesses include Transportation, Non-regulated Generation and other non-regulated investments described in Note 1(a).
Alliant Energy’s administrative support services are directly charged to the applicable segment where practicable. In all other cases, administrative support services are allocated to the applicable segment based on services agreements. Intersegment revenues were not material to Alliant Energy’s operations and there was no single customer whose revenues were 10% or more of Alliant Energy’s consolidated revenues. Certain financial information relating to Alliant Energy’s business segments, services and geographic information was as follows (in millions):
| Utility |  | Non-Regulated, |  | Alliant Energy
2015 | Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
Operating revenues |  | $2,770.5 |  |  |  | $381.2 |  |  |  | $57.9 |  |  |  | $3,209.6 |  |  |  | $44.0 |  |  |  | $3,253.6 |
Depreciation and amortization | 358.6 |  |  | 31.1 |  |  | 1.8 |  |  | 391.5 |  |  | 9.8 |  |  | 401.3 |
Operating income | 514.1 |  |  | 34.6 |  |  | 1.9 |  |  | 550.6 |  |  | 26.4 |  |  | 577.0 |
Interest expense |  |  |  |  |  |  | 189.2 |  |  | (2.1 | ) |  | 187.1 |
Equity (income) loss from unconsolidated investments, net | (35.1 | ) |  | — |  |  | — |  |  | (35.1 | ) |  | 1.3 |  |  | (33.8 | )
Income taxes |  |  |  |  |  |  | 60.2 |  |  | 10.2 |  |  | 70.4 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 362.3 |  |  | 15.9 |  |  | 378.2 |
Total assets | 10,211.3 |  |  | 939.3 |  |  | 828.9 |  |  | 11,979.5 |  |  | 515.7 |  |  | 12,495.2 |
Investments in equity method subsidiaries | 302.0 |  |  | — |  |  | — |  |  | 302.0 |  |  | 0.9 |  |  | 302.9 |
Construction and acquisition expenditures | 855.8 |  |  | 106.4 |  |  | 1.4 |  |  | 963.6 |  |  | 70.7 |  |  | 1,034.3 |
| Utility |  | Non-Regulated, |  | Alliant Energy
2014 | Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
Operating revenues |  | $2,713.6 |  |  |  | $517.5 |  |  |  | $66.1 |  |  |  | $3,297.2 |  |  |  | $53.1 |  |  |  | $3,350.3 |
Depreciation and amortization | 347.0 |  |  | 29.9 |  |  | 1.8 |  |  | 378.7 |  |  | 9.4 |  |  | 388.1 |
Operating income | 442.4 |  |  | 53.8 |  |  | 14.0 |  |  | 510.2 |  |  | 33.4 |  |  | 543.6 |
Interest expense |  |  |  |  |  |  | 176.3 |  |  | 4.3 |  |  | 180.6 |
Equity (income) loss from unconsolidated investments, net | (42.8 | ) |  | — |  |  | — |  |  | (42.8 | ) |  | 2.4 |  |  | (40.4 | )
Income taxes |  |  |  |  |  |  | 36.4 |  |  | 7.9 |  |  | 44.3 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 362.0 |  |  | 21.1 |  |  | 383.1 |
Total assets | 9,660.4 |  |  | 913.5 |  |  | 993.9 |  |  | 11,567.8 |  |  | 495.7 |  |  | 12,063.5 |
Investments in equity method subsidiaries | 294.3 |  |  | — |  |  | — |  |  | 294.3 |  |  | 2.3 |  |  | 296.6 |
Construction and acquisition expenditures | 774.8 |  |  | 63.2 |  |  | 0.9 |  |  | 838.9 |  |  | 63.9 |  |  | 902.8 |
| Utility |  | Non-Regulated, |  | Alliant Energy
2013 | Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
Operating revenues |  | $2,689.0 |  |  |  | $464.8 |  |  |  | $71.3 |  |  |  | $3,225.1 |  |  |  | $51.7 |  |  |  | $3,276.8 |
Depreciation and amortization | 333.0 |  |  | 28.8 |  |  | 1.5 |  |  | 363.3 |  |  | 7.6 |  |  | 370.9 |
Operating income | 444.5 |  |  | 57.3 |  |  | 6.3 |  |  | 508.1 |  |  | 25.8 |  |  | 533.9 |
Interest expense |  |  |  |  |  |  | 166.3 |  |  | 6.5 |  |  | 172.8 |
Equity income from unconsolidated investments, net | (43.7 | ) |  | — |  |  | — |  |  | (43.7 | ) |  | — |  |  | (43.7 | )
Income taxes |  |  |  |  |  |  | 49.3 |  |  | 4.6 |  |  | 53.9 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 349.5 |  |  | 8.8 |  |  | 358.3 |
Total assets | 9,018.6 |  |  | 859.3 |  |  | 712.2 |  |  | 10,590.1 |  |  | 502.4 |  |  | 11,092.5 |
Investments in equity method subsidiaries | 279.1 |  |  | — |  |  | — |  |  | 279.1 |  |  | 2.3 |  |  | 281.4 |
Construction and acquisition expenditures | 677.3 |  |  | 47.0 |  |  | 7.3 |  |  | 731.6 |  |  | 66.7 |  |  | 798.3 |
Services - Alliant Energy’s consolidated operating revenues by segment, which were substantially all related to services, were as follows:
| 2015 |  | 2014 |  | 2013
Utility electric operations | 85 | % |  | 81 | % |  | 82 | %
Utility gas operations | 12 | % |  | 15 | % |  | 14 | %
Utility other | 2 | % |  | 2 | % |  | 2 | %
Other | 1 | % |  | 2 | % |  | 2 | %
| 100 | % |  | 100 | % |  | 100 | %
Geographic Information - At December 31, 2015, 2014 and 2013, Alliant Energy, IPL and WPL did not have any long-lived assets to be held and used in foreign countries. IPL - IPL is a utility primarily serving retail customers in Iowa and includes three reportable segments: a) electric operations; b) gas operations; and c) other, which includes steam operations and the unallocated portions of the utility business. Various line items in the following tables are not allocated to the electric and gas segments for management reporting purposes, and therefore, are included only in “Total.” Intersegment revenues were not material to IPL’s operations and there was no single customer whose revenues were 10% or more of IPL’s consolidated revenues. Certain financial information relating to IPL’s business segments was as follows (in millions):
2015 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,503.8 |  |  |  | $217.3 |  |  |  | $53.4 |  |  |  | $1,774.5 |
Depreciation and amortization | 187.9 |  |  | 17.5 |  |  | 1.8 |  |  | 207.2 |
Operating income | 218.8 |  |  | 17.7 |  |  | 5.4 |  |  | 241.9 |
Interest expense |  |  |  |  |  |  | 96.8 |
Income tax benefit |  |  |  |  |  |  | (22.7 | )
Earnings available for common stock |  |  |  |  |  |  | 186.0 |
Total assets | 5,754.1 |  |  | 548.2 |  |  | 406.8 |  |  | 6,709.1 |
Construction and acquisition expenditures | 561.2 |  |  | 56.7 |  |  | 1.4 |  |  | 619.3 |
2014 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,493.3 |  |  |  | $296.5 |  |  |  | $58.3 |  |  |  | $1,848.1 |
Depreciation and amortization | 178.7 |  |  | 17.0 |  |  | 1.8 |  |  | 197.5 |
Operating income | 166.8 |  |  | 25.7 |  |  | 16.7 |  |  | 209.2 |
Interest expense |  |  |  |  |  |  | 89.9 |
Income tax benefit |  |  |  |  |  |  | (48.9 | )
Earnings available for common stock |  |  |  |  |  |  | 181.6 |
Total assets | 5,398.3 |  |  | 544.1 |  |  | 507.8 |  |  | 6,450.2 |
Construction and acquisition expenditures | 490.0 |  |  | 35.1 |  |  | 0.9 |  |  | 526.0 |
2013 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,491.8 |  |  |  | $273.9 |  |  |  | $53.1 |  |  |  | $1,818.8 |
Depreciation and amortization | 173.1 |  |  | 16.5 |  |  | 1.5 |  |  | 191.1 |
Operating income | 173.1 |  |  | 29.8 |  |  | 9.1 |  |  | 212.0 |
Interest expense |  |  |  |  |  |  | 81.3 |
Income tax benefit |  |  |  |  |  |  | (36.3 | )
Earnings available for common stock |  |  |  |  |  |  | 172.0 |
Total assets | 4,905.3 |  |  | 518.8 |  |  | 369.8 |  |  | 5,793.9 |
Construction and acquisition expenditures | 365.4 |  |  | 27.5 |  |  | 7.3 |  |  | 400.2 |
WPL - WPL is a utility serving customers in Wisconsin and includes three reportable segments: a) electric operations; b) gas operations; and c) other, which includes the unallocated portions of the utility business. Various line items in the following tables are not allocated to the electric and gas segments for management reporting purposes, and therefore, are included only in “Total.” Intersegment revenues were not material to WPL’s operations and there was no single customer whose revenues were 10% or more of WPL’s consolidated revenues. Certain financial information relating to WPL’s business segments was as follows (in millions):
2015 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,266.7 |  |  |  | $163.9 |  |  |  | $4.5 |  |  |  | $1,435.1 |
Depreciation and amortization | 170.7 |  |  | 13.6 |  |  | — |  |  | 184.3 |
Operating income (loss) | 295.3 |  |  | 16.9 |  |  | (3.5 | ) |  | 308.7 |
Interest expense |  |  |  |  |  |  | 92.4 |
Equity income from unconsolidated investments | (35.1 | ) |  | — |  |  | — |  |  | (35.1 | )
Income taxes |  |  |  |  |  |  | 82.9 |
Earnings available for common stock |  |  |  |  |  |  | 176.3 |
Total assets | 4,457.2 |  |  | 391.1 |  |  | 422.1 |  |  | 5,270.4 |
Investments in equity method subsidiaries | 302.0 |  |  | — |  |  | — |  |  | 302.0 |
Construction and acquisition expenditures | 294.6 |  |  | 49.7 |  |  | — |  |  | 344.3 |
2014 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,220.3 |  |  |  | $221.0 |  |  |  | $7.8 |  |  |  | $1,449.1 |
Depreciation and amortization | 168.3 |  |  | 12.9 |  |  | — |  |  | 181.2 |
Operating income (loss) | 275.6 |  |  | 28.1 |  |  | (2.7 | ) |  | 301.0 |
Interest expense |  |  |  |  |  |  | 86.4 |
Equity income from unconsolidated investments | (42.8 | ) |  | — |  |  | — |  |  | (42.8 | )
Income taxes |  |  |  |  |  |  | 85.3 |
Earnings available for common stock |  |  |  |  |  |  | 180.4 |
Total assets | 4,262.1 |  |  | 369.4 |  |  | 486.1 |  |  | 5,117.6 |
Investments in equity method subsidiaries | 294.3 |  |  | — |  |  | — |  |  | 294.3 |
Construction and acquisition expenditures | 284.8 |  |  | 28.1 |  |  | — |  |  | 312.9 |
2013 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,197.2 |  |  |  | $190.9 |  |  |  | $18.2 |  |  |  | $1,406.3 |
Depreciation and amortization | 159.9 |  |  | 12.3 |  |  | — |  |  | 172.2 |
Operating income (loss) | 271.4 |  |  | 27.5 |  |  | (2.8 | ) |  | 296.1 |
Interest expense |  |  |  |  |  |  | 85.0 |
Equity income from unconsolidated investments | (43.7 | ) |  | — |  |  | — |  |  | (43.7 | )
Income taxes |  |  |  |  |  |  | 85.6 |
Earnings available for common stock |  |  |  |  |  |  | 177.5 |
Total assets | 4,113.3 |  |  | 340.5 |  |  | 342.4 |  |  | 4,796.2 |
Investments in equity method subsidiaries | 279.1 |  |  | — |  |  | — |  |  | 279.1 |
Construction and acquisition expenditures | 311.9 |  |  | 19.5 |  |  | — |  |  | 331.4 |
IPL [Member] |
Segment Reporting Information [Line Items] |
Segments Of Business | SEGMENTS OF BUSINESS Alliant Energy - Alliant Energy’s principal businesses as of December 31, 2015 are:
• | Utility - includes the operations of IPL and WPL, which primarily serve retail customers in Iowa and Wisconsin. The utility business has three reportable segments: a) utility electric operations; b) utility gas operations; and c) utility other, which includes steam operations and the unallocated portions of the utility business. Various line items in the following tables are not allocated to the electric and gas segments for management reporting purposes, and therefore, are included only in “Total Utility.”
• | Non-regulated, Parent and Other - includes the operations of Resources and its subsidiaries, Corporate Services, the Alliant Energy parent company, and any Alliant Energy parent company consolidating adjustments. Resources’ businesses include Transportation, Non-regulated Generation and other non-regulated investments described in Note 1(a).
Alliant Energy’s administrative support services are directly charged to the applicable segment where practicable. In all other cases, administrative support services are allocated to the applicable segment based on services agreements. Intersegment revenues were not material to Alliant Energy’s operations and there was no single customer whose revenues were 10% or more of Alliant Energy’s consolidated revenues. Certain financial information relating to Alliant Energy’s business segments, services and geographic information was as follows (in millions):
| Utility |  | Non-Regulated, |  | Alliant Energy
2015 | Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
Operating revenues |  | $2,770.5 |  |  |  | $381.2 |  |  |  | $57.9 |  |  |  | $3,209.6 |  |  |  | $44.0 |  |  |  | $3,253.6 |
Depreciation and amortization | 358.6 |  |  | 31.1 |  |  | 1.8 |  |  | 391.5 |  |  | 9.8 |  |  | 401.3 |
Operating income | 514.1 |  |  | 34.6 |  |  | 1.9 |  |  | 550.6 |  |  | 26.4 |  |  | 577.0 |
Interest expense |  |  |  |  |  |  | 189.2 |  |  | (2.1 | ) |  | 187.1 |
Equity (income) loss from unconsolidated investments, net | (35.1 | ) |  | — |  |  | — |  |  | (35.1 | ) |  | 1.3 |  |  | (33.8 | )
Income taxes |  |  |  |  |  |  | 60.2 |  |  | 10.2 |  |  | 70.4 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 362.3 |  |  | 15.9 |  |  | 378.2 |
Total assets | 10,211.3 |  |  | 939.3 |  |  | 828.9 |  |  | 11,979.5 |  |  | 515.7 |  |  | 12,495.2 |
Investments in equity method subsidiaries | 302.0 |  |  | — |  |  | — |  |  | 302.0 |  |  | 0.9 |  |  | 302.9 |
Construction and acquisition expenditures | 855.8 |  |  | 106.4 |  |  | 1.4 |  |  | 963.6 |  |  | 70.7 |  |  | 1,034.3 |
| Utility |  | Non-Regulated, |  | Alliant Energy
2014 | Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
Operating revenues |  | $2,713.6 |  |  |  | $517.5 |  |  |  | $66.1 |  |  |  | $3,297.2 |  |  |  | $53.1 |  |  |  | $3,350.3 |
Depreciation and amortization | 347.0 |  |  | 29.9 |  |  | 1.8 |  |  | 378.7 |  |  | 9.4 |  |  | 388.1 |
Operating income | 442.4 |  |  | 53.8 |  |  | 14.0 |  |  | 510.2 |  |  | 33.4 |  |  | 543.6 |
Interest expense |  |  |  |  |  |  | 176.3 |  |  | 4.3 |  |  | 180.6 |
Equity (income) loss from unconsolidated investments, net | (42.8 | ) |  | — |  |  | — |  |  | (42.8 | ) |  | 2.4 |  |  | (40.4 | )
Income taxes |  |  |  |  |  |  | 36.4 |  |  | 7.9 |  |  | 44.3 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 362.0 |  |  | 21.1 |  |  | 383.1 |
Total assets | 9,660.4 |  |  | 913.5 |  |  | 993.9 |  |  | 11,567.8 |  |  | 495.7 |  |  | 12,063.5 |
Investments in equity method subsidiaries | 294.3 |  |  | — |  |  | — |  |  | 294.3 |  |  | 2.3 |  |  | 296.6 |
Construction and acquisition expenditures | 774.8 |  |  | 63.2 |  |  | 0.9 |  |  | 838.9 |  |  | 63.9 |  |  | 902.8 |
| Utility |  | Non-Regulated, |  | Alliant Energy
2013 | Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
Operating revenues |  | $2,689.0 |  |  |  | $464.8 |  |  |  | $71.3 |  |  |  | $3,225.1 |  |  |  | $51.7 |  |  |  | $3,276.8 |
Depreciation and amortization | 333.0 |  |  | 28.8 |  |  | 1.5 |  |  | 363.3 |  |  | 7.6 |  |  | 370.9 |
Operating income | 444.5 |  |  | 57.3 |  |  | 6.3 |  |  | 508.1 |  |  | 25.8 |  |  | 533.9 |
Interest expense |  |  |  |  |  |  | 166.3 |  |  | 6.5 |  |  | 172.8 |
Equity income from unconsolidated investments, net | (43.7 | ) |  | — |  |  | — |  |  | (43.7 | ) |  | — |  |  | (43.7 | )
Income taxes |  |  |  |  |  |  | 49.3 |  |  | 4.6 |  |  | 53.9 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 349.5 |  |  | 8.8 |  |  | 358.3 |
Total assets | 9,018.6 |  |  | 859.3 |  |  | 712.2 |  |  | 10,590.1 |  |  | 502.4 |  |  | 11,092.5 |
Investments in equity method subsidiaries | 279.1 |  |  | — |  |  | — |  |  | 279.1 |  |  | 2.3 |  |  | 281.4 |
Construction and acquisition expenditures | 677.3 |  |  | 47.0 |  |  | 7.3 |  |  | 731.6 |  |  | 66.7 |  |  | 798.3 |
Services - Alliant Energy’s consolidated operating revenues by segment, which were substantially all related to services, were as follows:
| 2015 |  | 2014 |  | 2013
Utility electric operations | 85 | % |  | 81 | % |  | 82 | %
Utility gas operations | 12 | % |  | 15 | % |  | 14 | %
Utility other | 2 | % |  | 2 | % |  | 2 | %
Other | 1 | % |  | 2 | % |  | 2 | %
| 100 | % |  | 100 | % |  | 100 | %
Geographic Information - At December 31, 2015, 2014 and 2013, Alliant Energy, IPL and WPL did not have any long-lived assets to be held and used in foreign countries. IPL - IPL is a utility primarily serving retail customers in Iowa and includes three reportable segments: a) electric operations; b) gas operations; and c) other, which includes steam operations and the unallocated portions of the utility business. Various line items in the following tables are not allocated to the electric and gas segments for management reporting purposes, and therefore, are included only in “Total.” Intersegment revenues were not material to IPL’s operations and there was no single customer whose revenues were 10% or more of IPL’s consolidated revenues. Certain financial information relating to IPL’s business segments was as follows (in millions):
2015 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,503.8 |  |  |  | $217.3 |  |  |  | $53.4 |  |  |  | $1,774.5 |
Depreciation and amortization | 187.9 |  |  | 17.5 |  |  | 1.8 |  |  | 207.2 |
Operating income | 218.8 |  |  | 17.7 |  |  | 5.4 |  |  | 241.9 |
Interest expense |  |  |  |  |  |  | 96.8 |
Income tax benefit |  |  |  |  |  |  | (22.7 | )
Earnings available for common stock |  |  |  |  |  |  | 186.0 |
Total assets | 5,754.1 |  |  | 548.2 |  |  | 406.8 |  |  | 6,709.1 |
Construction and acquisition expenditures | 561.2 |  |  | 56.7 |  |  | 1.4 |  |  | 619.3 |
2014 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,493.3 |  |  |  | $296.5 |  |  |  | $58.3 |  |  |  | $1,848.1 |
Depreciation and amortization | 178.7 |  |  | 17.0 |  |  | 1.8 |  |  | 197.5 |
Operating income | 166.8 |  |  | 25.7 |  |  | 16.7 |  |  | 209.2 |
Interest expense |  |  |  |  |  |  | 89.9 |
Income tax benefit |  |  |  |  |  |  | (48.9 | )
Earnings available for common stock |  |  |  |  |  |  | 181.6 |
Total assets | 5,398.3 |  |  | 544.1 |  |  | 507.8 |  |  | 6,450.2 |
Construction and acquisition expenditures | 490.0 |  |  | 35.1 |  |  | 0.9 |  |  | 526.0 |
2013 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,491.8 |  |  |  | $273.9 |  |  |  | $53.1 |  |  |  | $1,818.8 |
Depreciation and amortization | 173.1 |  |  | 16.5 |  |  | 1.5 |  |  | 191.1 |
Operating income | 173.1 |  |  | 29.8 |  |  | 9.1 |  |  | 212.0 |
Interest expense |  |  |  |  |  |  | 81.3 |
Income tax benefit |  |  |  |  |  |  | (36.3 | )
Earnings available for common stock |  |  |  |  |  |  | 172.0 |
Total assets | 4,905.3 |  |  | 518.8 |  |  | 369.8 |  |  | 5,793.9 |
Construction and acquisition expenditures | 365.4 |  |  | 27.5 |  |  | 7.3 |  |  | 400.2 |
WPL - WPL is a utility serving customers in Wisconsin and includes three reportable segments: a) electric operations; b) gas operations; and c) other, which includes the unallocated portions of the utility business. Various line items in the following tables are not allocated to the electric and gas segments for management reporting purposes, and therefore, are included only in “Total.” Intersegment revenues were not material to WPL’s operations and there was no single customer whose revenues were 10% or more of WPL’s consolidated revenues. Certain financial information relating to WPL’s business segments was as follows (in millions):
2015 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,266.7 |  |  |  | $163.9 |  |  |  | $4.5 |  |  |  | $1,435.1 |
Depreciation and amortization | 170.7 |  |  | 13.6 |  |  | — |  |  | 184.3 |
Operating income (loss) | 295.3 |  |  | 16.9 |  |  | (3.5 | ) |  | 308.7 |
Interest expense |  |  |  |  |  |  | 92.4 |
Equity income from unconsolidated investments | (35.1 | ) |  | — |  |  | — |  |  | (35.1 | )
Income taxes |  |  |  |  |  |  | 82.9 |
Earnings available for common stock |  |  |  |  |  |  | 176.3 |
Total assets | 4,457.2 |  |  | 391.1 |  |  | 422.1 |  |  | 5,270.4 |
Investments in equity method subsidiaries | 302.0 |  |  | — |  |  | — |  |  | 302.0 |
Construction and acquisition expenditures | 294.6 |  |  | 49.7 |  |  | — |  |  | 344.3 |
2014 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,220.3 |  |  |  | $221.0 |  |  |  | $7.8 |  |  |  | $1,449.1 |
Depreciation and amortization | 168.3 |  |  | 12.9 |  |  | — |  |  | 181.2 |
Operating income (loss) | 275.6 |  |  | 28.1 |  |  | (2.7 | ) |  | 301.0 |
Interest expense |  |  |  |  |  |  | 86.4 |
Equity income from unconsolidated investments | (42.8 | ) |  | — |  |  | — |  |  | (42.8 | )
Income taxes |  |  |  |  |  |  | 85.3 |
Earnings available for common stock |  |  |  |  |  |  | 180.4 |
Total assets | 4,262.1 |  |  | 369.4 |  |  | 486.1 |  |  | 5,117.6 |
Investments in equity method subsidiaries | 294.3 |  |  | — |  |  | — |  |  | 294.3 |
Construction and acquisition expenditures | 284.8 |  |  | 28.1 |  |  | — |  |  | 312.9 |
2013 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,197.2 |  |  |  | $190.9 |  |  |  | $18.2 |  |  |  | $1,406.3 |
Depreciation and amortization | 159.9 |  |  | 12.3 |  |  | — |  |  | 172.2 |
Operating income (loss) | 271.4 |  |  | 27.5 |  |  | (2.8 | ) |  | 296.1 |
Interest expense |  |  |  |  |  |  | 85.0 |
Equity income from unconsolidated investments | (43.7 | ) |  | — |  |  | — |  |  | (43.7 | )
Income taxes |  |  |  |  |  |  | 85.6 |
Earnings available for common stock |  |  |  |  |  |  | 177.5 |
Total assets | 4,113.3 |  |  | 340.5 |  |  | 342.4 |  |  | 4,796.2 |
Investments in equity method subsidiaries | 279.1 |  |  | — |  |  | — |  |  | 279.1 |
Construction and acquisition expenditures | 311.9 |  |  | 19.5 |  |  | — |  |  | 331.4 |
WPL [Member] |
Segment Reporting Information [Line Items] |
Segments Of Business | SEGMENTS OF BUSINESS Alliant Energy - Alliant Energy’s principal businesses as of December 31, 2015 are:
• | Utility - includes the operations of IPL and WPL, which primarily serve retail customers in Iowa and Wisconsin. The utility business has three reportable segments: a) utility electric operations; b) utility gas operations; and c) utility other, which includes steam operations and the unallocated portions of the utility business. Various line items in the following tables are not allocated to the electric and gas segments for management reporting purposes, and therefore, are included only in “Total Utility.”
• | Non-regulated, Parent and Other - includes the operations of Resources and its subsidiaries, Corporate Services, the Alliant Energy parent company, and any Alliant Energy parent company consolidating adjustments. Resources’ businesses include Transportation, Non-regulated Generation and other non-regulated investments described in Note 1(a).
Alliant Energy’s administrative support services are directly charged to the applicable segment where practicable. In all other cases, administrative support services are allocated to the applicable segment based on services agreements. Intersegment revenues were not material to Alliant Energy’s operations and there was no single customer whose revenues were 10% or more of Alliant Energy’s consolidated revenues. Certain financial information relating to Alliant Energy’s business segments, services and geographic information was as follows (in millions):
| Utility |  | Non-Regulated, |  | Alliant Energy
2015 | Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
Operating revenues |  | $2,770.5 |  |  |  | $381.2 |  |  |  | $57.9 |  |  |  | $3,209.6 |  |  |  | $44.0 |  |  |  | $3,253.6 |
Depreciation and amortization | 358.6 |  |  | 31.1 |  |  | 1.8 |  |  | 391.5 |  |  | 9.8 |  |  | 401.3 |
Operating income | 514.1 |  |  | 34.6 |  |  | 1.9 |  |  | 550.6 |  |  | 26.4 |  |  | 577.0 |
Interest expense |  |  |  |  |  |  | 189.2 |  |  | (2.1 | ) |  | 187.1 |
Equity (income) loss from unconsolidated investments, net | (35.1 | ) |  | — |  |  | — |  |  | (35.1 | ) |  | 1.3 |  |  | (33.8 | )
Income taxes |  |  |  |  |  |  | 60.2 |  |  | 10.2 |  |  | 70.4 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 362.3 |  |  | 15.9 |  |  | 378.2 |
Total assets | 10,211.3 |  |  | 939.3 |  |  | 828.9 |  |  | 11,979.5 |  |  | 515.7 |  |  | 12,495.2 |
Investments in equity method subsidiaries | 302.0 |  |  | — |  |  | — |  |  | 302.0 |  |  | 0.9 |  |  | 302.9 |
Construction and acquisition expenditures | 855.8 |  |  | 106.4 |  |  | 1.4 |  |  | 963.6 |  |  | 70.7 |  |  | 1,034.3 |
| Utility |  | Non-Regulated, |  | Alliant Energy
2014 | Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
Operating revenues |  | $2,713.6 |  |  |  | $517.5 |  |  |  | $66.1 |  |  |  | $3,297.2 |  |  |  | $53.1 |  |  |  | $3,350.3 |
Depreciation and amortization | 347.0 |  |  | 29.9 |  |  | 1.8 |  |  | 378.7 |  |  | 9.4 |  |  | 388.1 |
Operating income | 442.4 |  |  | 53.8 |  |  | 14.0 |  |  | 510.2 |  |  | 33.4 |  |  | 543.6 |
Interest expense |  |  |  |  |  |  | 176.3 |  |  | 4.3 |  |  | 180.6 |
Equity (income) loss from unconsolidated investments, net | (42.8 | ) |  | — |  |  | — |  |  | (42.8 | ) |  | 2.4 |  |  | (40.4 | )
Income taxes |  |  |  |  |  |  | 36.4 |  |  | 7.9 |  |  | 44.3 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 362.0 |  |  | 21.1 |  |  | 383.1 |
Total assets | 9,660.4 |  |  | 913.5 |  |  | 993.9 |  |  | 11,567.8 |  |  | 495.7 |  |  | 12,063.5 |
Investments in equity method subsidiaries | 294.3 |  |  | — |  |  | — |  |  | 294.3 |  |  | 2.3 |  |  | 296.6 |
Construction and acquisition expenditures | 774.8 |  |  | 63.2 |  |  | 0.9 |  |  | 838.9 |  |  | 63.9 |  |  | 902.8 |
| Utility |  | Non-Regulated, |  | Alliant Energy
2013 | Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
Operating revenues |  | $2,689.0 |  |  |  | $464.8 |  |  |  | $71.3 |  |  |  | $3,225.1 |  |  |  | $51.7 |  |  |  | $3,276.8 |
Depreciation and amortization | 333.0 |  |  | 28.8 |  |  | 1.5 |  |  | 363.3 |  |  | 7.6 |  |  | 370.9 |
Operating income | 444.5 |  |  | 57.3 |  |  | 6.3 |  |  | 508.1 |  |  | 25.8 |  |  | 533.9 |
Interest expense |  |  |  |  |  |  | 166.3 |  |  | 6.5 |  |  | 172.8 |
Equity income from unconsolidated investments, net | (43.7 | ) |  | — |  |  | — |  |  | (43.7 | ) |  | — |  |  | (43.7 | )
Income taxes |  |  |  |  |  |  | 49.3 |  |  | 4.6 |  |  | 53.9 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 349.5 |  |  | 8.8 |  |  | 358.3 |
Total assets | 9,018.6 |  |  | 859.3 |  |  | 712.2 |  |  | 10,590.1 |  |  | 502.4 |  |  | 11,092.5 |
Investments in equity method subsidiaries | 279.1 |  |  | — |  |  | — |  |  | 279.1 |  |  | 2.3 |  |  | 281.4 |
Construction and acquisition expenditures | 677.3 |  |  | 47.0 |  |  | 7.3 |  |  | 731.6 |  |  | 66.7 |  |  | 798.3 |
Services - Alliant Energy’s consolidated operating revenues by segment, which were substantially all related to services, were as follows:
| 2015 |  | 2014 |  | 2013
Utility electric operations | 85 | % |  | 81 | % |  | 82 | %
Utility gas operations | 12 | % |  | 15 | % |  | 14 | %
Utility other | 2 | % |  | 2 | % |  | 2 | %
Other | 1 | % |  | 2 | % |  | 2 | %
| 100 | % |  | 100 | % |  | 100 | %
Geographic Information - At December 31, 2015, 2014 and 2013, Alliant Energy, IPL and WPL did not have any long-lived assets to be held and used in foreign countries. IPL - IPL is a utility primarily serving retail customers in Iowa and includes three reportable segments: a) electric operations; b) gas operations; and c) other, which includes steam operations and the unallocated portions of the utility business. Various line items in the following tables are not allocated to the electric and gas segments for management reporting purposes, and therefore, are included only in “Total.” Intersegment revenues were not material to IPL’s operations and there was no single customer whose revenues were 10% or more of IPL’s consolidated revenues. Certain financial information relating to IPL’s business segments was as follows (in millions):
2015 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,503.8 |  |  |  | $217.3 |  |  |  | $53.4 |  |  |  | $1,774.5 |
Depreciation and amortization | 187.9 |  |  | 17.5 |  |  | 1.8 |  |  | 207.2 |
Operating income | 218.8 |  |  | 17.7 |  |  | 5.4 |  |  | 241.9 |
Interest expense |  |  |  |  |  |  | 96.8 |
Income tax benefit |  |  |  |  |  |  | (22.7 | )
Earnings available for common stock |  |  |  |  |  |  | 186.0 |
Total assets | 5,754.1 |  |  | 548.2 |  |  | 406.8 |  |  | 6,709.1 |
Construction and acquisition expenditures | 561.2 |  |  | 56.7 |  |  | 1.4 |  |  | 619.3 |
2014 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,493.3 |  |  |  | $296.5 |  |  |  | $58.3 |  |  |  | $1,848.1 |
Depreciation and amortization | 178.7 |  |  | 17.0 |  |  | 1.8 |  |  | 197.5 |
Operating income | 166.8 |  |  | 25.7 |  |  | 16.7 |  |  | 209.2 |
Interest expense |  |  |  |  |  |  | 89.9 |
Income tax benefit |  |  |  |  |  |  | (48.9 | )
Earnings available for common stock |  |  |  |  |  |  | 181.6 |
Total assets | 5,398.3 |  |  | 544.1 |  |  | 507.8 |  |  | 6,450.2 |
Construction and acquisition expenditures | 490.0 |  |  | 35.1 |  |  | 0.9 |  |  | 526.0 |
2013 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,491.8 |  |  |  | $273.9 |  |  |  | $53.1 |  |  |  | $1,818.8 |
Depreciation and amortization | 173.1 |  |  | 16.5 |  |  | 1.5 |  |  | 191.1 |
Operating income | 173.1 |  |  | 29.8 |  |  | 9.1 |  |  | 212.0 |
Interest expense |  |  |  |  |  |  | 81.3 |
Income tax benefit |  |  |  |  |  |  | (36.3 | )
Earnings available for common stock |  |  |  |  |  |  | 172.0 |
Total assets | 4,905.3 |  |  | 518.8 |  |  | 369.8 |  |  | 5,793.9 |
Construction and acquisition expenditures | 365.4 |  |  | 27.5 |  |  | 7.3 |  |  | 400.2 |
WPL - WPL is a utility serving customers in Wisconsin and includes three reportable segments: a) electric operations; b) gas operations; and c) other, which includes the unallocated portions of the utility business. Various line items in the following tables are not allocated to the electric and gas segments for management reporting purposes, and therefore, are included only in “Total.” Intersegment revenues were not material to WPL’s operations and there was no single customer whose revenues were 10% or more of WPL’s consolidated revenues. Certain financial information relating to WPL’s business segments was as follows (in millions):
2015 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,266.7 |  |  |  | $163.9 |  |  |  | $4.5 |  |  |  | $1,435.1 |
Depreciation and amortization | 170.7 |  |  | 13.6 |  |  | — |  |  | 184.3 |
Operating income (loss) | 295.3 |  |  | 16.9 |  |  | (3.5 | ) |  | 308.7 |
Interest expense |  |  |  |  |  |  | 92.4 |
Equity income from unconsolidated investments | (35.1 | ) |  | — |  |  | — |  |  | (35.1 | )
Income taxes |  |  |  |  |  |  | 82.9 |
Earnings available for common stock |  |  |  |  |  |  | 176.3 |
Total assets | 4,457.2 |  |  | 391.1 |  |  | 422.1 |  |  | 5,270.4 |
Investments in equity method subsidiaries | 302.0 |  |  | — |  |  | — |  |  | 302.0 |
Construction and acquisition expenditures | 294.6 |  |  | 49.7 |  |  | — |  |  | 344.3 |
2014 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,220.3 |  |  |  | $221.0 |  |  |  | $7.8 |  |  |  | $1,449.1 |
Depreciation and amortization | 168.3 |  |  | 12.9 |  |  | — |  |  | 181.2 |
Operating income (loss) | 275.6 |  |  | 28.1 |  |  | (2.7 | ) |  | 301.0 |
Interest expense |  |  |  |  |  |  | 86.4 |
Equity income from unconsolidated investments | (42.8 | ) |  | — |  |  | — |  |  | (42.8 | )
Income taxes |  |  |  |  |  |  | 85.3 |
Earnings available for common stock |  |  |  |  |  |  | 180.4 |
Total assets | 4,262.1 |  |  | 369.4 |  |  | 486.1 |  |  | 5,117.6 |
Investments in equity method subsidiaries | 294.3 |  |  | — |  |  | — |  |  | 294.3 |
Construction and acquisition expenditures | 284.8 |  |  | 28.1 |  |  | — |  |  | 312.9 |
2013 | Electric |  | Gas |  | Other |  | Total
Operating revenues |  | $1,197.2 |  |  |  | $190.9 |  |  |  | $18.2 |  |  |  | $1,406.3 |
Depreciation and amortization | 159.9 |  |  | 12.3 |  |  | — |  |  | 172.2 |
Operating income (loss) | 271.4 |  |  | 27.5 |  |  | (2.8 | ) |  | 296.1 |
Interest expense |  |  |  |  |  |  | 85.0 |
Equity income from unconsolidated investments | (43.7 | ) |  | — |  |  | — |  |  | (43.7 | )
Income taxes |  |  |  |  |  |  | 85.6 |
Earnings available for common stock |  |  |  |  |  |  | 177.5 |
Total assets | 4,113.3 |  |  | 340.5 |  |  | 342.4 |  |  | 4,796.2 |
Investments in equity method subsidiaries | 279.1 |  |  | — |  |  | — |  |  | 279.1 |
Construction and acquisition expenditures | 311.9 |  |  | 19.5 |  |  | — |  |  | 331.4 |

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- Definition The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8981-108599 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 41 -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e9038-108599 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8971-108599 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8595-108599 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8380-108599 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8933-108599 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 26 -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8844-108599 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 35 -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8984-108599 Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 40 -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e9031-108599 Reference 10: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 42 -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e9054-108599 Reference 11: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8538-108599 Reference 12: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 29 -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8864-108599 Reference 13: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 31 -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8924-108599 Reference 14: 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=6534315&loc=d3e8906-108599 + Details
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