XML 161 R127.htm IDEA: XBRL DOCUMENT v3.8.0.1
Segments Of Business (Schedule Of Segment Of Business) (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Segment Reporting Information [Line Items]                      
Operating revenues $ 856.1 $ 906.9 $ 765.3 $ 853.9 $ 797.0 $ 924.6 $ 754.6 $ 843.8 $ 3,382.2 $ 3,320.0 $ 3,253.6
Depreciation and amortization                 461.8 411.6 401.3
Operating income (loss) 129.7 231.5 149.3 142.9 99.9 162.6 128.6 145.9 653.4 537.0 577.0
Interest expense                 215.6 196.2 187.1
Equity (income) loss from unconsolidated investments, net                 (44.8) (39.6) (33.8)
Income tax expense (benefit)                 66.7 59.4 70.4
Net income (loss) attributable to common shareowners 93.8 168.8 94.3 100.4 62.7 128.4 83.9 96.5 457.3 371.5 378.2
Total assets 14,187.8       13,373.8       14,187.8 13,373.8 12,495.2
Investments in equity method subsidiaries 381.4       326.0       381.4 326.0 302.9
Construction and acquisition expenditures                 1,466.9 1,196.8 1,034.3
IPL [Member]                      
Segment Reporting Information [Line Items]                      
Operating revenues 472.2 527.4 420.2 450.5 434.5 516.2 411.0 458.7 1,870.3 1,820.4 1,774.5
Depreciation and amortization                 245.0 210.8 207.2
Operating income (loss) 49.2 131.8 66.3 49.6 34.9 125.9 48.0 62.0 296.9 270.8 241.9
Interest expense                 112.4 103.2 96.8
Income tax expense (benefit)                 (10.9) (5.9) (22.7)
Net income (loss) attributable to common shareowners 16.4 120.4 42.8 37.2 24.0 114.1 31.9 45.6 216.8 215.6 186.0
Total assets 7,606.0       7,304.7       7,606.0 7,304.7  
WPL [Member]                      
Segment Reporting Information [Line Items]                      
Operating revenues 374.7 370.2 334.8 393.1 352.2 397.0 334.3 375.6 1,472.8 1,459.1 1,435.1
Depreciation and amortization                 212.9 192.5 184.3
Operating income (loss) 72.8 90.7 73.7 86.0 58.2 115.0 75.0 78.8 323.2 327.0 308.7
Interest expense                 93.8 91.4 92.4
Equity (income) loss from unconsolidated investments, net                 (0.7) (39.8) (35.1)
Income tax expense (benefit)                 61.9 93.3 82.9
Net income (loss) attributable to common shareowners 53.2 $ 49.8 $ 38.1 $ 45.5 31.7 $ 69.0 $ 43.2 $ 46.5 186.6 190.4 176.3
Total assets 5,756.5       5,290.3       5,756.5 5,290.3  
Electric [Member]                      
Segment Reporting Information [Line Items]                      
Operating revenues                 2,894.7 2,875.5 2,770.5
Depreciation and amortization                 412.0 367.0 358.6
Operating income (loss)                 586.5 571.9 514.1
Equity (income) loss from unconsolidated investments, net                 (0.7) (0.7) (0.9)
Total assets 11,396.2       10,722.9       11,396.2 10,722.9 9,918.0
Investments in equity method subsidiaries 8.3       7.7       8.3 7.7 8.7
Construction and acquisition expenditures                 1,154.9 994.0 852.5
Electric [Member] | IPL [Member]                      
Segment Reporting Information [Line Items]                      
Operating revenues                 1,598.9 1,569.7 1,503.8
Depreciation and amortization                 215.1 189.4 187.9
Operating income (loss)                 281.1 252.0 218.8
Total assets 6,524.4       6,278.2       6,524.4 6,278.2 5,754.1
Construction and acquisition expenditures                 594.1 598.1 561.2
Electric [Member] | WPL [Member]                      
Segment Reporting Information [Line Items]                      
Operating revenues                 1,295.8 1,305.8 1,266.7
Depreciation and amortization                 196.9 177.6 170.7
Operating income (loss)                 305.4 319.9 295.3
Equity (income) loss from unconsolidated investments, net                 (0.7) (0.7) (0.9)
Total assets 4,871.8       4,444.7       4,871.8 4,444.7 4,163.9
Investments in equity method subsidiaries 8.3       7.7       8.3 7.7 8.7
Construction and acquisition expenditures                 592.4 395.9 291.3
Gas [Member]                      
Segment Reporting Information [Line Items]                      
Operating revenues                 400.9 355.4 381.2
Depreciation and amortization                 38.2 34.2 31.1
Operating income (loss)                 45.3 30.7 34.6
Equity (income) loss from unconsolidated investments, net                 0.0 0.0 0.0
Total assets 1,199.8       1,091.1       1,199.8 1,091.1 939.3
Investments in equity method subsidiaries 0.0       0.0       0.0 0.0 0.0
Construction and acquisition expenditures                 125.2 137.1 106.4
Gas [Member] | IPL [Member]                      
Segment Reporting Information [Line Items]                      
Operating revenues                 226.0 204.0 217.3
Depreciation and amortization                 22.2 19.3 17.5
Operating income (loss)                 20.8 15.5 17.7
Total assets 727.9       653.3       727.9 653.3 548.2
Construction and acquisition expenditures                 80.7 91.5 56.7
Gas [Member] | WPL [Member]                      
Segment Reporting Information [Line Items]                      
Operating revenues                 174.9 151.4 163.9
Depreciation and amortization                 16.0 14.9 13.6
Operating income (loss)                 24.5 15.2 16.9
Equity (income) loss from unconsolidated investments, net                 0.0 0.0 0.0
Total assets 471.9       437.8       471.9 437.8 391.1
Investments in equity method subsidiaries 0.0       0.0       0.0 0.0 0.0
Construction and acquisition expenditures                 44.5 45.6 49.7
Other Utility [Member]                      
Segment Reporting Information [Line Items]                      
Operating revenues                 47.5 48.6 57.9
Depreciation and amortization                 7.7 2.1 1.8
Operating income (loss)                 (11.7) (4.8) 1.9
Equity (income) loss from unconsolidated investments, net                 0.0 0.0 0.0
Total assets 766.5       781.0       766.5 781.0 828.9
Investments in equity method subsidiaries 0.0       0.0       0.0 0.0 0.0
Construction and acquisition expenditures                 1.7 0.1 1.4
Other Utility [Member] | IPL [Member]                      
Segment Reporting Information [Line Items]                      
Operating revenues                 45.4 46.7 53.4
Depreciation and amortization                 7.7 2.1 1.8
Operating income (loss)                 (5.0) 3.3 5.4
Total assets 353.7       373.2       353.7 373.2 406.8
Construction and acquisition expenditures                 1.2 0.1 1.4
Other Utility [Member] | WPL [Member]                      
Segment Reporting Information [Line Items]                      
Operating revenues                 2.1 1.9 4.5
Depreciation and amortization                 0.0 0.0 0.0
Operating income (loss)                 (6.7) (8.1) (3.5)
Equity (income) loss from unconsolidated investments, net                 0.0 (39.1) (34.2)
Total assets 412.8       407.8       412.8 407.8 715.4
Investments in equity method subsidiaries 0.0       0.0       0.0 0.0 293.3
Construction and acquisition expenditures                 0.5 11.5 3.3
Utility Business [Member]                      
Segment Reporting Information [Line Items]                      
Operating revenues                 3,343.1 3,279.5 3,209.6
Depreciation and amortization                 457.9 403.3 391.5
Operating income (loss)                 620.1 597.8 550.6
Interest expense                 206.2 194.6 189.2
Equity (income) loss from unconsolidated investments, net                 (0.7) (0.7) (0.9)
Income tax expense (benefit)                 51.0 71.4 46.2
Net income (loss) attributable to common shareowners                 403.4 385.2 343.4
Total assets 13,362.5       12,595.0       13,362.5 12,595.0 11,686.2
Investments in equity method subsidiaries 8.3       7.7       8.3 7.7 8.7
Construction and acquisition expenditures                 1,281.8 1,131.2 960.3
Utility Business [Member] | IPL [Member]                      
Segment Reporting Information [Line Items]                      
Operating revenues                 1,870.3 1,820.4 1,774.5
Depreciation and amortization                 245.0 210.8 207.2
Operating income (loss)                 296.9 270.8 241.9
Interest expense                 112.4 103.2 96.8
Income tax expense (benefit)                 (10.9) (5.9) (22.7)
Net income (loss) attributable to common shareowners                 216.8 215.6 186.0
Total assets 7,606.0       7,304.7       7,606.0 7,304.7 6,709.1
Construction and acquisition expenditures                 676.0 689.7 619.3
Utility Business [Member] | WPL [Member]                      
Segment Reporting Information [Line Items]                      
Operating revenues                 1,472.8 1,459.1 1,435.1
Depreciation and amortization                 212.9 192.5 184.3
Operating income (loss)                 323.2 327.0 308.7
Interest expense                 93.8 91.4 92.4
Equity (income) loss from unconsolidated investments, net                 (0.7) (39.8) (35.1)
Income tax expense (benefit)                 61.9 93.3 82.9
Net income (loss) attributable to common shareowners                 186.6 190.4 176.3
Total assets 5,756.5       5,290.3       5,756.5 5,290.3 5,270.4
Investments in equity method subsidiaries 8.3       7.7       8.3 7.7 302.0
Construction and acquisition expenditures                 637.4 453.0 344.3
Non-Utility [Member]                      
Segment Reporting Information [Line Items]                      
Operating revenues                 39.1 40.5 44.0
Depreciation and amortization                 3.9 8.3 9.8
Operating income (loss)                 33.3 (60.8) 26.4
Interest expense                 9.4 1.6  
Interest income                     (2.1)
Equity (income) loss from unconsolidated investments, net                 (44.1) (38.9) (32.9)
Income tax expense (benefit)                 15.7 (12.0) 24.2
Net income (loss) attributable to common shareowners                 53.9 (13.7) 34.8
Total assets 825.3       778.8       825.3 778.8 809.0
Investments in equity method subsidiaries $ 373.1       $ 318.3       373.1 318.3 294.2
Construction and acquisition expenditures                 $ 185.1 $ 65.6 $ 74.0