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Segments Of Business (Schedule Of Segment Of Business) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Segment Reporting Information [Line Items] |  |  |
Revenues | $ 3,669 | $ 3,416 | $ 3,648
Depreciation and amortization | 657 | 615 | 567
Operating income (loss) | 795 | 740 | 778
Interest expense | 277 | 275 | 273
Equity income from unconsolidated investments, net | (62) | (61) | (53)
Income tax expense (benefit) | (74) | (57) | 69
Net income attributable to common shareowners | 659 | 614 | 557
Total assets | 18,553 | 17,710 | 16,701
Investments in equity method subsidiaries | 508 | 476 | 458
Construction and acquisition expenditures | 1,169 | 1,366 | 1,640
IPL [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 2,063 | 1,947 | 2,089
Operating income (loss) | 460 | 410 | 403
Interest expense | 139 | 139 | 127
Income tax expense (benefit) | (36) | (47) | 24
Net income attributable to common shareowners | 350 | 324 | 284
Total assets | 9,996 | 9,849 |
WPL [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 1,523 | 1,395 | 1,476
Operating income (loss) | 308 | 306 | 347
Interest expense | 105 | 104 | 102
Income tax expense (benefit) | (51) | (19) | 49
Total assets | 7,518 | 6,912 |
Electric [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 3,081 | 2,920 | 3,064
Depreciation and amortization | 591 | 556 | 513
Operating income (loss) | 716 | 643 | 679
Equity income from unconsolidated investments, net | (2) | (2) | (1)
Total assets | 14,924 | 14,358 | 13,659
Investments in equity method subsidiaries | 17 | 11 | 9
Construction and acquisition expenditures | 980 | 1,109 | 1,439
Electric [Member] | IPL [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 1,752 | 1,695 | 1,781
Depreciation and amortization | 338 | 321 | 295
Operating income (loss) | 420 | 358 | 360
Total assets | 8,602 | 8,518 | 8,075
Construction and acquisition expenditures | 342 | 626 | 964
Electric [Member] | WPL [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 1,329 | 1,225 | 1,283
Depreciation and amortization | 253 | 235 | 218
Operating income (loss) | 296 | 285 | 319
Total assets | 6,322 | 5,840 | 5,584
Construction and acquisition expenditures | 638 | 483 | 475
Gas [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 456 | 373 | 455
Depreciation and amortization | 54 | 49 | 47
Operating income (loss) | 63 | 74 | 70
Equity income from unconsolidated investments, net | 0 | 0 | 0
Total assets | 1,487 | 1,413 | 1,269
Investments in equity method subsidiaries | 0 | 0 | 0
Construction and acquisition expenditures | 90 | 182 | 100
Gas [Member] | IPL [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 265 | 208 | 264
Depreciation and amortization | 31 | 30 | 29
Operating income (loss) | 43 | 50 | 39
Total assets | 819 | 766 | 734
Construction and acquisition expenditures | 42 | 59 | 56
Gas [Member] | WPL [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 191 | 165 | 191
Depreciation and amortization | 23 | 19 | 18
Operating income (loss) | 20 | 24 | 31
Total assets | 668 | 647 | 535
Construction and acquisition expenditures | 48 | 123 | 44
Other Utility [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 49 | 49 | 46
Depreciation and amortization | 6 | 5 | 3
Operating income (loss) | (11) | (1) | 1
Equity income from unconsolidated investments, net | 0 | 0 | 0
Total assets | 1,103 | 990 | 856
Investments in equity method subsidiaries | 0 | 0 | 0
Construction and acquisition expenditures | 0 | 2 | 0
Other Utility [Member] | IPL [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 46 | 44 | 44
Depreciation and amortization | 6 | 5 | 3
Operating income (loss) | (3) | 2 | 4
Total assets | 575 | 565 | 468
Construction and acquisition expenditures | 0 | 2 | 0
Other Utility [Member] | WPL [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 3 | 5 | 2
Depreciation and amortization | 0 | 0 | 0
Operating income (loss) | (8) | (3) | (3)
Total assets | 528 | 425 | 388
Construction and acquisition expenditures | 0 | 0 | 0
Utility Business [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 3,586 | 3,342 | 3,565
Depreciation and amortization | 651 | 610 | 563
Operating income (loss) | 768 | 716 | 750
Interest expense | 244 | 243 | 229
Equity income from unconsolidated investments, net | (2) | (2) | (1)
Income tax expense (benefit) | (87) | (66) | 73
Net income attributable to common shareowners | 618 | 573 | 517
Total assets | 17,514 | 16,761 | 15,784
Investments in equity method subsidiaries | 17 | 11 | 9
Construction and acquisition expenditures | 1,070 | 1,293 | 1,539
Utility Business [Member] | IPL [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 2,063 | 1,947 | 2,089
Depreciation and amortization | 375 | 356 | 327
Operating income (loss) | 460 | 410 | 403
Interest expense | 139 | 139 | 127
Income tax expense (benefit) | (36) | (47) | 24
Net income attributable to common shareowners | 350 | 324 | 284
Total assets | 9,996 | 9,849 | 9,277
Construction and acquisition expenditures | 384 | 687 | 1,020
Utility Business [Member] | WPL [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 1,523 | 1,395 | 1,476
Depreciation and amortization | 276 | 254 | 236
Operating income (loss) | 308 | 306 | 347
Interest expense | 105 | 104 | 102
Income tax expense (benefit) | (51) | (19) | 49
Net income attributable to common shareowners | 268 | 249 | 233
Total assets | 7,518 | 6,912 | 6,507
Construction and acquisition expenditures | 686 | 606 | 519
Non-Utility [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 83 | 74 | 83
Depreciation and amortization | 6 | 5 | 4
Operating income (loss) | 27 | 24 | 28
Interest expense | 33 | 32 | 44
Equity income from unconsolidated investments, net | (60) | (59) | (52)
Income tax expense (benefit) | 13 | 9 | (4)
Net income attributable to common shareowners | 41 | 41 | 40
Total assets | 1,039 | 949 | 917
Investments in equity method subsidiaries | 491 | 465 | 449
Construction and acquisition expenditures | $ 99 | $ 73 | $ 101

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