XML 40 R20.htm IDEA: XBRL DOCUMENT
v3.24.2.u1

Segments Of Business | 6 Months Ended
--- | ---
Jun. 30, 2024
Segment Reporting Information [Line Items] |
Segments Of Business | SEGMENTS OF BUSINESS Certain financial information relating to Alliant Energy’s, IPL’s and WPL’s business segments is as follows. Intersegment revenues were not material to their respective operations. Refer to Note 2 for discussion of asset valuation charges recorded in the second quarter of 2024 related to IPL’s Lansing Generating Station, which decreased the assets for “Utility - Electric,” and N ote 11 for discussion of additional AROs recorded in the second quarter of 2024 substantially due to the enactment of the revised CCR Rule, which primarily increased the assets for “Utility - Electric.”
Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Three Months Ended June 30, 2024 |  |  |  |  |  |  |  |  |  |  |
Revenues | $789 |  | $69 |  | $10 |  | $868 |  | $26 |  | $894
Operating income (loss) | 131 |  | 1 |  | (16) |  | 116 |  | 14 |  | 130
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 82 |  | 5 |  | 87
Three Months Ended June 30, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $799 |  | $77 |  | $13 |  | $889 |  | $23 |  | $912
Operating income | 200 |  | 2 |  | 7 |  | 209 |  | 8 |  | 217
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 161 |  | (1) |  | 160
Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Six Months Ended June 30, 2024 |  |  |  |  |  |  |  |  |  |  |
Revenues | $1,580 |  | $273 |  | $24 |  | $1,877 |  | $48 |  | $1,925
Operating income (loss) | 295 |  | 48 |  | (11) |  | 332 |  | 20 |  | 352
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 237 |  | 8 |  | 245
Six Months Ended June 30, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $1,567 |  | $353 |  | $25 |  | $1,945 |  | $45 |  | $1,990
Operating income | 363 |  | 52 |  | 11 |  | 426 |  | 13 |  | 439
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 321 |  | 2 |  | 323
IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended June 30, 2024 |  |  |  |  |  |  |
Revenues | $404 |  | $40 |  | $9 |  | $453
Operating income (loss) | 34 |  | (1) |  | (17) |  | 16
Net income |  |  |  |  |  |  | 18
Three Months Ended June 30, 2023 |  |  |  |  |  |  |
Revenues | $431 |  | $44 |  | $12 |  | $487
Operating income | 105 |  | — |  | 5 |  | 110
Net income |  |  |  |  |  |  | 89
Six Months Ended June 30, 2024 |  |  |  |  |  |  |
Revenues | $795 |  | $148 |  | $23 |  | $966
Operating income (loss) | 91 |  | 21 |  | (11) |  | 101
Net income |  |  |  |  |  |  | 81
Six Months Ended June 30, 2023 |  |  |  |  |  |  |
Revenues | $819 |  | $194 |  | $24 |  | $1,037
Operating income | 171 |  | 27 |  | 8 |  | 206
Net income |  |  |  |  |  |  | 161
WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended June 30, 2024 |  |  |  |  |  |  |
Revenues | $385 |  | $29 |  | $1 |  | $415
Operating income | 97 |  | 2 |  | 1 |  | 100
Net income |  |  |  |  |  |  | 64
Three Months Ended June 30, 2023 |  |  |  |  |  |  |
Revenues | $368 |  | $33 |  | $1 |  | $402
Operating income | 95 |  | 2 |  | 2 |  | 99
Net income |  |  |  |  |  |  | 72
Six Months Ended June 30, 2024 |  |  |  |  |  |  |
Revenues | $785 |  | $125 |  | $1 |  | $911
Operating income | 204 |  | 27 |  | — |  | 231
Net income |  |  |  |  |  |  | 156
Six Months Ended June 30, 2023 |  |  |  |  |  |  |
Revenues | $748 |  | $159 |  | $1 |  | $908
Operating income | 192 |  | 25 |  | 3 |  | 220
Net income |  |  |  |  |  |  | 160
IPL [Member] |
Segment Reporting Information [Line Items] |
Segments Of Business | SEGMENTS OF BUSINESS Certain financial information relating to Alliant Energy’s, IPL’s and WPL’s business segments is as follows. Intersegment revenues were not material to their respective operations. Refer to Note 2 for discussion of asset valuation charges recorded in the second quarter of 2024 related to IPL’s Lansing Generating Station, which decreased the assets for “Utility - Electric,” and N ote 11 for discussion of additional AROs recorded in the second quarter of 2024 substantially due to the enactment of the revised CCR Rule, which primarily increased the assets for “Utility - Electric.”
Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Three Months Ended June 30, 2024 |  |  |  |  |  |  |  |  |  |  |
Revenues | $789 |  | $69 |  | $10 |  | $868 |  | $26 |  | $894
Operating income (loss) | 131 |  | 1 |  | (16) |  | 116 |  | 14 |  | 130
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 82 |  | 5 |  | 87
Three Months Ended June 30, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $799 |  | $77 |  | $13 |  | $889 |  | $23 |  | $912
Operating income | 200 |  | 2 |  | 7 |  | 209 |  | 8 |  | 217
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 161 |  | (1) |  | 160
Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Six Months Ended June 30, 2024 |  |  |  |  |  |  |  |  |  |  |
Revenues | $1,580 |  | $273 |  | $24 |  | $1,877 |  | $48 |  | $1,925
Operating income (loss) | 295 |  | 48 |  | (11) |  | 332 |  | 20 |  | 352
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 237 |  | 8 |  | 245
Six Months Ended June 30, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $1,567 |  | $353 |  | $25 |  | $1,945 |  | $45 |  | $1,990
Operating income | 363 |  | 52 |  | 11 |  | 426 |  | 13 |  | 439
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 321 |  | 2 |  | 323
IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended June 30, 2024 |  |  |  |  |  |  |
Revenues | $404 |  | $40 |  | $9 |  | $453
Operating income (loss) | 34 |  | (1) |  | (17) |  | 16
Net income |  |  |  |  |  |  | 18
Three Months Ended June 30, 2023 |  |  |  |  |  |  |
Revenues | $431 |  | $44 |  | $12 |  | $487
Operating income | 105 |  | — |  | 5 |  | 110
Net income |  |  |  |  |  |  | 89
Six Months Ended June 30, 2024 |  |  |  |  |  |  |
Revenues | $795 |  | $148 |  | $23 |  | $966
Operating income (loss) | 91 |  | 21 |  | (11) |  | 101
Net income |  |  |  |  |  |  | 81
Six Months Ended June 30, 2023 |  |  |  |  |  |  |
Revenues | $819 |  | $194 |  | $24 |  | $1,037
Operating income | 171 |  | 27 |  | 8 |  | 206
Net income |  |  |  |  |  |  | 161
WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended June 30, 2024 |  |  |  |  |  |  |
Revenues | $385 |  | $29 |  | $1 |  | $415
Operating income | 97 |  | 2 |  | 1 |  | 100
Net income |  |  |  |  |  |  | 64
Three Months Ended June 30, 2023 |  |  |  |  |  |  |
Revenues | $368 |  | $33 |  | $1 |  | $402
Operating income | 95 |  | 2 |  | 2 |  | 99
Net income |  |  |  |  |  |  | 72
Six Months Ended June 30, 2024 |  |  |  |  |  |  |
Revenues | $785 |  | $125 |  | $1 |  | $911
Operating income | 204 |  | 27 |  | — |  | 231
Net income |  |  |  |  |  |  | 156
Six Months Ended June 30, 2023 |  |  |  |  |  |  |
Revenues | $748 |  | $159 |  | $1 |  | $908
Operating income | 192 |  | 25 |  | 3 |  | 220
Net income |  |  |  |  |  |  | 160
WPL [Member] |
Segment Reporting Information [Line Items] |
Segments Of Business | SEGMENTS OF BUSINESS Certain financial information relating to Alliant Energy’s, IPL’s and WPL’s business segments is as follows. Intersegment revenues were not material to their respective operations. Refer to Note 2 for discussion of asset valuation charges recorded in the second quarter of 2024 related to IPL’s Lansing Generating Station, which decreased the assets for “Utility - Electric,” and N ote 11 for discussion of additional AROs recorded in the second quarter of 2024 substantially due to the enactment of the revised CCR Rule, which primarily increased the assets for “Utility - Electric.”
Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Three Months Ended June 30, 2024 |  |  |  |  |  |  |  |  |  |  |
Revenues | $789 |  | $69 |  | $10 |  | $868 |  | $26 |  | $894
Operating income (loss) | 131 |  | 1 |  | (16) |  | 116 |  | 14 |  | 130
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 82 |  | 5 |  | 87
Three Months Ended June 30, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $799 |  | $77 |  | $13 |  | $889 |  | $23 |  | $912
Operating income | 200 |  | 2 |  | 7 |  | 209 |  | 8 |  | 217
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 161 |  | (1) |  | 160
Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Six Months Ended June 30, 2024 |  |  |  |  |  |  |  |  |  |  |
Revenues | $1,580 |  | $273 |  | $24 |  | $1,877 |  | $48 |  | $1,925
Operating income (loss) | 295 |  | 48 |  | (11) |  | 332 |  | 20 |  | 352
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 237 |  | 8 |  | 245
Six Months Ended June 30, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $1,567 |  | $353 |  | $25 |  | $1,945 |  | $45 |  | $1,990
Operating income | 363 |  | 52 |  | 11 |  | 426 |  | 13 |  | 439
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 321 |  | 2 |  | 323
IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended June 30, 2024 |  |  |  |  |  |  |
Revenues | $404 |  | $40 |  | $9 |  | $453
Operating income (loss) | 34 |  | (1) |  | (17) |  | 16
Net income |  |  |  |  |  |  | 18
Three Months Ended June 30, 2023 |  |  |  |  |  |  |
Revenues | $431 |  | $44 |  | $12 |  | $487
Operating income | 105 |  | — |  | 5 |  | 110
Net income |  |  |  |  |  |  | 89
Six Months Ended June 30, 2024 |  |  |  |  |  |  |
Revenues | $795 |  | $148 |  | $23 |  | $966
Operating income (loss) | 91 |  | 21 |  | (11) |  | 101
Net income |  |  |  |  |  |  | 81
Six Months Ended June 30, 2023 |  |  |  |  |  |  |
Revenues | $819 |  | $194 |  | $24 |  | $1,037
Operating income | 171 |  | 27 |  | 8 |  | 206
Net income |  |  |  |  |  |  | 161
WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended June 30, 2024 |  |  |  |  |  |  |
Revenues | $385 |  | $29 |  | $1 |  | $415
Operating income | 97 |  | 2 |  | 1 |  | 100
Net income |  |  |  |  |  |  | 64
Three Months Ended June 30, 2023 |  |  |  |  |  |  |
Revenues | $368 |  | $33 |  | $1 |  | $402
Operating income | 95 |  | 2 |  | 2 |  | 99
Net income |  |  |  |  |  |  | 72
Six Months Ended June 30, 2024 |  |  |  |  |  |  |
Revenues | $785 |  | $125 |  | $1 |  | $911
Operating income | 204 |  | 27 |  | — |  | 231
Net income |  |  |  |  |  |  | 156
Six Months Ended June 30, 2023 |  |  |  |  |  |  |
Revenues | $748 |  | $159 |  | $1 |  | $908
Operating income | 192 |  | 25 |  | 3 |  | 220
Net income |  |  |  |  |  |  | 160

X
- 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/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-22 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 15 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-15 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 31 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-31 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-32 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-42 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-32 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 40 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-40 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -Name Accounting Standards Codification -Publisher FASB -URI https://asc.fasb.org//280/tableOfContent Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 26 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-26 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 34 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-34 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 41 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-41 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 21 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-21 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 21 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-21 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-32 + Details
Name: | us-gaap_SegmentReportingDisclosureTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_SegmentReportingInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=lnt_IplMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=lnt_WplMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |