XML 32 R12.htm IDEA: XBRL DOCUMENT
v3.21.2

Revenues | 6 Months Ended
--- | ---
Jun. 30, 2021
Disaggregation of Revenue [Line Items] |
Revenues from Contracts with Customers | REVENUES Disaggregation of revenues from contracts with customers, which correlates to revenues for each reportable segment, was as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Three Months Ended June 30 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $258 |  | $251 |  | $142 |  | $136 |  | $116 |  | $115
Retail - commercial | 175 |  | 163 |  | 115 |  | 109 |  | 60 |  | 54
Retail - industrial | 210 |  | 197 |  | 116 |  | 114 |  | 94 |  | 83
Wholesale | 47 |  | 40 |  | 15 |  | 13 |  | 32 |  | 27
Bulk power and other | 27 |  | 24 |  | 14 |  | 16 |  | 13 |  | 8
Total Electric Utility | 717 |  | 675 |  | 402 |  | 388 |  | 315 |  | 287
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 39 |  | 33 |  | 24 |  | 18 |  | 15 |  | 15
Retail - commercial | 19 |  | 15 |  | 12 |  | 8 |  | 7 |  | 7
Retail - industrial | 3 |  | 2 |  | 2 |  | 2 |  | 1 |  | —
Transportation/other | 8 |  | 9 |  | 5 |  | 6 |  | 3 |  | 3
Total Gas Utility | 69 |  | 59 |  | 43 |  | 34 |  | 26 |  | 25
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 9 |  | 9 |  | 9 |  | 9 |  | — |  | —
Other utility | 1 |  | 1 |  | 1 |  | 1 |  | — |  | —
Total Other Utility | 10 |  | 10 |  | 10 |  | 10 |  | — |  | —
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Transportation and other | 21 |  | 19 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 21 |  | 19 |  | — |  | — |  | — |  | —
Total revenues | $817 |  | $763 |  | $455 |  | $432 |  | $341 |  | $312
| Alliant Energy |  | IPL |  | WPL
Six Months Ended June 30 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $520 |  | $517 |  | $281 |  | $283 |  | $239 |  | $234
Retail - commercial | 347 |  | 346 |  | 225 |  | 229 |  | 122 |  | 117
Retail - industrial | 412 |  | 407 |  | 228 |  | 235 |  | 184 |  | 172
Wholesale | 87 |  | 80 |  | 26 |  | 27 |  | 61 |  | 53
Bulk power and other | 52 |  | 55 |  | 28 |  | 39 |  | 24 |  | 16
Total Electric Utility | 1,418 |  | 1,405 |  | 788 |  | 813 |  | 630 |  | 592
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 138 |  | 124 |  | 76 |  | 67 |  | 62 |  | 57
Retail - commercial | 72 |  | 60 |  | 39 |  | 32 |  | 33 |  | 28
Retail - industrial | 8 |  | 6 |  | 5 |  | 4 |  | 3 |  | 2
Transportation/other | 21 |  | 21 |  | 14 |  | 14 |  | 7 |  | 7
Total Gas Utility | 239 |  | 211 |  | 134 |  | 117 |  | 105 |  | 94
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 18 |  | 19 |  | 18 |  | 19 |  | — |  | —
Other utility | 5 |  | 3 |  | 4 |  | 2 |  | 1 |  | 1
Total Other Utility | 23 |  | 22 |  | 22 |  | 21 |  | 1 |  | 1
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Transportation and other | 38 |  | 41 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 38 |  | 41 |  | — |  | — |  | — |  | —
Total revenues | $1,718 |  | $1,679 |  | $944 |  | $951 |  | $736 |  | $687
IPL [Member] |
Disaggregation of Revenue [Line Items] |
Revenues from Contracts with Customers | REVENUES Disaggregation of revenues from contracts with customers, which correlates to revenues for each reportable segment, was as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Three Months Ended June 30 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $258 |  | $251 |  | $142 |  | $136 |  | $116 |  | $115
Retail - commercial | 175 |  | 163 |  | 115 |  | 109 |  | 60 |  | 54
Retail - industrial | 210 |  | 197 |  | 116 |  | 114 |  | 94 |  | 83
Wholesale | 47 |  | 40 |  | 15 |  | 13 |  | 32 |  | 27
Bulk power and other | 27 |  | 24 |  | 14 |  | 16 |  | 13 |  | 8
Total Electric Utility | 717 |  | 675 |  | 402 |  | 388 |  | 315 |  | 287
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 39 |  | 33 |  | 24 |  | 18 |  | 15 |  | 15
Retail - commercial | 19 |  | 15 |  | 12 |  | 8 |  | 7 |  | 7
Retail - industrial | 3 |  | 2 |  | 2 |  | 2 |  | 1 |  | —
Transportation/other | 8 |  | 9 |  | 5 |  | 6 |  | 3 |  | 3
Total Gas Utility | 69 |  | 59 |  | 43 |  | 34 |  | 26 |  | 25
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 9 |  | 9 |  | 9 |  | 9 |  | — |  | —
Other utility | 1 |  | 1 |  | 1 |  | 1 |  | — |  | —
Total Other Utility | 10 |  | 10 |  | 10 |  | 10 |  | — |  | —
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Transportation and other | 21 |  | 19 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 21 |  | 19 |  | — |  | — |  | — |  | —
Total revenues | $817 |  | $763 |  | $455 |  | $432 |  | $341 |  | $312
| Alliant Energy |  | IPL |  | WPL
Six Months Ended June 30 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $520 |  | $517 |  | $281 |  | $283 |  | $239 |  | $234
Retail - commercial | 347 |  | 346 |  | 225 |  | 229 |  | 122 |  | 117
Retail - industrial | 412 |  | 407 |  | 228 |  | 235 |  | 184 |  | 172
Wholesale | 87 |  | 80 |  | 26 |  | 27 |  | 61 |  | 53
Bulk power and other | 52 |  | 55 |  | 28 |  | 39 |  | 24 |  | 16
Total Electric Utility | 1,418 |  | 1,405 |  | 788 |  | 813 |  | 630 |  | 592
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 138 |  | 124 |  | 76 |  | 67 |  | 62 |  | 57
Retail - commercial | 72 |  | 60 |  | 39 |  | 32 |  | 33 |  | 28
Retail - industrial | 8 |  | 6 |  | 5 |  | 4 |  | 3 |  | 2
Transportation/other | 21 |  | 21 |  | 14 |  | 14 |  | 7 |  | 7
Total Gas Utility | 239 |  | 211 |  | 134 |  | 117 |  | 105 |  | 94
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 18 |  | 19 |  | 18 |  | 19 |  | — |  | —
Other utility | 5 |  | 3 |  | 4 |  | 2 |  | 1 |  | 1
Total Other Utility | 23 |  | 22 |  | 22 |  | 21 |  | 1 |  | 1
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Transportation and other | 38 |  | 41 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 38 |  | 41 |  | — |  | — |  | — |  | —
Total revenues | $1,718 |  | $1,679 |  | $944 |  | $951 |  | $736 |  | $687
WPL [Member] |
Disaggregation of Revenue [Line Items] |
Revenues from Contracts with Customers | REVENUES Disaggregation of revenues from contracts with customers, which correlates to revenues for each reportable segment, was as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Three Months Ended June 30 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $258 |  | $251 |  | $142 |  | $136 |  | $116 |  | $115
Retail - commercial | 175 |  | 163 |  | 115 |  | 109 |  | 60 |  | 54
Retail - industrial | 210 |  | 197 |  | 116 |  | 114 |  | 94 |  | 83
Wholesale | 47 |  | 40 |  | 15 |  | 13 |  | 32 |  | 27
Bulk power and other | 27 |  | 24 |  | 14 |  | 16 |  | 13 |  | 8
Total Electric Utility | 717 |  | 675 |  | 402 |  | 388 |  | 315 |  | 287
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 39 |  | 33 |  | 24 |  | 18 |  | 15 |  | 15
Retail - commercial | 19 |  | 15 |  | 12 |  | 8 |  | 7 |  | 7
Retail - industrial | 3 |  | 2 |  | 2 |  | 2 |  | 1 |  | —
Transportation/other | 8 |  | 9 |  | 5 |  | 6 |  | 3 |  | 3
Total Gas Utility | 69 |  | 59 |  | 43 |  | 34 |  | 26 |  | 25
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 9 |  | 9 |  | 9 |  | 9 |  | — |  | —
Other utility | 1 |  | 1 |  | 1 |  | 1 |  | — |  | —
Total Other Utility | 10 |  | 10 |  | 10 |  | 10 |  | — |  | —
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Transportation and other | 21 |  | 19 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 21 |  | 19 |  | — |  | — |  | — |  | —
Total revenues | $817 |  | $763 |  | $455 |  | $432 |  | $341 |  | $312
| Alliant Energy |  | IPL |  | WPL
Six Months Ended June 30 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $520 |  | $517 |  | $281 |  | $283 |  | $239 |  | $234
Retail - commercial | 347 |  | 346 |  | 225 |  | 229 |  | 122 |  | 117
Retail - industrial | 412 |  | 407 |  | 228 |  | 235 |  | 184 |  | 172
Wholesale | 87 |  | 80 |  | 26 |  | 27 |  | 61 |  | 53
Bulk power and other | 52 |  | 55 |  | 28 |  | 39 |  | 24 |  | 16
Total Electric Utility | 1,418 |  | 1,405 |  | 788 |  | 813 |  | 630 |  | 592
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 138 |  | 124 |  | 76 |  | 67 |  | 62 |  | 57
Retail - commercial | 72 |  | 60 |  | 39 |  | 32 |  | 33 |  | 28
Retail - industrial | 8 |  | 6 |  | 5 |  | 4 |  | 3 |  | 2
Transportation/other | 21 |  | 21 |  | 14 |  | 14 |  | 7 |  | 7
Total Gas Utility | 239 |  | 211 |  | 134 |  | 117 |  | 105 |  | 94
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 18 |  | 19 |  | 18 |  | 19 |  | — |  | —
Other utility | 5 |  | 3 |  | 4 |  | 2 |  | 1 |  | 1
Total Other Utility | 23 |  | 22 |  | 22 |  | 21 |  | 1 |  | 1
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Transportation and other | 38 |  | 41 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 38 |  | 41 |  | — |  | — |  | — |  | —
Total revenues | $1,718 |  | $1,679 |  | $944 |  | $951 |  | $736 |  | $687

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_DisaggregationOfRevenueLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -URI http://asc.fasb.org/topic&trid=49130388 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130551-203045 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 13 -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130556-203045 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 12 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130550-203045 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 12 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 12 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 12 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130558-203045 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 12 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045 + Details
Name: | us-gaap_RevenueFromContractWithCustomerTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
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: |