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Regulatory Matters | 3 Months Ended
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Mar. 31, 2022
Public Utilities, General Disclosures [Line Items] |
Regulatory Matters | REGULATORY MATTERS Regulatory Assets and Regulatory Liabilities - Regulatory assets were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| March 31, 2022 |  | December 31, 2021 |  | March 31, 2022 |  | December 31, 2021 |  | March 31, 2022 |  | December 31, 2021
Tax-related | $949 |  | $934 |  | $896 |  | $884 |  | $53 |  | $50
Pension and OPEB costs | 453 |  | 462 |  | 224 |  | 228 |  | 229 |  | 234
Asset retirement obligations | 134 |  | 128 |  | 94 |  | 89 |  | 40 |  | 39
Assets retired early | 88 |  | 92 |  | 64 |  | 66 |  | 24 |  | 26
IPL’s DAEC PPA amendment | 84 |  | 90 |  | 84 |  | 90 |  | — |  | —
WPL’s Western Wisconsin gas distribution expansion investments | 50 |  | 52 |  | — |  | — |  | 50 |  | 52
Commodity cost recovery | 42 |  | 42 |  | 2 |  | 2 |  | 40 |  | 40
Other | 119 |  | 140 |  | 68 |  | 84 |  | 51 |  | 56
| $1,919 |  | $1,940 |  | $1,432 |  | $1,443 |  | $487 |  | $497
Regulatory liabilities were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| March 31, 2022 |  | December 31, 2021 |  | March 31, 2022 |  | December 31, 2021 |  | March 31, 2022 |  | December 31, 2021
Tax-related | $578 |  | $585 |  | $310 |  | $312 |  | $268 |  | $273
Cost of removal obligations | 391 |  | 384 |  | 256 |  | 252 |  | 135 |  | 132
Derivatives | 258 |  | 166 |  | 125 |  | 77 |  | 133 |  | 89
Electric transmission cost recovery | 50 |  | 51 |  | 29 |  | 27 |  | 21 |  | 24
WPL’s West Riverside liquidated damages | 35 |  | 36 |  | — |  | — |  | 35 |  | 36
Other | 60 |  | 49 |  | 34 |  | 23 |  | 26 |  | 26
| $1,372 |  | $1,271 |  | $754 |  | $691 |  | $618 |  | $580
IPL [Member] |
Public Utilities, General Disclosures [Line Items] |
Regulatory Matters | REGULATORY MATTERS Regulatory Assets and Regulatory Liabilities - Regulatory assets were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| March 31, 2022 |  | December 31, 2021 |  | March 31, 2022 |  | December 31, 2021 |  | March 31, 2022 |  | December 31, 2021
Tax-related | $949 |  | $934 |  | $896 |  | $884 |  | $53 |  | $50
Pension and OPEB costs | 453 |  | 462 |  | 224 |  | 228 |  | 229 |  | 234
Asset retirement obligations | 134 |  | 128 |  | 94 |  | 89 |  | 40 |  | 39
Assets retired early | 88 |  | 92 |  | 64 |  | 66 |  | 24 |  | 26
IPL’s DAEC PPA amendment | 84 |  | 90 |  | 84 |  | 90 |  | — |  | —
WPL’s Western Wisconsin gas distribution expansion investments | 50 |  | 52 |  | — |  | — |  | 50 |  | 52
Commodity cost recovery | 42 |  | 42 |  | 2 |  | 2 |  | 40 |  | 40
Other | 119 |  | 140 |  | 68 |  | 84 |  | 51 |  | 56
| $1,919 |  | $1,940 |  | $1,432 |  | $1,443 |  | $487 |  | $497
Regulatory liabilities were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| March 31, 2022 |  | December 31, 2021 |  | March 31, 2022 |  | December 31, 2021 |  | March 31, 2022 |  | December 31, 2021
Tax-related | $578 |  | $585 |  | $310 |  | $312 |  | $268 |  | $273
Cost of removal obligations | 391 |  | 384 |  | 256 |  | 252 |  | 135 |  | 132
Derivatives | 258 |  | 166 |  | 125 |  | 77 |  | 133 |  | 89
Electric transmission cost recovery | 50 |  | 51 |  | 29 |  | 27 |  | 21 |  | 24
WPL’s West Riverside liquidated damages | 35 |  | 36 |  | — |  | — |  | 35 |  | 36
Other | 60 |  | 49 |  | 34 |  | 23 |  | 26 |  | 26
| $1,372 |  | $1,271 |  | $754 |  | $691 |  | $618 |  | $580
WPL [Member] |
Public Utilities, General Disclosures [Line Items] |
Regulatory Matters | REGULATORY MATTERS Regulatory Assets and Regulatory Liabilities - Regulatory assets were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| March 31, 2022 |  | December 31, 2021 |  | March 31, 2022 |  | December 31, 2021 |  | March 31, 2022 |  | December 31, 2021
Tax-related | $949 |  | $934 |  | $896 |  | $884 |  | $53 |  | $50
Pension and OPEB costs | 453 |  | 462 |  | 224 |  | 228 |  | 229 |  | 234
Asset retirement obligations | 134 |  | 128 |  | 94 |  | 89 |  | 40 |  | 39
Assets retired early | 88 |  | 92 |  | 64 |  | 66 |  | 24 |  | 26
IPL’s DAEC PPA amendment | 84 |  | 90 |  | 84 |  | 90 |  | — |  | —
WPL’s Western Wisconsin gas distribution expansion investments | 50 |  | 52 |  | — |  | — |  | 50 |  | 52
Commodity cost recovery | 42 |  | 42 |  | 2 |  | 2 |  | 40 |  | 40
Other | 119 |  | 140 |  | 68 |  | 84 |  | 51 |  | 56
| $1,919 |  | $1,940 |  | $1,432 |  | $1,443 |  | $487 |  | $497
Regulatory liabilities were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| March 31, 2022 |  | December 31, 2021 |  | March 31, 2022 |  | December 31, 2021 |  | March 31, 2022 |  | December 31, 2021
Tax-related | $578 |  | $585 |  | $310 |  | $312 |  | $268 |  | $273
Cost of removal obligations | 391 |  | 384 |  | 256 |  | 252 |  | 135 |  | 132
Derivatives | 258 |  | 166 |  | 125 |  | 77 |  | 133 |  | 89
Electric transmission cost recovery | 50 |  | 51 |  | 29 |  | 27 |  | 21 |  | 24
WPL’s West Riverside liquidated damages | 35 |  | 36 |  | — |  | — |  | 35 |  | 36
Other | 60 |  | 49 |  | 34 |  | 23 |  | 26 |  | 26
| $1,372 |  | $1,271 |  | $754 |  | $691 |  | $618 |  | $580

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