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v3.20.2

Regulatory Matters (Tables) | 6 Months Ended
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Jun. 30, 2020
Regulatory Assets [Line Items] |
Regulatory Assets | Regulatory assets were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2020 |  | December 31, 2019 |  | June 30, 2020 |  | December 31, 2019 |  | June 30, 2020 |  | December 31, 2019
Tax-related |  | $842.5 |  |  |  | $817.6 |  |  |  | $797.4 |  |  |  | $776.8 |  |  |  | $45.1 |  |  |  | $40.8 |
Pension and OPEB costs | 501.2 |  |  | 524.0 |  |  | 251.3 |  |  | 262.5 |  |  | 249.9 |  |  | 261.5 |
Assets retired early | 122.9 |  |  | 134.0 |  |  | 81.8 |  |  | 87.9 |  |  | 41.1 |  |  | 46.1 |
Asset retirement obligations | 114.0 |  |  | 111.8 |  |  | 78.2 |  |  | 76.2 |  |  | 35.8 |  |  | 35.6 |
IPL’s DAEC PPA amendment | 109.4 |  |  | 108.2 |  |  | 109.4 |  |  | 108.2 |  |  | — |  |  | — |
Derivatives | 47.0 |  |  | 39.5 |  |  | 20.5 |  |  | 18.3 |  |  | 26.5 |  |  | 21.2 |
Emission allowances | 19.8 |  |  | 21.1 |  |  | 19.8 |  |  | 21.1 |  |  | — |  |  | — |
Other | 86.2 |  |  | 88.5 |  |  | 46.5 |  |  | 48.3 |  |  | 39.7 |  |  | 40.2 |
|  | $1,843.0 |  |  |  | $1,844.7 |  |  |  | $1,404.9 |  |  |  | $1,399.3 |  |  |  | $438.1 |  |  |  | $445.4 |
Regulatory Liabilities | Regulatory liabilities were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2020 |  | December 31, 2019 |  | June 30, 2020 |  | December 31, 2019 |  | June 30, 2020 |  | December 31, 2019
Tax-related |  | $779.0 |  |  |  | $835.6 |  |  |  | $343.6 |  |  |  | $350.9 |  |  |  | $435.4 |  |  |  | $484.7 |
Cost of removal obligations | 385.8 |  |  | 387.7 |  |  | 256.4 |  |  | 257.0 |  |  | 129.4 |  |  | 130.7 |
Electric transmission cost recovery | 66.3 |  |  | 88.6 |  |  | 30.7 |  |  | 51.3 |  |  | 35.6 |  |  | 37.3 |
Commodity cost recovery | 30.1 |  |  | 24.2 |  |  | 14.0 |  |  | 8.8 |  |  | 16.1 |  |  | 15.4 |
Derivatives | 28.8 |  |  | 19.9 |  |  | 26.3 |  |  | 17.4 |  |  | 2.5 |  |  | 2.5 |
WPL’s earnings sharing mechanism | 20.4 |  |  | 21.9 |  |  | — |  |  | — |  |  | 20.4 |  |  | 21.9 |
Other | 60.6 |  |  | 45.7 |  |  | 46.9 |  |  | 29.3 |  |  | 13.7 |  |  | 16.4 |
|  | $1,371.0 |  |  |  | $1,423.6 |  |  |  | $717.9 |  |  |  | $714.7 |  |  |  | $653.1 |  |  |  | $708.9 |
IPL [Member] |
Regulatory Assets [Line Items] |
Regulatory Assets | Regulatory assets were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2020 |  | December 31, 2019 |  | June 30, 2020 |  | December 31, 2019 |  | June 30, 2020 |  | December 31, 2019
Tax-related |  | $842.5 |  |  |  | $817.6 |  |  |  | $797.4 |  |  |  | $776.8 |  |  |  | $45.1 |  |  |  | $40.8 |
Pension and OPEB costs | 501.2 |  |  | 524.0 |  |  | 251.3 |  |  | 262.5 |  |  | 249.9 |  |  | 261.5 |
Assets retired early | 122.9 |  |  | 134.0 |  |  | 81.8 |  |  | 87.9 |  |  | 41.1 |  |  | 46.1 |
Asset retirement obligations | 114.0 |  |  | 111.8 |  |  | 78.2 |  |  | 76.2 |  |  | 35.8 |  |  | 35.6 |
IPL’s DAEC PPA amendment | 109.4 |  |  | 108.2 |  |  | 109.4 |  |  | 108.2 |  |  | — |  |  | — |
Derivatives | 47.0 |  |  | 39.5 |  |  | 20.5 |  |  | 18.3 |  |  | 26.5 |  |  | 21.2 |
Emission allowances | 19.8 |  |  | 21.1 |  |  | 19.8 |  |  | 21.1 |  |  | — |  |  | — |
Other | 86.2 |  |  | 88.5 |  |  | 46.5 |  |  | 48.3 |  |  | 39.7 |  |  | 40.2 |
|  | $1,843.0 |  |  |  | $1,844.7 |  |  |  | $1,404.9 |  |  |  | $1,399.3 |  |  |  | $438.1 |  |  |  | $445.4 |
Regulatory Liabilities | Regulatory liabilities were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2020 |  | December 31, 2019 |  | June 30, 2020 |  | December 31, 2019 |  | June 30, 2020 |  | December 31, 2019
Tax-related |  | $779.0 |  |  |  | $835.6 |  |  |  | $343.6 |  |  |  | $350.9 |  |  |  | $435.4 |  |  |  | $484.7 |
Cost of removal obligations | 385.8 |  |  | 387.7 |  |  | 256.4 |  |  | 257.0 |  |  | 129.4 |  |  | 130.7 |
Electric transmission cost recovery | 66.3 |  |  | 88.6 |  |  | 30.7 |  |  | 51.3 |  |  | 35.6 |  |  | 37.3 |
Commodity cost recovery | 30.1 |  |  | 24.2 |  |  | 14.0 |  |  | 8.8 |  |  | 16.1 |  |  | 15.4 |
Derivatives | 28.8 |  |  | 19.9 |  |  | 26.3 |  |  | 17.4 |  |  | 2.5 |  |  | 2.5 |
WPL’s earnings sharing mechanism | 20.4 |  |  | 21.9 |  |  | — |  |  | — |  |  | 20.4 |  |  | 21.9 |
Other | 60.6 |  |  | 45.7 |  |  | 46.9 |  |  | 29.3 |  |  | 13.7 |  |  | 16.4 |
|  | $1,371.0 |  |  |  | $1,423.6 |  |  |  | $717.9 |  |  |  | $714.7 |  |  |  | $653.1 |  |  |  | $708.9 |
WPL [Member] |
Regulatory Assets [Line Items] |
Regulatory Assets | Regulatory assets were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2020 |  | December 31, 2019 |  | June 30, 2020 |  | December 31, 2019 |  | June 30, 2020 |  | December 31, 2019
Tax-related |  | $842.5 |  |  |  | $817.6 |  |  |  | $797.4 |  |  |  | $776.8 |  |  |  | $45.1 |  |  |  | $40.8 |
Pension and OPEB costs | 501.2 |  |  | 524.0 |  |  | 251.3 |  |  | 262.5 |  |  | 249.9 |  |  | 261.5 |
Assets retired early | 122.9 |  |  | 134.0 |  |  | 81.8 |  |  | 87.9 |  |  | 41.1 |  |  | 46.1 |
Asset retirement obligations | 114.0 |  |  | 111.8 |  |  | 78.2 |  |  | 76.2 |  |  | 35.8 |  |  | 35.6 |
IPL’s DAEC PPA amendment | 109.4 |  |  | 108.2 |  |  | 109.4 |  |  | 108.2 |  |  | — |  |  | — |
Derivatives | 47.0 |  |  | 39.5 |  |  | 20.5 |  |  | 18.3 |  |  | 26.5 |  |  | 21.2 |
Emission allowances | 19.8 |  |  | 21.1 |  |  | 19.8 |  |  | 21.1 |  |  | — |  |  | — |
Other | 86.2 |  |  | 88.5 |  |  | 46.5 |  |  | 48.3 |  |  | 39.7 |  |  | 40.2 |
|  | $1,843.0 |  |  |  | $1,844.7 |  |  |  | $1,404.9 |  |  |  | $1,399.3 |  |  |  | $438.1 |  |  |  | $445.4 |
Regulatory Liabilities | Regulatory liabilities were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2020 |  | December 31, 2019 |  | June 30, 2020 |  | December 31, 2019 |  | June 30, 2020 |  | December 31, 2019
Tax-related |  | $779.0 |  |  |  | $835.6 |  |  |  | $343.6 |  |  |  | $350.9 |  |  |  | $435.4 |  |  |  | $484.7 |
Cost of removal obligations | 385.8 |  |  | 387.7 |  |  | 256.4 |  |  | 257.0 |  |  | 129.4 |  |  | 130.7 |
Electric transmission cost recovery | 66.3 |  |  | 88.6 |  |  | 30.7 |  |  | 51.3 |  |  | 35.6 |  |  | 37.3 |
Commodity cost recovery | 30.1 |  |  | 24.2 |  |  | 14.0 |  |  | 8.8 |  |  | 16.1 |  |  | 15.4 |
Derivatives | 28.8 |  |  | 19.9 |  |  | 26.3 |  |  | 17.4 |  |  | 2.5 |  |  | 2.5 |
WPL’s earnings sharing mechanism | 20.4 |  |  | 21.9 |  |  | — |  |  | — |  |  | 20.4 |  |  | 21.9 |
Other | 60.6 |  |  | 45.7 |  |  | 46.9 |  |  | 29.3 |  |  | 13.7 |  |  | 16.4 |
|  | $1,371.0 |  |  |  | $1,423.6 |  |  |  | $717.9 |  |  |  | $714.7 |  |  |  | $653.1 |  |  |  | $708.9 |

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