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v3.19.2

Regulatory Matters (Tables) | 6 Months Ended
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Jun. 30, 2019
Regulatory Assets [Line Items] |
Regulatory Assets | Regulatory assets were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2019 |  | December 31, 2018 |  | June 30, 2019 |  | December 31, 2018 |  | June 30, 2019 |  | December 31, 2018
Tax-related |  | $815.5 |  |  |  | $820.6 |  |  |  | $780.2 |  |  |  | $783.1 |  |  |  | $35.3 |  |  |  | $37.5 |
Pension and OPEB costs | 522.9 |  |  | 542.3 |  |  | 264.7 |  |  | 274.0 |  |  | 258.2 |  |  | 268.3 |
Asset retirement obligations | 111.0 |  |  | 110.8 |  |  | 76.2 |  |  | 76.3 |  |  | 34.8 |  |  | 34.5 |
IPL’s DAEC PPA amendment | 107.1 |  |  | — |  |  | 107.1 |  |  | — |  |  | — |  |  | — |
EGUs retired early | 102.8 |  |  | 111.6 |  |  | 51.7 |  |  | 55.4 |  |  | 51.1 |  |  | 56.2 |
Derivatives | 30.6 |  |  | 28.0 |  |  | 13.4 |  |  | 15.1 |  |  | 17.2 |  |  | 12.9 |
Emission allowances | 22.4 |  |  | 23.6 |  |  | 22.4 |  |  | 23.6 |  |  | — |  |  | — |
Other | 94.6 |  |  | 100.4 |  |  | 48.8 |  |  | 51.5 |  |  | 45.8 |  |  | 48.9 |
|  | $1,806.9 |  |  |  | $1,737.3 |  |  |  | $1,364.5 |  |  |  | $1,279.0 |  |  |  | $442.4 |  |  |  | $458.3 |
Regulatory Liabilities | Regulatory liabilities were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2019 |  | December 31, 2018 |  | June 30, 2019 |  | December 31, 2018 |  | June 30, 2019 |  | December 31, 2018
Tax-related |  | $853.8 |  |  |  | $890.6 |  |  |  | $365.6 |  |  |  | $390.1 |  |  |  | $488.2 |  |  |  | $500.5 |
Cost of removal obligations | 399.2 |  |  | 401.2 |  |  | 269.5 |  |  | 273.3 |  |  | 129.7 |  |  | 127.9 |
Electric transmission cost recovery | 101.5 |  |  | 104.0 |  |  | 52.7 |  |  | 47.7 |  |  | 48.8 |  |  | 56.3 |
WPL’s earnings sharing mechanism | 25.2 |  |  | 25.4 |  |  | — |  |  | — |  |  | 25.2 |  |  | 25.4 |
Commodity cost recovery | 22.7 |  |  | 16.8 |  |  | 11.9 |  |  | 11.9 |  |  | 10.8 |  |  | 4.9 |
Other | 40.5 |  |  | 55.2 |  |  | 20.2 |  |  | 31.9 |  |  | 20.3 |  |  | 23.3 |
|  | $1,442.9 |  |  |  | $1,493.2 |  |  |  | $719.9 |  |  |  | $754.9 |  |  |  | $723.0 |  |  |  | $738.3 |
IPL [Member] |
Regulatory Assets [Line Items] |
Regulatory Assets | Regulatory assets were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2019 |  | December 31, 2018 |  | June 30, 2019 |  | December 31, 2018 |  | June 30, 2019 |  | December 31, 2018
Tax-related |  | $815.5 |  |  |  | $820.6 |  |  |  | $780.2 |  |  |  | $783.1 |  |  |  | $35.3 |  |  |  | $37.5 |
Pension and OPEB costs | 522.9 |  |  | 542.3 |  |  | 264.7 |  |  | 274.0 |  |  | 258.2 |  |  | 268.3 |
Asset retirement obligations | 111.0 |  |  | 110.8 |  |  | 76.2 |  |  | 76.3 |  |  | 34.8 |  |  | 34.5 |
IPL’s DAEC PPA amendment | 107.1 |  |  | — |  |  | 107.1 |  |  | — |  |  | — |  |  | — |
EGUs retired early | 102.8 |  |  | 111.6 |  |  | 51.7 |  |  | 55.4 |  |  | 51.1 |  |  | 56.2 |
Derivatives | 30.6 |  |  | 28.0 |  |  | 13.4 |  |  | 15.1 |  |  | 17.2 |  |  | 12.9 |
Emission allowances | 22.4 |  |  | 23.6 |  |  | 22.4 |  |  | 23.6 |  |  | — |  |  | — |
Other | 94.6 |  |  | 100.4 |  |  | 48.8 |  |  | 51.5 |  |  | 45.8 |  |  | 48.9 |
|  | $1,806.9 |  |  |  | $1,737.3 |  |  |  | $1,364.5 |  |  |  | $1,279.0 |  |  |  | $442.4 |  |  |  | $458.3 |
Regulatory Liabilities | Regulatory liabilities were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2019 |  | December 31, 2018 |  | June 30, 2019 |  | December 31, 2018 |  | June 30, 2019 |  | December 31, 2018
Tax-related |  | $853.8 |  |  |  | $890.6 |  |  |  | $365.6 |  |  |  | $390.1 |  |  |  | $488.2 |  |  |  | $500.5 |
Cost of removal obligations | 399.2 |  |  | 401.2 |  |  | 269.5 |  |  | 273.3 |  |  | 129.7 |  |  | 127.9 |
Electric transmission cost recovery | 101.5 |  |  | 104.0 |  |  | 52.7 |  |  | 47.7 |  |  | 48.8 |  |  | 56.3 |
WPL’s earnings sharing mechanism | 25.2 |  |  | 25.4 |  |  | — |  |  | — |  |  | 25.2 |  |  | 25.4 |
Commodity cost recovery | 22.7 |  |  | 16.8 |  |  | 11.9 |  |  | 11.9 |  |  | 10.8 |  |  | 4.9 |
Other | 40.5 |  |  | 55.2 |  |  | 20.2 |  |  | 31.9 |  |  | 20.3 |  |  | 23.3 |
|  | $1,442.9 |  |  |  | $1,493.2 |  |  |  | $719.9 |  |  |  | $754.9 |  |  |  | $723.0 |  |  |  | $738.3 |
WPL [Member] |
Regulatory Assets [Line Items] |
Regulatory Assets | Regulatory assets were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2019 |  | December 31, 2018 |  | June 30, 2019 |  | December 31, 2018 |  | June 30, 2019 |  | December 31, 2018
Tax-related |  | $815.5 |  |  |  | $820.6 |  |  |  | $780.2 |  |  |  | $783.1 |  |  |  | $35.3 |  |  |  | $37.5 |
Pension and OPEB costs | 522.9 |  |  | 542.3 |  |  | 264.7 |  |  | 274.0 |  |  | 258.2 |  |  | 268.3 |
Asset retirement obligations | 111.0 |  |  | 110.8 |  |  | 76.2 |  |  | 76.3 |  |  | 34.8 |  |  | 34.5 |
IPL’s DAEC PPA amendment | 107.1 |  |  | — |  |  | 107.1 |  |  | — |  |  | — |  |  | — |
EGUs retired early | 102.8 |  |  | 111.6 |  |  | 51.7 |  |  | 55.4 |  |  | 51.1 |  |  | 56.2 |
Derivatives | 30.6 |  |  | 28.0 |  |  | 13.4 |  |  | 15.1 |  |  | 17.2 |  |  | 12.9 |
Emission allowances | 22.4 |  |  | 23.6 |  |  | 22.4 |  |  | 23.6 |  |  | — |  |  | — |
Other | 94.6 |  |  | 100.4 |  |  | 48.8 |  |  | 51.5 |  |  | 45.8 |  |  | 48.9 |
|  | $1,806.9 |  |  |  | $1,737.3 |  |  |  | $1,364.5 |  |  |  | $1,279.0 |  |  |  | $442.4 |  |  |  | $458.3 |
Regulatory Liabilities | Regulatory liabilities were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2019 |  | December 31, 2018 |  | June 30, 2019 |  | December 31, 2018 |  | June 30, 2019 |  | December 31, 2018
Tax-related |  | $853.8 |  |  |  | $890.6 |  |  |  | $365.6 |  |  |  | $390.1 |  |  |  | $488.2 |  |  |  | $500.5 |
Cost of removal obligations | 399.2 |  |  | 401.2 |  |  | 269.5 |  |  | 273.3 |  |  | 129.7 |  |  | 127.9 |
Electric transmission cost recovery | 101.5 |  |  | 104.0 |  |  | 52.7 |  |  | 47.7 |  |  | 48.8 |  |  | 56.3 |
WPL’s earnings sharing mechanism | 25.2 |  |  | 25.4 |  |  | — |  |  | — |  |  | 25.2 |  |  | 25.4 |
Commodity cost recovery | 22.7 |  |  | 16.8 |  |  | 11.9 |  |  | 11.9 |  |  | 10.8 |  |  | 4.9 |
Other | 40.5 |  |  | 55.2 |  |  | 20.2 |  |  | 31.9 |  |  | 20.3 |  |  | 23.3 |
|  | $1,442.9 |  |  |  | $1,493.2 |  |  |  | $719.9 |  |  |  | $754.9 |  |  |  | $723.0 |  |  |  | $738.3 |

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