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Derivative Instruments (Tables) | 12 Months Ended
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Dec. 31, 2021
Derivative [Line Items] |
Notional Amounts of Derivative Instruments | As of December 31, 2021, gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts and FTRs that were accounted for as commodity derivative instruments were as follows (units in thousands):
|  |  | FTRs |  | Natural Gas |  | Coal |  | Diesel Fuel
|  |  |  |  | MWhs |  | Years |  | Dths |  | Years |  | Tons |  | Years |  | Gallons |  | Years
Alliant Energy |  |  |  |  | 9,135 |  |  | 2022 |  | 191,670 |  |  | 2022-2030 |  | 3,193 |  |  | 2022-2023 |  | 3,024 |  |  | 2022
IPL |  |  |  |  | 2,647 |  |  | 2022 |  | 100,560 |  |  | 2022-2030 |  | 1,270 |  |  | 2022-2023 |  | — |  |  | —
WPL |  |  |  |  | 6,488 |  |  | 2022 |  | 91,110 |  |  | 2022-2030 |  | 1,923 |  |  | 2022-2023 |  | 3,024 |  |  | 2022
Fair Value of Financial Instruments | At December 31, the fair values of current derivative assets are included in “Other current assets,” non-current derivative assets are included in “Deferred charges and other,” current derivative liabilities are included in “Other current liabilities” and non-current derivative liabilities are included in “Other liabilities” on the balance sheets as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
| 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Current derivative assets | $113 |  | $24 |  | $48 |  | $20 |  | $65 |  | $4
Non-current derivative assets | 63 |  | 10 |  | 36 |  | 9 |  | 27 |  | 1
Current derivative liabilities | 8 |  | 9 |  | 4 |  | 3 |  | 4 |  | 6
Non-current derivative liabilities | 1 |  | 16 |  | — |  | 9 |  | 1 |  | 7
IPL [Member] |
Derivative [Line Items] |
Notional Amounts of Derivative Instruments | As of December 31, 2021, gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts and FTRs that were accounted for as commodity derivative instruments were as follows (units in thousands):
|  |  | FTRs |  | Natural Gas |  | Coal |  | Diesel Fuel
|  |  |  |  | MWhs |  | Years |  | Dths |  | Years |  | Tons |  | Years |  | Gallons |  | Years
Alliant Energy |  |  |  |  | 9,135 |  |  | 2022 |  | 191,670 |  |  | 2022-2030 |  | 3,193 |  |  | 2022-2023 |  | 3,024 |  |  | 2022
IPL |  |  |  |  | 2,647 |  |  | 2022 |  | 100,560 |  |  | 2022-2030 |  | 1,270 |  |  | 2022-2023 |  | — |  |  | —
WPL |  |  |  |  | 6,488 |  |  | 2022 |  | 91,110 |  |  | 2022-2030 |  | 1,923 |  |  | 2022-2023 |  | 3,024 |  |  | 2022
Fair Value of Financial Instruments | At December 31, the fair values of current derivative assets are included in “Other current assets,” non-current derivative assets are included in “Deferred charges and other,” current derivative liabilities are included in “Other current liabilities” and non-current derivative liabilities are included in “Other liabilities” on the balance sheets as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
| 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Current derivative assets | $113 |  | $24 |  | $48 |  | $20 |  | $65 |  | $4
Non-current derivative assets | 63 |  | 10 |  | 36 |  | 9 |  | 27 |  | 1
Current derivative liabilities | 8 |  | 9 |  | 4 |  | 3 |  | 4 |  | 6
Non-current derivative liabilities | 1 |  | 16 |  | — |  | 9 |  | 1 |  | 7
WPL [Member] |
Derivative [Line Items] |
Notional Amounts of Derivative Instruments | As of December 31, 2021, gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts and FTRs that were accounted for as commodity derivative instruments were as follows (units in thousands):
|  |  | FTRs |  | Natural Gas |  | Coal |  | Diesel Fuel
|  |  |  |  | MWhs |  | Years |  | Dths |  | Years |  | Tons |  | Years |  | Gallons |  | Years
Alliant Energy |  |  |  |  | 9,135 |  |  | 2022 |  | 191,670 |  |  | 2022-2030 |  | 3,193 |  |  | 2022-2023 |  | 3,024 |  |  | 2022
IPL |  |  |  |  | 2,647 |  |  | 2022 |  | 100,560 |  |  | 2022-2030 |  | 1,270 |  |  | 2022-2023 |  | — |  |  | —
WPL |  |  |  |  | 6,488 |  |  | 2022 |  | 91,110 |  |  | 2022-2030 |  | 1,923 |  |  | 2022-2023 |  | 3,024 |  |  | 2022
Fair Value of Financial Instruments | At December 31, the fair values of current derivative assets are included in “Other current assets,” non-current derivative assets are included in “Deferred charges and other,” current derivative liabilities are included in “Other current liabilities” and non-current derivative liabilities are included in “Other liabilities” on the balance sheets as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
| 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Current derivative assets | $113 |  | $24 |  | $48 |  | $20 |  | $65 |  | $4
Non-current derivative assets | 63 |  | 10 |  | 36 |  | 9 |  | 27 |  | 1
Current derivative liabilities | 8 |  | 9 |  | 4 |  | 3 |  | 4 |  | 6
Non-current derivative liabilities | 1 |  | 16 |  | — |  | 9 |  | 1 |  | 7

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