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Derivative Instruments (Tables)

12 Months Ended

Dec. 31, 2020

Derivative [Line Items]

Notional Amounts of Derivative Instruments

As of December 31, 2020, 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															9,285						2021						208,542						2021-2028						5,648						2021-2023						5,544						2021-2022
IPL															3,398						2021						109,063						2021-2028						2,548						2021-2023						—						—
WPL															5,887						2021						99,479						2021-2027						3,100						2021-2023						5,544						2021-2022

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
			2020						2019						2020						2019						2020						2019
Current derivative assets			$24						$16						$20						$12						$4						$4
Non-current derivative assets			10						11						9						10						1						1
Current derivative liabilities			9						19						3						9						6						10
Non-current derivative liabilities			16						19						9						9						7						10

IPL [Member]

Derivative [Line Items]

Notional Amounts of Derivative Instruments

As of December 31, 2020, 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															9,285						2021						208,542						2021-2028						5,648						2021-2023						5,544						2021-2022
IPL															3,398						2021						109,063						2021-2028						2,548						2021-2023						—						—
WPL															5,887						2021						99,479						2021-2027						3,100						2021-2023						5,544						2021-2022

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
			2020						2019						2020						2019						2020						2019
Current derivative assets			$24						$16						$20						$12						$4						$4
Non-current derivative assets			10						11						9						10						1						1
Current derivative liabilities			9						19						3						9						6						10
Non-current derivative liabilities			16						19						9						9						7						10

WPL [Member]

Derivative [Line Items]

Notional Amounts of Derivative Instruments

As of December 31, 2020, 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															9,285						2021						208,542						2021-2028						5,648						2021-2023						5,544						2021-2022
IPL															3,398						2021						109,063						2021-2028						2,548						2021-2023						—						—
WPL															5,887						2021						99,479						2021-2027						3,100						2021-2023						5,544						2021-2022

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
			2020						2019						2020						2019						2020						2019
Current derivative assets			$24						$16						$20						$12						$4						$4
Non-current derivative assets			10						11						9						10						1						1
Current derivative liabilities			9						19						3						9						6						10
Non-current derivative liabilities			16						19						9						9						7						10

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Tabular disclosure of the location and fair value amounts of derivative instruments (and nonderivative instruments that are designated and qualify as hedging instruments) reported in the statement of financial position.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
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Tabular disclosure of the notional amounts of outstanding derivative positions.

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-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
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