Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2022

Statement [Line Items]

Fair Value Measurements

Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions):

Alliant Energy	June 30, 2022					December 31, 2021
		Fair Value					Fair Value
	Carrying	Level	Level	Level		Carrying	Level	Level	Level
	Amount	1	2	3	Total	Amount	1	2	3	Total
Assets:
Money market fund investments	$9	$9	$—	$—	$9	$32	$32	$—	$—	$32
Derivatives	359	—	272	87	359	176	—	146	30	176
Deferred proceeds	244	—	—	244	244	214	—	—	214	214
Liabilities:
Derivatives	95	—	80	15	95	9	—	8	1	9
Long-term debt (incl. current maturities)	7,714	—	7,402	1	7,403	7,368	—	8,329	1	8,330

IPL	June 30, 2022					December 31, 2021
		Fair Value					Fair Value
	Carrying	Level	Level	Level		Carrying	Level	Level	Level
	Amount	1	2	3	Total	Amount	1	2	3	Total
Assets:
Money market fund investments	$9	$9	$—	$—	$9	$32	$32	$—	$—	$32
Derivatives	207	—	138	69	207	84	—	65	19	84
Deferred proceeds	244	—	—	244	244	214	—	—	214	214
Liabilities:
Derivatives	67	—	56	11	67	4	—	3	1	4
Long-term debt	3,645	—	3,445	—	3,445	3,643	—	4,124	—	4,124

WPL	June 30, 2022					December 31, 2021
		Fair Value					Fair Value
	Carrying	Level	Level	Level		Carrying	Level	Level	Level
	Amount	1	2	3	Total	Amount	1	2	3	Total
Assets:
Derivatives	$152	$—	$134	$18	$152	$92	$—	$81	$11	$92
Liabilities:
Derivatives	28	—	24	4	28	5	—	5	—	5
Long-term debt (incl. current maturities)	2,430	—	2,370	—	2,370	2,429	—	2,862	—	2,862

Fair Value Measurements Using Significant Unobservable Inputs

Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions):

Alliant Energy	Commodity Contract Derivative
	Assets and (Liabilities), net		Deferred Proceeds
Three Months Ended June 30	2022	2021	2022	2021
Beginning balance, April 1	$10	$15	$227	$107
Total net gains (losses) included in changes in net assets (realized/unrealized)	(10)	8	—	—
Purchases	79	21	—	—
Settlements (a)	(7)	(5)	17	47
Ending balance, June 30	$72	$39	$244	$154
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30	($10)	$8	$—	$—

Alliant Energy	Commodity Contract Derivative
	Assets and (Liabilities), net		Deferred Proceeds
Six Months Ended June 30	2022	2021	2022	2021
Beginning balance, January 1	$29	$29	$214	$188
Total net gains (losses) included in changes in net assets (realized/unrealized)	(16)	1	—	—
Purchases	79	21	—	—
Settlements (a)	(20)	(12)	30	(34)
Ending balance, June 30	$72	$39	$244	$154
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30	($16)	$1	$—	$—

IPL	Commodity Contract Derivative
	Assets and (Liabilities), net		Deferred Proceeds
Three Months Ended June 30	2022	2021	2022	2021
Beginning balance, April 1	$7	$14	$227	$107
Total net gains (losses) included in changes in net assets (realized/unrealized)	(3)	4	—	—
Purchases	58	16	—	—
Settlements (a)	(4)	(4)	17	47
Ending balance, June 30	$58	$30	$244	$154
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30	($3)	$4	$—	$—

IPL	Commodity Contract Derivative
	Assets and (Liabilities), net		Deferred Proceeds
Six Months Ended June 30	2022	2021	2022	2021
Beginning balance, January 1	$18	$26	$214	$188
Total net losses included in changes in net assets (realized/unrealized)	(7)	(2)	—	—
Purchases	58	16	—	—
Settlements (a)	(11)	(10)	30	(34)
Ending balance, June 30	$58	$30	$244	$154
The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at June 30	($8)	($2)	$—	$—

WPL	Commodity Contract Derivative
	Assets and (Liabilities), net
Three Months Ended June 30	2022	2021
Beginning balance, April 1	$3	$1
Total net gains (losses) included in changes in net assets (realized/unrealized)	(7)	4
Purchases	21	5
Settlements	(3)	(1)
Ending balance, June 30	$14	$9
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30	($7)	$4

WPL	Commodity Contract Derivative
	Assets and (Liabilities), net
Six Months Ended June 30	2022	2021
Beginning balance, January 1	$11	$3
Total net gains (losses) included in changes in net assets (realized/unrealized)	(9)	3
Purchases	21	5
Settlements	(9)	(2)
Ending balance, June 30	$14	$9
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30	($8)	$3

(a)Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for expected credit losses associated with the receivables sold and cash amounts received from the receivables sold.

Fair Value Of Net Derivative Assets (Liabilities)

The fair value of FTR and natural gas commodity contracts categorized as Level 3 was recognized as net derivative assets (liabilities) as follows (in millions):

	Alliant Energy		IPL		WPL
	Excluding FTRs	FTRs	Excluding FTRs	FTRs	Excluding FTRs	FTRs
June 30, 2022	($11)	$83	($8)	$66	($3)	$17
December 31, 2021	9	20	8	10	1	10

IPL [Member]

Statement [Line Items]

Fair Value Measurements

Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions):

Alliant Energy	June 30, 2022					December 31, 2021
		Fair Value					Fair Value
	Carrying	Level	Level	Level		Carrying	Level	Level	Level
	Amount	1	2	3	Total	Amount	1	2	3	Total
Assets:
Money market fund investments	$9	$9	$—	$—	$9	$32	$32	$—	$—	$32
Derivatives	359	—	272	87	359	176	—	146	30	176
Deferred proceeds	244	—	—	244	244	214	—	—	214	214
Liabilities:
Derivatives	95	—	80	15	95	9	—	8	1	9
Long-term debt (incl. current maturities)	7,714	—	7,402	1	7,403	7,368	—	8,329	1	8,330

IPL	June 30, 2022					December 31, 2021
		Fair Value					Fair Value
	Carrying	Level	Level	Level		Carrying	Level	Level	Level
	Amount	1	2	3	Total	Amount	1	2	3	Total
Assets:
Money market fund investments	$9	$9	$—	$—	$9	$32	$32	$—	$—	$32
Derivatives	207	—	138	69	207	84	—	65	19	84
Deferred proceeds	244	—	—	244	244	214	—	—	214	214
Liabilities:
Derivatives	67	—	56	11	67	4	—	3	1	4
Long-term debt	3,645	—	3,445	—	3,445	3,643	—	4,124	—	4,124

WPL	June 30, 2022					December 31, 2021
		Fair Value					Fair Value
	Carrying	Level	Level	Level		Carrying	Level	Level	Level
	Amount	1	2	3	Total	Amount	1	2	3	Total
Assets:
Derivatives	$152	$—	$134	$18	$152	$92	$—	$81	$11	$92
Liabilities:
Derivatives	28	—	24	4	28	5	—	5	—	5
Long-term debt (incl. current maturities)	2,430	—	2,370	—	2,370	2,429	—	2,862	—	2,862

Fair Value Measurements Using Significant Unobservable Inputs

Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions):

Alliant Energy	Commodity Contract Derivative
	Assets and (Liabilities), net		Deferred Proceeds
Three Months Ended June 30	2022	2021	2022	2021
Beginning balance, April 1	$10	$15	$227	$107
Total net gains (losses) included in changes in net assets (realized/unrealized)	(10)	8	—	—
Purchases	79	21	—	—
Settlements (a)	(7)	(5)	17	47
Ending balance, June 30	$72	$39	$244	$154
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30	($10)	$8	$—	$—

Alliant Energy	Commodity Contract Derivative
	Assets and (Liabilities), net		Deferred Proceeds
Six Months Ended June 30	2022	2021	2022	2021
Beginning balance, January 1	$29	$29	$214	$188
Total net gains (losses) included in changes in net assets (realized/unrealized)	(16)	1	—	—
Purchases	79	21	—	—
Settlements (a)	(20)	(12)	30	(34)
Ending balance, June 30	$72	$39	$244	$154
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30	($16)	$1	$—	$—

IPL	Commodity Contract Derivative
	Assets and (Liabilities), net		Deferred Proceeds
Three Months Ended June 30	2022	2021	2022	2021
Beginning balance, April 1	$7	$14	$227	$107
Total net gains (losses) included in changes in net assets (realized/unrealized)	(3)	4	—	—
Purchases	58	16	—	—
Settlements (a)	(4)	(4)	17	47
Ending balance, June 30	$58	$30	$244	$154
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30	($3)	$4	$—	$—

IPL	Commodity Contract Derivative
	Assets and (Liabilities), net		Deferred Proceeds
Six Months Ended June 30	2022	2021	2022	2021
Beginning balance, January 1	$18	$26	$214	$188
Total net losses included in changes in net assets (realized/unrealized)	(7)	(2)	—	—
Purchases	58	16	—	—
Settlements (a)	(11)	(10)	30	(34)
Ending balance, June 30	$58	$30	$244	$154
The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at June 30	($8)	($2)	$—	$—

WPL	Commodity Contract Derivative
	Assets and (Liabilities), net
Three Months Ended June 30	2022	2021
Beginning balance, April 1	$3	$1
Total net gains (losses) included in changes in net assets (realized/unrealized)	(7)	4
Purchases	21	5
Settlements	(3)	(1)
Ending balance, June 30	$14	$9
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30	($7)	$4

WPL	Commodity Contract Derivative
	Assets and (Liabilities), net
Six Months Ended June 30	2022	2021
Beginning balance, January 1	$11	$3
Total net gains (losses) included in changes in net assets (realized/unrealized)	(9)	3
Purchases	21	5
Settlements	(9)	(2)
Ending balance, June 30	$14	$9
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30	($8)	$3

(a)Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for expected credit losses associated with the receivables sold and cash amounts received from the receivables sold.

Fair Value Of Net Derivative Assets (Liabilities)

The fair value of FTR and natural gas commodity contracts categorized as Level 3 was recognized as net derivative assets (liabilities) as follows (in millions):

	Alliant Energy		IPL		WPL
	Excluding FTRs	FTRs	Excluding FTRs	FTRs	Excluding FTRs	FTRs
June 30, 2022	($11)	$83	($8)	$66	($3)	$17
December 31, 2021	9	20	8	10	1	10

WPL [Member]

Statement [Line Items]

Fair Value Measurements

Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions):

Alliant Energy	June 30, 2022					December 31, 2021
		Fair Value					Fair Value
	Carrying	Level	Level	Level		Carrying	Level	Level	Level
	Amount	1	2	3	Total	Amount	1	2	3	Total
Assets:
Money market fund investments	$9	$9	$—	$—	$9	$32	$32	$—	$—	$32
Derivatives	359	—	272	87	359	176	—	146	30	176
Deferred proceeds	244	—	—	244	244	214	—	—	214	214
Liabilities:
Derivatives	95	—	80	15	95	9	—	8	1	9
Long-term debt (incl. current maturities)	7,714	—	7,402	1	7,403	7,368	—	8,329	1	8,330

IPL	June 30, 2022					December 31, 2021
		Fair Value					Fair Value
	Carrying	Level	Level	Level		Carrying	Level	Level	Level
	Amount	1	2	3	Total	Amount	1	2	3	Total
Assets:
Money market fund investments	$9	$9	$—	$—	$9	$32	$32	$—	$—	$32
Derivatives	207	—	138	69	207	84	—	65	19	84
Deferred proceeds	244	—	—	244	244	214	—	—	214	214
Liabilities:
Derivatives	67	—	56	11	67	4	—	3	1	4
Long-term debt	3,645	—	3,445	—	3,445	3,643	—	4,124	—	4,124

WPL	June 30, 2022					December 31, 2021
		Fair Value					Fair Value
	Carrying	Level	Level	Level		Carrying	Level	Level	Level
	Amount	1	2	3	Total	Amount	1	2	3	Total
Assets:
Derivatives	$152	$—	$134	$18	$152	$92	$—	$81	$11	$92
Liabilities:
Derivatives	28	—	24	4	28	5	—	5	—	5
Long-term debt (incl. current maturities)	2,430	—	2,370	—	2,370	2,429	—	2,862	—	2,862

Fair Value Measurements Using Significant Unobservable Inputs

Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions):

Alliant Energy	Commodity Contract Derivative
	Assets and (Liabilities), net		Deferred Proceeds
Three Months Ended June 30	2022	2021	2022	2021
Beginning balance, April 1	$10	$15	$227	$107
Total net gains (losses) included in changes in net assets (realized/unrealized)	(10)	8	—	—
Purchases	79	21	—	—
Settlements (a)	(7)	(5)	17	47
Ending balance, June 30	$72	$39	$244	$154
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30	($10)	$8	$—	$—

Alliant Energy	Commodity Contract Derivative
	Assets and (Liabilities), net		Deferred Proceeds
Six Months Ended June 30	2022	2021	2022	2021
Beginning balance, January 1	$29	$29	$214	$188
Total net gains (losses) included in changes in net assets (realized/unrealized)	(16)	1	—	—
Purchases	79	21	—	—
Settlements (a)	(20)	(12)	30	(34)
Ending balance, June 30	$72	$39	$244	$154
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30	($16)	$1	$—	$—

IPL	Commodity Contract Derivative
	Assets and (Liabilities), net		Deferred Proceeds
Three Months Ended June 30	2022	2021	2022	2021
Beginning balance, April 1	$7	$14	$227	$107
Total net gains (losses) included in changes in net assets (realized/unrealized)	(3)	4	—	—
Purchases	58	16	—	—
Settlements (a)	(4)	(4)	17	47
Ending balance, June 30	$58	$30	$244	$154
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30	($3)	$4	$—	$—

IPL	Commodity Contract Derivative
	Assets and (Liabilities), net		Deferred Proceeds
Six Months Ended June 30	2022	2021	2022	2021
Beginning balance, January 1	$18	$26	$214	$188
Total net losses included in changes in net assets (realized/unrealized)	(7)	(2)	—	—
Purchases	58	16	—	—
Settlements (a)	(11)	(10)	30	(34)
Ending balance, June 30	$58	$30	$244	$154
The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at June 30	($8)	($2)	$—	$—

WPL	Commodity Contract Derivative
	Assets and (Liabilities), net
Three Months Ended June 30	2022	2021
Beginning balance, April 1	$3	$1
Total net gains (losses) included in changes in net assets (realized/unrealized)	(7)	4
Purchases	21	5
Settlements	(3)	(1)
Ending balance, June 30	$14	$9
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30	($7)	$4

WPL	Commodity Contract Derivative
	Assets and (Liabilities), net
Six Months Ended June 30	2022	2021
Beginning balance, January 1	$11	$3
Total net gains (losses) included in changes in net assets (realized/unrealized)	(9)	3
Purchases	21	5
Settlements	(9)	(2)
Ending balance, June 30	$14	$9
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30	($8)	$3

(a)Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for expected credit losses associated with the receivables sold and cash amounts received from the receivables sold.

Fair Value Of Net Derivative Assets (Liabilities)

The fair value of FTR and natural gas commodity contracts categorized as Level 3 was recognized as net derivative assets (liabilities) as follows (in millions):

	Alliant Energy		IPL		WPL
	Excluding FTRs	FTRs	Excluding FTRs	FTRs	Excluding FTRs	FTRs
June 30, 2022	($11)	$83	($8)	$66	($3)	$17
December 31, 2021	9	20	8	10	1	10