XML 37 R17.htm IDEA: XBRL DOCUMENT v3.24.1.u1
Fair Value Measurements
3 Months Ended
Mar. 31, 2024
Fair Value Measurements FAIR VALUE MEASUREMENTS
Fair Value of Financial Instruments - The carrying amounts of current assets and current liabilities approximate fair value because of the short maturity of such financial instruments. Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions):
Alliant EnergyMarch 31, 2024December 31, 2023
Fair ValueFair Value
CarryingLevelLevelLevelCarryingLevelLevelLevel
Amount123TotalAmount123Total
Assets:
Money market fund investments$10 $10 $— $— $10 $45 $45 $— $— $45 
Commodity derivatives56  46 10 56 88 — 59 29 88 
Interest rate derivatives3  3  3 — — 
Deferred proceeds184   184 184 216 — — 216 216 
Liabilities:
Commodity derivatives94  91 3 94 98 — 93 98 
Long-term debt (incl. current maturities)9,333  9,051  9,051 9,034 — 8,677 — 8,677 
IPLMarch 31, 2024December 31, 2023
Fair ValueFair Value
CarryingLevelLevelLevelCarryingLevelLevelLevel
Amount123TotalAmount123Total
Assets:
Money market fund investments$6 $6 $— $— $6 $45 $45 $— $— $45 
Commodity derivatives34  26 8 34 54 — 30 24 54 
Deferred proceeds184   184 184 216 — — 216 216 
Liabilities:
Commodity derivatives30  27 3 30 30 — 25 30 
Long-term debt (incl. current maturities)3,945  3,607  3,607 3,945 — 3,664 — 3,664 
WPLMarch 31, 2024December 31, 2023
Fair ValueFair Value
CarryingLevelLevelLevelCarryingLevelLevelLevel
Amount123TotalAmount123Total
Assets:
Commodity derivatives$22 $— $20 $2 $22 $34 $— $29 $5 $34 
Liabilities:
Commodity derivatives64  64  64 68 — 68 — 68 
Long-term debt3,367  3,176  3,176 3,070 — 2,933 — 2,933 

Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions):
Alliant EnergyCommodity Contract Derivative
Assets and (Liabilities), netDeferred Proceeds
Three Months Ended March 312024202320242023
Beginning balance, January 1 $24$19$216$185
Total net losses included in changes in net assets (realized/unrealized)(3)(4)
Settlements (a)(14)(20)(32)(32)
Ending balance, March 31
$7($5)$184$153
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 March 31
($3)($4)$—$—
IPLCommodity Contract Derivative
Assets and (Liabilities), netDeferred Proceeds
Three Months Ended March 312024202320242023
Beginning balance, January 1 $19$16$216$185
Total net gains (losses) included in changes in net assets (realized/unrealized)
(4)1
Settlements (a)(10)(17)(32)(32)
Ending balance, March 31
$5$—$184$153
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 March 31
($4)$1$—$—
WPLCommodity Contract Derivative
Assets and (Liabilities), net
Three Months Ended March 3120242023
Beginning balance, January 1 $5$3
Total net gains (losses) included in changes in net assets (realized/unrealized)
1(5)
Settlements(4)(3)
Ending balance, March 31
$2($5)
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 March 31
$1($5)
(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.

Commodity Contracts - 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 EnergyIPLWPL
Excluding FTRsFTRsExcluding FTRsFTRsExcluding FTRsFTRs
March 31, 2024($1)$8($1)$6$—$2
December 31, 20233213165
IPL [Member]  
Fair Value Measurements FAIR VALUE MEASUREMENTS
Fair Value of Financial Instruments - The carrying amounts of current assets and current liabilities approximate fair value because of the short maturity of such financial instruments. Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions):
Alliant EnergyMarch 31, 2024December 31, 2023
Fair ValueFair Value
CarryingLevelLevelLevelCarryingLevelLevelLevel
Amount123TotalAmount123Total
Assets:
Money market fund investments$10 $10 $— $— $10 $45 $45 $— $— $45 
Commodity derivatives56  46 10 56 88 — 59 29 88 
Interest rate derivatives3  3  3 — — 
Deferred proceeds184   184 184 216 — — 216 216 
Liabilities:
Commodity derivatives94  91 3 94 98 — 93 98 
Long-term debt (incl. current maturities)9,333  9,051  9,051 9,034 — 8,677 — 8,677 
IPLMarch 31, 2024December 31, 2023
Fair ValueFair Value
CarryingLevelLevelLevelCarryingLevelLevelLevel
Amount123TotalAmount123Total
Assets:
Money market fund investments$6 $6 $— $— $6 $45 $45 $— $— $45 
Commodity derivatives34  26 8 34 54 — 30 24 54 
Deferred proceeds184   184 184 216 — — 216 216 
Liabilities:
Commodity derivatives30  27 3 30 30 — 25 30 
Long-term debt (incl. current maturities)3,945  3,607  3,607 3,945 — 3,664 — 3,664 
WPLMarch 31, 2024December 31, 2023
Fair ValueFair Value
CarryingLevelLevelLevelCarryingLevelLevelLevel
Amount123TotalAmount123Total
Assets:
Commodity derivatives$22 $— $20 $2 $22 $34 $— $29 $5 $34 
Liabilities:
Commodity derivatives64  64  64 68 — 68 — 68 
Long-term debt3,367  3,176  3,176 3,070 — 2,933 — 2,933 

Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions):
Alliant EnergyCommodity Contract Derivative
Assets and (Liabilities), netDeferred Proceeds
Three Months Ended March 312024202320242023
Beginning balance, January 1 $24$19$216$185
Total net losses included in changes in net assets (realized/unrealized)(3)(4)
Settlements (a)(14)(20)(32)(32)
Ending balance, March 31
$7($5)$184$153
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 March 31
($3)($4)$—$—
IPLCommodity Contract Derivative
Assets and (Liabilities), netDeferred Proceeds
Three Months Ended March 312024202320242023
Beginning balance, January 1 $19$16$216$185
Total net gains (losses) included in changes in net assets (realized/unrealized)
(4)1
Settlements (a)(10)(17)(32)(32)
Ending balance, March 31
$5$—$184$153
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 March 31
($4)$1$—$—
WPLCommodity Contract Derivative
Assets and (Liabilities), net
Three Months Ended March 3120242023
Beginning balance, January 1 $5$3
Total net gains (losses) included in changes in net assets (realized/unrealized)
1(5)
Settlements(4)(3)
Ending balance, March 31
$2($5)
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 March 31
$1($5)
(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.

Commodity Contracts - 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 EnergyIPLWPL
Excluding FTRsFTRsExcluding FTRsFTRsExcluding FTRsFTRs
March 31, 2024($1)$8($1)$6$—$2
December 31, 20233213165
WPL [Member]  
Fair Value Measurements FAIR VALUE MEASUREMENTS
Fair Value of Financial Instruments - The carrying amounts of current assets and current liabilities approximate fair value because of the short maturity of such financial instruments. Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions):
Alliant EnergyMarch 31, 2024December 31, 2023
Fair ValueFair Value
CarryingLevelLevelLevelCarryingLevelLevelLevel
Amount123TotalAmount123Total
Assets:
Money market fund investments$10 $10 $— $— $10 $45 $45 $— $— $45 
Commodity derivatives56  46 10 56 88 — 59 29 88 
Interest rate derivatives3  3  3 — — 
Deferred proceeds184   184 184 216 — — 216 216 
Liabilities:
Commodity derivatives94  91 3 94 98 — 93 98 
Long-term debt (incl. current maturities)9,333  9,051  9,051 9,034 — 8,677 — 8,677 
IPLMarch 31, 2024December 31, 2023
Fair ValueFair Value
CarryingLevelLevelLevelCarryingLevelLevelLevel
Amount123TotalAmount123Total
Assets:
Money market fund investments$6 $6 $— $— $6 $45 $45 $— $— $45 
Commodity derivatives34  26 8 34 54 — 30 24 54 
Deferred proceeds184   184 184 216 — — 216 216 
Liabilities:
Commodity derivatives30  27 3 30 30 — 25 30 
Long-term debt (incl. current maturities)3,945  3,607  3,607 3,945 — 3,664 — 3,664 
WPLMarch 31, 2024December 31, 2023
Fair ValueFair Value
CarryingLevelLevelLevelCarryingLevelLevelLevel
Amount123TotalAmount123Total
Assets:
Commodity derivatives$22 $— $20 $2 $22 $34 $— $29 $5 $34 
Liabilities:
Commodity derivatives64  64  64 68 — 68 — 68 
Long-term debt3,367  3,176  3,176 3,070 — 2,933 — 2,933 

Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions):
Alliant EnergyCommodity Contract Derivative
Assets and (Liabilities), netDeferred Proceeds
Three Months Ended March 312024202320242023
Beginning balance, January 1 $24$19$216$185
Total net losses included in changes in net assets (realized/unrealized)(3)(4)
Settlements (a)(14)(20)(32)(32)
Ending balance, March 31
$7($5)$184$153
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 March 31
($3)($4)$—$—
IPLCommodity Contract Derivative
Assets and (Liabilities), netDeferred Proceeds
Three Months Ended March 312024202320242023
Beginning balance, January 1 $19$16$216$185
Total net gains (losses) included in changes in net assets (realized/unrealized)
(4)1
Settlements (a)(10)(17)(32)(32)
Ending balance, March 31
$5$—$184$153
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 March 31
($4)$1$—$—
WPLCommodity Contract Derivative
Assets and (Liabilities), net
Three Months Ended March 3120242023
Beginning balance, January 1 $5$3
Total net gains (losses) included in changes in net assets (realized/unrealized)
1(5)
Settlements(4)(3)
Ending balance, March 31
$2($5)
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 March 31
$1($5)
(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.

Commodity Contracts - 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 EnergyIPLWPL
Excluding FTRsFTRsExcluding FTRsFTRsExcluding FTRsFTRs
March 31, 2024($1)$8($1)$6$—$2
December 31, 20233213165