v3.25.2
Commitments And Contingencies (Tables)
 6 Months Ended
Jun. 30, 2025
Commitments and Contingencies [Line Items]  
Other Purchase Commitments At June 30, 2025, the related minimum future commitments, excluding amounts for purchased power commitments that do not have minimum thresholds but will require payment when electricity is generated by the provider, were as follows (in millions):
Alliant EnergyIPLWPL
Natural gas$783$439$344
Coal1386177
Other (a)1175329
$1,038$553$450

(a)Includes individual commitments incurred during the normal course of business that exceeded $1 million at June 30, 2025.
MGP Site Estimated Future Costs And Recorded Liabilities At June 30, 2025, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, which are not discounted, were as follows (in millions):
Alliant EnergyIPLWPL
Range of estimated future costs$8 
-
$30$6 
-
$19$2 
-
$11
Current and non-current environmental liabilities$13$8$5
IPL [Member]  
Commitments and Contingencies [Line Items]  
Other Purchase Commitments At June 30, 2025, the related minimum future commitments, excluding amounts for purchased power commitments that do not have minimum thresholds but will require payment when electricity is generated by the provider, were as follows (in millions):
Alliant EnergyIPLWPL
Natural gas$783$439$344
Coal1386177
Other (a)1175329
$1,038$553$450

(a)Includes individual commitments incurred during the normal course of business that exceeded $1 million at June 30, 2025.
MGP Site Estimated Future Costs And Recorded Liabilities At June 30, 2025, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, which are not discounted, were as follows (in millions):
Alliant EnergyIPLWPL
Range of estimated future costs$8 
-
$30$6 
-
$19$2 
-
$11
Current and non-current environmental liabilities$13$8$5
WPL [Member]  
Commitments and Contingencies [Line Items]  
Other Purchase Commitments At June 30, 2025, the related minimum future commitments, excluding amounts for purchased power commitments that do not have minimum thresholds but will require payment when electricity is generated by the provider, were as follows (in millions):
Alliant EnergyIPLWPL
Natural gas$783$439$344
Coal1386177
Other (a)1175329
$1,038$553$450

(a)Includes individual commitments incurred during the normal course of business that exceeded $1 million at June 30, 2025.
MGP Site Estimated Future Costs And Recorded Liabilities At June 30, 2025, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, which are not discounted, were as follows (in millions):
Alliant EnergyIPLWPL
Range of estimated future costs$8 
-
$30$6 
-
$19$2 
-
$11
Current and non-current environmental liabilities$13$8$5