v3.25.2
Commitments and Contingencies - Schedule of Estimated Accrued Costs (Details)
$ in Millions
 6 Months Ended
Jun. 30, 2025
USD ($)
Minnesota and Indiana Gas Service Territories  
Loss Contingencies [Line Items]  
Liability recorded for environmental loss contingencies $ 13
Minnesota and Indiana Gas Service Territories | Minimum  
Loss Contingencies [Line Items]  
Estimated remediation costs $ 8
Years to resolve contingency 5 years
Minnesota and Indiana Gas Service Territories | Maximum  
Loss Contingencies [Line Items]  
Estimated remediation costs $ 47
Years to resolve contingency 50 years
Minnesota Service Territory | CERC  
Loss Contingencies [Line Items]  
Liability recorded for environmental loss contingencies $ 11
Minnesota Service Territory | CERC | Minimum  
Loss Contingencies [Line Items]  
Estimated remediation costs $ 7
Years to resolve contingency 5 years
Minnesota Service Territory | CERC | Maximum  
Loss Contingencies [Line Items]  
Estimated remediation costs $ 41
Years to resolve contingency 50 years