Commitments and Contingencies - Schedule of Estimated Accrued Costs (Details) $ in Millions	6 Months Ended
	Jun. 30, 2022 USD ($)
Minnesota and Indiana Gas Service Territories
Loss Contingencies [Line Items]
Liability recorded for environmental loss contingencies	$ 16
Minnesota and Indiana Gas Service Territories | Minimum
Loss Contingencies [Line Items]
Estimated remediation costs	$ 12
Years to resolve contingency	5 years
Minnesota and Indiana Gas Service Territories | Maximum
Loss Contingencies [Line Items]
Estimated remediation costs	$ 51
Years to resolve contingency	50 years
Minnesota Service Territory | CERC
Loss Contingencies [Line Items]
Liability recorded for environmental loss contingencies	$ 14
Minnesota Service Territory | CERC | Minimum
Loss Contingencies [Line Items]
Estimated remediation costs	$ 11
Years to resolve contingency	5 years
Minnesota Service Territory | CERC | Maximum
Loss Contingencies [Line Items]
Estimated remediation costs	$ 44
Years to resolve contingency	50 years