Commitments and Contingencies - Estimated Range of Possible Remediation Costs (Details) - Minnesota and Indiana Gas Service Territories $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($)
Loss Contingencies [Line Items]
Amount accrued for remediation	$ 16
Minimum
Loss Contingencies [Line Items]
Site Contingency Loss Exposure	$ 12
Years to resolve contingency	5 years
Maximum
Loss Contingencies [Line Items]
Site Contingency Loss Exposure	$ 51
Years to resolve contingency	50 years
CERC Corp
Loss Contingencies [Line Items]
Amount accrued for remediation	$ 14
CERC Corp | Minimum
Loss Contingencies [Line Items]
Site Contingency Loss Exposure	$ 11
Years to resolve contingency	5 years
CERC Corp | Maximum
Loss Contingencies [Line Items]
Site Contingency Loss Exposure	$ 44
Years to resolve contingency	50 years