Background and Basis of Presentation (Details)	6 Months Ended
	Jun. 30, 2021 registrant state publicUtilityCompany shares
Number of registrants | registrant	3
Enable Midstream Partners
Ownership percentage of equity method investment	100.00%
Enable Midstream Partners | Variable Interest Entity, Not Primary Beneficiary
Ownership percentage of equity method investment	53.70%
Enable Midstream Partners | Series A Preferred Units
Preferred units held (in shares) | shares	14,520,000
Natural Gas
Number of states in which the entity performs gas delivery services	48
CERC Corp | Natural Gas
Number of states in which entity operates	6
Number of states in which the entity performs gas delivery services	48
Vectren
Number of owned and operated utility companies | publicUtilityCompany	3
Enable GP, LLC | CenterPoint Energy
Management rights ownership (as a percent)	50.00%
Incentive distribution rights (as a percent)	40.00%