Held for Sale and Divestitures (CenterPoint Energy and CERC) - Narrative (Details) mi in Thousands, numberOfCustomer in Millions, $ in Millions		3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)	Feb. 19, 2024 USD ($) numberOfCustomer mi	May 21, 2023 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from divestitures				$ 0	$ 145
Loss on divestitures		$ 0	$ 12	0	$ 12
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations | Energy Systems Group
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Equity purchase agreement, purchase price								$ 157
Proceeds from divestitures	$ 154
Adjustments on working capital		$ 2		$ 2
Loss on divestitures						$ 13
Transaction costs						3
Current tax expense of divestiture						$ 32
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations | CERC | Louisiana and Mississippi Regulated Natural Gas LDC Businesses
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Purchase price							$ 1,200
Miles of pipeline (in miles) | mi							12
Number of customers (more than) | numberOfCustomer							0.3