Held for Sale and Divestitures (CenterPoint Energy and CERC) - Pre Tax Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (Loss) Before Income Taxes	$ 261	$ 217	$ 689	$ 620
CERC
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (Loss) Before Income Taxes	62	53	386	325
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations | Louisiana and Mississippi Regulated Natural Gas LDC Businesses
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (Loss) Before Income Taxes	3	3	44	35
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations | Louisiana and Mississippi Regulated Natural Gas LDC Businesses | CERC
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (Loss) Before Income Taxes	$ 3	3	$ 44	35
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]
Income (Loss) Before Income Taxes		$ 2		$ (4)