Divestitures (CenterPoint Energy and CERC) - Schedule of Assets and Liabilities Classified as Held-For-Sale (Details) - USD ($) $ in Millions	Jun. 30, 2022	May 31, 2022	Dec. 31, 2021
Disposal Group, Including Discontinued Operation, Assets, Current [Abstract]
Total current assets held for sale	$ 0		$ 2,338
Disposal Group, Including Discontinued Operation, Liabilities, Current [Abstract]
Total current liabilities held for sale	0		562
CERC
Disposal Group, Including Discontinued Operation, Assets, Current [Abstract]
Total current assets held for sale	0		2,084
Disposal Group, Including Discontinued Operation, Liabilities, Current [Abstract]
Total current liabilities held for sale	$ 0		562
Arkansas and Oklahoma Natural Gas Businesses | Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations
Disposal Group, Including Discontinued Operation, Assets, Current [Abstract]
Receivables, net		$ 15	46
Accrued unbilled revenues			48
Natural gas inventory			46
Materials and supplies			9
Property, plant and equipment, net			1,314
Goodwill			398
Regulatory assets			471
Other			6
Total current assets held for sale			2,338
Disposal Group, Including Discontinued Operation, Liabilities, Current [Abstract]
Short term borrowings			36
Accounts payable			40
Taxes accrued			7
Customer deposits			12
Regulatory liabilities			365
Other			102
Total current liabilities held for sale			562
Arkansas and Oklahoma Natural Gas Businesses | Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations | CERC
Disposal Group, Including Discontinued Operation, Assets, Current [Abstract]
Receivables, net		$ 15	46
Accrued unbilled revenues			48
Natural gas inventory			46
Materials and supplies			9
Property, plant and equipment, net			1,314
Goodwill			144
Regulatory assets			471
Other			6
Total current assets held for sale			2,084
Disposal Group, Including Discontinued Operation, Liabilities, Current [Abstract]
Short term borrowings			36
Accounts payable			40
Taxes accrued			7
Customer deposits			12
Regulatory liabilities			365
Other			102
Total current liabilities held for sale			$ 562