Goodwill and Other Intangibles (CenterPoint Energy and CERC ) (Details) - USD ($)	3 Months Ended			12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Mar. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Goodwill [Line Items]
Goodwill				$ 4,294,000,000	$ 4,294,000,000
Goodwill transferred				972,000,000	972,000,000
Goodwill impairment	$ 0	$ 0		0	0	$ 185,000,000
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount				63,000,000	63,000,000
Accumulated Amortization				(25,000,000)	(19,000,000)
Net Balance				38,000,000	44,000,000
2023				6,000,000
2024				5,000,000
2025				5,000,000
2026				5,000,000
2027				4,000,000
Indiana Electric Integrated
Goodwill [Line Items]
Goodwill impairment			$ 185,000,000
Fair value of goodwill			$ 936,000,000
Customer Relationships
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount				33,000,000	33,000,000
Accumulated Amortization				(16,000,000)	(12,000,000)
Net Balance				17,000,000	21,000,000
Trade Names
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount				16,000,000	16,000,000
Accumulated Amortization				(6,000,000)	(5,000,000)
Net Balance				10,000,000	11,000,000
Operation and maintenance agreements
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount				12,000,000	12,000,000
Accumulated Amortization				(2,000,000)	(1,000,000)
Net Balance				10,000,000	11,000,000
Other
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount				2,000,000	2,000,000
Accumulated Amortization				(1,000,000)	(1,000,000)
Net Balance				1,000,000	1,000,000
Electric
Goodwill [Line Items]
Goodwill				936,000,000	936,000,000
Accumulated goodwill impairment charge						185,000,000
Natural Gas
Goodwill [Line Items]
Goodwill				2,920,000,000	2,920,000,000
Held for Sale					398,000,000
Corporate and Other
Goodwill [Line Items]
Goodwill				438,000,000	438,000,000
Depreciation and amortization expense
Finite-Lived Intangible Assets, Net [Abstract]
Amortization of intangible assets in Non-utility cost of revenues				6,000,000	6,000,000	6,000,000
Non-utility cost of revenues
Finite-Lived Intangible Assets, Net [Abstract]
Amortization of intangible assets in Non-utility cost of revenues				1,000,000	1,000,000	$ 2,000,000
CERC Corp
Goodwill [Line Items]
Goodwill				$ 1,583,000,000	1,583,000,000
CERC Corp | Natural Gas
Goodwill [Line Items]
Held for Sale					$ 144,000,000