Short-term Borrowings and Long-term Debt - Schedule of Revolving Credit Facilities (Details) $ in Millions	12 Months Ended
Dec. 31, 2023 USD ($) day	Dec. 31, 2022 USD ($)
Debt Instrument [Line Items]
Size of credit facility	$ 4,000	$ 4,000
Number of days until commercial paper maturity \| day	60
SIGECO
Debt Instrument [Line Items]
Size of credit facility	$ 250	250
Houston Electric
Debt Instrument [Line Items]
Size of credit facility	300	300
CERC Corp
Debt Instrument [Line Items]
Size of credit facility	$ 1,050	1,050
Number of days until commercial paper maturity \| day	30
Line of Credit \| SIGECO
Debt Instrument [Line Items]
Percentage on limitation of debt to total capitalization under covenant (in hundredths)	65.00%
Ratio of indebtedness to net capital	0.465
Line of Credit \| Houston Electric
Debt Instrument [Line Items]
Percentage on limitation of debt to total capitalization under covenant (in hundredths)	67.50%
Ratio of indebtedness to net capital	0.526
Line of Credit \| CERC Corp
Debt Instrument [Line Items]
Percentage on limitation of debt to total capitalization under covenant (in hundredths)	65.00%
Ratio of indebtedness to net capital	0.402
Line of Credit \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate \| SIGECO
Debt Instrument [Line Items]
Basis spread (as a percent)	1.125%
Line of Credit \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate \| Houston Electric
Debt Instrument [Line Items]
Basis spread (as a percent)	1.25%
Line of Credit \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate \| CERC Corp
Debt Instrument [Line Items]
Basis spread (as a percent)	1.125%
Revolving Credit Facility
Debt Instrument [Line Items]
Loans	$ 0	0
Revolving Credit Facility \| SIGECO
Debt Instrument [Line Items]
Loans	0	0
Revolving Credit Facility \| Houston Electric
Debt Instrument [Line Items]
Loans	0	0
Revolving Credit Facility \| CERC Corp
Debt Instrument [Line Items]
Loans	0	0
Letter of Credit
Debt Instrument [Line Items]
Loans	1	11
Letter of Credit \| SIGECO
Debt Instrument [Line Items]
Loans	0	0
Letter of Credit \| Houston Electric
Debt Instrument [Line Items]
Loans	0	0
Letter of Credit \| CERC Corp
Debt Instrument [Line Items]
Loans	1	0
CenterPoint Energy commercial paper
Debt Instrument [Line Items]
Loans	1,520	2,575
CenterPoint Energy commercial paper \| SIGECO
Debt Instrument [Line Items]
Loans	$ 0	$ 0
Weighted average interest rate (as a percent)	0.00%	0.00%
CenterPoint Energy commercial paper \| Houston Electric
Debt Instrument [Line Items]
Loans	$ 0	$ 0
Weighted average interest rate (as a percent)	0.00%	0.00%
CenterPoint Energy commercial paper \| CERC Corp
Debt Instrument [Line Items]
Loans	$ 484	$ 805
Weighted average interest rate (as a percent)	5.53%	4.67%
Parent Company
Debt Instrument [Line Items]
Size of credit facility	$ 2,400	$ 2,400
Parent Company \| Line of Credit
Debt Instrument [Line Items]
Percentage on limitation of debt to total capitalization under covenant (in hundredths)	65.00%
Ratio of indebtedness to net capital	0.596
Percentage on limitation of debt to total capitalization under covenant amended (in hundredths)	70.00%
Expected restoration costs	$ 100
Consecutive period for system restoration costs to exceed $100 million (in months)	12
Parent Company \| Line of Credit \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Basis spread (as a percent)	1.50%
Parent Company \| Revolving Credit Facility
Debt Instrument [Line Items]
Loans	$ 0	0
Parent Company \| Letter of Credit
Debt Instrument [Line Items]
Loans	0	11
Parent Company \| CenterPoint Energy commercial paper
Debt Instrument [Line Items]
Loans	$ 1,036	$ 1,770
Weighted average interest rate (as a percent)	5.54%	4.71%

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Indebtedness divided by net capital.

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