Short-term Borrowings and Long-term Debt - Debt Transactions (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) numberOfTranche
CERC Corp
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 2,000
General Mortgage Bonds | Houston Electric
Debt Instrument [Line Items]
Aggregate Principal Amount	1,400
Proceeds from issuance of long-term debt and capital securities, net	890
Term Loan
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt, net of discounts and issuance expenses and fees	$ 250
Senior Notes | CERC Corp
Debt Instrument [Line Items]
Debt instrument interest rate (as a percent)	0.70%
Proceeds from issuance of long-term debt, net of discounts and issuance expenses and fees	$ 1,200
First Mortgage Bonds | SIGECO
Debt Instrument [Line Items]
Debt instrument, number of tranche | numberOfTranche	3
Securitization Bonds | SIGECO
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt, net of discounts and issuance expenses and fees	$ 337
Senior Notes, Term Loan, Securitization Bonds, FMBs and GMBs
Debt Instrument [Line Items]
Aggregate Principal Amount	6,041
General Mortgage Bonds 4.95% Due 2033 | General Mortgage Bonds | Houston Electric
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 600
Debt instrument interest rate (as a percent)	4.95%
General Mortgage Bonds 5.30% Due 2053 | General Mortgage Bonds | Houston Electric
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 300
Debt instrument interest rate (as a percent)	5.30%
General Mortgage Bonds 5.20% Due 2028 | General Mortgage Bonds | Houston Electric
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 500
Debt instrument interest rate (as a percent)	5.20%
Proceeds from issuance of long-term debt and capital securities, net	$ 496
CERC Term Loan 0.85% Due 2024 | Term Loan | CERC Corp
Debt Instrument [Line Items]
Aggregate Principal Amount	500
Proceeds from issuance of long-term debt, net of discounts and issuance expenses and fees	$ 500
CERC Term Loan 0.85% Due 2024 | Term Loan | CERC Corp | SOFR
Debt Instrument [Line Items]
Basis spread (as a percent)	0.85%
Adjustment to basis spread (as a percent)	0.10%
CERC Senior Notes 5.25% Due 2028 | Senior Notes | CERC Corp
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 600
Debt instrument interest rate (as a percent)	5.25%
Proceeds from issuance of long-term debt, net of discounts and issuance expenses and fees	$ 308
Interest payable	3
CERC Senior Notes 5.40% Due 2033 | Senior Notes | CERC Corp
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 600
Debt instrument interest rate (as a percent)	5.40%
CERC Senior Notes, 5.25% Due May 2028 | Senior Notes | CERC Corp
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 300
Debt instrument interest rate (as a percent)	5.25%
CNP First Mortgage Bonds 4.98% Due 2028 | First Mortgage Bonds | SIGECO
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 100
Debt instrument interest rate (as a percent)	4.98%
CNP First Mortgage Bonds 5.04% Due 2033 | First Mortgage Bonds | SIGECO
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 80
Debt instrument interest rate (as a percent)	5.04%
CNP Term Loan 1.50% Due 2023
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 250
CNP Term Loan 1.50% Due 2023 | Term Loan
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 250
CNP Term Loan 1.50% Due 2023 | Term Loan | SOFR
Debt Instrument [Line Items]
Debt instrument interest rate (as a percent)	1.50%
Basis spread (as a percent)	1.50%
Adjustment to basis spread (as a percent)	0.10%
CNP Securitization Bonds | Securitization Bonds | SIGECO
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 341
CNP Securitization Bonds | Securitization Bonds | SIGECO | Minimum
Debt Instrument [Line Items]
Debt instrument interest rate (as a percent)	5.026%
CNP Securitization Bonds | Securitization Bonds | SIGECO | Maximum
Debt Instrument [Line Items]
Debt instrument interest rate (as a percent)	5.172%
CNP Convertible Notes 4.25% Due 2026 | Convertible Notes
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 1,000
Debt instrument interest rate (as a percent)	4.25%
Proceeds from issuance of long-term debt, net of discounts and issuance expenses and fees	$ 985
CNP Senior Notes 5.25% Due 2026 | Senior Notes
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 400
Debt instrument interest rate (as a percent)	5.25%
Proceeds from issuance of long-term debt, net of discounts and issuance expenses and fees	$ 397
CNP First Mortgage Bonds 5.75% to 6% Due 2034 | First Mortgage Bonds | SIGECO
Debt Instrument [Line Items]
Aggregate Principal Amount	470
Proceeds from issuance of long-term debt and capital securities, net	$ 467
CNP First Mortgage Bonds 5.75% to 6% Due 2034 | First Mortgage Bonds | SIGECO | Minimum
Debt Instrument [Line Items]
Debt instrument interest rate (as a percent)	5.75%
CNP First Mortgage Bonds 5.75% to 6% Due 2034 | First Mortgage Bonds | SIGECO | Maximum
Debt Instrument [Line Items]
Debt instrument interest rate (as a percent)	6.00%
Various New or Existing Projects | General Mortgage Bonds | Houston Electric
Debt Instrument [Line Items]
Proceeds form issuance of debt, amount to be disbursed or allocated to finance or refinance projects	$ 296
Term Loan Due February 2024 | Term Loan | CERC Corp
Debt Instrument [Line Items]
Aggregate Principal Amount	500
CNP First Mortgage Bonds, 4.98% Due 2028 And 5.04% Due 2033 | First Mortgage Bonds | SIGECO
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt, net of discounts and issuance expenses and fees	179
CNP First Mortgage Bonds 5.75% Due 2029 | First Mortgage Bonds | SIGECO
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 180
Debt instrument interest rate (as a percent)	5.75%
CNP First Mortgage Bonds 5.91% Due 2030 | First Mortgage Bonds | SIGECO
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 105
Debt instrument interest rate (as a percent)	5.91%
CNP First Mortgage Bonds 6.00% Due 2034 | First Mortgage Bonds | SIGECO
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 185
Debt instrument interest rate (as a percent)	6.00%
General Company Purposes, Including Houstons Electric Borrowings Under the Centerpoint Energy Money Pool | General Mortgage Bonds | Houston Electric
Debt Instrument [Line Items]
Proceeds form issuance of debt, amount to be disbursed or allocated to finance or refinance projects	$ 593