Equity Securities and Indexed Debt Securities (ZENS) (CenterPoint Energy) - Schedule of Reference Shares (Details) - shares	Sep. 30, 2023	Dec. 31, 2022
AT&T Common | Subordinated Debt ZENS
Debt and Equity Securities, FV-NI [Line Items]
Number of shares referenced in exchangeable subordinated note (in shares)	0.7185	0.7185
Charter Common | Subordinated Debt ZENS
Debt and Equity Securities, FV-NI [Line Items]
Number of shares referenced in exchangeable subordinated note (in shares)	0.061382	0.061382
WBD Common | Subordinated Debt ZENS
Debt and Equity Securities, FV-NI [Line Items]
Number of shares referenced in exchangeable subordinated note (in shares)	0.173817	0.173817