Equity Securities and Indexed Debt Securities (ZENS) (CenterPoint Energy) - Schedule of Gain (Loss) On Equity Securities (CenterPoint Energy) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt and Equity Securities, FV-NI [Line Items]
Total Gains (Losses) on Equity Securities	$ 31	$ (227)	$ (172)
AT&T Common
Debt and Equity Securities, FV-NI [Line Items]
Total Gains (Losses) on Equity Securities	(17)	(63)	(43)
Charter Common
Debt and Equity Securities, FV-NI [Line Items]
Total Gains (Losses) on Equity Securities	43	(273)	(8)
WBD Common
Debt and Equity Securities, FV-NI [Line Items]
Total Gains (Losses) on Equity Securities	5	23	0
Energy Transfer Common Units
Debt and Equity Securities, FV-NI [Line Items]
Total Gains (Losses) on Equity Securities	0	95	(124)
Energy Transfer Series G Preferred Units
Debt and Equity Securities, FV-NI [Line Items]
Total Gains (Losses) on Equity Securities	0	(9)	2
Other
Debt and Equity Securities, FV-NI [Line Items]
Total Gains (Losses) on Equity Securities	$ 0	$ 0	$ 1