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, 2022	Dec. 31, 2021	Dec. 31, 2020
Debt and Equity Securities, FV-NI [Line Items]
Gain (loss) on equity securities	$ (227)	$ (172)	$ 49
AT&T Common
Debt and Equity Securities, FV-NI [Line Items]
Gain (loss) on equity securities	(63)	(43)	(105)
Charter Common
Debt and Equity Securities, FV-NI [Line Items]
Gain (loss) on equity securities	(273)	(8)	154
WBD Common
Debt and Equity Securities, FV-NI [Line Items]
Gain (loss) on equity securities	23	0	0
Energy Transfer Common Units
Debt and Equity Securities, FV-NI [Line Items]
Gain (loss) on equity securities	95	(124)	0
Energy Transfer Series G Preferred Units
Debt and Equity Securities, FV-NI [Line Items]
Gain (loss) on equity securities	(9)	2	0
Other
Debt and Equity Securities, FV-NI [Line Items]
Gain (loss) on equity securities	$ 0	$ 1	$ 0