Earnings Per Share (CenterPoint Energy) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Numerator:
Income from continuing operations	$ 118	$ 190	$ 443	$ 721
Less: Preferred stock dividend requirement	12	11	24	24
Income available to common shareholders - basic and diluted	106	179	419	697
Income available to common shareholders - basic and diluted	$ 106	$ 179	$ 419	$ 697
Denominator:
Weighted average common shares outstanding - basic (in shares)	631,057	629,475	630,685	629,306
Plus: Incremental shares from assumed conversions:
Weighted average common shares outstanding - diluted (in shares)	633,005	631,663	633,030	631,494
Earnings Per Common Share:
Basic Earnings Per Common Share (in dollars per share)	$ 0.17	$ 0.28	$ 0.66	$ 1.11
Diluted Earnings (Loss) Per Common Share
Diluted Earnings Per Common Share (in dollars per share)	$ 0.17	$ 0.28	$ 0.66	$ 1.10
Restricted stock
Plus: Incremental shares from assumed conversions:
Restricted stock (in shares)	1,948	2,188	2,345	2,188