Earnings Per Share (CenterPoint Energy) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Numerator:
Income Before Income Taxes	$ 917	$ 1,057	$ 668
Less: Preferred stock dividend requirement	50	49	95
Income available to common shareholders from continuing operations - basic	867	1,008	573
Income available to common shareholders from continuing operations - diluted	867	1,008	573
Income available to common shareholders from discontinued operations - basic	0	0	818
Income available to common shareholders from discontinued operations - diluted	0	0	818
Income available to common shareholders - basic	867	1,008	1,391
Income available to common shareholders - diluted	$ 867	$ 1,008	$ 1,391
Denominator:
Weighted average common shares outstanding - basic (in shares)	630,947	629,415	592,933
Weighted average common shares outstanding - diluted (in shares)	633,179	632,346	609,938
Earnings per common share:
Basic earnings per common share - continuing operations (in dollars per share)	$ 1.37	$ 1.60	$ 0.97
Basic earnings per common share - discontinued operations (in dollars per share)	0	0	1.38
Basic earnings per common share (in dollars per share)	1.37	1.60	2.35
Basic Earnings Per Common Share
Diluted earnings per common share - continuing operations (in dollars per share)	1.37	1.59	0.94
Diluted earnings per common share - discontinued operations (in dollars per share)	0	0	1.34
Diluted earnings per common share (in dollars per share)	$ 1.37	$ 1.59	$ 2.28
Restricted stock
Denominator:
Restricted stock (in shares)	2,232	2,931	5,181
Series B Preferred Stock
Numerator:
Less: Preferred stock dividend requirement	$ 50	$ 49	$ 95
Anti-dilutive Incremental Shares Excluded from Denominator for Diluted Earnings Computation:
Series B preferred stock (in shares)	0	0	23,906
Series C Preferred Stock
Denominator:
Series C preferred stock (in shares)	0	0	11,824