Earnings Per Share (CenterPoint Energy) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Numerator:
Income from continuing operations	$ 325	$ 531
Less: Preferred stock dividend requirement	12	13
Income available to common shareholders - basic and diluted	313	518
Income available to common shareholders - basic and diluted	$ 313	$ 518
Denominator:
Weighted average common shares outstanding - basic	630,309	629,134
Plus: Incremental shares from assumed conversions:
Weighted average common shares outstanding - diluted	633,051	631,304
Earnings Per Common Share:
Basic Earnings Per Common Share (in dollars per share)	$ 0.50	$ 0.82
Diluted Earnings (Loss) Per Common Share
Diluted Earnings Per Common Share (in dollars per share)	$ 0.49	$ 0.82
Restricted stock
Plus: Incremental shares from assumed conversions:
Restricted stock	2,742	2,170