Goodwill (CenterPoint Energy and CERC) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Dec. 31, 2020
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 4,160
Held For Sale	217
Goodwill, ending balance	3,943
CERC
Goodwill [Roll Forward]
Goodwill, beginning balance	1,583
Held For Sale	122
Goodwill, ending balance	1,461
Electric
Goodwill [Roll Forward]
Goodwill, beginning balance	936
Held For Sale	0
Goodwill, ending balance	936
Goodwill, Impaired, Accumulated Impairment Loss [Abstract]
Accumulated goodwill impairment charge		$ 185
Natural gas
Goodwill [Roll Forward]
Goodwill, beginning balance	2,920
Held For Sale	217
Goodwill, ending balance	2,703
Corporate and Other
Goodwill [Roll Forward]
Goodwill, beginning balance	304
Held For Sale	0
Goodwill, ending balance	$ 304