Reportable Segments - Revenues by Products and Services (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Operating revenues	$ 8,696	$ 9,321	$ 8,352
CenterPoint Energy
Segment Reporting Information [Line Items]
Operating revenues	8,696	9,321	8,352
CenterPoint Energy | Electric delivery
Segment Reporting Information [Line Items]
Operating revenues	3,701	3,438	3,158
CenterPoint Energy | Retail electric sales
Segment Reporting Information [Line Items]
Operating revenues	569	630	559
CenterPoint Energy | Wholesale electric sales
Segment Reporting Information [Line Items]
Operating revenues	20	40	46
CenterPoint Energy | Retail gas sales
Segment Reporting Information [Line Items]
Operating revenues	4,078	4,759	4,157
CenterPoint Energy | Gas transportation
Segment Reporting Information [Line Items]
Operating revenues	11	12	12
CenterPoint Energy | Energy products and services
Segment Reporting Information [Line Items]
Operating revenues	317	442	420
Houston Electric
Segment Reporting Information [Line Items]
Operating revenues	3,677	3,412	3,134
Houston Electric | Electric delivery
Segment Reporting Information [Line Items]
Operating revenues	3,677	3,412	3,134
Houston Electric | Retail electric sales
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Houston Electric | Wholesale electric sales
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Houston Electric | Retail gas sales
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Houston Electric | Gas transportation
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Houston Electric | Energy products and services
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
CERC Corp
Segment Reporting Information [Line Items]
Operating revenues	4,149	4,800	4,200
CERC Corp | Electric delivery
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
CERC Corp | Retail electric sales
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
CERC Corp | Wholesale electric sales
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
CERC Corp | Retail gas sales
Segment Reporting Information [Line Items]
Operating revenues	3,951	4,613	4,021
CERC Corp | Gas transportation
Segment Reporting Information [Line Items]
Operating revenues	11	12	12
CERC Corp | Energy products and services
Segment Reporting Information [Line Items]
Operating revenues	$ 187	$ 175	$ 167