Reportable Segments - Revenues by Products and Services (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Operating revenues	$ 9,321	$ 8,352	$ 7,418
CenterPoint Energy
Segment Reporting Information [Line Items]
Operating revenues	9,321	8,352	7,418
CenterPoint Energy | Electric delivery
Segment Reporting Information [Line Items]
Operating revenues	3,438	3,158	2,941
CenterPoint Energy | Retail electric sales
Segment Reporting Information [Line Items]
Operating revenues	630	559	515
CenterPoint Energy | Wholesale electric sales
Segment Reporting Information [Line Items]
Operating revenues	40	46	14
CenterPoint Energy | Retail gas sales
Segment Reporting Information [Line Items]
Operating revenues	4,759	4,157	3,462
CenterPoint Energy | Gas transportation and processing
Segment Reporting Information [Line Items]
Operating revenues	12	12	15
CenterPoint Energy | Energy products and services
Segment Reporting Information [Line Items]
Operating revenues	442	420	471
Houston Electric
Segment Reporting Information [Line Items]
Operating revenues	3,412	3,134	2,911
Houston Electric | Electric delivery
Segment Reporting Information [Line Items]
Operating revenues	3,412	3,134	2,911
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 and processing
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	4,800	4,200	3,531
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	4,613	4,021	3,362
CERC Corp | Gas transportation and processing
Segment Reporting Information [Line Items]
Operating revenues	12	12	15
CERC Corp | Energy products and services
Segment Reporting Information [Line Items]
Operating revenues	$ 175	$ 167	$ 154