Property, Plant and Equipment (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) MW	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross	$ 40,396	$ 37,728
Property plant and equipment and finance lease assets, gross	40,396	37,728
Accumulated Depreciation & Amortization	10,543	10,585
Property plant and equipment and finance lease assets, accumulated depreciation and amortization	10,543	10,585
Property, plant and equipment	29,853	27,143
Finance ROU assets	526	621
Property plant and equipment and finance lease assets, net	29,853	27,143
Depreciation and Amortization [Abstract]
Depreciation	1,092	1,013	$ 1,024
Amortization of securitized regulatory assets	163	191	213
Other amortization	146	84	79
Total	1,401	1,288	1,316
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance	610	659
Accretion expense	23	20
Revisions in estimate	(43)	(69)
Ending balance	590	610	659
Houston Electric
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross	19,515	17,753
Property plant and equipment and finance lease assets, gross	19,515	17,753
Accumulated Depreciation & Amortization	4,469	4,292
Property plant and equipment and finance lease assets, accumulated depreciation and amortization	4,469	4,292
Property, plant and equipment	15,046	13,461
Finance ROU assets	526	621
Property plant and equipment and finance lease assets, net	15,046	13,461
Depreciation and Amortization [Abstract]
Depreciation	484	434	391
Amortization of securitized regulatory assets	155	191	213
Other amortization	109	45	38
Total	748	670	642
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance	36	42
Accretion expense	1	1
Revisions in estimate	3	(7)
Ending balance	40	36	42
CERC Corp
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross	15,672	14,379
Property plant and equipment and finance lease assets, gross	15,672	14,379
Accumulated Depreciation & Amortization	4,169	3,973
Property plant and equipment and finance lease assets, accumulated depreciation and amortization	4,169	3,973
Property, plant and equipment	11,503	10,406
Finance ROU assets	0	0
Property plant and equipment and finance lease assets, net	11,503	10,406
Depreciation and Amortization [Abstract]
Depreciation	459	420	466
Amortization of securitized regulatory assets	0	0	0
Other amortization	34	28	17
Total	493	448	483
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance	420	479
Accretion expense	16	15
Revisions in estimate	(56)	(74)
Ending balance	$ 380	420	$ 479
Electric transmission and distribution
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives (in years)	37 years
Property, Plant and Equipment, Gross	$ 19,151	19,154
Accumulated Depreciation & Amortization	4,762	5,317
Property, plant and equipment	$ 14,389	13,837
Electric transmission and distribution | Houston Electric
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives (in years)	37 years
Property, Plant and Equipment, Gross	$ 16,800	14,791
Accumulated Depreciation & Amortization	3,641	3,556
Property, plant and equipment	$ 13,159	11,235
Electric generation
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives (in years)	25 years
Property, Plant and Equipment, Gross	$ 1,381	2,120
Accumulated Depreciation & Amortization	315	813
Property, plant and equipment	$ 1,066	1,307
Natural gas distribution
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives (in years)	32 years
Property, Plant and Equipment, Gross	$ 16,492	15,097
Accumulated Depreciation & Amortization	4,337	4,135
Property, plant and equipment	$ 12,155	10,962
Natural gas distribution | CERC Corp
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives (in years)	31 years
Property, Plant and Equipment, Gross	$ 15,591	14,316
Accumulated Depreciation & Amortization	4,136	3,946
Property, plant and equipment	$ 11,455	10,370
Finance ROU asset mobile generation
Property, Plant and Equipment, Net, by Type [Abstract]
Finance Lease, term of contract (in years)	7 years 6 months
Finance lease right of use assets, gross	$ 662	662
Finance lease right of use assets, accumulated amortization	136	41
Finance ROU assets	$ 526	621
Finance ROU asset mobile generation | Houston Electric
Property, Plant and Equipment, Net, by Type [Abstract]
Finance Lease, term of contract (in years)	7 years 6 months
Finance lease right of use assets, gross	$ 662	662
Finance lease right of use assets, accumulated amortization	136	41
Finance ROU assets	$ 526	621
Other property
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives (in years)	22 years
Property, Plant and Equipment, Gross	$ 2,710	695
Accumulated Depreciation & Amortization	993	279
Property, plant and equipment	$ 1,717	416
Other property | Houston Electric
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives (in years)	20 years
Property, Plant and Equipment, Gross	$ 2,053	2,300
Accumulated Depreciation & Amortization	692	695
Property, plant and equipment	$ 1,361	1,605
Other property | CERC Corp
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives (in years)	15 years
Property, Plant and Equipment, Gross	$ 81	63
Accumulated Depreciation & Amortization	33	27
Property, plant and equipment	$ 48	$ 36
SIGECO
Property, Plant and Equipment, Net, by Type [Abstract]
Number of megawatts (in MW) | MW	300
SIGECO's share of cost of Warrick Unit 4	$ 198
SIGECO's share of accumulated depreciation of Warrick Unit 4	$ 171