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Property, Plant and Equipment (Details) $ in Millions | 12 Months Ended
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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 |  |

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