Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Income Tax Contingency [Line Items]
Effective income tax rate (as a percent)	18.00%	19.00%
Deferred remeasurement benefit	$ 25
Interest and penalties on uncertain tax liability	30
Change in valuation allowance, income tax benefit	21
Increase in unrecognized tax benefits is reasonably possible as a result of a lapse in statutes	$ 3
Houston Electric
Income Tax Contingency [Line Items]
Effective income tax rate (as a percent)	20.00%	23.00%
CERC
Income Tax Contingency [Line Items]
Effective income tax rate (as a percent)	19.00%	22.00%
Deferred remeasurement benefit	$ 24
Change in valuation allowance, income tax benefit	$ 21

Deferred Remeasurement Benefit

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- Definition

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-12

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-12

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- Definition

Amount of increase reasonably possible in the next twelve months for the unrecognized tax benefit.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (d)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-15

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- Definition

Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-15

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