Related Party Transactions (Houston Electric and CERC) - Schedule of Money Pool Investments (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Houston Electric \| Investments
Related Party Transaction [Line Items]
Weighted average interest rate	5.59%	4.75%
CERC Corp \| Investments
Related Party Transaction [Line Items]
Weighted average interest rate	5.59%	4.75%
Accounts and notes receivable (payable) - affiliate companies \| Houston Electric
Related Party Transaction [Line Items]
Money pool investments (borrowings)	$ 238	$ (642)
Accounts and notes receivable (payable) - affiliate companies \| CERC Corp
Related Party Transaction [Line Items]
Money pool investments (borrowings)	$ 1	$ 0

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(c)(2)(i))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(c)(2)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(g)(3))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

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