Contribution From Parent

No definition available.

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- Definition

Money Pool Investments (Borrowings)

+ References

No definition available.

+ Details

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- Definition

Weighted average interest rate of outstanding investments in money pool.

+ References

No definition available.

+ Details

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- Definition

Amount of net service charges from (billings to) related party during the period, excluding transactions that are eliminated in consolidated or combined financial statements.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Payment Of Dividends To Parent

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

Amount of transactions with related party during the financial reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-3

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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

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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- Details

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- Details

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- Details

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- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=cnp_CenterpointEnergyMember
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- Details

Name:	us-gaap_RelatedPartyTransactionAxis=us-gaap_InvestmentsMember
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- Details

Name:	dei_LegalEntityAxis=cnp_CercCorpMember
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Related Party Transactions (Houston Electric and CERC) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Houston Electric
Related Party Transaction [Line Items]
Money pool investments (borrowings)	$ 573		$ 238
Cash dividends paid to parent	36	$ 51
Houston Electric \| Additional Paid-in-Capital
Related Party Transaction [Line Items]
Contribution from parent	230	650
Houston Electric \| Operation and maintenance expense
Related Party Transaction [Line Items]
Net affiliate service charges (billings)	(1)	(3)
Houston Electric \| Operation and maintenance expense \| CenterPoint Energy
Related Party Transaction [Line Items]
Corporate service charges	$ 35	35
Houston Electric \| Investments
Related Party Transaction [Line Items]
Weighted average interest rate	5.55%		5.59%
CERC
Related Party Transaction [Line Items]
Money pool investments (borrowings)	$ 0		$ 1
Cash dividends paid to parent	115	204
CERC \| Additional Paid-in-Capital
Related Party Transaction [Line Items]
Contribution from parent	0	0
CERC \| Operation and maintenance expense
Related Party Transaction [Line Items]
Net affiliate service charges (billings)	1	3
CERC \| Operation and maintenance expense \| CenterPoint Energy
Related Party Transaction [Line Items]
Corporate service charges	$ 51	$ 50
CERC \| Investments
Related Party Transaction [Line Items]
Weighted average interest rate	0.00%		5.59%