Entity's interest in incentive distribution rights held by the general partner.

No definition available.

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- Definition

Represents the percentage of management rights in the general partner of Enable

+ References

No definition available.

+ Details

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- Definition

Number of States in which the Entity Performs Gas Delivery Services

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
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- Definition

Represents the number of Series A Preferred Units held as of the balance sheet date.

+ References

No definition available.

+ Details

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Data Type:	xbrli:sharesItemType
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- Definition

Sales price of outstanding equity interests

+ References

No definition available.

+ Details

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

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

The number of states the entity operates in as of the balance sheet date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3213-108585

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

- Definition

The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3179-108585

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_BusinessAcquisitionAxis=cnp_VectrenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=cnp_EnableMidstreamPartnersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Data Type:	na
Balance Type:
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Data Type:	na
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- Details

Name:	dei_LegalEntityAxis=cnp_CercCorpMember
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- Details

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- Details

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Background (Details) $ in Millions			12 Months Ended
Background (Details) $ in Millions	Apr. 09, 2020 USD ($)	Feb. 01, 2019 USD ($)	Dec. 31, 2020 USD ($) state shares	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Cash proceeds from sale			$ 1,215	$ 0	$ 0
Infrastructure Services Disposal Group [Member]
Sales price of outstanding equity interests			850
Cash proceeds from sale	$ 850		854
Energy Services [Member]
Cash proceeds from sale			$ 365
Vectren [Member]
Cash paid to acquire Vectren		$ 6,000		$ 5,982
Enable Midstream Partners [Member]
Ownership percentage of equity method investment			53.70%	53.70%
Enable Midstream Partners [Member] \| Series A Preferred Units [Member]
Preferred units held \| shares			14,520,000
Enable GP, LLC [Member]
Management rights ownership percentage			50.00%
Incentive distribution right			40.00%
CERC Corp [Member]
Cash proceeds from sale			$ 365
CERC Corp [Member] \| Natural Gas [Member]
Number of states in which entity operates \| state			6
CERC Corp [Member] \| Natural Gas Distribution
Number of States in which the Entity Performs Gas Delivery Services \| state			48
CenterPoint Energy [Member] \| Enable GP, LLC [Member]
Management rights ownership percentage			50.00%
Incentive distribution right			40.00%