Annualized fee received for retained CES obligation guarantees

No definition available.

Name:	cnp_AnnualizedfeereceivedforretainedCESobligationguarantees
Namespace Prefix:	cnp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Energy savings commitments not guaranteed

+ References

No definition available.

+ Details

Name:	cnp_EnergySavingsCommitmentsNotGuaranteed
Namespace Prefix:	cnp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of sites identified where the entity may potentially have some remedial responsibility

+ References

No definition available.

+ Details

Name:	cnp_Environmentalremediationnumberofsiteswithpotentialremedialresponsibility
Namespace Prefix:	cnp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Estimated Remaining Exposure

+ References

No definition available.

+ Details

Name:	cnp_EstimatedRemainingExposure
Namespace Prefix:	cnp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Estimated Capital Expenditure to Clean Ash Ponds

+ References

No definition available.

+ Details

Name:	cnp_Estimatedcapitalexpendituretocleanashponds
Namespace Prefix:	cnp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Exposure Period After Closing

+ References

No definition available.

+ Details

Name:	cnp_ExposurePeriodAfterClosing
Namespace Prefix:	cnp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Exposure Period Until Increased Fee

+ References

No definition available.

+ Details

Name:	cnp_ExposurePeriodUntilIncreasedFee
Namespace Prefix:	cnp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Guarantor Obligations, Maximum Payment Receivable

+ References

No definition available.

+ Details

Name:	cnp_GuarantorObligationsMaximumPaymentReceivable
Namespace Prefix:	cnp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of Owned Coal Ash Ponds

+ References

No definition available.

+ Details

Name:	cnp_NumberOfOwnedCoalAshPonds
Namespace Prefix:	cnp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of warranties the wholly owned subsidiary has outstanding in its role as general contractor.

+ References

No definition available.

+ Details

Name:	cnp_NumberOfWarrantyObligationsOutstanding
Namespace Prefix:	cnp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the absolute number of surety bonds the wholly owned subsidiary has outstanding in its role as general contractor

+ References

No definition available.

+ Details

Name:	cnp_Numberofsuretybondobligationsoutstanding
Namespace Prefix:	cnp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of work yet to be completed by wholly owned subsidiary on projects with open surety bonds.

+ References

No definition available.

+ Details

Name:	cnp_Percentageofworkyettobecompletedonprojectswithopensuretybonds
Namespace Prefix:	cnp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face amount of individual surety bonds the wholly-owned subsidiary has outstanding

+ References

No definition available.

+ Details

Name:	cnp_Performanceguaranteeobligationsoutstandingfaceamount
Namespace Prefix:	cnp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Quarterly increase of fee received for retained CES guarantee exposure

+ References

No definition available.

+ Details

Name:	cnp_QuarterlyincreaseoffeereceivedforretainedCESguaranteeexposure
Namespace Prefix:	cnp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Solar Array Generating Capacity

+ References

No definition available.

+ Details

Name:	cnp_SolarArrayGeneratingCapacity
Namespace Prefix:	cnp_
Data Type:	dtr-types:powerItemType
Balance Type:	na
Period Type:	instant

- Definition

Warranty obligations outstanding face amount

+ References

No definition available.

+ Details

Name:	cnp_WarrantyObligationsOutstandingFaceAmount
Namespace Prefix:	cnp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

+ Details

Name:	us-gaap_AssetRetirementObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=124440162&loc=d3e12069-110248

+ Details

Name:	us-gaap_GuaranteeObligationsCurrentCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=124440162&loc=d3e12069-110248

+ Details

Name:	us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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.

+ Details

Name:	us-gaap_LongTermPurchaseCommitmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of pending claims pertaining to a loss contingency.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349

+ Details

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

- Details

Name:	cnp_AshPondFacilityAxis=cnp_FBCulleyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	cnp_AshPondFacilityAxis=cnp_ABBrownMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=cnp_EnergyServicesDisposalGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	cnp_BuildTransferAgreementAxis=cnp_PoseySolarMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_EnvironmentalRemediationSiteAxis=cnp_IndianaGasServiceTerritoryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_EnvironmentalRemediationSiteAxis=cnp_SIGECOMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=cnp_VectrenProxyStatementMateriallyIncompleteRelatedToMergerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=cnp_CercCorpMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=cnp_ShellEnergySolutionsAmericaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=cnp_IndianaElectricMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cnp_EnergyServicesDisposalGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Commitments and Contingencies - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) ashPond gasManufacturingAndStorageSite	Dec. 31, 2020 USD ($)	Oct. 27, 2021 MW	Feb. 09, 2021 MW	Dec. 31, 2019 USD ($)	Jul. 31, 2018 lawsuit
Purchase Obligations
Number of surety bond obligations outstanding	53
Performance guarantee obligations outstanding face amount	$ 569
Percentage of work yet to be completed on projects with open surety bonds	30.00%
Number of warranty obligations outstanding	35
Warranty obligations outstanding face amount	$ 550
Energy savings commitments not guaranteed	1,200
Maximum exposure amount	$ 514
Number of coal ash ponds owned \| ashPond	3
Asset retirement obligation	$ 741	$ 787			$ 539
F.B. Culley
Purchase Obligations
Number of coal ash ponds owned \| ashPond	2
A.B. Brown
Purchase Obligations
Number of coal ash ponds owned \| ashPond	1
Energy Services Disposal Group
Purchase Obligations
Guarantor obligations	$ 0	0
Posey Solar
Purchase Obligations
Solar array generating capacity (in Megawatts) \| MW			200	300
Indiana Gas Service Territory
Purchase Obligations
Environmental remediation number of sites with potential remedial responsibility \| gasManufacturingAndStorageSite	26
SIGECO
Purchase Obligations
Environmental remediation number of sites with potential remedial responsibility \| gasManufacturingAndStorageSite	5
Vectren Proxy Statement Materially Incomplete Related to Merger
Purchase Obligations
Number of pending claims \| lawsuit						7
CERC Corp
Purchase Obligations
Asset retirement obligation	$ 490	571			$ 325
CERC Corp \| Shell Energy Solutions America
Purchase Obligations
Maximum payment receivable	$ 40
CERC Corp \| Energy Services Disposal Group
Purchase Obligations
Exposure period after closing	90 days
Exposure period until fee increases	3 months
Guarantor obligations	$ 0	0
Indiana Electric
Purchase Obligations
Asset retirement obligation	90
Indiana Electric \| Minimum
Purchase Obligations
Estimated capital expenditure to clean ash ponds	60
Indiana Electric \| Maximum
Purchase Obligations
Estimated capital expenditure to clean ash ponds	$ 80
Energy Services Disposal Group \| CERC Corp
Purchase Obligations
Annualized fee received for retained CES obligation guarantees	3.00%
Quarterly increase of fee received for retained CES guarantee exposure	1.00%
Estimated remaining exposure		$ 23