Name:	pnw_AllRiskInsuranceForPropertyDamageAndDecontaminationAtPaloVerde
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the annual limit per incident with respect to the maximum assessment per reactor under the program for each nuclear incident, to be periodically adjusted for inflation.

No definition available.

Name:	pnw_AnnualLimitPerIncidentWithRespectToMaximumAssessment
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the annual payment limitation with respect to maximum potential retrospective assessment.

No definition available.

Name:	pnw_AnnualPaymentLimitationWithRespectToMaximumPotentialRetrospectiveAssessment
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the collateral assurance provided that depends upon rating triggers such as a rating downgrade to non-investment grade under NEIL policies.

No definition available.

Name:	pnw_CollateralAssuranceBasedOnRatingTriggers
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

Name:	pnw_CommitmentsAndContingenciesLineItems
Namespace Prefix:	pnw_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Increase (Decrease) Unrecorded Unconditional Purchase Obligation

No definition available.

Name:	pnw_IncreaseDecreaseUnrecordedUnconditionalPurchaseObligation
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Maximum Amount that Could be Incurred under Retrospective Assessment of NEIL Policies

No definition available.

Name:	pnw_MaximumAmountthatCouldbeIncurredunderRetrospectiveAssessmentofNEILPolicies
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the maximum assessment per reactor under the program for each nuclear incident.

No definition available.

Name:	pnw_MaximumAssessmentPerReactorForEachNuclearIncident
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the maximum available nuclear liability insurance which is provided by commercial insurance carriers, maintained by Palo Verde as required by the Price Anderson Nuclear Industries Indemnity Act.

No definition available.

Name:	pnw_MaximumAvailableNuclearLiabilityInsurance
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the maximum insurance amount against public liability per occurrence for a nuclear incident.

No definition available.

Name:	pnw_MaximumInsuranceCoveragePerIncident
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the maximum potential retrospective assessment per incident based on the interest of APS in the three Palo Verde units.

No definition available.

Name:	pnw_MaximumPotentialRetrospectiveAssessmentPerIncident
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Number of VIE lessor trusts with whom agreements have been made to sell and lease back interests in certain nuclear generating assets and related common facilities.

No definition available.

Name:	pnw_NumberOfVIELessorTrusts
Namespace Prefix:	pnw_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Represents the period to provide collateral assurance based on rating triggers such as a rating downgrade to non-investment grade under NEIL policies (in days).

No definition available.

Name:	pnw_PeriodToProvideCollateralAssuranceBasedOnRatingTriggers
Namespace Prefix:	pnw_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the remaining nuclear liability insurance that is provided through mandatory industry wide retrospective assessment program.

No definition available.

Name:	pnw_RemainingNuclearLiabilityInsuranceThroughMandatoryIndustryWideRetrospectiveAssessmentProgram
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The increase (decrease) during the reporting period in regulated liabilities. Regulated liabilities are created when regulatory agency permits an entity to defer revenues to the balance sheet.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

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

Amount of judgment or settlement awarded to (against) the entity in respect of litigation.

No definition available.

Name:	us-gaap_LitigationSettlementAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Cash received for the settlement of litigation during the current period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3536-108585

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

- References

No definition available.

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

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 440

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6394976&loc=d3e25336-109308

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

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the remainder of the fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

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

Name:	us-gaap_LitigationCaseAxis=pnw_ArizonaPublicServiceCompanyandPaloVerdeOwnersvs.UnitedStatesDepartmentofEnergySpentNuclearFuelandWasteDisposalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=pnw_FourCornersandOcotilloPlantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchasedAxis=pnw_GasGenerationsProjectsandSelectiveCatalyticReductionControlTechnologiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=pnw_OcotilloPlantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchasedAxis=pnw_GasGenerationProjectsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=pnw_FourCornersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchasedAxis=pnw_SelectiveCatalyticReductionControlTechnologiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: