Name:	pnw_AllRiskInsuranceForPropertyDamageAndDecontaminationAtPaloVerde
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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
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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

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

No definition available.

Name:	pnw_AnnualPaymentLimitationWithRespectToMaximumPotentialRetrospectiveAssessment
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Data Type:	xbrli:monetaryItemType
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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

Fuel and Purchased Power Commitments and Purchase Obligations [Abstract]

No definition available.

Name:	pnw_FuelandPurchasedPowerCommitmentsandPurchaseObligationsAbstract
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Data Type:	xbrli:stringItemType
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Gain Contingency, New Claims Filed, Number

No definition available.

Name:	pnw_GainContingencyNewClaimsFiledNumber
Namespace Prefix:	pnw_
Data Type:	xbrli:integerItemType
Balance Type:	na
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
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Represents the maximum assessment per reactor under the program for each nuclear incident.

No definition available.

Name:	pnw_MaximumAssessmentPerReactorForEachNuclearIncident
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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
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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
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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
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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Palo Verde Nuclear Generating Station [Abstract]

No definition available.

Name:	pnw_PaloVerdeNuclearGeneratingStationAbstract
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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
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Period Type:	duration

The net present value of an unrecorded unconditional purchase obligation as of the balance sheet date.

No definition available.

Name:	pnw_UnrecordedUnconditionalPurchaseObligationPresentValue
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount awarded from other party in judgment or settlement of litigation.

No definition available.

Name:	us-gaap_LitigationSettlementAmountAwardedFromOtherParty
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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the fifth 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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=77896938&loc=d3e25336-109308

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Data Type:	xbrli:monetaryItemType
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Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the next 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.

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Data Type:	xbrli:monetaryItemType
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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.

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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.

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Data Type:	xbrli:monetaryItemType
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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.

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount of the unrecorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).

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Data Type:	xbrli:monetaryItemType
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Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing after the fifth 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.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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The amount purchased during the period under an unrecorded unconditional purchase obligation (for example, under the take-or-pay or throughput contract).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=77896938&loc=d3e25336-109308

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Data Type:	xbrli:monetaryItemType
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Name:	us-gaap_UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchasedAxis=us-gaap_PublicUtilitiesInventoryFuelMember
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Data Type:	na
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Period Type:

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

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

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

Name:	srt_LitigationCaseAxis=pnw_ArizonaPublicServiceCompanyandPaloVerdeOwnersvs.UnitedStatesDepartmentofEnergySpentNuclearFuelandWasteDisposalMember
Namespace Prefix:
Data Type:	na
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