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

Deferred Fuel and Purchased Power Regulatory Asset (Liability), Current

No definition available.

Name:	pnw_DeferredFuelandPurchasedPowerRegulatoryAssetLiabilityCurrent
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the forward component of increase in PSA.

No definition available.

Name:	pnw_ForwardComponentOfPSARate
Namespace Prefix:	pnw_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

Represents the historical component of increase in PSA.

No definition available.

Name:	pnw_HistoricalComponentOfPSARate
Namespace Prefix:	pnw_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

The amortization of deferred fuel and purchased power costs.

No definition available.

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

Represents the PSA rate (power supply adjustor) which provides for the adjustment of retail rates to reflect variations in retail fuel and purchased power costs.

No definition available.

Name:	pnw_PSARate
Namespace Prefix:	pnw_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

Represents the PSA rate prior for the prior years (power supply adjustor) which provides for the adjustment of retail rates to reflect variations in retail fuel and purchased power costs.

No definition available.

Name:	pnw_PSARateInPriorYears
Namespace Prefix:	pnw_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

Proposed Fixed Grid Access Charge on New Residential Solar Customers

No definition available.

Name:	pnw_ProposedFixedGridAccessChargeonNewResidentialSolarCustomers
Namespace Prefix:	pnw_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

Public Utilities, Request to Build Additional Utility Scale Solar, Capacity

No definition available.

Name:	pnw_PublicUtilitiesRequesttoBuildAdditionalUtilityScaleSolarCapacity
Namespace Prefix:	pnw_
Data Type:	num:powerItemType
Balance Type:	na
Period Type:	instant

Public Utilities, Request to Build Additional Utility Scale Solar, Number of Customers

No definition available.

Name:	pnw_PublicUtilitiesRequesttoBuildAdditionalUtilityScaleSolarNumberofCustomers
Namespace Prefix:	pnw_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents the amount of approved budget.

No definition available.

Name:	pnw_RateMatterApprovedBudget
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Approximate percentage of increase in the average retail customer bill due to request for net retail base rate increase.

No definition available.

Name:	pnw_RateMatterApproximatePercentageOfIncreaseInAverageRetailCustomerBill
Namespace Prefix:	pnw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the current base rate for fuel and purchased power costs.

No definition available.

Name:	pnw_RateMatterBaseFuelRateCurrent
Namespace Prefix:	pnw_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

Represents information pertaining to cap percentage of retail revenues.

No definition available.

Name:	pnw_RateMatterCapPercentageOfRetailRevenue
Namespace Prefix:	pnw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the Charge on future customers who install rooftop solar panels under order issued on net metering proposal.

No definition available.

Name:	pnw_RateMatterChargeOnFutureCustomersWhoInstallRooftopSolarPanels
Namespace Prefix:	pnw_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

Represents the percentage of cumulative energy savings for current year.

No definition available.

Name:	pnw_RateMatterCumulativeEnergySavingsForCurrentYearPercentage
Namespace Prefix:	pnw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the amount of estimated monthly collection due to charge on future customers who install rooftop solar panels under order issued on net metering proposal.

No definition available.

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

Rate Matter Estimated Monthly Collection Due to Charge on New Residential Solar Customers

No definition available.

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

The period of time which the staff of the regulatory entity generally requires prior to issuance of its findings.

No definition available.

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

Represents fixed costs recovered by the LFCR mechanism per non-residential kWh lost.

No definition available.

Name:	pnw_RateMatterFixedCostRecoverablePerNonResidentialPowerLost
Namespace Prefix:	pnw_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

Represents fixed costs recovered by the LFCR mechanism per residential kWh lost.

No definition available.

Name:	pnw_RateMatterFixedCostRecoverablePerResidentialPowerLost
Namespace Prefix:	pnw_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

Rate Matter, Number of Resource Savings Projects

No definition available.

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

The period of time covered by a plan to implement a standard enacted by a regulatory authority.

No definition available.

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

The period of time subsequent to the findings of the staff of the regulatory entity in which the parties agreed to process the rate matter in good faith.

No definition available.

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

Represents the amount of proposed budget.

No definition available.

Name:	pnw_RateMatterProposedBudget
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Rate Matter, Proposed Rate Reduction Percentage

No definition available.

Name:	pnw_RateMatterProposedRateReductionPercentage
Namespace Prefix:	pnw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The increase in annual wholesale transmission rates as a result of a regulatory action.

No definition available.

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

Represents the base rate for fuel and purchased power costs as per the terms of the settlement agreement of a regulatory matter.

No definition available.

Name:	pnw_SettlementAgreementBaseFuelRateProposed
Namespace Prefix:	pnw_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

Represents the elimination of the current sharing provision of fuel and purchased power costs.

No definition available.

Name:	pnw_SettlementAgreementCurrentSharingProvisionOfFuelAndPurchasedPowerCostsElimination
Namespace Prefix:	pnw_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

Amount of decrease in fuel-related base rates as per the terms of the settlement agreement of a regulatory matter.

No definition available.

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

Amount of cost recovery due to modifications to the Environmental Improvement Surcharge (EIS) as per the terms of the settlement agreement of a regulatory matter.

No definition available.

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

Amount of increase in non-fuel base rates as per the terms of the settlement agreement of a regulatory matter.

No definition available.

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

Percentage of deferral of property taxes in all years, if Arizona property tax rates decrease.

No definition available.

Name:	pnw_SettlementAgreementPercentageOfDeferralOfPropertyTaxesIfArizonaPropertyTaxRatesDecrease
Namespace Prefix:	pnw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Percentage of deferral of property taxes in year one, if Arizona property tax rates increase.

No definition available.

Name:	pnw_SettlementAgreementPercentageOfDeferralOfPropertyTaxesIfArizonaPropertyTaxRatesIncreaseYearOne
Namespace Prefix:	pnw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Percentage of deferral of property taxes for year three and thereafter, if Arizona property tax rates increase.

No definition available.

Name:	pnw_SettlementAgreementPercentageOfDeferralOfPropertyTaxesIfArizonaPropertyTaxRatesIncreaseYearThreeAndThereafter
Namespace Prefix:	pnw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Percentage of deferral of property taxes in year two, if Arizona property tax rates increase.

No definition available.

Name:	pnw_SettlementAgreementPercentageOfDeferralOfPropertyTaxesIfArizonaPropertyTaxRatesIncreaseYearTwo
Namespace Prefix:	pnw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Estimated amount of transfer of cost recovery for certain renewable energy projects from the RES surcharge to base rates as per the terms of the settlement agreement of a regulatory matter.

No definition available.

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

The increase (decrease) during the reporting period in unrecovered fuel costs for a regulated utility company.

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

Percentage of public utility's approved debt to capital, including debt and equity.

No definition available.

Name:	us-gaap_PublicUtilitiesApprovedDebtCapitalStructurePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Percentage of public utility's approved equity to capital, including debt and equity.

No definition available.

Name:	us-gaap_PublicUtilitiesApprovedEquityCapitalStructurePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Amount of public utility's approved rate increase (decrease) by regulatory agency.

No definition available.

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

Percentage of public utility's approved return on equity.

No definition available.

Name:	us-gaap_PublicUtilitiesApprovedReturnOnEquityPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

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.

No definition available.

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

- References

No definition available.

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

Amount of public utility's requested rate increase (decrease) with regulatory agency.

No definition available.

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

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

Name:	pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis=pnw_FilingWithArizonaCorporationCommissionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RegulatoryAgencyAxis=pnw_ArizonaCorporationCommissionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	pnw_YearOfRateCasesAxis=pnw_RetailRateCaseFilingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=pnw_ArizonaRenewableEnergyStandardAndTariffMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis=pnw_CostRecoveryMechanismsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=pnw_ArizonaRenewableEnergyStandardAndTariff2014Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	pnw_PublicUtilityProgramAxis=pnw_AZSunProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	pnw_PublicUtilityProgramAxis=pnw_AlternativetoAZSunProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	pnw_PublicUtilityProgramAxis=pnw_AlternativetoAZSunProgramPhase1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	pnw_PublicUtilityProgramAxis=pnw_AlternativetoAZSunProgramPhase2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=pnw_ArizonaRenewableEnergyStandardandTariff2015Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=pnw_ArizonaRenewableEnergyStandardandTariff2016Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=pnw_DemandSideManagementAdjustorCharge2013Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=pnw_DemandSideManagementAdjustorCharge2014Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=pnw_DemandSideManagementAdjustorCharge2015Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=pnw_DemandSideManagementAdjustorCharge2016Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=pnw_PowerSupplyAdjustorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=pnw_OpenAccessTransmissionTariffMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RegulatoryAgencyAxis=pnw_UnitedStatesFederalEnergyRegulatoryCommissionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=pnw_LostFixedCostRecoveryMechanismsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: