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Regulatory Matters (Details) (USD $) | 3 Months Ended | 0 Months Ended |  |  |  |  |
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Mar. 31, 2015 | Mar. 31, 2014 | Jan. 01, 2014 | Jan. 06, 2012 | Jun. 01, 2011 | Jan. 15, 2015 | Jan. 15, 2014 | Feb. 12, 2013 | Feb. 01, 2015 | Feb. 01, 2014 | Jun. 01, 2014 | Apr. 02, 2015 | Apr. 15, 2014 Customer MW | Dec. 31, 2012 | Jun. 01, 2012 | Dec. 31, 2014 | Jul. 01, 2014 | Jul. 12, 2013
Change in regulatory asset |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred fuel and purchased power costs-current period | $ 17,671,000 us-gaap_IncreaseDecreaseInRegulatoryClauseRevenue | $ 31,630,000 us-gaap_IncreaseDecreaseInRegulatoryClauseRevenue |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amounts charged to customers | 5,614,000 pnw_IncreaseDecreaseDeferredFuelAndPurchasedPowerAmortization | 8,022,000 pnw_IncreaseDecreaseDeferredFuelAndPurchasedPowerAmortization |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
APS |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Change in regulatory asset |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred fuel and purchased power costs-current period | 17,671,000 us-gaap_IncreaseDecreaseInRegulatoryClauseRevenue / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember | 31,630,000 us-gaap_IncreaseDecreaseInRegulatoryClauseRevenue / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amounts charged to customers | 5,614,000 pnw_IncreaseDecreaseDeferredFuelAndPurchasedPowerAmortization / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember | 8,022,000 pnw_IncreaseDecreaseDeferredFuelAndPurchasedPowerAmortization / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
APS | Lost Fixed Cost Recovery Mechanism |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Change in regulatory asset |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of retail revenues | 1.00%pnw_RateMatterCapPercentageOfRetailRevenue / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_LostFixedCostRecoveryMechanismsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
APS | ACC | Net Metering |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Change in regulatory asset |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Charge on future customers who install rooftop solar panels (in dollars per kWh) | 0.70 pnw_RateMatterChargeOnFutureCustomersWhoInstallRooftopSolarPanels / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_NetMeteringMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember |  | 0.70 pnw_RateMatterChargeOnFutureCustomersWhoInstallRooftopSolarPanels / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_NetMeteringMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated monthly collection due to charge on future customers who install rooftop solar panels |  |  | 4.90 pnw_RateMatterEstimatedMonthlyCollectionDueToChargeOnFutureCustomersWhoInstallRooftopSolarPanels / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_NetMeteringMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Filing with the Arizona Corporation Commission | APS | ACC | Retail rate case filing |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory Matters |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net retail rate increase |  |  |  |  | 95,500,000 us-gaap_PublicUtilitiesRequestedRateIncreaseDecreaseAmount / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |
Approximate percentage of increase in the average retail customer bill |  |  |  |  | 6.60%pnw_RateMatterApproximatePercentageOfIncreaseInAverageRetailCustomerBill / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |
Settlement Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net change in base rates |  |  |  | 0 us-gaap_PublicUtilitiesApprovedRateIncreaseDecreaseAmount / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Non-fuel base rate increase |  |  |  | 116,300,000 pnw_SettlementAgreementNonFuelBaseRateIncrease / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fuel-related base rate decrease |  |  |  | 153,100,000 pnw_SettlementAgreementFuelRelatedBaseRateDecrease / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Current base fuel rate (in dollars per kWh) |  |  |  | 0.03757 pnw_RateMatterBaseFuelRateCurrent / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Approved base fuel rate (in dollars per kWh) |  |  |  | 0.03207 pnw_SettlementAgreementBaseFuelRateProposed / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated amount of transfer of cost recovery for certain renewable energy projects from the RES surcharge to base rates |  |  |  | 36,800,000 pnw_SettlementAgreementTransferOfCostRecoveryToBaseRates / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Authorized return on common equity (as a percent) |  |  |  | 10.00%us-gaap_PublicUtilitiesApprovedReturnOnEquityPercentage / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of debt in capital structure |  |  |  | 46.10%us-gaap_PublicUtilitiesApprovedDebtCapitalStructurePercentage / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of common equity in capital structure |  |  |  | 53.90%us-gaap_PublicUtilitiesApprovedEquityCapitalStructurePercentage / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Deferral of property taxes in 2012, if Arizona property tax rates increase (as a percent) |  |  |  | 25.00%pnw_SettlementAgreementPercentageOfDeferralOfPropertyTaxesIfArizonaPropertyTaxRatesIncreaseYearOne / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Deferral of property taxes in 2013, if Arizona property tax rates increase (as a percent) |  |  |  | 50.00%pnw_SettlementAgreementPercentageOfDeferralOfPropertyTaxesIfArizonaPropertyTaxRatesIncreaseYearTwo / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Deferral of property taxes for 2014 and subsequent years, if Arizona property tax rates increase (as a percent) |  |  |  | 75.00%pnw_SettlementAgreementPercentageOfDeferralOfPropertyTaxesIfArizonaPropertyTaxRatesIncreaseYearThreeAndThereafter / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Deferral of property taxes in all years, if Arizona property tax rates decrease (as a percent) |  |  |  | 100.00%pnw_SettlementAgreementPercentageOfDeferralOfPropertyTaxesIfArizonaPropertyTaxRatesDecrease / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Elimination of the sharing provision of fuel and purchased power costs |  |  |  | 9 pnw_SettlementAgreementCurrentSharingProvisionOfFuelAndPurchasedPowerCostsElimination / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Period to process the subsequent rate cases |  |  |  | 12 months |  |  |  |  |  |  |  |  |  |  |  |  |  |
ACC staff sufficiency findings, general period of time |  |  |  | 30 days |  |  |  |  |  |  |  |  |  |  |  |  |  |
Filing with the Arizona Corporation Commission | APS | ACC | Retail rate case filing | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Settlement Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Annual cost recovery due to modifications to the Environmental Improvement Surcharge |  |  |  | 5,000,000 pnw_SettlementAgreementModificationsToEISCostRecovery / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / pnw_YearOfRateCasesAxis = pnw_RetailRateCaseFilingMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cost Recovery Mechanisms | APS | 2013 DSMAC |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Settlement Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of proposed budget |  |  |  |  |  |  |  |  |  |  |  |  |  | 87,600,000 pnw_RateMatterProposedBudget / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_DemandSideManagementAdjustorCharge2013Member / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember |  |  |  |
Amount of approved budget | 68,900,000 pnw_RateMatterApprovedBudget / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_DemandSideManagementAdjustorCharge2013Member / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cost Recovery Mechanisms | APS | 2014 DSMAC |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Settlement Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of approved budget | 68,900,000 pnw_RateMatterApprovedBudget / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_DemandSideManagementAdjustorCharge2014Member / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cost Recovery Mechanisms | APS | 2015 DSMAC |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Settlement Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of proposed budget | 68,900,000 pnw_RateMatterProposedBudget / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_DemandSideManagementAdjustorCharge2015Member / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cost Recovery Mechanisms | APS | Lost Fixed Cost Recovery Mechanism |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Change in regulatory asset |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fixed costs recoverable per residential power lost (in dollars per kWh) | 0.031 pnw_RateMatterFixedCostRecoverablePerResidentialPowerLost / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_LostFixedCostRecoveryMechanismsMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fixed costs recoverable per non-residential power lost (in dollars per kWh) | 0.023 pnw_RateMatterFixedCostRecoverablePerNonResidentialPowerLost / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_LostFixedCostRecoveryMechanismsMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of adjustment approved representing prorated sales losses |  |  |  |  |  | 38,500,000 pnw_AmountOfAdjustmentRepresentingProratedSalesLossesApproved / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_LostFixedCostRecoveryMechanismsMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember | 25,300,000 pnw_AmountOfAdjustmentRepresentingProratedSalesLossesApproved / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_LostFixedCostRecoveryMechanismsMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember | 5,100,000 pnw_AmountOfAdjustmentRepresentingProratedSalesLossesApproved / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_LostFixedCostRecoveryMechanismsMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember |  |  |  |  |  |  |  |  |  |
Cost Recovery Mechanisms | APS | ACC | RES |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Settlement Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Plan term | 5 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cost Recovery Mechanisms | APS | ACC | 2013 DSMAC |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Settlement Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of cumulative energy savings for current year |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.00%pnw_RateMatterCumulativeEnergySavingsForCurrentYearPercentage / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_DemandSideManagementAdjustorCharge2013Member / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember |  |  |
Cost Recovery Mechanisms | APS | ACC | RES implementation plan covering 2014-2018 timeframe |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Settlement Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of proposed budget |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 154,000,000 pnw_RateMatterProposedBudget / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_ArizonaRenewableEnergyStandardAndTariffAnnualImplementationPlan2014To2018Member / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember | 143,000,000 pnw_RateMatterProposedBudget / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_ArizonaRenewableEnergyStandardAndTariffAnnualImplementationPlan2014To2018Member / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember
Amount of approved budget |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 152,000,000 pnw_RateMatterApprovedBudget / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_ArizonaRenewableEnergyStandardAndTariffAnnualImplementationPlan2014To2018Member / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember |  |
Cost Recovery Mechanisms | APS | ACC | Power Supply Adjustor (PSA) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Change in regulatory asset |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance | 7,000,000 pnw_DeferredFuelandPurchasedPowerRegulatoryAssetLiabilityCurrent / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_PowerSupplyAdjustorMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember | 21,000,000 pnw_DeferredFuelandPurchasedPowerRegulatoryAssetLiabilityCurrent / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_PowerSupplyAdjustorMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember | 21,000,000 pnw_DeferredFuelandPurchasedPowerRegulatoryAssetLiabilityCurrent / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_PowerSupplyAdjustorMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred fuel and purchased power costs-current period | (18,000,000)us-gaap_IncreaseDecreaseInRegulatoryClauseRevenue / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_PowerSupplyAdjustorMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember | (32,000,000)us-gaap_IncreaseDecreaseInRegulatoryClauseRevenue / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_PowerSupplyAdjustorMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amounts charged to customers | (5,000,000)pnw_IncreaseDecreaseDeferredFuelAndPurchasedPowerAmortization / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_PowerSupplyAdjustorMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember | (8,000,000)pnw_IncreaseDecreaseDeferredFuelAndPurchasedPowerAmortization / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_PowerSupplyAdjustorMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ending balance | (16,000,000)pnw_DeferredFuelandPurchasedPowerRegulatoryAssetLiabilityCurrent / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_PowerSupplyAdjustorMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember | (19,000,000)pnw_DeferredFuelandPurchasedPowerRegulatoryAssetLiabilityCurrent / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_PowerSupplyAdjustorMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
PSA rate (in dollars per kWh) |  |  |  |  |  |  |  |  | 0.000887 pnw_PSARate / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_PowerSupplyAdjustorMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember |  |  |  |  |  |  |  |  |
PSA rate for prior year (in dollars per kWh) |  |  |  |  |  |  |  |  |  | 0.001557 pnw_PSARateInPriorYears / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_PowerSupplyAdjustorMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember |  |  |  |  |  |  |  |
Forward component of increase in PSA (in dollars per kWh) |  |  |  |  |  |  |  |  | 0.001131 pnw_ForwardComponentOfPSARate / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_PowerSupplyAdjustorMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember |  |  |  |  |  |  |  |  |
Historical component of increase in PSA (in dollars per kWh) |  |  |  |  |  |  |  |  | (0.000244)pnw_HistoricalComponentOfPSARate / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_PowerSupplyAdjustorMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember |  |  |  |  |  |  |  |  |
Cost Recovery Mechanisms | APS | FERC | Transmission Rates, Transmission Cost Adjustor and Other Transmission Matters |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Change in regulatory asset |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Increase in annual wholesale transmission rates |  |  |  |  |  |  |  |  |  |  | 5,900,000 pnw_RateMattersIncreaseInCostRecovery / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_OpenAccessTransmissionTariffMember / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_CostRecoveryMechanismsMember / us-gaap_RegulatoryAgencyAxis = pnw_UnitedStatesFederalEnergyRegulatoryCommissionMember |  |  |  |  |  |  |
Subsequent Event | APS | ACC | Net Metering |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Change in regulatory asset |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Charge on future customers who install rooftop solar panels (in dollars per kWh) |  |  |  |  |  |  |  |  |  |  |  | 0.70 pnw_RateMatterChargeOnFutureCustomersWhoInstallRooftopSolarPanels / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_NetMeteringMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember |  |  |  |  |  |
Proposed fixed grid access charge on new residential solar customers (in dollars per KWh) |  |  |  |  |  |  |  |  |  |  |  | 3.00 pnw_ProposedFixedGridAccessChargeonNewResidentialSolarCustomers / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_NetMeteringMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember |  |  |  |  |  |
Estimated monthly collection due to charge on new residential solar customers |  |  |  |  |  |  |  |  |  |  |  | $ 21 pnw_RateMatterEstimatedMonthlyCollectionDuetoChargeonNewResidentialSolarCustomers / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_NetMeteringMember / us-gaap_RegulatoryAgencyAxis = pnw_ArizonaCorporationCommissionMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember |  |  |  |  |  |
AZ Sun Program | Filing with the Arizona Corporation Commission | APS | 2014 RES |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Settlement Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Request to build additional utility scale solar, capacity |  |  |  |  |  |  |  |  |  |  |  |  | 20 pnw_PublicUtilitiesRequesttoBuildAdditionalUtilityScaleSolarCapacity / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_ArizonaRenewableEnergyStandardAndTariff2014Member / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / pnw_PublicUtilityProgramAxis = pnw_AZSunProgramMember |  |  |  |  |
Alternative to AZ Sun Program | Filing with the Arizona Corporation Commission | APS | 2014 RES |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Settlement Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Request to build additional utility scale solar, capacity |  |  |  |  |  |  |  |  |  |  |  |  | 10 pnw_PublicUtilitiesRequesttoBuildAdditionalUtilityScaleSolarCapacity / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_ArizonaRenewableEnergyStandardAndTariff2014Member / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / pnw_PublicUtilityProgramAxis = pnw_AlternativetoAZSunProgramMember |  |  |  |  |
Additional capacity from APS-owned non AZ Sun projects, impacted customers |  |  |  |  |  |  |  |  |  |  |  |  | 1,500 pnw_PublicUtilitiesRequesttoBuildAdditionalUtilityScaleSolarNumberofCustomers / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_ArizonaRenewableEnergyStandardAndTariff2014Member / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / pnw_PublicUtilityProgramAxis = pnw_AlternativetoAZSunProgramMember |  |  |  |  |
Alternative to AZ Sun Program, Phase 1 | Filing with the Arizona Corporation Commission | APS | 2014 RES |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Settlement Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Request to build additional utility scale solar, capacity |  |  |  |  |  |  |  |  |  |  |  |  | 8 pnw_PublicUtilitiesRequesttoBuildAdditionalUtilityScaleSolarCapacity / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_ArizonaRenewableEnergyStandardAndTariff2014Member / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / pnw_PublicUtilityProgramAxis = pnw_AlternativetoAZSunProgramPhase1Member |  |  |  |  |
Alternative to AZ Sun Program Phase 2 | Filing with the Arizona Corporation Commission | APS | 2014 RES |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Settlement Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Request to build additional utility scale solar, capacity |  |  |  |  |  |  |  |  |  |  |  |  | 2 pnw_PublicUtilitiesRequesttoBuildAdditionalUtilityScaleSolarCapacity / dei_LegalEntityAxis = pnw_ArizonaPublicServiceCompanyMember / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = pnw_ArizonaRenewableEnergyStandardAndTariff2014Member / pnw_PublicUtilitiesRegulatoryRegulatoryMattersAxis = pnw_FilingWithArizonaCorporationCommissionMember / pnw_PublicUtilityProgramAxis = pnw_AlternativetoAZSunProgramPhase2Member |  |  |  |  |

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