XML 70 R54.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Commitments and Contingencies - Palo Verde Nuclear Generating Station and Contractual Obligations (Details) |  | 9 Months Ended |
--- | --- | --- | ---
Aug. 18, 2014 USD ($) | Sep. 30, 2017 USD ($) time_period power_plant claim | Dec. 31, 1986 Trust
Commitments and Contingencies |  |  |
Purchase obligation, increase (decrease) as a result of variable components |  | $ 1,000,000,000 |
Breach of Contract for Disposal of Spent Nuclear Fuel and/or High Level Radioactive Waste |  |  |
Commitments and Contingencies |  |  |
Litigation settlement amount | $ 57,400,000 |  |
Proceeds from legal settlements |  | 65,200,000 |
Arizona Public Service Company |  |  |
Commitments and Contingencies |  |  |
Maximum insurance against public liability per occurrence for a nuclear incident (up to) |  | 13,400,000,000 |
Maximum available nuclear liability insurance (up to) |  | 450,000,000 |
Remaining nuclear liability insurance through mandatory industry wide retrospective assessment program |  | 13,000,000,000 |
Maximum retrospective premium assessment per reactor for each nuclear liability incident |  | 127,300,000 |
Annual limit per incident with respect to maximum retrospective premium assessment |  | $ 19,000,000 |
Number of VIE lessor trusts |  | 3 | 3
Maximum potential retrospective assessment per incident of APS |  | $ 111,100,000 |
Annual payment limitation with respect to maximum potential retrospective premium assessment |  | 16,600,000 |
Amount of "all risk" (including nuclear hazards) insurance for property damage to, and decontamination of, property at Palo Verde |  | 2,800,000,000 |
Maximum amount that APS could incur under the current NEIL policies for each retrospective assessment |  | 24,000,000 |
Collateral assurance provided based on rating triggers |  | $ 64,800,000 |
Period to provide collateral assurance based on rating triggers |  | 20 days |
Arizona Public Service Company | Breach of Contract for Disposal of Spent Nuclear Fuel and/or High Level Radioactive Waste |  |  |
Commitments and Contingencies |  |  |
Litigation settlement amount | $ 16,700,000 |  |
Number of claims submitted | claim |  | 3 |
Number of settlement agreement time periods | time_period |  | 3 |
Proceeds from legal settlements |  | $ 19,000,000 |

X
- Definition Represents the "all risk" (including nuclear hazards) insurance for property damage to, and decontamination of, property at Palo Verde of which a substantial portion must first be applied to stabilization and decontamination. + References No definition available. + Details
Name: | pnw_AllRiskInsuranceForPropertyDamageAndDecontaminationAtPaloVerde
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition 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. + References No definition available. + Details
Name: | pnw_AnnualLimitPerIncidentWithRespectToMaximumAssessment
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the annual payment limitation with respect to maximum potential retrospective assessment. + References No definition available. + Details
Name: | pnw_AnnualPaymentLimitationWithRespectToMaximumPotentialRetrospectiveAssessment
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the collateral assurance provided that depends upon rating triggers such as a rating downgrade to non-investment grade under NEIL policies. + References No definition available. + Details
Name: | pnw_CollateralAssuranceBasedOnRatingTriggers
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | pnw_CommitmentsAndContingenciesLineItems
Namespace Prefix: | pnw_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Gain Contingency, New Claims Filed, Number + References No definition available. + Details
Name: | pnw_GainContingencyNewClaimsFiledNumber
Namespace Prefix: | pnw_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Gain Contingency, Number of Settlement Agreement Time Periods + References No definition available. + Details
Name: | pnw_GainContingencyNumberofSettlementAgreementTimePeriods
Namespace Prefix: | pnw_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum Amount that Could be Incurred under Retrospective Assessment of NEIL Policies + References No definition available. + Details
Name: | pnw_MaximumAmountthatCouldbeIncurredunderRetrospectiveAssessmentofNEILPolicies
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the maximum assessment per reactor under the program for each nuclear incident. + References No definition available. + Details
Name: | pnw_MaximumAssessmentPerReactorForEachNuclearIncident
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition 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. + References No definition available. + Details
Name: | pnw_MaximumAvailableNuclearLiabilityInsurance
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the maximum insurance amount against public liability per occurrence for a nuclear incident. + References No definition available. + Details
Name: | pnw_MaximumInsuranceCoveragePerIncident
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the maximum potential retrospective assessment per incident based on the interest of APS in the three Palo Verde units. + References No definition available. + Details
Name: | pnw_MaximumPotentialRetrospectiveAssessmentPerIncident
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition 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. + References No definition available. + Details
Name: | pnw_NumberOfVIELessorTrusts
Namespace Prefix: | pnw_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition 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). + References No definition available. + Details
Name: | pnw_PeriodToProvideCollateralAssuranceBasedOnRatingTriggers
Namespace Prefix: | pnw_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the remaining nuclear liability insurance that is provided through mandatory industry wide retrospective assessment program. + References No definition available. + Details
Name: | pnw_RemainingNuclearLiabilityInsuranceThroughMandatoryIndustryWideRetrospectiveAssessmentProgram
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount awarded from other party in judgment or settlement of litigation. + References No definition available. + Details
Name: | us-gaap_LitigationSettlementAmountAwardedFromOtherParty
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Cash received for the settlement of litigation during the current period. + References 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=98514028&loc=d3e3536-108585 + Details
Name: | us-gaap_ProceedsFromLegalSettlements
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of change that payments under a contractual obligation might vary as facts and circumstances change. + References No definition available. + Details
Name: | us-gaap_UnrecordedUnconditionalPurchaseObligationChangeOfAmountAsResultOfVariableComponents
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Details
Name: | dei_LegalEntityAxis=pnw_ArizonaPublicServiceCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |