XML 112 R88.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Commitments and Contingencies - Palo Verde Nuclear Generating Station and Contractual Obligations (Details) |  | 12 Months Ended |
--- | --- | --- | ---
Aug. 18, 2014 USD ($) | Dec. 31, 2018 USD ($) Trust | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) | Dec. 31, 1986 Trust
ARIZONA PUBLIC SERVICE COMPANY |  |  |  |  |
Palo Verde Nuclear Generating Station [Abstract] |  |  |  |  |
Maximum insurance against public liability per occurrence for a nuclear incident |  | $ 14,100,000,000 |  |  |
Maximum available nuclear liability insurance |  | 450,000,000 |  |  |
Remaining nuclear liability insurance through mandatory industry wide retrospective assessment program |  | 13,600,000,000 |  |  |
Maximum assessment per reactor for each nuclear incident |  | 137,600,000 |  |  |
Annual limit per incident with respect to maximum assessment |  | $ 20,500,000 |  |  |
Number of VIE lessor trusts | Trust |  | 3 |  |  | 3
Maximum potential retrospective assessment per incident of APS |  | $ 120,100,000 |  |  |
Annual payment limitation with respect to maximum potential retrospective assessment |  | 17,900,000 |  |  |
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 |  | 24,800,000 |  |  |
Collateral assurance provided based on rating triggers |  | $ 71,200,000 |  |  |
Period to provide collateral assurance based on rating triggers |  | 20 days |  |  |
Fuel and Purchased Power Commitments and Purchase Obligations [Abstract] |  |  |  |  |
2019 |  | $ 622,000,000 |  |  |
2020 |  | 555,000,000 |  |  |
2021 |  | 558,000,000 |  |  |
2022 |  | 563,000,000 |  |  |
2023 |  | 560,000,000 |  |  |
Thereafter |  | 5,900,000,000 |  |  |
ARIZONA PUBLIC SERVICE COMPANY | Coal take-or-pay commitments |  |  |  |  |
Fuel and Purchased Power Commitments and Purchase Obligations [Abstract] |  |  |  |  |
2019 |  | 179,879,000 |  |  |
2020 |  | 181,059,000 |  |  |
2021 |  | 184,944,000 |  |  |
2022 |  | 186,244,000 |  |  |
2023 |  | 187,518,000 |  |  |
Thereafter |  | 1,422,253,000 |  |  |
Total obligation |  | 2,341,900,000 |  |  |
Present value of commitments |  | 1,700,000,000 |  |  |
Total purchases |  | 206,093,000 | $ 165,220,000 | $ 160,066,000 |
ARIZONA PUBLIC SERVICE COMPANY | Renewable energy credits |  |  |  |  |
Fuel and Purchased Power Commitments and Purchase Obligations [Abstract] |  |  |  |  |
2019 |  | 37,000,000 |  |  |
2020 |  | 36,000,000 |  |  |
2021 |  | 34,000,000 |  |  |
2022 |  | 31,000,000 |  |  |
2023 |  | 30,000,000 |  |  |
Thereafter |  | 155,000,000 |  |  |
ARIZONA PUBLIC SERVICE COMPANY | Coal Mine Reclamation Obligations |  |  |  |  |
Fuel and Purchased Power Commitments and Purchase Obligations [Abstract] |  |  |  |  |
2019 |  | 32,000,000 |  |  |
2020 |  | 21,000,000 |  |  |
2021 |  | 21,000,000 |  |  |
2022 |  | 22,000,000 |  |  |
2023 |  | 24,000,000 |  |  |
Thereafter |  | 167,000,000 |  |  |
ARIZONA PUBLIC SERVICE COMPANY | Coal Mine Reclamation Balance Sheet Obligations |  |  |  |  |
Fuel and Purchased Power Commitments and Purchase Obligations [Abstract] |  |  |  |  |
Total obligation |  | 213,000,000 | $ 216,000,000 |  |
Arizona Public Service Company and Palo Verde Owners vs. United States Department of Energy - Spent Nuclear Fuel and Waste Disposal |  |  |  |  |
Palo Verde Nuclear Generating Station [Abstract] |  |  |  |  |
Settlement amount, awarded to company | $ 57,400,000 | 10,200,000 |  |  |
Proceeds from legal settlements |  | 74,200,000 |  |  |
Arizona Public Service Company and Palo Verde Owners vs. United States Department of Energy - Spent Nuclear Fuel and Waste Disposal | ARIZONA PUBLIC SERVICE COMPANY |  |  |  |  |
Palo Verde Nuclear Generating Station [Abstract] |  |  |  |  |
Settlement amount, awarded to company | $ 16,700,000 | 3,000,000.0 |  |  |
Proceeds from legal settlements |  | $ 21,600,000 |  |  |

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
- Definition Fuel and Purchased Power Commitments and Purchase Obligations [Abstract] + References No definition available. + Details
Name: | pnw_FuelandPurchasedPowerCommitmentsandPurchaseObligationsAbstract
Namespace Prefix: | pnw_
Data Type: | xbrli:stringItemType
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 Palo Verde Nuclear Generating Station [Abstract] + References No definition available. + Details
Name: | pnw_PaloVerdeNuclearGeneratingStationAbstract
Namespace Prefix: | pnw_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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 The net present value of an unrecorded unconditional purchase obligation as of the balance sheet date. + References No definition available. + Details
Name: | pnw_UnrecordedUnconditionalPurchaseObligationPresentValue
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 25 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=109223946&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 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. + References 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 + Details
Name: | us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnFifthAnniversary
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition 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. + References 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 + Details
Name: | us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnFirstAnniversary
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition 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. + References 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 + Details
Name: | us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition 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. + References 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 + Details
Name: | us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnSecondAnniversary
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition 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. + References 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 + Details
Name: | us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnThirdAnniversary
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition 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). + References 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 + Details
Name: | us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition 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. + References 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 + Details
Name: | us-gaap_UnrecordedUnconditionalPurchaseObligationDueAfterFiveYears
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount purchased during the period under an unrecorded unconditional purchase obligation (for example, under the take-or-pay or throughput contract). + References 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 + Details
Name: | us-gaap_UnrecordedUnconditionalPurchaseObligationPurchases
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Details
Name: | us-gaap_UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchasedAxis=us-gaap_PublicUtilitiesInventoryFuelMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchasedAxis=pnw_RenewableEnergyCreditsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchasedAxis=pnw_CoalMineReclamationObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchasedAxis=pnw_CoalMineReclamationBalanceSheetObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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