XML 126 R105.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Fair Value Measurements - Significant Unobservable Inputs Used to Value Level 3 Instruments (Details 2) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2023 USD ($) $ / MWh $ / MMBTU | Dec. 31, 2022 USD ($) $ / MMBTU $ / MWh
Information regarding the entity's internally developed significant unobservable inputs used to value its level 3 instruments |  |
Assets | $ 1,570,845 | $ 1,552,870
Liabilities |  | 42,446
Level 3 |  |
Information regarding the entity's internally developed significant unobservable inputs used to value its level 3 instruments |  |
Assets | 6,616 | 26,132
Liabilities |  | 31,020
Level 3 | Forward Contracts | Commodity Contracts |  |
Information regarding the entity's internally developed significant unobservable inputs used to value its level 3 instruments |  |
Assets | 6,616 | 26,132
Liabilities | $ 1,695 | $ 31,020
Level 3 | Forward Contracts | Valuation Technique, Discounted Cash Flow | Commodity Contracts | Weighted Average |  |
Information regarding the entity's internally developed significant unobservable inputs used to value its level 3 instruments |  |
Electricity forward price (in usd per MWh) | $ / MWh | 158.08 | 163.92
Natural gas forward price (in usd per MMBTu) | $ / MMBTU | 0.03 | (5.08)
Level 3 | Forward Contracts | Valuation Technique, Discounted Cash Flow | Commodity Contracts | Minimum |  |
Information regarding the entity's internally developed significant unobservable inputs used to value its level 3 instruments |  |
Electricity forward price (in usd per MWh) | $ / MWh | 37.79 | 37.79
Natural gas forward price (in usd per MMBTu) | $ / MMBTU | 0.00 | (11.81)
Level 3 | Forward Contracts | Valuation Technique, Discounted Cash Flow | Commodity Contracts | Maximum |  |
Information regarding the entity's internally developed significant unobservable inputs used to value its level 3 instruments |  |
Electricity forward price (in usd per MWh) | $ / MWh | 259.04 | 310.69
Natural gas forward price (in usd per MMBTu) | $ / MMBTU | 0.08 | 0
Level 3 | Forward Contracts | Valuation Technique, Discounted Cash Flow | Electricity: | Commodity Contracts |  |
Information regarding the entity's internally developed significant unobservable inputs used to value its level 3 instruments |  |
Assets | $ 6,587 | $ 26,132
Liabilities | 658 | 1,759
Level 3 | Forward Contracts | Valuation Technique, Discounted Cash Flow | Natural Gas: | Commodity Contracts |  |
Information regarding the entity's internally developed significant unobservable inputs used to value its level 3 instruments |  |
Assets | 29 | 0
Liabilities | $ 1,037 | $ 29,261

X
- Definition Fair Value Inputs, Electricity Forward Price + References No definition available. + Details
Name: | pnw_FairValueInputsElectricityForwardPrice
Namespace Prefix: | pnw_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair Value Inputs, Natural Gas Froward Price + References No definition available. + Details
Name: | pnw_FairValueInputsNaturalGasFrowardPrice
Namespace Prefix: | pnw_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-2 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition 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. + References No definition available. + Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of financial and nonfinancial obligations. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-2 + Details
Name: | us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_ForwardContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CommodityContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=us-gaap_ValuationTechniqueDiscountedCashFlowMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_WeightedAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_ElectricityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=srt_NaturalGasReservesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |