XML 78 R65.htm IDEA: XBRL DOCUMENT
v3.25.3

Regulatory Matters - Schedule of Changes in The Deferred Fuel and Purchased Power Regulatory Asset (Details) - USD ($) $ in Thousands | 9 Months Ended
--- | ---
Sep. 30, 2025 | Sep. 30, 2024
Change in regulatory asset |  |
Deferred fuel and purchased power costs | $ 276,327 | $ 244,109
Amounts charged to customers | (358,871) | (340,030)
APS |  |
Change in regulatory asset |  |
Deferred fuel and purchased power costs | 276,327 | 244,109
Amounts charged to customers | (358,871) | (340,030)
Power Supply Adjustor (PSA) | ACC | APS |  |
Change in regulatory asset |  |
Balance at beginning of period | 287,597 | 463,195
Deferred fuel and purchased power costs | 276,327 | 244,109
Amounts charged to customers | (358,871) | (340,030)
Balance at end of period | $ 205,053 | $ 367,274

X
- Definition Deferred Fuel And Purchased Power Regulatory Asset (Liability), Current + References No definition available. + Details
Name: | pnw_DeferredFuelAndPurchasedPowerRegulatoryAssetLiabilityCurrent
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition The amortization of deferred fuel and purchased power costs. + References No definition available. + Details
Name: | pnw_IncreaseDecreaseDeferredFuelAndPurchasedPowerAmortization
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The increase (decrease) during the reporting period in unrecovered fuel costs for a regulated utility company. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (a) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-28 + Details
Name: | us-gaap_IncreaseDecreaseInRegulatoryClauseRevenue
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_PublicUtilitiesRegulatoryProceedingAxis=pnw_PowerSupplyAdjustorMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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