XML 117 R91.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Retirement Plans and Other Postretirement Benefits - Additional Information (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items] |  |  |
Funded percentage | 99.00% | 102.00% |
Partnership funding commitments, contribution amount (up to) | $ 50,000,000 |  |
Partnership funding commitments, funded amount | $ 38,000,000 |  |
Arizona Public Service Company |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
APS's employees share of total cost of the plans (as a percent) | 99.00% |  |
Other Benefits Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Expected long-term return on plan assets for next fiscal year (as a percent) | 7.15% |  |
Retiree medical cost reimbursement | $ 27,000,000 | $ 23,000,000 | $ 26,000,000
Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Expected long-term return on plan assets for next fiscal year (as a percent) | 7.05% |  |
Minimum contributions under MAP-21 | $ 0 |  |
Pinnacle West |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Expenses recorded for the defined contribution savings plan | $ 14,000,000 | $ 12,000,000 | $ 12,000,000

X
- Definition Defined Benefit Plan, Accumulated Benefit Obligation, Funded Percentage + References No definition available. + Details
Name: | pnw_DefinedBenefitPlanAccumulatedBenefitObligationFundedPercentage
Namespace Prefix: | pnw_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation during next fiscal year. + References No definition available. + Details
Name: | pnw_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssetsForNextFiscalYear
Namespace Prefix: | pnw_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Benefit Plan - Partnership Funding Commitments, Funded Amount + References No definition available. + Details
Name: | pnw_DefinedBenefitPlanPartnershipFundingCommitmentsFundedAmount
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Defined Benefit Plan - Partnership Funding Commitments, Maximum Contribution Amount + References No definition available. + Details
Name: | pnw_DefinedBenefitPlanPartnershipFundingCommitmentsMaximumContributionAmount
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Defined Benefit Plan Retiree Medical Cost Reimbursement + References No definition available. + Details
Name: | pnw_DefinedBenefitPlanRetireeMedicalCostReimbursement
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Defined Benefit Plans Estimated Minimum Future Employer Contributions, Next Three Fiscal Years + References No definition available. + Details
Name: | pnw_DefinedBenefitPlansEstimatedMinimumFutureEmployerContributionsNextThreeFiscalYears
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of the subsidiary's share of the total cost of the benefit plans relative to the consolidated entity's total cost. + References No definition available. + Details
Name: | pnw_DefinedContributionPlanCostRecognizedPercentage
Namespace Prefix: | pnw_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

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_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of cost for defined contribution plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 70 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480794/715-70-50-1 + Details
Name: | us-gaap_DefinedContributionPlanCostRecognized
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_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=srt_ParentCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |