XML 146 R117.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Investments in Nuclear Decommissioning Trusts and Other Special Use Funds - Additional Information (Details) - USD ($) $ in Thousands |  | 12 Months Ended
--- | --- | ---
Jan. 04, 2021 | Dec. 31, 2021 | Dec. 31, 2020
Other Benefits |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Transfer to active union medical account | $ 106,000 | $ 105,852 | $ 0
Arizona Public Service Company |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Employee medical claims amount |  | $ 15,000 | $ 14,000
Arizona Public Service Company | Other Benefits |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Transfer to active union medical account | $ 106,000 |  |

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

X
- Definition Amount of increase (decrease) in plan assets of defined benefit plan from assets transferred into (from) plan. + References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanAssetsTransferredToFromPlan
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_ScheduleOfEquityMethodInvestmentsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
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: |