Name:	pnw_CostsRelatedToInvestigationAndStudyUnderSuperfundSite
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Litigation Settlement, Percent of Settlement

No definition available.

Name:	pnw_LitigationSettlementPercentofSettlement
Namespace Prefix:	pnw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Loss Contingency, Civil Penalty Amount

No definition available.

Name:	pnw_LossContingencyCivilPenaltyAmount
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Loss Contingency, Environmental Mitigation Project Cost

No definition available.

Name:	pnw_LossContingencyEnvironmentalMitigationProjectCost
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Loss Contingency, Number of Units

No definition available.

Name:	pnw_LossContingencyNumberofUnits
Namespace Prefix:	pnw_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Power Outage Capacity of Transmission Line that Tripped out of Service

No definition available.

Name:	pnw_PowerOutageCapacityofTransmissionLinethatTrippedoutofService
Namespace Prefix:	pnw_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

Represents the number of customers losing service after the generation and transmission resources were lost in the power outage.

No definition available.

Name:	pnw_PowerOutageNumberOfCustomersLosingService
Namespace Prefix:	pnw_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents the period, after the transmission line went off-line, until the generation and transmission resources were lost in the power outage.

No definition available.

Name:	pnw_PowerOutagePeriodOverWhichGenerationAndTransmissionResourcesWereLost
Namespace Prefix:	pnw_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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.

No definition available.

Name:	us-gaap_LossContingenciesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Number of defendants named in a legal action.

No definition available.

Name:	us-gaap_LossContingencyNumberOfDefendants
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Name:	dei_LegalEntityAxis=pnw_ArizonaPublicServiceCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=pnw_ContaminatedGroundwaterWellsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LitigationCaseAxis=pnw_CleanAirActCitizenLawsuitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: