Name:	pnw_DebtInstrumentCovenantConsolidatedDebtToTotalConsolidatedCapitalizationRatio
Namespace Prefix:	pnw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The actual consolidated debt to total consolidated capitalization ratio, which the entity is required to maintain pursuant to a debt covenant.

No definition available.

Name:	pnw_DebtInstrumentCovenantConsolidatedDebtToTotalConsolidatedCapitalizationRatioActual
Namespace Prefix:	pnw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- References

No definition available.

Name:	pnw_DebtProvisionsAbstract
Namespace Prefix:	pnw_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The common equity ratio (defined as the total shareholder equity divided by the sum of total shareholder equity and long-term debt, including current maturities of long-term debt), which the entity is required to maintain pursuant to an order from a regulatory authority.

No definition available.

Name:	pnw_PublicUtilityOrderCommonStockholdersEquityRatio
Namespace Prefix:	pnw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The amount of total shareholder equity required in order for the entity to pay dividends pursuant to an order from a regulatory authority.

No definition available.

Name:	pnw_PublicUtilityOrderDividendRestrictionsShareholderEquity
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Represents the long-term debt authorization pursuant to an order from a regulatory authority.

No definition available.

Name:	pnw_PublicUtilityOrderLongTermDebtAuthorization
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The sum of total shareholder equity and long-term debt less current maturities, including a portion of APS' current maturities of long-term debt.

No definition available.

Name:	pnw_ShareholderEquityAndLongTermDebtAndCurrentMaturities
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Face (par) amount of debt instrument at time of issuance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Contractual interest rate for funds borrowed, under the debt agreement.

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

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

Face (par) amount of the original debt instrument that was repurchased.

No definition available.

Name:	us-gaap_DebtInstrumentRepurchasedFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

No definition available.

Name:	us-gaap_RepaymentsOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 4.E)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(31))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_StockholdersEquity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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

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

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_LegalEntityAxis=us-gaap_ParentCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_DebtInstrumentAxis=pnw_TermLoanFacilityMaturingApril222019Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_CreditFacilityAxis=pnw_TermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_DebtInstrumentAxis=pnw_UnsecuredSeniorNotes3.75PercentMatureon15May2046Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_DebtInstrumentAxis=pnw_ArizonaPollutionControlCorporationRevenueRefundingBonds2009SeriesDandEMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_BalanceSheetLocationAxis=pnw_CurrentMaturitiesofLongtermDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_DebtInstrumentAxis=pnw_ArizonaPollutionControlCorporationRevenueRefundingBonds2009SeriesAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_DebtInstrumentAxis=pnw_UnsecuredSeniorNotes6.25PercentMatureon01August2016Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_DebtInstrumentAxis=pnw_UnsecuredSeniorNotes2.55PercentMatureon15September2026Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_DebtInstrumentAxis=pnw_ArizonaPollutionControlCorporationRevenueRefundingBond2009SeriesBMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: