Name:	pnw_AllRiskInsuranceForPropertyDamageAndDecontaminationAtPaloVerde
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Data Type:	xbrli:monetaryItemType
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Represents the annual limit per incident with respect to the maximum assessment per reactor under the program for each nuclear incident, to be periodically adjusted for inflation.

No definition available.

Name:	pnw_AnnualLimitPerIncidentWithRespectToMaximumAssessment
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Represents the annual payment limitation with respect to maximum potential retrospective assessment.

No definition available.

Name:	pnw_AnnualPaymentLimitationWithRespectToMaximumPotentialRetrospectiveAssessment
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Represents the collateral assurance provided that depends upon rating triggers such as a rating downgrade to non-investment grade under NEIL policies.

No definition available.

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Costs related to site-wide groundwater remedial investigation and feasibility study work plan because subsidiary has been found to be potentially responsible parties ("PRPs") with liability for cleanup of hazardous substances that contaminates the soil, water or air, under the Comprehensive Environmental Response, Compensation and Liability Act ("Superfund").

No definition available.

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Fuel and Purchased Power Commitments and Purchase Obligations [Abstract]

No definition available.

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Gain Contingency, New Claims Filed, Number

No definition available.

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Gain Contingency, Number of Settlement Agreement Time Periods

No definition available.

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Maximum Amount that Could be Incurred under Retrospective Assessment of NEIL Policies

No definition available.

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Data Type:	xbrli:monetaryItemType
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Represents the maximum assessment per reactor under the program for each nuclear incident.

No definition available.

Name:	pnw_MaximumAssessmentPerReactorForEachNuclearIncident
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Represents the maximum available nuclear liability insurance which is provided by commercial insurance carriers, maintained by Palo Verde as required by the Price Anderson Nuclear Industries Indemnity Act.

No definition available.

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Represents the maximum insurance amount against public liability per occurrence for a nuclear incident.

No definition available.

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Data Type:	xbrli:monetaryItemType
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Represents the maximum potential retrospective assessment per incident based on the interest of APS in the three Palo Verde units.

No definition available.

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Number of VIE lessor trusts with whom agreements have been made to sell and lease back interests in certain nuclear generating assets and related common facilities.

No definition available.

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Palo Verde Nuclear Generating Station [Abstract]

No definition available.

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Represents the period to provide collateral assurance based on rating triggers such as a rating downgrade to non-investment grade under NEIL policies (in days).

No definition available.

Name:	pnw_PeriodToProvideCollateralAssuranceBasedOnRatingTriggers
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Data Type:	xbrli:durationItemType
Balance Type:	na
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Represents the remaining nuclear liability insurance that is provided through mandatory industry wide retrospective assessment program.

No definition available.

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Data Type:	xbrli:monetaryItemType
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The net present value of an unrecorded unconditional purchase obligation as of the balance sheet date.

No definition available.

Name:	pnw_UnrecordedUnconditionalPurchaseObligationPresentValue
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Data Type:	xbrli:monetaryItemType
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Amount awarded from other party in judgment or settlement of litigation.

No definition available.

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Data Type:	xbrli:monetaryItemType
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Number of defendants named in a legal action.

No definition available.

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Data Type:	xbrli:integerItemType
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Number of plaintiffs that have filed claims pertaining to a loss contingency.

No definition available.

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Data Type:	xbrli:integerItemType
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Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123406679&loc=d3e25336-109308

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Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of the unrecorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).

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Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123406679&loc=d3e25336-109308

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The amount purchased during the period under an unrecorded unconditional purchase obligation (for example, under the take-or-pay or throughput contract).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=123406679&loc=d3e25336-109308

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Data Type:	xbrli:monetaryItemType
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Data Type:	na
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Namespace Prefix:
Data Type:	na
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Namespace Prefix:
Data Type:	na
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Period Type:

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