Settlement agreement, ACC approved rate adjustment, annualized customer impact

No definition available.

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Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the amount of net receipt due to negotiation of alternate arrangement.

+ References

No definition available.

+ Details

Name:	pnw_TransmissionTerminationAgreementNetReceiptDueToNegotiationOfAlternateArrangement
Namespace Prefix:	pnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the capacity rights over the Arizona Transmission System assigned to third-parties under negotiation of alternate arrangement.

+ References

No definition available.

+ Details

Name:	pnw_TransmissionTerminationAgreementPowerCapacityRightsAssignedToThirdParties
Namespace Prefix:	pnw_
Data Type:	num:powerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the capacity rights related to marketing and trading group for transmission of the additional power received assigned to third-parties under negotiation of alternate arrangement.

+ References

No definition available.

+ Details

Name:	pnw_TransmissionTerminationAgreementPowerCapacityRightsRelatedToMarketingAndTradingGroupForTransmissionOfAdditionalPowerReceiveAssignedToThirdParties
Namespace Prefix:	pnw_
Data Type:	num:powerItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

+ Details

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

- Definition

Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 340

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382

+ Details

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

- Definition

The amortization period for recovery of the individual regulatory noncurrent asset in a schedule of regulatory noncurrent assets.

+ References

No definition available.

+ Details

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

- Details

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

- Details

Name:	us-gaap_BusinessAcquisitionAxis=pnw_SouthernCaliforniaEdisonCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=pnw_FourCornersUnits4And5Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryAssetAxis=pnw_FourCornersCostDeferralMember
Namespace Prefix:
Data Type:	na
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Regulatory Matters - Four Corners (Details) (USD $)	0 Months Ended			12 Months Ended
Regulatory Matters - Four Corners (Details) (USD $)	Dec. 30, 2013	Dec. 30, 2013 MW	Dec. 23, 2014	Dec. 31, 2014	Dec. 31, 2013	Jan. 10, 2014
Acquisition
Regulatory assets, non-current				$ 1,054,087,000us-gaap_RegulatoryAssetsNoncurrent	$ 711,712,000us-gaap_RegulatoryAssetsNoncurrent
APS
Acquisition
Regulatory assets, non-current				1,054,087,000	711,712,000
Four Corners cost deferral
Acquisition
Regulatory assets, non-current				70,000,000	37,000,000
SCE \| Four Corners \| APS
Acquisition
Net receipt due to negotiation of alternate arrangement	40,000,000
Capacity rights over the Arizona transmission system assign to third-parties		1,555
Capacity rights related to marketing and trading group for transmission of the additional power received assign to third-parties		300
Four Corners Units 4 and 5 \| SCE \| APS
Acquisition
Ownership interest acquired	48.00%	48.00%				48.00%
Settlement agreement, ACC approved rate adjustment, annualized customer impact			57,100,000
Four Corners Units 4 and 5 \| SCE \| Four Corners cost deferral \| APS
Acquisition
Regulatory assets, non-current				$ 77,000,000
Regulatory asset amortization period				P10Y