Palo Verde Sale Leaseback Variable-Interest Entities (Details) (USD $)	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Palo Verde Sale Leaseback Variable-Interest Entities
Increase in net income due to consolidation of Palo Verde Sale Leaseback Trusts	$ 7,154,000	$ 4,769,000	$ 12,615,000	$ 9,886,000
Amounts relating to the VIEs included in Condensed Consolidated Balance Sheets
Property plant and equipment, net of accumulated depreciation	134,799,000		134,799,000		137,956,000
Current maturities of long-term debt	903,516,000		903,516,000		631,879,000
Long-term debt less current maturities	83,130,000		83,130,000		96,803,000
Equity-Noncontrolling interests	101,905,000		101,905,000		91,899,000
Regulatory assets	983,394,000		983,394,000		986,370,000
ARIZONA PUBLIC SERVICE COMPANY
Palo Verde Sale Leaseback Variable-Interest Entities
Number of VIE lessor trusts	3		3
Lease payments per year			49,000,000
Increase in net income due to consolidation of Palo Verde Sale Leaseback Trusts	7,184,000	4,778,000	12,654,000	9,906,000
Amounts relating to the VIEs included in Condensed Consolidated Balance Sheets
Property plant and equipment, net of accumulated depreciation	134,799,000		134,799,000		137,956,000
Current maturities of long-term debt	903,516,000		903,516,000		456,879,000
Long-term debt less current maturities	83,130,000		83,130,000		96,803,000
Equity-Noncontrolling interests	101,128,000		101,128,000		91,084,000
Regulatory assets	983,394,000		983,394,000		986,370,000
ARIZONA PUBLIC SERVICE COMPANY \| Consolidation of VIEs
Palo Verde Sale Leaseback Variable-Interest Entities
Increase in net income due to consolidation of Palo Verde Sale Leaseback Trusts	7,000,000		13,000,000
Amounts relating to the VIEs included in Condensed Consolidated Balance Sheets
Property plant and equipment, net of accumulated depreciation	135,000,000		135,000,000		138,000,000
Current maturities of long-term debt	30,000,000		30,000,000		29,000,000
Long-term debt less current maturities	83,000,000		83,000,000		97,000,000
Equity-Noncontrolling interests	101,000,000		101,000,000		91,000,000
Regulatory assets	34,000,000		34,000,000		33,000,000
Maximum payment to the VIEs' noncontrolling equity participants upon the occurrence of certain unlikely events			145,000,000
VIE debt to be assumed upon the occurrence of certain unlikely events			$ 113,000,000

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.

Name:	pnw_NumberOfVIELessorTrusts
Namespace Prefix:	pnw
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Variable Interest entity long term debt.

+ Details

Name:	pnw_SaleLeasebackLessorNotes
Namespace Prefix:	pnw
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Required payment to Variable Interest Entity Noncontrolling interest holders upon the occurrence of certain events.

+ Details

Name:	pnw_VariableInterestEntityEntityMaximumLossExposureToNoncontrollingInterestsPaymentAmount
Namespace Prefix:	pnw
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of exposure to loss, upon the occurrence of certain events, in the form of assumed debt that is already reflected in the Consolidated Balance Sheets, as a result of involvement with the Variable Interest Entity (VIE).

+ Details

Name:	pnw_VariableInterestEntityLossExposureToDebtAssumedAmount
Namespace Prefix:	pnw
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Obligation related to long-term debt (excluding convertible debt) and capital leases, the portion which is due in one year or less in the future.

+ References

+ Details

Name:	us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which is directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest).

+ References

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 210.5-02.31)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph A3
-Appendix A

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 27
-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph 38
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 7
-Section 03
-Paragraph 20

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Name Accounting Research Bulletin (ARB)
-Publisher AICPA
-Number 51
-Paragraph 26
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_MinorityInterest
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The portion of net Income or Loss attributable to the noncontrolling interest (if any) deducted in order to derive the portion attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=6921930&loc=SL4573702-111684

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
-Paragraph 4J
-URI http://asc.fasb.org/extlink&oid=6922042&loc=SL4591551-111686

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph 38
-Subparagraph a
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph 38
-Subparagraph c(1)
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph A1, A4, A5
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
-Paragraph 4K
-URI http://asc.fasb.org/extlink&oid=6922042&loc=SL4591552-111686

+ Details

Name:	us-gaap_NetIncomeLossAttributableToNoncontrollingInterest
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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 Statement of Financial Accounting Standard (FAS)
-Number 71
-Paragraph 9, 10
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: 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

Name:	us-gaap_RegulatoryAssetsNoncurrent
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The yearly payments due under the lease entered into in connection with the transaction involving the sale of property to another party and the lease of the property back to the seller.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 40
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6456341&loc=d3e50796-112755

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 16
-Subparagraph d
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 98
-Paragraph 17
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6452660&loc=d3e36991-112694

+ Details

Name:	us-gaap_SaleLeasebackTransactionAnnualRentalPayments
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_VariableInterestEntityClassificationOfCarryingAmountAssetsAndLiabilitiesNetAbstract
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The carrying amount of the consolidated Variable Interest Entity's assets included in the reporting entity's statement of financial position.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (bb)
-URI http://asc.fasb.org/extlink&oid=6970148&loc=d3e5710-111685

+ Details

Name:	us-gaap_VariableInterestEntityConsolidatedCarryingAmountAssets
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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.

+ Details

Name:	us-gaap_VariableInterestEntityLineItems
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration