XML 54 R37.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Long-Term Debt and Liquidity Matters - Narrative (Details) | Aug. 31, 2016 USD ($) | Aug. 01, 2016 USD ($) | Sep. 30, 2016 USD ($) Facility | Sep. 20, 2016 USD ($) | Jun. 01, 2016 USD ($) | May 13, 2016 USD ($) | May 12, 2016 USD ($) | May 06, 2016 USD ($) | Apr. 22, 2016 USD ($) | Mar. 31, 2016 USD ($) | Dec. 31, 2015 USD ($)
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Shot-term debt |  |  | $ 117,300,000 |  |  |  |  |  |  |  | $ 0
Debt Provisions |  |  |  |  |  |  |  |  |  |  |
Total shareholder equity |  |  | 4,853,346,000 |  |  |  |  |  |  |  | 4,583,917,000
Pinnacle West | Revolving Credit Facility | Revolving credit facility maturing in May 2019 |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Current borrowing capacity on credit facility |  |  |  |  |  |  | $ 200,000,000 |  |  |  |
Pinnacle West | Revolving Credit Facility | Revolving credit facility maturing May 2021 |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Current borrowing capacity on credit facility |  |  |  |  |  | $ 200,000,000 |  |  |  |  |
Maximum borrowing capacity on credit facility upon satisfaction of certain conditions and consent of lenders (up to) |  |  | 300,000,000 |  |  |  |  |  |  |  |
Outstanding borrowings |  |  | 0 |  |  |  |  |  |  |  |
Pinnacle West | Revolving Credit Facility | Revolving credit facility maturing in August 2017 |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Maximum borrowing capacity on credit facility upon satisfaction of certain conditions and consent of lenders (up to) | $ 75,000,000 |  |  |  |  |  |  |  |  |  |
Debt instrument, term | 364 days |  |  |  |  |  |  |  |  |  |
Shot-term debt |  |  | 34,000,000 |  |  |  |  |  |  |  |
Pinnacle West | Letter of Credit | Revolving credit facility maturing May 2021 |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Outstanding letters of credit |  |  | 0 |  |  |  |  |  |  |  |
Pinnacle West | Commercial paper | Revolving credit facility maturing May 2021 |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Commercial paper |  |  | 0 |  |  |  |  |  |  |  |
APS |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Shot-term debt |  |  | 83,300,000 |  |  |  |  |  |  |  | 0
Debt Provisions |  |  |  |  |  |  |  |  |  |  |
Total shareholder equity |  |  | 4,946,651,000 |  |  |  |  |  |  |  | 4,679,254,000
APS | ACC |  |  |  |  |  |  |  |  |  |  |
Debt Provisions |  |  |  |  |  |  |  |  |  |  |
Total shareholder equity |  |  | 4,900,000,000 |  |  |  |  |  |  |  |
Total capitalization |  |  | 9,200,000,000 |  |  |  |  |  |  |  |
Dividend restrictions, shareholder equity required |  |  | $ 3,700,000,000 |  |  |  |  |  |  |  |
APS | ACC | Minimum |  |  |  |  |  |  |  |  |  |  |
Debt Provisions |  |  |  |  |  |  |  |  |  |  |
Required common equity ratio ordered by ACC (as a percent) (at least) |  |  | 40.00% |  |  |  |  |  |  |  |
APS | Arizona pollution control corporation revenue refunding bonds, 2009 series A |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, repurchased face amount |  |  |  |  | $ 13,000,000 |  |  |  |  |  |
APS | Revolving Credit Facility | Revolving credit facility maturing in May 2019 |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Current borrowing capacity on credit facility |  |  |  |  |  |  | $ 500,000,000 |  |  |  |
APS | Revolving Credit Facility | Revolving Credit Facilities Maturing in 2020 and 2021 |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Current borrowing capacity on credit facility |  |  | $ 1,000,000,000 |  |  |  |  |  |  |  |
Maximum borrowing capacity on credit facility upon satisfaction of certain conditions and consent of lenders (up to) |  |  | 1,400,000,000 |  |  |  |  |  |  |  |
Outstanding borrowings |  |  | $ 0 |  |  |  |  |  |  |  |
Number of line of credit facilities | Facility |  |  | 2 |  |  |  |  |  |  |  |
APS | Revolving Credit Facility | Revolving credit facility maturing May 2021 |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Current borrowing capacity on credit facility |  |  | $ 500,000,000 |  |  | $ 500,000,000 |  |  |  |  |
Maximum borrowing capacity on credit facility upon satisfaction of certain conditions and consent of lenders (up to) |  |  | 700,000,000 |  |  |  |  |  |  |  |
APS | Revolving Credit Facility | Revolving credit facility maturing September 2020 |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Current borrowing capacity on credit facility |  |  | 500,000,000 |  |  |  |  |  |  |  |
Maximum borrowing capacity on credit facility upon satisfaction of certain conditions and consent of lenders (up to) |  |  | 700,000,000 |  |  |  |  |  |  |  |
APS | Commercial paper |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Maximum commercial paper support available under credit facility |  |  | 500,000,000 |  |  |  |  |  |  | $ 500,000,000 | $ 250,000,000
APS | Commercial paper | Revolving Credit Facilities Maturing in 2020 and 2021 |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Commercial paper |  |  | $ 83,000,000 |  |  |  |  |  |  |  |
APS | Secured debt | Term loan facility maturing April 22, 2019 |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Debt issued |  |  |  |  |  |  |  |  | $ 100,000,000 |  |
Senior Notes | APS | Unsecured senior notes 3.75 percent mature on 15 May, 2046 |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Debt issued |  |  |  |  |  |  |  | $ 350,000,000 |  |  |
Debt instrument, stated interest rate |  |  |  |  |  |  |  | 3.75% |  |  |
Senior Notes | APS | Unsecured senior notes 6.25 percent maturing on 01 August, 2016 |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Debt instrument, stated interest rate |  | 6.25% |  |  |  |  |  |  |  |  |
Repayments of debt |  | $ 250,000,000 |  |  |  |  |  |  |  |  |
Senior Notes | APS | Unsecured senior notes 2.55 percent maturing on 15 September, 2026 |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Debt issued |  |  |  | $ 250,000,000 |  |  |  |  |  |  |
Debt instrument, stated interest rate |  |  |  | 2.55% |  |  |  |  |  |  |
Current Maturities of Long-term Debt | APS | Arizona pollution control corporation revenue refunding bonds, 2009 series D and E |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, repurchased face amount |  |  |  |  | $ 64,000,000 |  |  |  |  |  |
Current Maturities of Long-term Debt | APS | Arizona pollution control corporation revenue refunding bond, 2009 series B |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, repurchased face amount |  |  |  | $ 27,000,000 |  |  |  |  |  |  |
LIBOR | Pinnacle West | Revolving Credit Facility | Revolving credit facility maturing in August 2017 |  |  |  |  |  |  |  |  |  |  |
Long-Term Debt and Liquidity Matters |  |  |  |  |  |  |  |  |  |  |
Debt instrument, basis spread on variable rate | 0.80% |  |  |  |  |  |  |  |  |  |

X
- References No definition available. + Details
Name: | pnw_DebtProvisionsAbstract
Namespace Prefix: | pnw_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the maximum borrowings available for the commercial paper program under the terms of line of credit facility. + References No definition available. + Details
Name: | pnw_LineOfCreditFacilityCommercialPaperProgramMaximumBorrowingCapacity
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Represents the number of line of credit facilities. + References No definition available. + Details
Name: | pnw_LineOfCreditFacilityNumberOfAgreements
Namespace Prefix: | pnw_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition 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. + References No definition available. + Details
Name: | pnw_PublicUtilityOrderCommonStockholdersEquityRatio
Namespace Prefix: | pnw_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The amount of total shareholder equity required in order for the entity to pay dividends pursuant to an order from a regulatory authority. + References No definition available. + Details
Name: | pnw_PublicUtilityOrderDividendRestrictionsShareholderEquity
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The sum of total shareholder equity and long-term debt less current maturities, including a portion of APS' current maturities of long-term debt. + References No definition available. + Details
Name: | pnw_ShareholderEquityAndLongTermDebtAndCurrentMaturities
Namespace Prefix: | pnw_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days. + 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(19)(a)(3)) -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 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(13)(2)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_CommercialPaper
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References 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 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + 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 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- 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. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of the original debt instrument that was repurchased. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentRepurchasedFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The total amount of the contingent obligation under letters of credit outstanding as of the reporting date. + References No definition available. + Details
Name: | us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + 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(22)) -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 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_LineOfCredit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility. + 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 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + 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 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations. + References No definition available. + Details
Name: | us-gaap_RepaymentsOfDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than 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 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(19)(a)) -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 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(13)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)(a)(1)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_ShortTermBorrowings
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition 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. + 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(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 + Details
Name: | us-gaap_StockholdersEquity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Details
Name: | us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnw_RevolvingCreditFacilityMaturingMay2019Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnw_RevolvingCreditFacilityMaturingMay2021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnw_RevolvingCreditFacilityMaturingAugust2017Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=us-gaap_LetterOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=us-gaap_CommercialPaperMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=pnw_ArizonaPublicServiceCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnw_RevolvingCreditFacilitiesMaturingin2020and2021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnw_RevolvingCreditFacilityMaturingSeptember2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

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

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

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

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

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

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

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |