| **Other Income and Other Expense (Details) - USD ($) $ in Thousands** | 12 Months Ended |
|-----------------------------------------------------------------------|-----------------|
||
| **Other income:**                                                     |            |   |   |
| Interest income                                                       | $ 3,497         | $ 884 | $ 493 |
| Miscellaneous                                                         | 509             | 17 | 128 |
| Total other income                                                    | 4,006           | 901 | 621 |
| **Other expense:**                                                    |            |   |   |
| Non-operating costs                                                   | (11,749)        | (9,235) | (11,292) |
| Investment losses — net                                         | (4,113)         | (1,747) | (2,080) |
| Miscellaneous                                                         | (5,677)         | (4,355) | (4,451) |
| Total other expense                                                   | (21,539)        | (15,337) | (17,823) |
| ARIZONA PUBLIC SERVICE COMPANY                                        |            |   |   |
| **Other income:**                                                     |            |   |   |
| Interest income                                                       | 2,858           | 261 | 163 |
| Gain on disposition of property                                       | 2,048           | 5,745 | 716 |
| Miscellaneous                                                         | 1,620           | 2,601 | 1,955 |
| Total other income                                                    | 6,526           | 8,607 | 2,834 |
| **Other expense:**                                                    |            |   |   |
| Non-operating costs                                                   | (12,395)        | (11,034) | (11,648) |
| Loss on disposition of property                                       | (5,424)         | (1,246) | (2,219) |
| Miscellaneous                                                         | (5,561)         | (5,234) | (5,152) |
| Total other expense                                                   | $ (23,380)      | $ (17,514) | $ (19,019) |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of miscellaneous other nonoperating expenses resulting from ancillary business-related activities (that is, excluding major activities considered as a part of the normal operations of the business).
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of miscellaneous other nonoperating income resulting from ancillary business-related activities (that is, excluding major activities considered as a part of the normal operations of the business).
+ References
No definition available.
+ Details**Name:**pnw_MiscellaneousOtherNonoperatingIncome**Namespace Prefix:**pnw_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of nonoperating costs resulting from the ancillary business-related activities (that is, excluding major activities considered as a part of the normal operations of the business) recognized during the period.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of gain (loss) on sale or disposal of property, plant and equipment assets, excluding oil and gas property and timber property.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=64827811&loc=d3e1361-107760Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=84176398&loc=d3e2941-110230
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The difference between the carrying value and the sale price of an investment.  A gain would be recognized when the sale price of the investment is greater than the carrying value of the investment.  This element refers to the Gain included in earnings and not to the cash proceeds of the sale.
+ References
No definition available.
+ Details**Name:**us-gaap_GainOnSaleOfInvestments**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The difference between the carrying value and the sale price of an investment.  A loss would be recognized when the sale price of the investment is less than the carrying value of the investment. This element refers to the Loss included in earnings and not to the cash proceeds of the sale.
+ References
No definition available.
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| X                                                                                                                                                                                                                    |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - References
No definition available.
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| X                                                                                                                                                                                                                   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of expense related to nonoperating activities, classified as other.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.9) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of income related to nonoperating activities, classified as other.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.7) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688
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| X                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------|
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