v3.26.1
Derivative Accounting (Tables)
 6 Months Ended
Jun. 30, 2026
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
Schedule of Outstanding Gross Notional Amount of Derivatives, which Represents Both Purchases and Sales
The following table shows the outstanding gross notional volume of energy derivatives, which represent both purchases and sales (does not reflect net position):
Quantity
CommodityUnit of MeasureJune 30, 2026December 31, 2025
PowerGigawatt-hour408 542 
GasBillion cubic feet246 211 
Schedule of Gains and Losses from Derivative Instruments Not Designated as Accounting Hedges Instruments The following table provides information about gains and losses from energy derivative instruments not designated as accounting hedging instruments (dollars in thousands):
Financial Statement Three Months Ended June 30,Six Months Ended June 30,
Commodity ContractsLocation2026202520262025
Net Gain (Loss) Recognized in Income
Fuel and purchased power (a)$(30,855)$(75,934)$(56,752)$40,770 
(a)Amounts are before the effect of PSA deferrals.
Schedule of the Entity's Fair Value of Risk Management Activities Reported on a Gross Basis and the Impacts on Offsetting Liabilities
The following tables provide information about the fair value of APS’s risk management activities reported on a gross basis and the impacts of offsetting.  These amounts relate to commodity contracts and are located in the assets and liabilities from risk management activities lines of APS’s Condensed Consolidated Balance Sheets (dollars in thousands):

As of June 30, 2026Gross 
Recognized 
Derivatives
 (a)		Amounts 
Offset
(b)		Net
 Recognized
 Derivatives		Other
 (c)		Amounts 
Reported on 
Balance Sheets
Current assets$782 $(782)$— $5 $5 
Investments and other assets1,230 (1,230)— — — 
Total assets2,012 (2,012)— 5 5 
Current liabilities(69,470)782 (68,688)(2,296)(70,984)
Deferred credits and other(11,373)1,230 (10,143)— (10,143)
Total liabilities(80,843)2,012 (78,831)(2,296)(81,127)
Total$(78,831)$— $(78,831)$(2,291)$(81,122)
(a)All of our gross recognized derivative instruments were subject to master netting arrangements.
(b)No cash collateral has been provided to or received by counterparties that is subject to offsetting.
(c)Represents cash collateral and cash margin that is not subject to offsetting. Amounts relate to non-derivative instruments, derivatives qualifying for scope exceptions, or collateral and margin posted in excess of the recognized derivative instrument.  Includes cash collateral received from counterparties of $2,296 thousand and cash margin provided to counterparties of $5 thousand.

As of December 31, 2025Gross
 Recognized
 Derivatives
 (a)		Amounts
Offset 
(b)		Net
 Recognized
 Derivatives		Other
 (c)		Amounts
 Reported on
 Balance Sheets
Current assets$12,640 $(9,395)$3,245 $5 $3,250 
Investments and other assets6,707 (1,570)5,137 — 5,137 
Total assets19,347 (10,965)8,382 5 8,387 
Current liabilities(41,970)9,395 (32,575)(2,566)(35,141)
Deferred credits and other(3,065)1,570 (1,495)— (1,495)
Total liabilities(45,035)10,965 (34,070)(2,566)(36,636)
Total$(25,688)$— $(25,688)$(2,561)$(28,249)
(a)All of our gross recognized derivative instruments were subject to master netting arrangements.
(b)No cash collateral has been provided to or received by counterparties that is subject to offsetting.
(c)Represents cash collateral and cash margin that is not subject to offsetting.  Amounts relate to non-derivative instruments, derivatives qualifying for scope exceptions, or collateral and margin posted in excess of the recognized derivative instrument.  Includes cash collateral received from counterparties of $2,566 thousand and cash margin provided to counterparties of $5 thousand.
Schedule of the Entity's Fair Value of Risk Management Activities Reported on a Gross Basis and the Impacts on Offsetting Assets
The following tables provide information about the fair value of APS’s risk management activities reported on a gross basis and the impacts of offsetting.  These amounts relate to commodity contracts and are located in the assets and liabilities from risk management activities lines of APS’s Condensed Consolidated Balance Sheets (dollars in thousands):

As of June 30, 2026Gross 
Recognized 
Derivatives
 (a)		Amounts 
Offset
(b)		Net
 Recognized
 Derivatives		Other
 (c)		Amounts 
Reported on 
Balance Sheets
Current assets$782 $(782)$— $5 $5 
Investments and other assets1,230 (1,230)— — — 
Total assets2,012 (2,012)— 5 5 
Current liabilities(69,470)782 (68,688)(2,296)(70,984)
Deferred credits and other(11,373)1,230 (10,143)— (10,143)
Total liabilities(80,843)2,012 (78,831)(2,296)(81,127)
Total$(78,831)$— $(78,831)$(2,291)$(81,122)
(a)All of our gross recognized derivative instruments were subject to master netting arrangements.
(b)No cash collateral has been provided to or received by counterparties that is subject to offsetting.
(c)Represents cash collateral and cash margin that is not subject to offsetting. Amounts relate to non-derivative instruments, derivatives qualifying for scope exceptions, or collateral and margin posted in excess of the recognized derivative instrument.  Includes cash collateral received from counterparties of $2,296 thousand and cash margin provided to counterparties of $5 thousand.

As of December 31, 2025Gross
 Recognized
 Derivatives
 (a)		Amounts
Offset 
(b)		Net
 Recognized
 Derivatives		Other
 (c)		Amounts
 Reported on
 Balance Sheets
Current assets$12,640 $(9,395)$3,245 $5 $3,250 
Investments and other assets6,707 (1,570)5,137 — 5,137 
Total assets19,347 (10,965)8,382 5 8,387 
Current liabilities(41,970)9,395 (32,575)(2,566)(35,141)
Deferred credits and other(3,065)1,570 (1,495)— (1,495)
Total liabilities(45,035)10,965 (34,070)(2,566)(36,636)
Total$(25,688)$— $(25,688)$(2,561)$(28,249)
(a)All of our gross recognized derivative instruments were subject to master netting arrangements.
(b)No cash collateral has been provided to or received by counterparties that is subject to offsetting.
(c)Represents cash collateral and cash margin that is not subject to offsetting.  Amounts relate to non-derivative instruments, derivatives qualifying for scope exceptions, or collateral and margin posted in excess of the recognized derivative instrument.  Includes cash collateral received from counterparties of $2,566 thousand and cash margin provided to counterparties of $5 thousand.
Schedule of Information about Derivative Instruments that have Credit-Risk-Related Contingent Features
The following table provides information about our energy derivative instruments that have credit-risk-related contingent features (dollars in thousands):
June 30, 2026
Aggregate fair value of derivative instruments in a net liability position$80,843 
Additional collateral in the event credit-risk related contingent features were fully triggered (a)52,202 
(a)This amount is after counterparty netting and includes those contracts which qualify for scope exceptions, which are excluded from the derivative details above.