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Debt Securities, Available-for-sale, Other

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Decommissioning And Other Special Use Fund Investments, Fair Value

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of unrealized gain on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of unrealized loss on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Sum of the carrying amounts as of the balance sheet date of all investments.

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Investments in Nuclear Decommissioning Trusts and Other Special Use Funds (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Variable Interest Entity \| Pinnacle West Captive Insurance Cell
Fair value of fixed income securities, summarized by contractual maturities
Special use fund	$ 35,000		$ 34,000
APS
Nuclear decommissioning trust fund assets
Fair Value	1,701,502		1,691,202
Total Unrealized Gains	354,982	$ 366,844
Total Unrealized Losses	(22,643)	(32,136)
Amortized cost	1,252,000		1,224,000
Realized gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds
Realized gains	1,658	54,572
Realized losses	(2,761)	(2,815)
Proceeds from the sale of securities	485,814	443,870
Fair value of fixed income securities, summarized by contractual maturities
Special use fund			34,200
APS \| Nuclear Decommissioning Trusts
Nuclear decommissioning trust fund assets
Fair Value	1,286,101		1,282,845
Realized gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds
Realized gains	1,658	54,492
Realized losses	(2,761)	(2,815)
Proceeds from the sale of securities	416,601	377,822
APS \| Other Special Use Funds
Nuclear decommissioning trust fund assets
Fair Value	415,401		408,357
Realized gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds
Realized gains	0	80
Realized losses	0	0
Proceeds from the sale of securities	69,213	66,048
APS \| Captive Insurance Cell
Realized gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds
Proceeds from the sale of securities	25,300
APS \| Equity securities
Nuclear decommissioning trust fund assets
Equity securities	453,987		460,432
Total Unrealized Gains	341,566	359,127
Total Unrealized Losses	(325)	(176)
APS \| Equity securities \| Nuclear Decommissioning Trusts
Nuclear decommissioning trust fund assets
Equity securities	416,753		435,470
APS \| Equity securities \| Other Special Use Funds
Nuclear decommissioning trust fund assets
Equity securities	37,234		24,962
APS \| Available for sale-fixed income securities
Nuclear decommissioning trust fund assets
Fair Value	1,242,795		1,199,584
Total Unrealized Gains	13,416	7,717
Total Unrealized Losses	(22,318)	(31,960)
Fair value of fixed income securities, summarized by contractual maturities
Less than one year	187,202
1 year – 5 years	497,753
5 years – 10 years	154,002
Greater than 10 years	403,838
Total	1,242,795
APS \| Available for sale-fixed income securities \| Nuclear Decommissioning Trusts
Nuclear decommissioning trust fund assets
Fair Value	866,658		844,040
Fair value of fixed income securities, summarized by contractual maturities
Less than one year	32,422
1 year – 5 years	292,409
5 years – 10 years	137,989
Greater than 10 years	403,838
Total	866,658
APS \| Available for sale-fixed income securities \| Other Special Use Funds
Nuclear decommissioning trust fund assets
Fair Value	376,137		355,544
APS \| Available for sale-fixed income securities \| Coal Reclamation Escrow Account
Fair value of fixed income securities, summarized by contractual maturities
Less than one year	90,167
1 year – 5 years	48,289
5 years – 10 years	0
Greater than 10 years	0
Total	138,456
APS \| Available for sale-fixed income securities \| Active Union Employee Medical Account
Fair value of fixed income securities, summarized by contractual maturities
Less than one year	39,464
1 year – 5 years	157,055
5 years – 10 years	16,013
Greater than 10 years	0
Total	212,532
APS \| Available for sale-fixed income securities \| Captive Insurance Cell
Fair value of fixed income securities, summarized by contractual maturities
Less than one year	25,149
1 year – 5 years	0
5 years – 10 years	0
Greater than 10 years	0
Total	25,149
APS \| Other
Nuclear decommissioning trust fund assets
Fair Value	4,720		31,186
Total Unrealized Gains	0	0
Total Unrealized Losses	0	$ 0
APS \| Other \| Nuclear Decommissioning Trusts
Nuclear decommissioning trust fund assets
Fair Value	2,690		3,335
APS \| Other \| Other Special Use Funds
Nuclear decommissioning trust fund assets
Fair Value	2,030		$ 27,851
Pinnacle West \| Variable Interest Entity \| Pinnacle West Captive Insurance Cell
Fair value of fixed income securities, summarized by contractual maturities
Special use fund	$ 35,100