Investments in Nuclear Decommissioning Trusts and Other Special Use Funds - Schedule of Investments in Nuclear Decommissioning Trusts and Other Special Use Funds (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Variable Interest Entity | Pinnacle West Captive Insurance Cell
Nuclear decommissioning trust fund assets
Special use fund	$ 40,000	$ 34,000
APS
Nuclear decommissioning trust fund assets
Total	1,848,993	1,691,202
Total Unrealized Gains	451,809	366,844
Total Unrealized Losses	(14,994)	(32,136)
Amortized cost	1,265,000	1,224,000
Special use fund		34,200
Realized gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds
Realized gains	13,068	76,062	$ 112,094
Realized losses	(11,749)	(21,966)	(41,780)
Proceeds from the sale of securities	1,855,200	1,686,094	1,679,722
APS | Nuclear Decommissioning Trusts
Nuclear decommissioning trust fund assets
Total	1,414,166	1,282,845
Realized gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds
Realized gains	12,826	75,690	111,922
Realized losses	(11,749)	(21,966)	(41,212)
Proceeds from the sale of securities	1,478,088	1,330,940	1,324,978
APS | Other Special Use Funds
Nuclear decommissioning trust fund assets
Total	434,827	408,357
Realized gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds
Realized gains	242	372	172
Realized losses	0	0	(568)
Proceeds from the sale of securities	377,112	355,154	$ 354,744
APS | Captive Insurance Cell
Nuclear decommissioning trust fund assets
Total Unrealized Gains	3,200
Realized gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds
Proceeds from the sale of securities	51,400
APS | Equity securities
Nuclear decommissioning trust fund assets
Equity securities	582,135	460,432
Total Unrealized Gains	433,044	359,127
Total Unrealized Losses	(1)	(176)
APS | Equity securities | Nuclear Decommissioning Trusts
Nuclear decommissioning trust fund assets
Equity securities	519,562	435,470
APS | Equity securities | Other Special Use Funds
Nuclear decommissioning trust fund assets
Equity securities	62,573	24,962
APS | Available for sale-fixed income securities
Nuclear decommissioning trust fund assets
Available for sale-fixed income securities	1,267,458	1,199,584
Total Unrealized Gains	18,765	7,717
Total Unrealized Losses	(14,993)	(31,960)
Fair value of fixed income securities, summarized by contractual maturities
Less than one year	163,764
1 year – 5 years	497,877
5 years – 10 years	189,684
Greater than 10 years	416,133
Total	1,267,458
APS | Available for sale-fixed income securities | Nuclear Decommissioning Trusts
Nuclear decommissioning trust fund assets
Available for sale-fixed income securities	898,403	844,040
Fair value of fixed income securities, summarized by contractual maturities
Less than one year	36,726
1 year – 5 years	272,413
5 years – 10 years	173,131
Greater than 10 years	416,133
Total	898,403
APS | Available for sale-fixed income securities | Other Special Use Funds
Nuclear decommissioning trust fund assets
Available for sale-fixed income securities	369,055	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	87,421
1 year – 5 years	68,348
5 years – 10 years	0
Greater than 10 years	0
Total	155,769
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	39,617
1 year – 5 years	157,116
5 years – 10 years	16,553
Greater than 10 years	0
Total	213,286
APS | Other
Nuclear decommissioning trust fund assets
Other	(600)	31,186
Total Unrealized Gains	0	0
Total Unrealized Losses	0	0
APS | Other | Nuclear Decommissioning Trusts
Nuclear decommissioning trust fund assets
Other	(3,799)	3,335
APS | Other | Other Special Use Funds
Nuclear decommissioning trust fund assets
Other	3,199	$ 27,851
Pinnacle West | Variable Interest Entity | Pinnacle West Captive Insurance Cell
Nuclear decommissioning trust fund assets
Special use fund	$ 40,300