Commitments and Contingencies (Details) $ in Thousands								3 Months Ended	136 Months Ended
	Mar. 21, 2024 USD ($)	Jan. 01, 2024 USD ($) trust	Oct. 31, 2023 claim	Jan. 17, 2023 USD ($)	Sep. 30, 2022 USD ($)	Jul. 03, 2018	Aug. 18, 2014 USD ($)	Mar. 31, 2024 USD ($) trust MW	Oct. 31, 2022 timePeriod claim	Apr. 18, 2023 USD ($)
Schedule of Commitments and Contingencies [Line Items]
Production tax credit guarantees								$ 31,000
Kūpono Solar
Schedule of Commitments and Contingencies [Line Items]
Non recourse construction financing agreement								$ 140,000		$ 140,000
Kūpono Solar
Schedule of Commitments and Contingencies [Line Items]
Project plant capacity (in MW's) | MW								42
Asset purchase agreement								20 years
APS
Schedule of Commitments and Contingencies [Line Items]
Maximum insurance against public liability per occurrence for a nuclear incident (up to)		$ 16,300,000
Maximum available nuclear liability insurance (up to)		500,000
Remaining nuclear liability insurance through mandatory industry wide retrospective assessment program		15,800,000
Maximum retrospective premium assessment per reactor for each nuclear liability incident		165,900
Annual limit per incident with respect to maximum retrospective premium assessment		$ 24,700
Number of VIE lessor trusts | trust		3						3
Maximum potential retrospective assessment per incident of APS		$ 144,900
Annual payment limitation with respect to maximum potential retrospective premium assessment		$ 21,600
Amount of "all risk" (including nuclear hazards) insurance for property damage to, and decontamination of, property at Palo Verde								$ 2,800,000
Maximum amount that could be incurred under retrospective assessment of NEIL policies								23,100
Collateral assurance provided based on rating triggers								$ 64,100
Period to provide collateral assurance based on rating triggers								20 days
Increase in contractual obligations								$ 295,000
Amount of leases not yet commenced								7,100,000
APS | Surety Bonds Expiring in 2025
Schedule of Commitments and Contingencies [Line Items]
Surety bonds expiring, amount								21,000
APS | Letter of Credit
Schedule of Commitments and Contingencies [Line Items]
Outstanding letters of credit								35,000
APS | Contaminated groundwater wells
Schedule of Commitments and Contingencies [Line Items]
Costs related to investigation and study under Superfund site								3,000
Costs related to oversight and remedial investigation of superfund site				$ 1,700
APS | Contaminated groundwater wells | Pending Litigation
Schedule of Commitments and Contingencies [Line Items]
Settlement amount					$ 20,700
NTEC | Four Corners
Schedule of Commitments and Contingencies [Line Items]
Asset purchase agreement, option to purchase, ownership interest, percentage						7.00%
Breach of Contract for Disposal of Spent Nuclear Fuel and/or High Level Radioactive Waste
Schedule of Commitments and Contingencies [Line Items]
Amount awarded from other party	$ 18,390						$ 18,460	138,200
Breach of Contract for Disposal of Spent Nuclear Fuel and/or High Level Radioactive Waste | APS
Schedule of Commitments and Contingencies [Line Items]
Number of claims submitted | claim			10						9
Gain contingency, number of settlement agreement time periods | timePeriod									9
Amount awarded from other party							$ 5,400	$ 40,200