Retirement Plans and Other Postretirement Benefits - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Funded percentage	99.00%	102.00%
Partnership funding commitments, contribution amount (up to)	$ 50,000,000
Partnership funding commitments, funded amount	$ 38,000,000
Arizona Public Service Company
Defined Benefit Plan Disclosure [Line Items]
APS's employees share of total cost of the plans (as a percent)	99.00%
Other Benefits Plans
Defined Benefit Plan Disclosure [Line Items]
Expected long-term return on plan assets for next fiscal year (as a percent)	7.15%
Retiree medical cost reimbursement	$ 27,000,000	$ 23,000,000	$ 26,000,000
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Expected long-term return on plan assets for next fiscal year (as a percent)	7.05%
Minimum contributions under MAP-21	$ 0
Pinnacle West
Defined Benefit Plan Disclosure [Line Items]
Expenses recorded for the defined contribution savings plan	$ 14,000,000	$ 12,000,000	$ 12,000,000