Income Taxes - Schedule of Components of the Net Deferred Income Tax Liability (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
DEFERRED TAX ASSETS
Risk management activities	$ 14,539	$ 31,411
Regulatory liabilities:
Excess deferred income taxes — Tax Cuts and Jobs Act	271,004	283,161
Asset retirement obligation and removal costs	81,308	113,312
Unamortized investment tax credits	66,327	68,521
Other postretirement benefits	58,862	56,070
Other	47,671	39,857
Operating lease liabilities	400,771	316,067
Pension liabilities	39,070	33,294
Coal reclamation liabilities	42,391	45,505
Renewable energy incentives	14,571	17,261
Credit and loss carryforwards	7,682	43,940
Employee benefit liabilities	57,853	49,222
Other	44,412	28,643
Total deferred tax assets	1,146,461	1,126,264
DEFERRED TAX LIABILITIES
Plant-related	(2,562,990)	(2,572,495)
Risk management activities	(4,089)	(1,682)
Pension and other postretirement assets	(83,401)	(78,853)
Other special use funds	(55,146)	(56,550)
Operating lease right-of-use assets	(400,771)	(316,067)
Regulatory assets:
Allowance for equity funds used during construction	(47,694)	(46,754)
Deferred fuel and purchased power	(84,393)	(149,078)
Pension benefits	(185,641)	(172,239)
Retired power plant costs	(16,904)	(20,659)
Other	(57,602)	(38,320)
Other	(43,383)	(36,107)
Total deferred tax liabilities	(3,590,934)	(3,542,744)
Deferred income taxes — net	(2,444,473)	(2,416,480)
Ocotillo deferral
Regulatory assets:
Defferal	(28,372)	(31,812)
SCR deferral
Regulatory assets:
Defferal	(20,548)	(22,128)
Arizona Public Service Company
DEFERRED TAX ASSETS
Risk management activities	14,539	31,411
Regulatory liabilities:
Excess deferred income taxes — Tax Cuts and Jobs Act	271,004	283,161
Asset retirement obligation and removal costs	81,308	113,312
Unamortized investment tax credits	66,327	68,521
Other postretirement benefits	58,862	56,070
Other	47,671	39,857
Operating lease liabilities	400,442	315,670
Pension liabilities	36,100	29,918
Coal reclamation liabilities	42,391	45,505
Renewable energy incentives	14,571	17,261
Credit and loss carryforwards	0	3,031
Employee benefit liabilities	56,561	48,551
Other	44,412	29,314
Total deferred tax assets	1,134,188	1,081,582
DEFERRED TAX LIABILITIES
Plant-related	(2,562,990)	(2,572,495)
Risk management activities	(4,089)	(1,682)
Pension and other postretirement assets	(82,925)	(78,297)
Other special use funds	(55,146)	(56,550)
Operating lease right-of-use assets	(400,443)	(315,670)
Regulatory assets:
Allowance for equity funds used during construction	(47,694)	(46,754)
Deferred fuel and purchased power	(84,393)	(149,078)
Pension benefits	(185,641)	(172,239)
Retired power plant costs	(16,904)	(20,659)
Other	(57,602)	(38,320)
Other	(7,378)	(7,595)
Total deferred tax liabilities	(3,554,125)	(3,513,279)
Deferred income taxes — net	$ (2,419,937)	$ (2,431,697)