Income Taxes - Components of Deferred Income Tax Liability (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
DEFERRED TAX ASSETS
Risk management activities	$ 677	$ 4,287
Regulatory liabilities:
Excess deferred income taxes — Tax Cuts and Jobs Act	306,915	319,091
Asset retirement obligation and removal costs	174,952	157,470
Unamortized investment tax credits	49,601	50,879
Other postretirement liabilities	92,654	95,778
Other	65,815	43,551
Operating lease liabilities	204,890	107,853
Pension liabilities	42,136	45,853
Coal reclamation liabilities	43,165	42,065
Renewable energy incentives	22,646	25,355
Credit and loss carryforwards	57,077	26,460
Other	74,184	78,113
Total deferred tax assets	1,134,712	996,755
DEFERRED TAX LIABILITIES
Plant-related	(2,570,613)	(2,489,899)
Risk management activities	(27,276)	(1,174)
Pension and other postretirement assets	(133,624)	(123,462)
Other special use funds	(64,610)	(42,927)
Operating lease right-of-use assets	(204,890)	(107,853)
Regulatory assets:
Allowance for equity funds used during construction	(42,616)	(41,038)
Deferred fuel and purchased power	(96,033)	(47,673)
Pension benefits	(126,010)	(116,219)
Retired power plant costs	(28,389)	(35,214)
Other	(123,902)	(106,227)
Other	(28,611)	(20,472)
Total deferred tax liabilities	(3,446,574)	(3,132,158)
Deferred income taxes — net	(2,311,862)	(2,135,403)
Arizona Public Service Company
DEFERRED TAX ASSETS
Risk management activities	677	4,287
Regulatory liabilities:
Excess deferred income taxes — Tax Cuts and Jobs Act	306,915	319,091
Asset retirement obligation and removal costs	174,952	157,470
Unamortized investment tax credits	49,601	50,879
Other postretirement liabilities	92,654	95,778
Other	65,815	43,551
Operating lease liabilities	204,378	107,414
Pension liabilities	37,814	40,168
Coal reclamation liabilities	43,165	42,065
Renewable energy incentives	22,646	25,355
Credit and loss carryforwards	18,902	8,034
Other	74,184	78,113
Total deferred tax assets	1,091,703	972,205
DEFERRED TAX LIABILITIES
Plant-related	(2,570,613)	(2,489,899)
Risk management activities	(27,276)	(1,174)
Pension and other postretirement assets	(132,769)	(122,580)
Other special use funds	(64,610)	(42,927)
Operating lease right-of-use assets	(204,378)	(107,414)
Regulatory assets:
Allowance for equity funds used during construction	(42,616)	(41,038)
Deferred fuel and purchased power	(96,033)	(47,673)
Pension benefits	(126,010)	(116,219)
Retired power plant costs	(28,389)	(35,214)
Other	(123,902)	(106,227)
Other	(6,808)	(5,513)
Total deferred tax liabilities	(3,423,404)	(3,115,878)
Deferred income taxes — net	$ (2,331,701)	$ (2,143,673)