Income Taxes - Effective Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Reconciliation Increases Reductions in Tax Expense [Abstract]
Federal income tax expense at statutory rate	$ 156,666	$ 136,127	$ 113,828
State income tax net of federal income tax benefit	22,656	19,146	18,599
State income tax credits net of federal income tax benefit	(7,015)	(8,951)	(8,519)
Net operating loss carryback tax benefit	(5,915)	0	0
Excess deferred income taxes — Tax Cuts and Jobs Act	(36,558)	(50,543)	(124,082)
Allowance for equity funds used during construction (see Note 1)	(4,180)	(2,747)	(2,476)
Palo Verde VIE noncontrolling interest (see Note 18)	(3,617)	(4,094)	(4,094)
Investment tax credit amortization	(7,620)	(7,510)	(6,851)
Other	(4,331)	(3,255)	(2,178)
Income tax expense/(benefit)	110,086	78,173	(15,773)
Arizona Public Service Company
Income Tax Reconciliation Increases Reductions in Tax Expense [Abstract]
Federal income tax expense at statutory rate	162,762	142,020	120,790
State income tax net of federal income tax benefit	23,339	20,124	19,267
State income tax credits net of federal income tax benefit	(5,277)	(7,213)	(6,781)
Net operating loss carryback tax benefit	0	0	0
Excess deferred income taxes — Tax Cuts and Jobs Act	(36,558)	(50,543)	(124,082)
Allowance for equity funds used during construction (see Note 1)	(4,180)	(2,747)	(2,476)
Palo Verde VIE noncontrolling interest (see Note 18)	(3,617)	(4,094)	(4,094)
Investment tax credit amortization	(7,620)	(7,510)	(6,851)
Other	(3,296)	(1,273)	(5,345)
Income tax expense/(benefit)	$ 125,553	$ 88,764	$ (9,572)