Income Taxes - Schedule of Comparison of Pretax Income from Federal Income Tax Rate to Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Effective Income Tax Rate Reconciliation [Line Items]
Income before income taxes	$ 738,369	$ 736,559	$ 595,693
Amount
Federal income tax expense at statutory rate	155,057	154,677	125,095
State income tax net of federal income tax benefit	23,610	23,735	17,832
Changes in Valuation Allowance	0	0	0
Share based compensation	(4,062)	(421)
Share based compensation			1,346
Palo Verde VIE noncontrolling interest (Note 12)	(3,173)	(3,617)	(3,617)
Other Nontaxable or Nondeductible Items	5,896	3,667	2,405
Effect of changes in tax laws or rates enacted in the current period	0	0	0
Solar or Wind Production Tax Credit	(14,698)	(15,206)	(8,441)
Other Federal Income Tax Credits	(19)	(242)	(650)
Investment credit amortization – deferral method	(12,625)	(9,425)	(9,495)
Changes in Unrecognized Tax Benefits	1,523	(28)	(1,961)
Excess deferred income taxes — Tax Cuts and Jobs Act	(36,558)	(36,559)	(36,558)
Allowance for equity funds used during construction (Note 1)	(7,005)	(2,545)	(5,964)
Other regulatory amortization	(2,758)	(1,796)	(1,828)
Other Adjustments	1,538	(1,711)	(1,252)
Income tax expense	$ 106,726	$ 110,529	$ 76,912
Percent
Federal income tax expense at statutory rate	21.00%	21.00%	21.00%
State income tax net of federal income tax benefit	3.20%	3.22%	2.99%
Changes in Valuation Allowance	0.00%	0.00%	0.00%
Share based compensation	(0.55%)	(0.06%)
Share based compensation			0.23%
Palo Verde VIE noncontrolling interest (Note 12)	(0.43%)	(0.49%)	(0.61%)
Other Nontaxable or Nondeductible Items	0.80%	0.50%	0.40%
Effect of changes in tax laws or rates enacted in the current period	0.00%	0.00%	0.00%
Solar or Wind Production Tax Credit	(1.99%)	(2.07%)	(1.42%)
Other Federal Income Tax Credits	0.00%	(0.03%)	(0.11%)
Investment credit amortization – deferral method	(1.71%)	(1.28%)	(1.59%)
Changes in Unrecognized Tax Benefits	0.21%	0.00%	(0.33%)
Excess deferred income taxes — Tax Cuts and Jobs Act	(4.95%)	(4.96%)	(6.14%)
Allowance for equity funds used during construction (Note 1)	(0.95%)	(0.35%)	(1.00%)
Other regulatory amortization	(0.38%)	(0.24%)	(0.31%)
Other Adjustments	0.20%	(0.23%)	(0.20%)
Income tax expense	14.45%	15.01%	12.91%
APS
Effective Income Tax Rate Reconciliation [Line Items]
Income before income taxes	$ 808,346	$ 786,142	$ 658,745
Amount
Federal income tax expense at statutory rate	169,753	165,090	138,337
State income tax net of federal income tax benefit	27,345	26,824	21,453
Changes in Valuation Allowance	0	0	0
Share based compensation	(2,482)
Share based compensation		23	997
Palo Verde VIE noncontrolling interest (Note 12)	(3,173)	(3,617)	(3,617)
Other Nontaxable or Nondeductible Items	1,727	694	263
Effect of changes in tax laws or rates enacted in the current period	0	0	0
Solar or Wind Production Tax Credit	(11,254)	(12,110)	(5,460)
Other Federal Income Tax Credits	(19)	(242)	(650)
Investment credit amortization – deferral method	(12,625)	(9,425)	(9,495)
Changes in Unrecognized Tax Benefits	1,483	(107)	(1,946)
Excess deferred income taxes — Tax Cuts and Jobs Act	(36,558)	(36,559)	(36,558)
Allowance for equity funds used during construction (Note 1)	(7,005)	(2,545)	(5,964)
Other regulatory amortization	(2,758)	(1,796)	(1,828)
Other Adjustments	1,485	763	(1,348)
Income tax expense	$ 125,919	$ 126,993	$ 94,184
Percent
Federal income tax expense at statutory rate	21.00%	21.00%	21.00%
State income tax net of federal income tax benefit	3.38%	3.41%	3.26%
Changes in Valuation Allowance	0.00%	0.00%	0.00%
Share based compensation	(0.31%)
Share based compensation		0.00%	0.15%
Palo Verde VIE noncontrolling interest (Note 12)	(0.39%)	(0.46%)	(0.55%)
Other Nontaxable or Nondeductible Items	0.21%	0.09%	0.04%
Effect of changes in tax laws or rates enacted in the current period	0.00%	0.00%	0.00%
Solar or Wind Production Tax Credit	(1.39%)	(1.54%)	(0.83%)
Other Federal Income Tax Credits	0.00%	(0.03%)	(0.10%)
Investment credit amortization – deferral method	(1.56%)	(1.20%)	(1.44%)
Changes in Unrecognized Tax Benefits	0.18%	(0.01%)	(0.30%)
Excess deferred income taxes — Tax Cuts and Jobs Act	(4.52%)	(4.65%)	(5.55%)
Allowance for equity funds used during construction (Note 1)	(0.87%)	(0.32%)	(0.91%)
Other regulatory amortization	(0.34%)	(0.23%)	(0.28%)
Other Adjustments	0.19%	0.09%	(0.19%)
Income tax expense	15.58%	16.15%	14.30%