CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 631,643	$ 626,030	$ 518,781
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on sale relating to BCE	0	(22,988)	(6,423)
Depreciation and amortization including nuclear fuel	969,615	956,184	854,136
Allowance for equity funds used during construction	(61,146)	(38,620)	(53,118)
Deferred income taxes	(50,850)	(20,923)	(24,310)
Deferred investment tax credit	58,772	(8,253)	77,065
Change in derivative instruments fair value	0	0	(777)
Stock compensation	27,457	23,532	17,341
Changes in current assets and liabilities:
Customer and other receivables	(51,275)	(12,696)	(61,983)
Accrued unbilled revenues	3,211	(9,350)	(2,789)
Materials, supplies and fossil fuel	(63,711)	(7,895)	(42,911)
Income tax receivable	(5,979)	332	13,754
Deferred fuel and purchased power	(324,482)	(250,288)	(549,877)
Deferred fuel and purchased power amortization	463,011	425,886	547,243
Other current assets	(42,991)	(50,225)	(19,550)
Accounts payable	171,138	(7,214)	(75,623)
Accrued taxes	10,742	9,030	2,393
Other current liabilities	18,714	47,329	40,510
Change in unrecognized tax benefits	81,090	75	1,177
Change in long-term regulatory assets	91,373	43,305	53,112
Change in long-term regulatory liabilities	37,205	9,416	28,495
Change in other long-term assets	(283,507)	(132,563)	(195,598)
Change in operating lease assets	151,522	98,214	90,525
Change in other long-term liabilities	138,934	24,719	61,903
Change in operating lease liabilities	(165,391)	(93,214)	(65,779)
Net cash provided by operating activities	1,805,095	1,609,823	1,207,697
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(2,624,618)	(2,249,195)	(1,846,370)
Contributions in aid of construction	306,380	311,358	180,866
Proceeds from sale relating to BCE	0	84,322	23,400
Allowance for borrowed funds used during construction	(47,733)	(48,270)	(43,564)
Proceeds from nuclear decommissioning trusts sales and other special use funds	1,855,200	1,686,094	1,679,722
Investment in nuclear decommissioning trusts and other special use funds	(1,858,991)	(1,709,526)	(1,681,845)
Other	(8,912)	(8,413)	(6,458)
Net cash used for investing activities	(2,378,674)	(1,933,630)	(1,694,249)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of long-term debt	1,742,754	1,313,229	689,349
Repayment of long-term debt	(800,000)	(875,000)	(32,740)
Short-term borrowings and (repayments) — net	213,555	(241,050)	241,900
Short-term debt borrowings under term loan facility	575,000	550,000	0
Short-term debt repayments under term loan facility	(600,000)	(350,000)	0
Dividends paid on common stock	(422,792)	(394,663)	(386,486)
Common stock equity issuance and purchases — net	84,613	341,429	(4,093)
Palo Verde sale leaseback noncontrolling interest acquisition	(198,744)	0	0
Capital activities by noncontrolling interests	(18,041)	(21,255)	(21,255)
Net cash provided by financing activities	576,345	322,690	486,675
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	2,766	(1,117)	123
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	3,838	4,955	4,832
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 6,604	$ 3,838	$ 4,955