CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
CURRENT ASSETS
Cash and cash equivalents	$ 7,032	$ 9,969
Customer and other receivables	603,197	391,923
Accrued unbilled revenues	221,023	133,980
Allowance for doubtful accounts (Note 2)	(23,999)	(25,354)
Materials and supplies (at average cost)	386,703	349,135
Income tax receivable	0	7,514
Fossil fuel (at average cost)	53,087	18,032
Assets from risk management activities (Note 7)	164,794	63,481
Deferred fuel and purchased power regulatory asset (Note 4)	445,025	388,148
Other regulatory assets (Note 4)	94,676	130,376
Other current assets	65,019	83,896
Total current assets	2,016,557	1,551,100
INVESTMENTS AND OTHER ASSETS
Nuclear decommissioning trusts (Notes 11 and 12)	1,025,913	1,294,757
Other special use funds (Notes 11 and 12)	359,394	358,410
Assets from risk management activities (Note 7)	86,864	46,908
Other assets	121,346	97,884
Total investments and other assets	1,593,517	1,797,959
PROPERTY, PLANT AND EQUIPMENT
Plant in service and held for future use	22,275,468	21,688,661
Accumulated depreciation and amortization	(7,798,591)	(7,504,603)
Net	14,476,877	14,184,058
Construction work in progress	1,684,481	1,329,478
Palo Verde sale leaseback, net of accumulated depreciation (Note 6)	91,264	94,166
Intangible assets, net of accumulated amortization	246,690	273,693
Nuclear fuel, net of accumulated amortization	115,227	106,039
Total property, plant and equipment	16,614,539	15,987,434
DEFERRED DEBITS
Regulatory assets (Note 4)	1,173,415	1,192,987
Operating lease right-of-use assets	806,509	890,057
Assets for pension and other postretirement benefits (Note 5)	595,511	545,723
Other	44,550	37,962
Total deferred debits	2,619,985	2,666,729
TOTAL ASSETS	22,844,598	22,003,222
CURRENT LIABILITIES
Accounts payable	475,362	393,083
Accrued taxes	285,689	168,645
Accrued interest	61,892	57,332
Common dividends payable	0	95,988
Short-term borrowings (Note 3)	466,820	292,000
Current maturities of long-term debt (Note 3)	27,628	150,000
Customer deposits	41,731	42,293
Liabilities from risk management activities (Note 7)	7,240	4,373
Liabilities for asset retirements	6,307	4,473
Operating lease liabilities	128,618	100,443
Regulatory liabilities (Note 4)	420,357	296,271
Other current liabilities	139,260	151,968
Total current liabilities	2,060,904	1,756,869
LONG-TERM DEBT LESS CURRENT MATURITIES (Note 3)	7,344,205	6,913,735
DEFERRED CREDITS AND OTHER
Deferred income taxes	2,418,914	2,311,862
Regulatory liabilities (Note 4)	2,108,289	2,499,213
Liabilities for asset retirements	785,540	762,909
Liabilities for pension benefits (Note 5)	148,403	152,865
Customer advances	362,140	257,151
Coal mine reclamation	178,095	174,616
Deferred investment tax credit	179,418	186,570
Unrecognized tax benefits	4,717	4,657
Operating lease liabilities	642,573	728,401
Other	249,287	232,914
Total deferred credits and other	7,077,376	7,311,158
COMMITMENTS AND CONTINGENCIES (Note 8)
EQUITY
Common stock, no par value; authorized 150,000,000 shares, 113,108,728 and 113,014,528 issued at respective dates	2,720,364	2,702,743
Treasury stock at cost; 36,204 and 87,608 shares at respective dates	(2,603)	(6,401)
Total common stock	2,717,761	2,696,342
Retained earnings	3,580,102	3,264,719
Accumulated other comprehensive loss (Note 13)	(53,300)	(54,861)
Total shareholders’ equity	6,244,563	5,906,200
Noncontrolling interests (Note 6)	117,550	115,260
Total equity	6,362,113	6,021,460
TOTAL LIABILITIES AND EQUITY	$ 22,844,598	$ 22,003,222