CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	$ 604,054	$ 584,570
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including nuclear fuel	532,341	515,742
Deferred fuel and purchased power	(224,541)	(82,679)
Deferred fuel and purchased power amortization	25,195	(9,295)
Allowance for equity funds used during construction	(30,549)	(24,652)
Deferred income taxes	104,128	91,077
Deferred investment tax credit	(8,333)	(8,541)
Stock compensation	16,708	12,119
Changes in current assets and liabilities:
Customer and other receivables	(110,584)	(118,998)
Accrued unbilled revenues	(58,334)	(47,176)
Materials, supplies and fossil fuel	(46,744)	6,843
Income tax receivable	6,792	17,402
Other current assets	(19,129)	(20,527)
Accounts payable	19,005	(6,400)
Accrued taxes	93,953	76,459
Other current liabilities	(26,491)	6,946
Change in other long-term assets	(177,566)	(10,152)
Change in other long-term liabilities	(39,392)	(210,719)
Net cash provided by operating activities	660,513	772,019
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,006,431)	(971,052)
Contributions in aid of construction	67,278	41,457
Allowance for borrowed funds used during construction	(15,466)	(13,488)
Proceeds from nuclear decommissioning trusts sales and other special use funds	797,179	607,885
Investment in nuclear decommissioning trusts and other special use funds	(815,193)	(624,249)
Other	10,321	3,944
Net cash used for investing activities	(962,312)	(955,503)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of long-term debt	596,999	1,483,822
Short-term borrowing and (repayments) - net	(25,000)	(42,750)
Short-term debt borrowings under revolving credit facility	0	751,690
Short-term debt repayments under revolving credit facility	(19,000)	(765,690)
Dividends paid on common stock	(275,329)	(258,924)
Repayment of long-term debt	0	(800,000)
Common stock equity issuances and (purchases) - net	477	(1,649)
Distributions to noncontrolling interests	(10,628)	(11,372)
Net cash provided by financing activities	267,519	355,127
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(34,280)	171,643
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	59,968	10,283
CASH AND CASH EQUIVALENTS AT END OF PERIOD	25,688	181,926
APS
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	611,616	597,446
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including nuclear fuel	532,260	515,679
Deferred fuel and purchased power	(224,541)	(82,679)
Deferred fuel and purchased power amortization	25,195	(9,295)
Allowance for equity funds used during construction	(30,549)	(24,652)
Deferred income taxes	81,255	52,795
Deferred investment tax credit	(8,333)	(8,541)
Changes in current assets and liabilities:
Customer and other receivables	(111,220)	(129,892)
Accrued unbilled revenues	(58,334)	(47,176)
Materials, supplies and fossil fuel	(46,744)	6,843
Income tax receivable	0	7,313
Other current assets	(20,678)	(18,512)
Accounts payable	19,776	(3,355)
Accrued taxes	121,917	132,662
Other current liabilities	(35,386)	7,981
Change in other long-term assets	(166,186)	(9,478)
Change in other long-term liabilities	(39,351)	(216,308)
Net cash provided by operating activities	650,697	770,831
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,006,431)	(971,052)
Contributions in aid of construction	67,278	41,457
Allowance for borrowed funds used during construction	(15,466)	(13,488)
Proceeds from nuclear decommissioning trusts sales and other special use funds	797,179	607,885
Investment in nuclear decommissioning trusts and other special use funds	(815,193)	(624,249)
Other	3,053	(1,260)
Net cash used for investing activities	(969,580)	(960,707)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of long-term debt	446,999	986,872
Short-term borrowing and (repayments) - net	125,000	0
Short-term debt borrowings under revolving credit facility	0	540,000
Short-term debt repayments under revolving credit facility	0	(540,000)
Dividends paid on common stock	(280,500)	(264,000)
Repayment of long-term debt	0	(350,000)
Distributions to noncontrolling interests	(10,628)	(11,372)
Net cash provided by financing activities	280,871	361,500
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(38,012)	171,624
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	57,310	10,169
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 19,298	$ 181,793