CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	$ 40,514	$ 34,866
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including nuclear fuel	176,409	173,168
Deferred fuel and purchased power	(52,210)	(5,785)
Deferred fuel and purchased power amortization	(564)	(1,808)
Allowance for equity funds used during construction	(9,207)	(7,697)
Deferred income taxes	(11,077)	(18,086)
Deferred investment tax credit	(529)	(465)
Stock compensation	11,337	6,282
Changes in current assets and liabilities:
Customer and other receivables	50,545	25,575
Accrued unbilled revenues	10,163	34,731
Materials, supplies and fossil fuel	(4,801)	5,445
Income tax receivable	6,792	1,128
Other current assets	(9,042)	(20,202)
Accounts payable	24,465	(5,192)
Accrued taxes	53,985	49,833
Other current liabilities	(46,028)	(63,096)
Change in other long-term assets	(36,777)	81,143
Change in other long-term liabilities	(1,963)	(106,212)
Net cash flow provided by operating activities	202,012	183,628
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(363,775)	(340,014)
Contributions in aid of construction	15,296	3,152
Allowance for borrowed funds used during construction	(4,994)	(4,076)
Proceeds from nuclear decommissioning trust sales and other special use funds	379,978	195,087
Investment in nuclear decommissioning trust and other special use funds	(380,548)	(195,658)
Other	5,974	349
Net cash flow used for investing activities	(348,069)	(341,160)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of long-term debt	150,000	0
Short-term borrowing and (repayments) — net	49,750	(76,675)
Short-term debt borrowings under revolving credit facility	0	751,690
Short-term debt repayments under revolving credit facility	(4,000)	(226,690)
Repayment of long-term debt	0	(150,000)
Dividends paid on common stock	(91,721)	(86,257)
Common stock equity issuance — net of purchases	(738)	(1,680)
Net cash flow provided by financing activities	103,291	210,388
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(42,766)	52,856
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	59,968	10,283
CASH AND CASH EQUIVALENTS AT END OF PERIOD	17,202	63,139
APS
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	40,160	40,218
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including nuclear fuel	176,389	173,147
Deferred fuel and purchased power	(52,210)	(5,785)
Deferred fuel and purchased power amortization	(564)	(1,808)
Allowance for equity funds used during construction	(9,207)	(7,697)
Deferred income taxes	(2,616)	(17,782)
Deferred investment tax credit	(529)	(465)
Changes in current assets and liabilities:
Customer and other receivables	50,103	15,045
Accrued unbilled revenues	10,163	34,731
Materials, supplies and fossil fuel	(4,801)	5,445
Income tax receivable	0	(1,411)
Other current assets	(8,825)	(18,164)
Accounts payable	23,881	(4,038)
Accrued taxes	62,204	54,243
Other current liabilities	(43,917)	(49,149)
Change in other long-term assets	(36,626)	82,178
Change in other long-term liabilities	(642)	(105,117)
Net cash flow provided by operating activities	202,963	193,591
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(363,775)	(340,014)
Contributions in aid of construction	15,296	3,152
Allowance for borrowed funds used during construction	(4,994)	(4,076)
Proceeds from nuclear decommissioning trust sales and other special use funds	379,978	195,087
Investment in nuclear decommissioning trust and other special use funds	(380,548)	(195,658)
Other	2,306	(900)
Net cash flow used for investing activities	(351,737)	(342,409)
CASH FLOWS FROM FINANCING ACTIVITIES
Short-term borrowing and (repayments) — net	199,500	0
Short-term debt borrowings under revolving credit facility	0	540,000
Short-term debt repayments under revolving credit facility	0	(110,000)
Repayment of long-term debt	0	(150,000)
Dividends paid on common stock	(93,500)	(88,000)
Net cash flow provided by financing activities	106,000	192,000
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(42,774)	43,182
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	57,310	10,169
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 14,536	$ 53,351