CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME	$ 22,791	$ 8,094
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including nuclear fuel	167,801	163,566
Deferred fuel and purchased power	16,709	(18,950)
Deferred fuel and purchased power amortization	12,872	20,002
Allowance for equity funds used during construction	(11,188)	(14,079)
Deferred income taxes	3,620	(229)
Deferred investment tax credit	(353)	(147)
Stock compensation	12,074	10,537
Changes in current assets and liabilities:
Customer and other receivables	15,476	89,518
Accrued unbilled revenues	23,093	(6,555)
Materials, supplies and fossil fuel	(13,057)	(16,607)
Other current assets	(10,115)	(664)
Accounts payable	26,593	(25,738)
Accrued taxes	45,130	45,984
Other current liabilities	(86,250)	(12,030)
Change in other long-term assets	(65,470)	(3,765)
Change in other long-term liabilities	13,706	(72,065)
Net cash flow provided by operating activities	173,432	166,872
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(259,792)	(361,037)
Contributions in aid of construction	7,938	8,569
Allowance for borrowed funds used during construction	(6,665)	(6,755)
Proceeds from nuclear decommissioning trust sales and other special use funds	179,048	130,456
Investment in nuclear decommissioning trust and other special use funds	(179,618)	(131,027)
Other	4,576	(1,299)
Net cash flow used for investing activities	(254,513)	(361,093)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of long-term debt	497,324	0
Short-term borrowing and payments — net	172,650	263,500
Short-term debt borrowings under revolving credit facility	0	36,000
Short-term debt repayments under revolving credit facility	(5,000)	(25,000)
Dividends paid on common stock	(80,897)	(75,903)
Repayment of long-term debt	(500,000)	0
Common stock equity issuance - net of purchases	(2,653)	(2,828)
Net cash flow provided by financing activities	81,424	195,769
NET INCREASE IN CASH AND CASH EQUIVALENTS	343	1,548
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	5,766	13,892
CASH AND CASH EQUIVALENTS AT END OF PERIOD	6,109	15,440
Supplemental disclosure of cash flow information
Income taxes, net of refunds	1	0
Interest, net of amounts capitalized	63,764	56,026
Significant non-cash investing and financing activities:
Accrued capital expenditures	95,879	86,991
APS
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME	33,149	14,472
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including nuclear fuel	167,779	162,853
Deferred fuel and purchased power	16,709	(18,950)
Deferred fuel and purchased power amortization	12,872	20,002
Allowance for equity funds used during construction	(11,188)	(14,079)
Deferred income taxes	(1,205)	533
Deferred investment tax credit	(353)	(147)
Changes in current assets and liabilities:
Customer and other receivables	16,541	90,647
Accrued unbilled revenues	23,093	(6,555)
Materials, supplies and fossil fuel	(13,057)	(16,747)
Other current assets	(9,598)	(1,237)
Accounts payable	30,774	(24,592)
Accrued taxes	54,234	54,106
Other current liabilities	(81,627)	(15,771)
Change in other long-term assets	(64,516)	3,722
Change in other long-term liabilities	14,525	(70,928)
Net cash flow provided by operating activities	188,132	177,329
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(259,446)	(355,039)
Contributions in aid of construction	7,938	8,569
Allowance for borrowed funds used during construction	(6,665)	(6,755)
Proceeds from nuclear decommissioning trust sales and other special use funds	179,048	130,456
Investment in nuclear decommissioning trust and other special use funds	(179,618)	(131,027)
Other	(1,140)	(1,183)
Net cash flow used for investing activities	(259,883)	(354,979)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of long-term debt	497,324	0
Short-term borrowing and payments — net	157,500	255,500
Short-term debt borrowings under revolving credit facility	0	25,000
Short-term debt repayments under revolving credit facility	0	(25,000)
Dividends paid on common stock	(82,700)	(77,700)
Repayment of long-term debt	(500,000)	0
Net cash flow provided by financing activities	72,124	177,800
NET INCREASE IN CASH AND CASH EQUIVALENTS	373	150
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	5,707	13,851
CASH AND CASH EQUIVALENTS AT END OF PERIOD	6,080	14,001
Supplemental disclosure of cash flow information
Income taxes, net of refunds	0	0
Interest, net of amounts capitalized	61,387	54,873
Significant non-cash investing and financing activities:
Accrued capital expenditures	$ 95,879	$ 86,944