CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME	$ 171,810	$ 179,706
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including nuclear fuel	332,185	325,550
Deferred fuel and purchased power	(16,702)	(50,112)
Deferred fuel and purchased power amortization	23,307	50,851
Allowance for equity funds used during construction	(18,760)	(27,152)
Deferred income taxes	4,326	33,711
Deferred investment tax credit	(2,656)	(2,778)
Stock compensation	13,725	13,189
Changes in current assets and liabilities:
Customer and other receivables	3,543	(18,672)
Accrued unbilled revenues	(56,487)	(95,453)
Materials, supplies and fossil fuel	(21,287)	(22,970)
Other current assets	(16,121)	11,069
Accounts payable	65,874	36,614
Accrued taxes	4,102	8,140
Other current liabilities	(61,270)	9,410
Change in other long-term assets	(82,850)	23,927
Change in other long-term liabilities	3,195	(79,228)
Net cash flow provided by operating activities	345,934	395,802
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(541,401)	(679,949)
Contributions in aid of construction	18,909	19,339
Allowance for borrowed funds used during construction	(11,159)	(13,046)
Proceeds from nuclear decommissioning trust sales and other special use funds	309,354	258,401
Investment in nuclear decommissioning trust and other special use funds	(310,494)	(259,542)
Other	7,153	(4,299)
Net cash flow used for investing activities	(527,638)	(679,096)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of long-term debt	497,324	0
Short-term borrowing and payments — net	363,973	500,849
Short-term debt borrowings	49,000	45,000
Short-term debt repayments	(57,000)	(25,000)
Dividends paid on common stock	(161,979)	(151,942)
Repayment of long-term debt	(500,000)	(82,000)
Common stock equity issuance - net of purchases	(2,360)	(2,294)
Distributions to noncontrolling interests	(11,372)	(11,372)
Net cash flow provided by financing activities	177,586	273,241
NET DECREASE IN CASH AND CASH EQUIVALENTS	(4,118)	(10,053)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	5,766	13,892
CASH AND CASH EQUIVALENTS AT END OF PERIOD	1,648	3,839
Supplemental disclosure of cash flow information
Income taxes, net of refunds	10,788	10,032
Interest, net of amounts capitalized	114,717	104,249
Significant non-cash investing and financing activities:
Accrued capital expenditures	108,056	65,995
APS
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME	188,199	197,170
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including nuclear fuel	332,143	323,934
Deferred fuel and purchased power	(16,702)	(50,112)
Deferred fuel and purchased power amortization	23,307	50,851
Allowance for equity funds used during construction	(18,760)	(27,152)
Deferred income taxes	(10,625)	10,372
Deferred investment tax credit	(2,656)	(2,778)
Changes in current assets and liabilities:
Customer and other receivables	3,645	(9,254)
Accrued unbilled revenues	(56,487)	(95,453)
Materials, supplies and fossil fuel	(21,287)	(23,073)
Other current assets	(14,613)	7,552
Accounts payable	68,399	39,573
Accrued taxes	(435)	26,412
Other current liabilities	(57,709)	7,395
Change in other long-term assets	(84,946)	34,947
Change in other long-term liabilities	3,253	(84,643)
Net cash flow provided by operating activities	334,726	405,741
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(541,401)	(670,841)
Contributions in aid of construction	18,909	19,339
Allowance for borrowed funds used during construction	(11,159)	(13,046)
Proceeds from nuclear decommissioning trust sales and other special use funds	309,354	258,227
Investment in nuclear decommissioning trust and other special use funds	(310,494)	(259,367)
Other	(1,612)	(1,221)
Net cash flow used for investing activities	(536,403)	(666,909)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of long-term debt	497,324	0
Short-term borrowing and payments — net	376,873	499,949
Short-term debt borrowings	0	25,000
Short-term debt repayments	0	(25,000)
Dividends paid on common stock	(165,500)	(155,500)
Repayment of long-term debt	(500,000)	(82,000)
Distributions to noncontrolling interests	(11,372)	(11,372)
Net cash flow provided by financing activities	197,325	251,077
NET DECREASE IN CASH AND CASH EQUIVALENTS	(4,352)	(10,091)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	5,707	13,851
CASH AND CASH EQUIVALENTS AT END OF PERIOD	1,355	3,760
Supplemental disclosure of cash flow information
Income taxes, net of refunds	35,573	24,689
Interest, net of amounts capitalized	107,169	98,478
Significant non-cash investing and financing activities:
Accrued capital expenditures	$ 108,056	$ 65,995