CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME	$ 8,094	$ 28,185
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including nuclear fuel	163,566	147,861
Deferred fuel and purchased power	(18,950)	(988)
Deferred fuel and purchased power amortization	20,002	(4,172)
Allowance for equity funds used during construction	(14,079)	(9,482)
Deferred income taxes	(229)	10,357
Deferred investment tax credit	(147)	(344)
Change in derivative instruments fair value	0	(101)
Stock compensation	10,537	9,997
Changes in current assets and liabilities:
Customer and other receivables	89,518	47,007
Accrued unbilled revenues	(6,555)	6,723
Materials, supplies and fossil fuel	(16,607)	(667)
Income tax receivable	0	(5,780)
Other current assets	(664)	(17,353)
Accounts payable	(25,738)	22,147
Accrued taxes	45,984	43,706
Other current liabilities	(12,030)	(101,801)
Change in margin and collateral accounts — assets	(396)	(12)
Change in margin and collateral accounts — liabilities	(1,092)	0
Change in other long-term assets	(3,369)	(36,836)
Change in other long-term liabilities	(70,973)	1,604
Net cash flow provided by operating activities	166,872	140,051
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(361,037)	(348,824)
Contributions in aid of construction	8,569	5,975
Allowance for borrowed funds used during construction	(6,755)	(4,472)
Proceeds from nuclear decommissioning trust sales	130,456	151,126
Investment in nuclear decommissioning trust	(131,027)	(151,696)
Other	(1,299)	(793)
Net cash flow used for investing activities	(361,093)	(348,684)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of long-term debt	0	255,441
Short-term borrowing and payments — net	263,500	22,097
Short-term debt borrowings under revolving credit facility	36,000	8,000
Short-term debt repayments under revolving credit facility	(25,000)	0
Dividends paid on common stock	(75,903)	(71,177)
Common stock equity issuance - net of purchases	(2,828)	(11,580)
Other	0	(1)
Net cash flow provided by financing activities	195,769	202,780
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	1,548	(5,853)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	13,892	8,881
CASH AND CASH EQUIVALENTS AT END OF PERIOD	15,440	3,028
Supplemental disclosure of cash flow information
Income taxes, net of refunds	0	(2)
Interest, net of amounts capitalized	56,026	54,280
Significant non-cash investing and financing activities:
Accrued capital expenditures	86,991	79,306
Arizona Public Service Company
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME	14,472	28,035
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including nuclear fuel	162,853	147,443
Deferred fuel and purchased power	(18,950)	(988)
Deferred fuel and purchased power amortization	20,002	(4,172)
Allowance for equity funds used during construction	(14,079)	(9,482)
Deferred income taxes	533	8,899
Deferred investment tax credit	(147)	(344)
Change in derivative instruments fair value	0	(101)
Changes in current assets and liabilities:
Customer and other receivables	90,647	60,782
Accrued unbilled revenues	(6,555)	6,723
Materials, supplies and fossil fuel	(16,747)	(631)
Other current assets	(1,237)	(15,007)
Accounts payable	(24,592)	22,847
Accrued taxes	54,106	47,817
Other current liabilities	(15,771)	(88,990)
Change in margin and collateral accounts — assets	(396)	(12)
Change in margin and collateral accounts — liabilities	(1,092)	0
Change in other long-term assets	4,118	(31,172)
Change in other long-term liabilities	(69,836)	1,888
Net cash flow provided by operating activities	177,329	173,535
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(355,039)	(343,139)
Contributions in aid of construction	8,569	5,975
Allowance for borrowed funds used during construction	(6,755)	(4,472)
Proceeds from nuclear decommissioning trust sales	130,456	151,126
Investment in nuclear decommissioning trust	(131,027)	(151,696)
Other	(1,183)	(774)
Net cash flow used for investing activities	(354,979)	(342,980)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of long-term debt	0	255,441
Short-term borrowing and payments — net	255,500	(19,003)
Short-term debt borrowings under revolving credit facility	25,000	0
Short-term debt repayments under revolving credit facility	(25,000)	0
Dividends paid on common stock	(77,700)	(72,900)
Net cash flow provided by financing activities	177,800	163,538
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	150	(5,907)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	13,851	8,840
CASH AND CASH EQUIVALENTS AT END OF PERIOD	14,001	2,933
Supplemental disclosure of cash flow information
Income taxes, net of refunds	0	0
Interest, net of amounts capitalized	54,873	53,129
Significant non-cash investing and financing activities:
Accrued capital expenditures	$ 86,944	$ 78,977