CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 507,949	$ 461,527	$ 456,190
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including nuclear fuel	610,629	565,011	571,664
Deferred fuel and purchased power	(48,405)	(60,303)	14,997
Deferred fuel and purchased power amortization	(14,767)	38,152	1,617
Allowance for equity funds used during construction	(47,011)	(42,140)	(35,215)
Deferred income taxes	248,164	206,870	236,819
Deferred investment tax credit	(4,587)	23,082	8,473
Change in derivative instruments fair value	(373)	(403)	(381)
Stock compensation	20,502	18,883	18,756
Change in derivative instruments fair value
Customer and other receivables	(93,797)	(2,489)	(22,219)
Accrued unbilled revenues	(4,485)	(11,709)	4,293
Materials, supplies and fossil fuel	(6,683)	(1,491)	(23,945)
Income tax receivable	3,751	(3,162)	2,509
Other current assets	(10,580)	(23,324)	3,145
Accounts payable	(23,769)	(66,917)	(34,266)
Accrued taxes	9,982	447	(2,013)
Other current liabilities	19,154	29,594	603
Change in margin and collateral accounts — assets	(300)	673	(324)
Change in margin and collateral accounts — liabilities	(533)	17,735	22,776
Change in unrecognized tax benefits	5,891	1,628	(10,328)
Change in long-term regulatory liabilities	45,764	14,682	(20,535)
Change in other long-term assets	(68,480)	(60,163)	2,426
Change in other long-term liabilities	(29,980)	(82,793)	(100,715)
Net cash flow provided by operating activities	1,118,036	1,023,390	1,094,327
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,408,774)	(1,275,472)	(1,076,087)
Contributions in aid of construction	23,708	64,296	46,546
Allowance for borrowed funds used during construction	(22,112)	(19,970)	(16,259)
Proceeds from nuclear decommissioning trust sales	542,246	633,410	478,813
Investment in nuclear decommissioning trust	(544,527)	(635,691)	(496,062)
Other	(19,078)	(18,651)	(3,184)
Net cash flow used for investing activities	(1,428,537)	(1,252,078)	(1,066,233)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of long-term debt	848,239	693,151	842,415
Repayment of long-term debt	(125,000)	(370,430)	(415,570)
Short-term borrowings and (repayments) — net	(107,800)	137,200	(147,400)
Short-term debt borrowings under revolving credit facility	58,000	40,000	0
Short-term debt repayments under revolving credit facility	(32,000)	0	0
Dividends paid on common stock	(289,793)	(274,229)	(260,027)
Common stock equity issuance and purchases - net	(13,390)	(4,867)	19,373
Distributions to noncontrolling interests	(22,744)	(22,744)	(35,002)
Other	0	0	1
Net cash flow provided by financing activities	315,512	198,081	3,790
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	5,011	(30,607)	31,884
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	8,881	39,488	7,604
CASH AND CASH EQUIVALENTS AT END OF YEAR	13,892	8,881	39,488
Supplemental disclosure of cash flow information:
Income taxes, net of refunds	2,186	9,956	6,550
Interest, net of amounts capitalized	189,288	184,462	170,209
Significant non-cash investing and financing activities:
Accrued capital expenditures	130,404	114,855	83,798
Dividends declared but not paid	77,667	72,926	69,363
ARIZONA PUBLIC SERVICE COMPANY
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	523,802	481,634	469,207
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including nuclear fuel	608,935	564,091	571,540
Deferred fuel and purchased power	(48,405)	(60,303)	14,997
Deferred fuel and purchased power amortization	(14,767)	38,152	1,617
Allowance for equity funds used during construction	(47,011)	(42,140)	(35,215)
Deferred income taxes	249,465	221,167	223,069
Deferred investment tax credit	(4,587)	23,082	8,473
Change in derivative instruments fair value	(373)	(403)	(381)
Change in derivative instruments fair value
Customer and other receivables	(68,040)	(1,601)	(21,040)
Accrued unbilled revenues	(4,485)	(11,709)	4,293
Materials, supplies and fossil fuel	(6,503)	(1,454)	(23,945)
Income tax receivable	11,174	(14,567)	0
Other current assets	(6,775)	(21,640)	4,498
Accounts payable	(26,561)	(67,543)	(34,891)
Accrued taxes	26,773	(13,912)	13,378
Other current liabilities	27,912	5,097	(3,718)
Change in margin and collateral accounts — assets	(300)	673	(324)
Change in margin and collateral accounts — liabilities	(533)	17,735	22,776
Change in unrecognized tax benefits	5,891	1,628	(10,328)
Change in long-term regulatory liabilities	45,764	14,682	(20,535)
Change in other long-term assets	(78,540)	(45,866)	(813)
Change in other long-term liabilities	(31,106)	(76,855)	(82,628)
Net cash flow provided by operating activities	1,161,730	1,009,948	1,100,030
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,381,930)	(1,248,010)	(1,072,053)
Contributions in aid of construction	23,708	64,296	46,546
Allowance for borrowed funds used during construction	(22,112)	(19,481)	(16,183)
Proceeds from nuclear decommissioning trust sales	542,246	633,410	478,813
Investment in nuclear decommissioning trust	(544,527)	(635,691)	(496,062)
Other	(18,538)	(13,865)	(1,093)
Net cash flow used for investing activities	(1,401,153)	(1,219,341)	(1,060,032)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of long-term debt	549,478	693,151	842,415
Repayment of long-term debt	0	(370,430)	(415,570)
Short-term borrowings and (repayments) — net	(135,500)	135,500	(147,400)
Dividends paid on common stock	(296,800)	(281,300)	(266,900)
Equity infusion from Pinnacle West	150,000	42,000	0
Distributions to noncontrolling interests	(22,744)	(22,744)	(35,002)
Net cash flow provided by financing activities	244,434	196,177	(22,457)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	5,011	(13,216)	17,541
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	8,840	22,056	4,515
CASH AND CASH EQUIVALENTS AT END OF YEAR	13,851	8,840	22,056
Supplemental disclosure of cash flow information:
Income taxes, net of refunds	(14,098)	26,864	14,831
Interest, net of amounts capitalized	184,210	181,809	167,670
Significant non-cash investing and financing activities:
Accrued capital expenditures	130,057	114,874	83,798
Dividends declared but not paid	$ 77,700	$ 72,900	$ 69,400