CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME	$ 481,447	$ 403,408
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including nuclear fuel	445,707	422,851
Deferred fuel and purchased power	(43,348)	(46,185)
Deferred fuel and purchased power amortization	(18,153)	28,366
Allowance for equity funds used during construction	(32,666)	(31,079)
Deferred income taxes	211,249	194,915
Deferred investment tax credit	(4,293)	(6,342)
Change in derivative instruments fair value	(254)	(278)
Stock compensation	16,553	27,588
Changes in current assets and liabilities:
Customer and other receivables	(206,920)	(77,908)
Accrued unbilled revenues	(44,027)	(54,291)
Materials, supplies and fossil fuel	(1,881)	(4,438)
Income tax receivable	3,751	589
Other current assets	(22,043)	(11,665)
Accounts payable	(24,258)	(57,237)
Accrued taxes	89,827	80,925
Other current liabilities	3,936	(12,383)
Change in margin and collateral accounts — assets	(1,826)	517
Change in margin and collateral accounts — liabilities	(1,625)	18,085
Change in unrecognized tax benefits	5,891	1,628
Change in other long-term assets	(59,963)	(59,589)
Change in other long-term liabilities	(25,180)	(52,427)
Net cash flow provided by operating activities	771,924	765,050
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,027,753)	(1,014,910)
Contributions in aid of construction	24,924	39,355
Allowance for borrowed funds used during construction	(15,378)	(14,848)
Proceeds from nuclear decommissioning trust sales	351,860	447,419
Investment in nuclear decommissioning trust	(353,001)	(449,129)
Other	(20,291)	(18,353)
Net cash flow used for investing activities	(1,039,639)	(1,010,466)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of long-term debt	549,478	693,151
Repayment of long-term debt	0	(353,560)
Short-term borrowing and payments — net	(68,800)	83,300
Short-term borrowings under revolving credit facility	23,000	34,000
Dividends paid on common stock	(213,927)	(203,115)
Common stock equity issuance - net of purchases	(8,870)	11,790
Distributions to noncontrolling interests	(11,372)	(11,372)
Other	(1)	1
Net cash flow provided by financing activities	269,508	254,195
NET INCREASE IN CASH AND CASH EQUIVALENTS	1,793	8,779
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	8,881	39,488
CASH AND CASH EQUIVALENTS AT END OF PERIOD	10,674	48,267
Cash paid during the period for:
Income taxes, net of refunds	2,185	2,562
Interest, net of amounts capitalized	147,149	146,691
Significant non-cash investing and financing activities:
Accrued capital expenditures	93,031	91,315
Arizona Public Service Company
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME	491,143	418,281
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including nuclear fuel	444,439	422,365
Deferred fuel and purchased power	(43,348)	(46,185)
Deferred fuel and purchased power amortization	(18,153)	28,366
Allowance for equity funds used during construction	(32,666)	(31,079)
Deferred income taxes	202,256	171,000
Deferred investment tax credit	(4,293)	(6,342)
Change in derivative instruments fair value	(254)	(278)
Changes in current assets and liabilities:
Customer and other receivables	(185,130)	(75,961)
Accrued unbilled revenues	(44,027)	(54,291)
Materials, supplies and fossil fuel	(1,755)	(4,368)
Income tax receivable	11,174	0
Other current assets	(19,100)	(9,857)
Accounts payable	(29,784)	(56,349)
Accrued taxes	102,638	107,955
Other current liabilities	11,747	(30,973)
Change in margin and collateral accounts — assets	(1,826)	517
Change in margin and collateral accounts — liabilities	(1,625)	18,085
Change in unrecognized tax benefits	5,891	1,628
Change in other long-term assets	(56,375)	(54,051)
Change in other long-term liabilities	(26,049)	(32,146)
Net cash flow provided by operating activities	804,903	766,317
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,008,723)	(992,735)
Contributions in aid of construction	24,924	39,355
Allowance for borrowed funds used during construction	(15,378)	(14,359)
Proceeds from nuclear decommissioning trust sales	351,860	447,419
Investment in nuclear decommissioning trust	(353,001)	(449,129)
Other	(18,098)	(14,016)
Net cash flow used for investing activities	(1,018,416)	(983,465)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of long-term debt	549,478	693,151
Repayment of long-term debt	0	(353,560)
Short-term borrowing and payments — net	(103,700)	83,300
Dividends paid on common stock	(219,100)	(208,400)
Distributions to noncontrolling interests	(11,372)	(11,372)
Net cash flow provided by financing activities	215,306	203,119
NET INCREASE IN CASH AND CASH EQUIVALENTS	1,793	(14,029)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	8,840	22,056
CASH AND CASH EQUIVALENTS AT END OF PERIOD	10,633	8,027
Cash paid during the period for:
Income taxes, net of refunds	132	10,533
Interest, net of amounts capitalized	142,779	144,984
Significant non-cash investing and financing activities:
Accrued capital expenditures	$ 94,769	$ 90,069