CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
CURRENT ASSETS
Cash and cash equivalents	$ 10,674	$ 8,881
Customer and other receivables	425,558	250,491
Accrued unbilled revenues	151,976	107,949
Allowance for doubtful accounts	(3,051)	(3,037)
Materials and supplies (at average cost)	257,455	253,979
Fossil fuel (at average cost)	27,013	28,608
Income tax receivable	0	3,751
Assets from risk management activities (Note 6)	358	19,694
Deferred fuel and purchased power regulatory asset (Note 3)	73,966	12,465
Other regulatory assets (Note 3)	184,351	94,410
Other current assets	45,905	45,028
Total current assets	1,174,205	822,219
INVESTMENTS AND OTHER ASSETS
Assets from risk management activities (Note 6)	1,692	1
Nuclear decommissioning trust (Note 11)	841,980	779,586
Other assets	88,818	69,063
Total investments and other assets	932,490	848,650
PROPERTY, PLANT AND EQUIPMENT
Plant in service and held for future use	17,310,294	17,341,888
Accumulated depreciation and amortization	(6,037,467)	(5,970,100)
Net	11,272,827	11,371,788
Construction work in progress	1,379,501	1,019,947
Palo Verde sale leaseback, net of accumulated depreciation (Note 5)	110,613	113,515
Intangible assets, net of accumulated amortization	256,198	90,022
Nuclear fuel, net of accumulated amortization	135,460	119,004
Total property, plant and equipment	13,154,599	12,714,276
DEFERRED DEBITS
Regulatory assets (Note 3)	1,381,179	1,313,428
Assets for other postretirement benefits (Note 4)	193,747	166,206
Other	141,647	139,474
Total deferred debits	1,716,573	1,619,108
TOTAL ASSETS	16,977,867	16,004,253
CURRENT LIABILITIES
Accounts payable	236,746	264,631
Accrued taxes	228,791	138,964
Accrued interest	49,218	52,835
Common dividends payable	0	72,926
Short-term borrowings (Note 2)	131,400	177,200
Current maturities of long-term debt (Note 2)	207,000	125,000
Customer deposits	69,690	82,520
Liabilities from risk management activities (Note 6)	50,469	25,836
Liabilities for asset retirements (Note 14)	1,559	9,135
Regulatory liabilities (Note 3)	120,671	99,899
Other current liabilities	207,599	244,000
Total current liabilities	1,303,143	1,292,946
LONG-TERM DEBT LESS CURRENT MATURITIES (Note 2)	4,491,048	4,021,785
DEFERRED CREDITS AND OTHER
Deferred income taxes	3,182,400	2,945,232
Regulatory liabilities (Note 3)	891,715	948,916
Liabilities for asset retirements (Note 14)	669,297	615,340
Liabilities for pension benefits (Note 4)	409,871	509,310
Liabilities from risk management activities (Note 6)	35,775	47,238
Customer advances	101,210	88,672
Coal mine reclamation	238,634	221,910
Deferred investment tax credit	205,870	210,162
Unrecognized tax benefits	12,943	10,046
Other	158,354	156,784
Total deferred credits and other	5,906,069	5,753,610
COMMITMENTS AND CONTINGENCIES (SEE NOTE 7)
EQUITY
Common stock, no par value; authorized 150,000,000 shares, 111,666,876 and 111,392,053 issued at respective dates	2,608,825	2,596,030
Treasury stock at cost; 9,864 and 55,317 shares at respective dates	(833)	(4,133)
Total common stock	2,607,992	2,591,897
Retained earnings	2,576,193	2,255,547
Accumulated other comprehensive loss:
Pension and other postretirement benefits	(39,091)	(39,070)
Derivative instruments	(3,026)	(4,752)
Total accumulated other comprehensive loss	(42,117)	(43,822)
Total shareholders’ equity	5,142,068	4,803,622
Noncontrolling interests (Note 5)	135,539	132,290
Total equity	5,277,607	4,935,912
TOTAL LIABILITIES AND EQUITY	16,977,867	16,004,253
Arizona Public Service Company
CURRENT ASSETS
Cash and cash equivalents	10,633	8,840
Customer and other receivables	417,229	262,611
Accrued unbilled revenues	151,976	107,949
Allowance for doubtful accounts	(3,051)	(3,037)
Materials and supplies (at average cost)	256,127	252,777
Fossil fuel (at average cost)	27,013	28,608
Income tax receivable	0	11,174
Assets from risk management activities (Note 6)	358	19,694
Deferred fuel and purchased power regulatory asset (Note 3)	73,966	12,465
Other regulatory assets (Note 3)	184,351	94,410
Other current assets	39,783	41,849
Total current assets	1,158,385	837,340
INVESTMENTS AND OTHER ASSETS
Assets from risk management activities (Note 6)	1,692	1
Nuclear decommissioning trust (Note 11)	841,980	779,586
Other assets	66,418	48,320
Total investments and other assets	910,090	827,907
PROPERTY, PLANT AND EQUIPMENT
Plant in service and held for future use	17,195,555	17,228,787
Accumulated depreciation and amortization	(5,951,233)	(5,881,941)
Net	11,244,322	11,346,846
Construction work in progress	1,335,398	989,497
Palo Verde sale leaseback, net of accumulated depreciation (Note 5)	110,613	113,515
Intangible assets, net of accumulated amortization	256,037	89,868
Nuclear fuel, net of accumulated amortization	135,460	119,004
Total property, plant and equipment	13,081,830	12,658,730
DEFERRED DEBITS
Regulatory assets (Note 3)	1,381,179	1,313,428
Assets for other postretirement benefits (Note 4)	190,306	162,911
Other	129,999	130,859
Total deferred debits	1,701,484	1,607,198
TOTAL ASSETS	16,851,789	15,931,175
CURRENT LIABILITIES
Accounts payable	227,507	259,161
Accrued taxes	233,214	130,576
Accrued interest	48,875	52,525
Common dividends payable	0	72,900
Short-term borrowings (Note 2)	31,800	135,500
Current maturities of long-term debt (Note 2)	82,000	0
Customer deposits	69,690	82,520
Liabilities from risk management activities (Note 6)	50,469	25,836
Liabilities for asset retirements (Note 14)	1,302	8,703
Regulatory liabilities (Note 3)	120,671	99,899
Other current liabilities	202,524	226,417
Total current liabilities	1,068,052	1,094,037
DEFERRED CREDITS AND OTHER
Deferred income taxes	3,223,966	2,999,295
Regulatory liabilities (Note 3)	891,715	948,916
Liabilities for asset retirements (Note 14)	660,815	607,234
Liabilities for pension benefits (Note 4)	389,867	488,253
Liabilities from risk management activities (Note 6)	35,775	47,238
Customer advances	101,210	88,672
Coal mine reclamation	222,993	206,645
Deferred investment tax credit	205,870	210,162
Unrecognized tax benefits	43,704	37,408
Other	143,423	143,560
Total deferred credits and other	5,919,338	5,777,383
COMMITMENTS AND CONTINGENCIES (SEE NOTE 7)
EQUITY
Total common stock	178,162	178,162
Additional paid-in capital	2,421,696	2,421,696
Retained earnings	2,661,570	2,331,245
Accumulated other comprehensive loss:
Pension and other postretirement benefits	(20,590)	(20,671)
Derivative instruments	(3,026)	(4,752)
Total accumulated other comprehensive loss	(23,616)	(25,423)
Total shareholders’ equity	5,237,812	4,905,680
Noncontrolling interests (Note 5)	135,539	132,290
Total equity	5,373,351	5,037,970
Long-term debt less current maturities (Note 2)	4,491,048	4,021,785
Total capitalization	9,864,399	9,059,755
TOTAL LIABILITIES AND EQUITY	$ 16,851,789	$ 15,931,175