CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
OPERATING REVENUES	$ 869,501	$ 974,123	$ 1,610,031	$ 1,666,837
OPERATING EXPENSES
Fuel and purchased power	242,222	257,087	472,810	454,197
Operations and maintenance	227,543	268,397	473,177	534,079
Depreciation and amortization	147,374	145,436	296,081	290,261
Taxes other than income taxes	55,090	53,607	110,180	107,207
Other expenses	683	7,434	1,110	7,597
Total	672,912	731,961	1,353,358	1,393,341
OPERATING INCOME	196,589	242,162	256,673	273,496
OTHER INCOME (DEDUCTIONS)
Allowance for equity funds used during construction	7,572	13,073	18,760	27,152
Pension and other postretirement non-service credits - net	6,374	12,006	11,488	24,865
Other income (Note 9)	12,885	6,598	20,054	10,583
Other expense (Note 9)	(4,350)	(3,771)	(8,708)	(7,000)
Total	22,481	27,906	41,594	55,600
INTEREST EXPENSE
Interest charges	57,465	60,708	118,118	119,662
Allowance for borrowed funds used during construction	(4,494)	(6,291)	(11,159)	(13,046)
Total	52,971	54,417	106,959	106,616
INCOME BEFORE INCOME TAXES	166,099	215,651	191,308	222,480
INCOME TAXES	17,080	44,039	19,498	42,774
NET INCOME	149,019	171,612	171,810	179,706
Less: Net income attributable to noncontrolling interests (Note 6)	4,874	4,874	9,747	9,747
NET INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 144,145	$ 166,738	$ 162,063	$ 169,959
WEIGHTED-AVERAGE COMMON SHARES OUTSTANDING
WEIGHTED-AVERAGE COMMON SHARES OUTSTANDING - BASIC (in shares)	112,337	112,115	112,381	112,067
WEIGHTED-AVERAGE COMMON SHARES OUTSTANDING - DILUTED (in shares)	112,651	112,471	112,734	112,482
EARNINGS PER WEIGHTED-AVERAGE COMMON SHARE OUTSTANDING
Net income attributable to common shareholders - basic (in dollars per share)	$ 1.28	$ 1.49	$ 1.44	$ 1.52
Net income attributable to common shareholders - diluted (in dollars per share)	$ 1.28	$ 1.48	$ 1.44	$ 1.51
APS
OPERATING REVENUES	$ 869,501	$ 971,963	$ 1,610,031	$ 1,663,969
OPERATING EXPENSES
Fuel and purchased power	242,222	270,138	472,810	472,148
Operations and maintenance	224,143	251,999	464,518	506,600
Depreciation and amortization	147,354	144,533	296,039	288,645
Taxes other than income taxes	55,081	53,269	110,159	106,511
Other expenses	683	434	1,110	597
Total	669,483	720,373	1,344,636	1,374,501
OPERATING INCOME	200,018	251,590	265,395	289,468
OTHER INCOME (DEDUCTIONS)
Allowance for equity funds used during construction	7,572	13,073	18,760	27,152
Pension and other postretirement non-service credits - net	6,757	12,389	12,256	25,586
Other income (Note 9)	11,691	6,235	18,107	10,007
Other expense (Note 9)	(3,428)	(3,372)	(7,306)	(6,318)
Total	22,592	28,325	41,817	56,427
INTEREST EXPENSE
Interest charges	53,591	57,731	110,256	113,889
Allowance for borrowed funds used during construction	(4,494)	(6,291)	(11,159)	(13,046)
Total	49,097	51,440	99,097	100,843
INCOME BEFORE INCOME TAXES	173,513	228,475	208,115	245,052
INCOME TAXES	18,463	45,776	19,916	47,882
NET INCOME	155,050	182,699	188,199	197,170
Less: Net income attributable to noncontrolling interests (Note 6)	4,874	4,874	9,747	9,747
NET INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 150,176	$ 177,825	$ 178,452	$ 187,423