CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
OPERATING REVENUES	$ 677,728	$ 677,167
OPERATING EXPENSES
Fuel and purchased power	212,395	221,285
Operations and maintenance	219,976	243,195
Depreciation and amortization	127,627	119,476
Taxes other than income taxes	43,836	42,501
Other expenses	388	548
Total	604,222	627,005
OPERATING INCOME	73,506	50,162
OTHER INCOME (DEDUCTIONS)
Allowance for equity funds used during construction	9,482	10,516
Other income (Note 8)	480	117
Other expense (Note 8)	(3,680)	(4,038)
Total	6,282	6,595
INTEREST EXPENSE
Interest charges	51,864	50,744
Allowance for borrowed funds used during construction	(4,472)	(5,227)
Total	47,392	45,517
INCOME BEFORE INCOME TAXES	32,396	11,240
INCOME TAXES	4,211	1,914
NET INCOME	28,185	9,326
Less: Net income attributable to noncontrolling interests (Note 5)	4,873	4,873
NET INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 23,312	$ 4,453
WEIGHTED-AVERAGE COMMON SHARES OUTSTANDING
WEIGHTED-AVERAGE COMMON SHARES OUTSTANDING - BASIC (in shares)	111,728	111,296
WEIGHTED-AVERAGE COMMON SHARES OUTSTANDING - DILUTED (in shares)	112,195	111,847
EARNINGS PER WEIGHTED-AVERAGE COMMON SHARE OUTSTANDING
Net income attributable to common shareholders - basic (in dollars per share)	$ 0.21	$ 0.04
Net income attributable to common shareholders - diluted (in dollars per share)	$ 0.21	$ 0.04
APS
ELECTRIC OPERATING REVENUES	$ 676,869	$ 676,632
OPERATING EXPENSES
Fuel and purchased power	217,104	221,285
Operations and maintenance	212,218	238,711
Depreciation and amortization	127,208	119,446
Income taxes	11,373	5,850
Taxes other than income taxes	43,498	42,410
Total	611,401	627,702
OPERATING INCOME	65,468	48,930
OTHER INCOME (DEDUCTIONS)
Income taxes	2,725	1,815
Allowance for equity funds used during construction	9,482	10,516
Other income (Note 8)	1,062	610
Other expense (Note 8)	(4,378)	(4,750)
Total	8,891	8,191
INTEREST EXPENSE
Interest on long-term debt	47,491	46,819
Interest on short-term borrowings	2,128	2,077
Debt discount, premium and expense	1,177	1,139
Allowance for borrowed funds used during construction	(4,472)	(5,040)
Total	46,324	44,995
NET INCOME	28,035	12,126
Less: Net income attributable to noncontrolling interests (Note 5)	4,873	4,873
NET INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 23,162	$ 7,253