CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
OPERATING REVENUES	$ 3,565,296	$ 3,498,682	$ 3,495,443
OPERATING EXPENSES
Fuel and purchased power	981,301	1,075,510	1,101,298
Operations and maintenance	924,443	911,319	868,377
Depreciation and amortization	534,118	485,829	494,422
Taxes other than income taxes	184,347	166,499	171,812
Other expenses	6,660	3,541	4,932
Total	2,630,869	2,642,698	2,640,841
OPERATING INCOME	934,427	855,984	854,602
OTHER INCOME (DEDUCTIONS)
Allowance for equity funds used during construction (Note 1)	47,011	42,140	35,215
Other income (Note 17)	4,006	901	621
Other expense (Note 17)	(21,539)	(15,337)	(17,823)
Total	29,478	27,704	18,013
INTEREST EXPENSE
Interest charges	219,796	205,720	194,964
Allowance for borrowed funds used during construction (Note 1)	(22,112)	(19,970)	(16,259)
Total	197,684	185,750	178,705
INCOME BEFORE INCOME TAXES	766,221	697,938	693,910
INCOME TAXES (Note 4)	258,272	236,411	237,720
NET INCOME	507,949	461,527	456,190
Less: Net income attributable to noncontrolling interests (Note 18)	19,493	19,493	18,933
NET INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 488,456	$ 442,034	$ 437,257
Weighted Average common shares outstanding — basic (in shares)	111,839	111,409	111,026
Weighted Average common shares outstanding — diluted (in shares)	112,367	112,046	111,552
EARNINGS PER WEIGHTED-AVERAGE COMMON SHARE OUTSTANDING
Net income attributable to common shareholders - basic (in dollars per share)	$ 4.37	$ 3.97	$ 3.94
Net income attributable to common shareholders — diluted (in dollars per share)	$ 4.35	$ 3.95	$ 3.92
ARIZONA PUBLIC SERVICE COMPANY
ELECTRIC OPERATING REVENUES	$ 3,554,139	$ 3,489,754	$ 3,492,357
OPERATING EXPENSES
Fuel and purchased power	992,744	1,082,625	1,101,298
Operations and maintenance	891,129	879,108	853,135
Depreciation and amortization	532,423	484,909	494,298
Taxes other than income taxes	182,979	165,779	171,499
Income taxes (Note 4)	275,295	259,353	260,143
Total	2,874,570	2,871,774	2,880,373
OPERATING INCOME	679,569	617,980	611,984
OTHER INCOME (DEDUCTIONS)
Income taxes (Note 4)	6,127	13,511	14,302
Allowance for equity funds used during construction (Note 1)	47,011	42,140	35,215
Other income (Note 17)	6,526	8,607	2,834
Other expense (Note 17)	(23,380)	(17,514)	(19,019)
Total	36,284	46,744	33,332
INTEREST EXPENSE
Interest on long-term debt	200,211	189,828	180,123
Interest on short-term borrowings	9,119	7,983	7,376
Debt discount, premium and expense	4,833	4,760	4,793
Allowance for borrowed funds used during construction (Note 1)	(22,112)	(19,481)	(16,183)
Total	192,051	183,090	176,109
INCOME TAXES (Note 4)	269,168	245,842	245,841
NET INCOME	523,802	481,634	469,207
Less: Net income attributable to noncontrolling interests (Note 18)	19,493	19,493	18,933
NET INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 504,309	$ 462,141	$ 450,274