SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - Statement of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CONDENSED FINANCIAL STATEMENTS
Operating revenues	$ 734,430	$ 1,199,146	$ 890,648	$ 671,219	$ 726,450	$ 1,172,667	$ 906,264	$ 686,251	$ 3,495,443	$ 3,491,632	$ 3,454,628
Operating expenses									2,640,841	2,680,390	2,608,305
OPERATING INCOME	109,834	445,111	231,973	67,684	60,184	421,775	254,113	75,170	854,602	811,242	846,323
Other
Total									18,013	18,652	11,261
Interest expense									194,964	200,950	201,888
Income tax benefit	22,847	139,555	67,371	7,947	5,007	134,753	74,540	6,405	237,720	220,705	230,591
NET INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 41,117	$ 257,116	$ 122,902	$ 16,122	$ 5,410	$ 243,961	$ 132,458	$ 15,766	437,257	397,595	406,074
Other comprehensive income									23,393	9,912	35,955
COMPREHENSIVE INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS									460,650	407,507	442,029
Pinnacle West
CONDENSED FINANCIAL STATEMENTS
Operating revenues									550	642	799
Operating expenses									12,733	23,507	24,930
OPERATING INCOME									(12,183)	(22,865)	(24,131)
Other
Equity in earnings of subsidiaries									446,508	411,528	420,926
Other expense									(3,302)	(3,276)	(1,999)
Total									443,206	408,252	418,927
Interest expense									2,672	3,663	3,226
INCOME BEFORE INCOME TAXES									428,351	381,724	391,570
Income tax benefit									(8,906)	(15,871)	(14,504)
NET INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS									437,257	397,595	406,074
Other comprehensive income									23,393	9,912	35,955
COMPREHENSIVE INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS									$ 460,650	$ 407,507	$ 442,029