SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
CONDENSED STATEMENTS OF INCOME
Operating revenues	$ 693,122	$ 1,109,475	$ 878,576	$ 620,631	$ 667,892	$ 1,124,841	$ 799,799	$ 648,847	$ 3,301,804	$ 3,241,379	$ 3,189,199
Operating expenses									2,450,049	2,494,871	2,474,316
OPERATING INCOME	101,289	447,970	254,489	48,007	78,715	435,017	196,992	35,784	851,755	746,508	714,883
Other
Total									4,200	16,367	18,532
Interest expense									214,616	241,995	244,174
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES									656,310	539,238	505,720
Income tax benefit	18,157	147,116	76,689	(4,645)	7,375	131,416	50,818	(6,005)	237,317	183,604	160,869
INCOME FROM CONTINUING OPERATIONS	34,905	252,874	130,930	284	19,544	253,273	93,185	(10,368)	418,993	355,634	344,851
Income (loss) from discontinued operations - net of income taxes									(5,829)	11,306	25,358
NET INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS	22,631	244,823	122,345	(8,257)	12,564	255,359	86,685	(15,135)	381,542	339,473	350,053
Other comprehensive income (loss) attributable to common shareholders									38,155	7,605	(28,180)
COMPREHENSIVE INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS									419,697	347,078	321,873
Pinnacle West
CONDENSED STATEMENTS OF INCOME
Operating revenues									6,133	1,034	2,810
Operating expenses									12,125	8,811	9,880
OPERATING INCOME									(5,992)	(7,777)	(7,070)
Other
Equity in earnings of subsidiaries									391,528	335,859	358,527
Other expense									(2,001)	(1,481)	(588)
Total									389,527	334,378	357,939
Interest expense									4,868	8,053	14,346
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES									378,667	318,548	336,523
Income tax benefit									(7,079)	(8,938)	(9,596)
INCOME FROM CONTINUING OPERATIONS									385,746	327,486	346,119
Income (loss) from discontinued operations - net of income taxes									(4,204)	11,987	3,934
NET INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS									381,542	339,473	350,053
Other comprehensive income (loss) attributable to common shareholders									38,155	7,604	(28,180)
COMPREHENSIVE INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS									$ 419,697	$ 347,077	$ 321,873