SCHEDULE I CONDENSED FINANCIAL INFORMATION OF REGISTRANT (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
CONDENSED STATEMENTS OF INCOME
Operating revenues	$ 667,892	$ 1,124,841	$ 799,799	$ 648,847	$ 3,241,379	$ 3,189,199	$ 3,153,656
Operating expenses					2,494,871	2,474,316	2,537,528
Operating loss	78,715	435,017	196,992	35,784	746,508	714,883	616,128
Other
Total					16,367	18,532	5,858
Interest expense					241,995	244,174	237,766
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES					539,238	505,720	394,599
Income tax benefit	7,375	131,416	50,818	(6,005)	183,604	160,869	138,551
INCOME FROM CONTINUING OPERATIONS	19,544	253,273	93,185	(10,368)	355,634	344,851	256,048
Income from discontinued operations - net of income taxes					11,306	25,358	(183,284)
Net income attributable to common shareholders	12,564	255,359	86,685	(15,135)	339,473	350,053	68,330
Pinnacle West
CONDENSED STATEMENTS OF INCOME
Operating revenues					1,034	2,810	1,157
Operating expenses					8,811	9,880	10,420
Operating loss					(7,777)	(7,070)	(9,263)
Other
Equity in earnings (losses) of subsidiaries					335,859	358,527	(37,214)
Other income (expense)					(1,481)	(588)	2,102
Total					334,378	357,939	(35,112)
Interest expense					8,053	14,346	14,129
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES					318,548	336,523	(58,504)
Income tax benefit					(8,938)	(9,596)	(14,060)
INCOME FROM CONTINUING OPERATIONS					327,486	346,119	(44,444)
Income from discontinued operations - net of income taxes					11,987	3,934	112,774
Net income attributable to common shareholders					$ 339,473	$ 350,053	$ 68,330