SCHEDULE I CONDENSED FINANCIAL INFORMATION OF REGISTRANT (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities
Net Income	$ 366,940	$ 370,209	$ 72,764
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	493,784	472,807	450,864
Gain on sale of energy-related business	(10,404)
Deferred income taxes	176,192	260,411	105,492
Customer and other receivables	40,626	(67,943)	12,292
Accounts payable	58,346	9,125	(27,328)
Accrued taxes and income tax receivable - net	12,068	24,222	(31,792)
Net cash flow provided by operating activities	1,125,583	750,457	1,067,305
Cash flows from investing activities
Proceeds from sale of energy-related products and services business	45,111
Net cash flow used for investing activities	(782,007)	(575,900)	(704,917)
Cash flows from financing activities
Issuance of long-term debt	470,353		867,469
Short-term borrowings and payments - net	(16,600)	(137,115)	(516,754)
Dividends paid on common stock	(221,728)	(216,979)	(205,076)
Repayment of long-term debt	(655,169)	(106,572)	(456,882)
Common stock equity issuance	15,841	255,971	3,302
Other	(2,668)	6,351	171
Net cash flow used for financing activities	(420,181)	(209,747)	(322,255)
Net increase (decrease) in cash and cash equivalents	(76,605)	(35,190)	40,133
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	110,188	145,378	105,245
CASH AND CASH EQUIVALENTS AT END OF YEAR	33,583	110,188	145,378
Pinnacle West
Cash flows from operating activities
Net Income	339,473	350,053	68,330
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in earnings (losses) of subsidiaries	(335,859)	(358,527)	37,214
Depreciation and amortization	97	143	127
Gain on sale of energy-related business	(10,404)
Deferred income taxes	7,387	40,342	(106,536)
Customer and other receivables	(24,201)	(18,175)	(2,303)
Accounts payable	(2,677)	7,468	466
Accrued taxes and income tax receivable - net	7,512	59,640	44,625
Dividends received from subsidiaries	228,900	207,000	170,000
Other net	19,270	423	(2,379)
Net cash flow provided by operating activities	229,498	288,367	209,544
Cash flows from investing activities
Investments in subsidiaries		(183,544)	(4,967)
Repayments of loans from subsidiaries	61,143	98,406	25,240
Proceeds from sale of energy-related products and services business	45,111
Advances of loans to subsidiaries	(64,970)	(119,293)	(21,587)
Proceeds from sale of life insurance policies	9,357
Net cash flow used for investing activities	50,641	(204,431)	(1,314)
Cash flows from financing activities
Issuance of long-term debt	175,000
Short-term borrowings and payments - net	(16,600)	(132,487)	4,566
Dividends paid on common stock	(221,728)	(216,979)	(205,076)
Repayment of long-term debt	(225,000)
Common stock equity issuance	15,841	255,971	3,302
Other	(2,667)
Net cash flow used for financing activities	(275,154)	(93,495)	(197,208)
Net increase (decrease) in cash and cash equivalents	4,985	(9,559)	11,022
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	7,725	17,284	6,262
CASH AND CASH EQUIVALENTS AT END OF YEAR	$ 12,710	$ 7,725	$ 17,284