SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities
Net Income	$ 413,164	$ 366,940	$ 370,209
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	481,262	493,784	472,807
Deferred income taxes	228,602	176,192	260,411
Customer and other receivables	14,587	40,626	(67,943)
Accounts payable	(96,600)	58,346	9,125
Net cash flow provided by operating activities	1,171,122	1,125,583	750,457
Cash flows from investing activities
Proceeds from sale of energy-related products and services business		45,111
Net cash flow used for investing activities	(872,994)	(782,007)	(575,900)
Cash flows from financing activities
Issuance of long-term debt	476,081	470,353
Short-term borrowings and payments - net	92,175	(16,600)	(137,115)
Dividends paid on common stock	(225,075)	(221,728)	(216,979)
Repayment of long-term debt	(654,286)	(655,169)	(106,572)
Common stock equity issuance	15,955	15,841	255,971
Other	170	(2,668)	6,351
Net cash flow used for financing activities	(305,509)	(420,181)	(209,747)
NET DECREASE IN CASH AND CASH EQUIVALENTS	(7,381)	(76,605)	(35,190)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	33,583	110,188	145,378
CASH AND CASH EQUIVALENTS AT END OF YEAR	26,202	33,583	110,188
Pinnacle West
Cash flows from operating activities
Net Income	381,542	339,473	350,053
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in earnings (losses) of subsidiaries	(391,528)	(335,859)	(358,527)
Depreciation and amortization	94	97	143
Gain on sale of energy-related business		(10,404)
Deferred income taxes	(15,135)	7,387	40,342
Customer and other receivables	28,763	(24,201)	(18,175)
Accounts payable	879	(2,677)	7,468
Accrued taxes and income tax receivable - net	(3,103)	7,512	59,640
Dividends received from subsidiaries	222,200	228,900	207,000
Other	(4,589)	19,270	423
Net cash flow provided by operating activities	219,123	229,498	288,367
Cash flows from investing activities
Investments in subsidiaries			(183,544)
Repayments of loans from subsidiaries	996	61,143	98,406
Proceeds from sale of energy-related products and services business		45,111
Advances of loans to subsidiaries	(1,200)	(64,970)	(119,293)
Proceeds from sale of life insurance policies		9,357
Net cash flow used for investing activities	(204)	50,641	(204,431)
Cash flows from financing activities
Issuance of long-term debt	125,000	175,000
Short-term borrowings and payments - net		(16,600)	(132,487)
Dividends paid on common stock	(225,075)	(221,728)	(216,979)
Repayment of long-term debt	(125,000)	(225,000)
Common stock equity issuance	15,955	15,841	255,971
Other	170	(2,667)
Net cash flow used for financing activities	(208,950)	(275,154)	(93,495)
NET DECREASE IN CASH AND CASH EQUIVALENTS	9,969	4,985	(9,559)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	12,710	7,725	17,284
CASH AND CASH EQUIVALENTS AT END OF YEAR	$ 22,679	$ 12,710	$ 7,725