SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - Consolidated Statements of Cash Flows (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
Cash Flows from Operating Activities
Net income	$ 45,978	$ 261,978	$ 127,507	$ 20,727	$ 9,535	$ 248,086	$ 141,384	$ 24,691	$ 456,190	$ 423,696	$ 439,966
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization									571,664	496,487	492,322
Deferred income taxes									236,819	159,023	249,296
Accounts receivable									(22,219)	(52,672)	(44,991)
Accounts payable									(34,266)	(353)	45,414
Net cash flow provided by operating activities									1,094,327	1,099,627	1,153,307
Cash flows from investing activities
Net cash flow used for investing activities									(1,066,233)	(922,668)	(1,009,401)
Cash flows from financing activities
Issuance of long-term debt									842,415	731,126	136,307
Dividends paid on common stock									(260,027)	(246,671)	(235,244)
Repayment of long-term debt									(415,570)	(652,578)	(122,828)
Common stock equity issuance - net of purchases									19,373	15,288	17,319
Other									1	161	299
Net cash flow provided by (used for) financing activities									3,790	(178,881)	(160,582)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS									31,884	(1,922)	(16,676)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR				7,604				9,526	7,604	9,526	26,202
CASH AND CASH EQUIVALENTS AT END OF YEAR	39,488				7,604				39,488	7,604	9,526
Pinnacle West
Cash Flows from Operating Activities
Net income									437,257	397,595	406,074
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in earnings of subsidiaries - net									(446,508)	(411,528)	(420,926)
Depreciation and amortization									92	94	95
Deferred income taxes									12,967	4,406	(28,806)
Accounts receivable									11,336	(22,945)	21,671
Accounts payable									637	2,017	(2,449)
Accrued taxes and income tax receivable - net									(12,882)	(1,795)	1,402
Dividends received from subsidiaries									266,900	253,600	242,100
Other									(6,995)	18,432	(15,065)
Net cash flow provided by operating activities									262,804	239,876	204,096
Cash flows from investing activities
Construction work in progress									(3,462)	0	0
Investments in subsidiaries									(3,491)	(10,236)	(3,400)
Repayments of loans from subsidiaries									157	322	2,149
Advances of loans to subsidiaries									(1,010)	(1,450)	(2,099)
Net cash flow used for investing activities									(7,806)	(11,364)	(3,350)
Cash flows from financing activities
Issuance of long-term debt									0	125,000	0
Dividends paid on common stock									(260,027)	(246,671)	(235,244)
Repayment of long-term debt									0	(125,000)	0
Common stock equity issuance - net of purchases									19,373	15,288	17,319
Other									0	161	298
Net cash flow provided by (used for) financing activities									(240,654)	(231,222)	(217,627)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS									14,344	(2,710)	(16,881)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR				$ 3,088				$ 5,798	3,088	5,798	22,679
CASH AND CASH EQUIVALENTS AT END OF YEAR	$ 17,432				$ 3,088				$ 17,432	$ 3,088	$ 5,798