SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - Consolidated Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash Flows from Operating Activities
Net income	$ 58,119	$ 267,900	$ 126,182	$ 9,326	$ 45,978	$ 261,978	$ 127,507	$ 20,727	$ 461,527	$ 456,190	$ 423,696
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization									565,011	571,664	496,487
Deferred income taxes									206,870	236,819	159,023
Accounts receivable									(2,489)	(22,219)	(52,672)
Accounts payable									(66,917)	(34,266)	(353)
Net cash flow provided by operating activities									1,023,390	1,094,327	1,099,627
Cash flows from investing activities
Net cash flow used for investing activities									(1,252,078)	(1,066,233)	(922,668)
Cash flows from financing activities
Issuance of long-term debt									693,151	842,415	731,126
Short-term debt borrowings under revolving credit facility									40,000	0	0
Dividends paid on common stock									(274,229)	(260,027)	(246,671)
Repayment of long-term debt									(370,430)	(415,570)	(652,578)
Common stock equity issuance and purchases - net									(4,867)	19,373	15,288
Other									0	1	161
Net cash flow provided by (used for) financing activities									198,081	3,790	(178,881)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS									(30,607)	31,884	(1,922)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR				39,488				7,604	39,488	7,604	9,526
CASH AND CASH EQUIVALENTS AT END OF YEAR	8,881				39,488				8,881	39,488	7,604
Pinnacle West
Cash Flows from Operating Activities
Net income									442,034	437,257	397,595
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in earnings of subsidiaries - net									(462,027)	(446,508)	(411,528)
Depreciation and amortization									85	92	94
Deferred income taxes									(12,402)	12,967	4,406
Accounts receivable									15,823	11,336	(22,945)
Accounts payable									10,402	637	2,017
Accrued taxes and income tax receivable - net									20,041	(12,882)	(1,795)
Dividends received from subsidiaries									239,300	266,900	253,600
Other									5,514	(6,995)	18,432
Net cash flow provided by operating activities									258,770	262,804	239,876
Cash flows from investing activities
Construction work in progress									(18,457)	(3,462)	0
Investments in subsidiaries									(19,242)	(3,491)	(10,236)
Repayments of loans from subsidiaries									1,026	157	322
Advances of loans to subsidiaries									(2,092)	(1,010)	(1,450)
Net cash flow used for investing activities									(38,765)	(7,806)	(11,364)
Cash flows from financing activities
Issuance of long-term debt									0	0	125,000
Short-term debt borrowings under revolving credit facility									40,000	0	0
Commercial Paper - net									1,700	0	0
Dividends paid on common stock									(274,229)	(260,027)	(246,671)
Repayment of long-term debt									0	0	(125,000)
Common stock equity issuance and purchases - net									(4,867)	19,373	15,288
Other									0	0	161
Net cash flow provided by (used for) financing activities									(237,396)	(240,654)	(231,222)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS									(17,391)	14,344	(2,710)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR				$ 17,432				$ 3,088	17,432	3,088	5,798
CASH AND CASH EQUIVALENTS AT END OF YEAR	$ 41				$ 17,432				$ 41	$ 17,432	$ 3,088