SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash Flows from Operating Activities
Net income	$ 635,944	$ 570,052	$ 557,813
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	719,141	686,253	664,140
Deferred income taxes	117,471	69,469	(1,479)
Accounts receivable	(72,559)	(18,191)	(12,789)
Accounts payable	20,267	(6,059)	50,641
Net cash provided by operating activities	860,014	966,365	956,726
Cash flows from investing activities
Net cash used for investing activities	(1,386,929)	(1,277,818)	(1,130,977)
Cash flows from financing activities
Issuance of long-term debt	746,999	1,596,672	1,092,188
Short-term debt borrowings under revolving credit facility	0	751,690	49,000
Short-term debt repayments under revolving credit facility	(19,000)	(770,690)	(65,000)
Short-term borrowings and (repayments) — net	142,000	73,325	54,275
Dividends paid on common stock	(369,478)	(350,577)	(329,643)
Repayment of long-term debt	0	(915,150)	(600,000)
Common stock equity issuance and purchases — net	(2,350)	(1,389)	692
Net cash provided by financing activities	476,916	361,138	178,768
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(49,999)	49,685	4,517
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	59,968	10,283	5,766
CASH AND CASH EQUIVALENTS AT END OF YEAR	9,969	59,968	10,283
Pinnacle West
Cash Flows from Operating Activities
Net income	618,720	550,559	538,320
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in earnings of subsidiaries — net	(628,916)	(566,147)	(562,946)
Depreciation and amortization	93	76	76
Deferred income taxes	(11,381)	33,007	(35,831)
Accounts receivable	8,897	(7,903)	182
Accounts payable	(2,598)	(1,964)	(2,129)
Accrued taxes and income tax receivables — net	16,079	9,610	16,400
Dividends received from subsidiaries	376,500	357,500	336,300
Other	4,214	20,163	(1,300)
Net cash provided by operating activities	381,608	394,901	289,072
Cash flows from investing activities
Investments in subsidiaries	(145,266)	(137,881)	1,557
Repayments of loans from subsidiaries	4,017	932	4,190
Advances of loans to subsidiaries	(12,256)	(7,261)	(4,165)
Net cash used for investing activities	(153,505)	(144,210)	1,582
Cash flows from financing activities
Issuance of long-term debt	300,000	496,950	0
Short-term debt borrowings under revolving credit facility	0	211,690	49,000
Short-term debt repayments under revolving credit facility	(19,000)	(230,690)	(65,000)
Short-term borrowings and (repayments) — net	(136,700)	73,325	54,275
Dividends paid on common stock	(369,478)	(350,577)	(329,643)
Repayment of long-term debt	0	(450,000)	0
Common stock equity issuance and purchases — net	(2,350)	(1,389)	692
Net cash provided by financing activities	(227,528)	(250,691)	(290,676)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	575	0	(22)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	19	19	41
CASH AND CASH EQUIVALENTS AT END OF YEAR	$ 594	$ 19	$ 19