CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 570,052	$ 557,813	$ 530,540
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including nuclear fuel	686,253	664,140	650,955
Deferred fuel and purchased power	(93,651)	(82,481)	(78,277)
Deferred fuel and purchased power amortization	(12,047)	49,508	116,750
Allowance for equity funds used during construction	(33,776)	(31,431)	(52,319)
Deferred income taxes	69,469	(1,479)	117,355
Deferred investment tax credit	(5,096)	(3,938)	(5,170)
Stock compensation	18,292	18,376	19,547
Changes in current assets and liabilities:
Customer and other receivables	(18,191)	(12,789)	37,530
Accrued unbilled revenues	(4,032)	9,005	(24,736)
Materials, supplies and fossil fuel	11,623	(51,826)	(6,103)
Income tax receivable	14,935	(21,727)	0
Other current assets	(30,640)	(3,507)	33,844
Accounts payable	(6,059)	50,641	(14,602)
Accrued taxes	14,652	(9,920)	6,597
Other current liabilities	22,520	(84,651)	28,174
Change in margin and collateral accounts — assets	404	(247)	143
Change in margin and collateral accounts — liabilities	100	(125)	(2,211)
Change in unrecognized tax benefits	2,220	2,704	(1,235)
Change in long-term regulatory liabilities	13,017	124,221	(109,284)
Change in other long-term assets	(67,453)	(82,895)	78,604
Change in other long-term liabilities	(186,227)	(132,666)	(48,958)
Net cash flow provided by operating activities	966,365	956,726	1,277,144
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,326,584)	(1,191,447)	(1,178,169)
Contributions in aid of construction	62,503	70,693	27,716
Allowance for borrowed funds used during construction	(18,530)	(18,528)	(25,180)
Proceeds from nuclear decommissioning trust sales and other special use funds	819,518	719,034	653,033
Investment in nuclear decommissioning trust and other special use funds	(822,608)	(722,181)	(672,165)
Other	7,883	11,452	1,941
Net cash flow used for investing activities	(1,277,818)	(1,130,977)	(1,192,824)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of long-term debt	1,596,672	1,092,188	445,245
Repayment of long-term debt	(915,150)	(600,000)	(182,000)
Short-term borrowings and (repayments) — net	73,325	54,275	(7,000)
Short-term debt borrowings under revolving credit facility	751,690	49,000	45,000
Short-term debt repayments under revolving credit facility	(770,690)	(65,000)	(57,000)
Dividends paid on common stock	(350,577)	(329,643)	(308,892)
Common stock equity issuance and purchases — net	(1,389)	692	(5,055)
Distributions to noncontrolling interests	(22,743)	(22,744)	(22,744)
Net cash flow provided by (used for) financing activities	361,138	178,768	(92,446)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	49,685	4,517	(8,126)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	10,283	5,766	13,892
CASH AND CASH EQUIVALENTS AT END OF YEAR	59,968	10,283	5,766
ARIZONA PUBLIC SERVICE COMPANY
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	587,521	584,764	589,758
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including nuclear fuel	686,168	664,055	649,295
Deferred fuel and purchased power	(93,651)	(82,481)	(78,277)
Deferred fuel and purchased power amortization	(12,047)	49,508	116,750
Allowance for equity funds used during construction	(33,776)	(31,431)	(52,319)
Deferred income taxes	36,462	48,367	59,927
Deferred investment tax credit	(5,096)	(3,938)	(5,170)
Changes in current assets and liabilities:
Customer and other receivables	(28,206)	(12,075)	35,406
Accrued unbilled revenues	(4,032)	9,005	(24,736)
Materials, supplies and fossil fuel	11,623	(51,826)	(6,206)
Income tax receivable	7,313	(7,313)	0
Other current assets	(24,669)	(1,461)	31,707
Accounts payable	(4,503)	53,258	(15,608)
Accrued taxes	12,642	(40,029)	19,008
Other current liabilities	29,587	(82,138)	25,070
Change in margin and collateral accounts — assets	404	(247)	143
Change in margin and collateral accounts — liabilities	100	(125)	(2,211)
Change in unrecognized tax benefits	2,220	2,704	(1,235)
Change in long-term regulatory liabilities	13,017	124,221	(109,284)
Change in other long-term assets	(65,139)	(85,725)	77,952
Change in other long-term liabilities	(186,871)	(129,682)	(55,169)
Net cash flow provided by operating activities	929,067	1,007,411	1,254,801
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,326,584)	(1,191,447)	(1,169,061)
Contributions in aid of construction	62,503	70,693	27,716
Allowance for borrowed funds used during construction	(18,530)	(18,528)	(25,180)
Proceeds from nuclear decommissioning trust sales and other special use funds	819,518	719,034	653,033
Investment in nuclear decommissioning trust and other special use funds	(822,608)	(722,181)	(672,165)
Other	(554)	6,336	(1,789)
Net cash flow used for investing activities	(1,286,255)	(1,136,093)	(1,187,446)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of long-term debt	1,099,722	1,092,188	295,245
Repayment of long-term debt	(465,150)	(600,000)	(182,000)
Short-term debt borrowings under revolving credit facility	540,000	0	25,000
Short-term debt repayments under revolving credit facility	(540,000)	0	(25,000)
Dividends paid on common stock	(357,500)	(336,300)	(316,000)
Equity infusion from Pinnacle West	150,000	0	150,000
Distributions to noncontrolling interests	(22,743)	(22,744)	(22,744)
Net cash flow provided by (used for) financing activities	404,329	133,144	(75,499)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	47,141	4,462	(8,144)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	10,169	5,707	13,851
CASH AND CASH EQUIVALENTS AT END OF YEAR	$ 57,310	$ 10,169	$ 5,707