CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
OPERATING REVENUES (NOTE 2)	$ 3,586,982	$ 3,471,209	$ 3,691,247
OPERATING EXPENSES
Fuel and purchased power	993,419	1,042,237	1,076,116
Operations and maintenance	958,910	941,616	1,036,744
Depreciation and amortization	614,378	590,929	582,354
Taxes other than income taxes	224,835	218,579	212,849
Other expenses	7,288	5,888	9,497
Total	2,798,830	2,799,249	2,917,560
Operating loss	788,152	671,960	773,687
OTHER INCOME (DEDUCTIONS)
Allowance for equity funds used during construction (Note 1)	33,776	31,431	52,319
Pension and other postretirement non-service credits - net (Note 8)	56,341	22,989	49,791
Other income (Note 17)	56,703	50,263	24,896
Other expense (Note 17)	(57,776)	(17,880)	(17,966)
Total	89,044	86,803	109,040
INTEREST EXPENSE
Interest charges	247,501	235,251	243,465
Allowance for borrowed funds used during construction (Note 1)	(18,530)	(18,528)	(25,180)
Total	228,971	216,723	218,285
INCOME BEFORE INCOME TAXES	648,225	542,040	664,442
Income tax benefit	78,173	(15,773)	133,902
NET INCOME	570,052	557,813	530,540
Less: Net income attributable to noncontrolling interests (Note 18)	19,493	19,493	19,493
NET INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 550,559	$ 538,320	$ 511,047
Net effect of dilutive securities:
Weighted Average common shares outstanding — basic (in shares)	112,666	112,443	112,129
Weighted Average common shares outstanding — diluted (in shares)	112,942	112,758	112,550
EARNINGS PER WEIGHTED-AVERAGE COMMON SHARE OUTSTANDING
Net income attributable to common shareholders - basic (in dollars per share)	$ 4.89	$ 4.79	$ 4.56
Net income attributable to common shareholders — diluted (in dollars per share)	$ 4.87	$ 4.77	$ 4.54
ARIZONA PUBLIC SERVICE COMPANY
OPERATING REVENUES (NOTE 2)	$ 3,586,982	$ 3,471,209	$ 3,688,342
OPERATING EXPENSES
Fuel and purchased power	993,419	1,042,237	1,094,020
Operations and maintenance	945,181	926,716	969,227
Depreciation and amortization	614,293	590,844	580,694
Taxes other than income taxes	224,790	218,540	212,136
Other expenses	7,288	5,888	2,497
Total	2,784,971	2,784,225	2,858,574
Operating loss	802,011	686,984	829,768
OTHER INCOME (DEDUCTIONS)
Allowance for equity funds used during construction (Note 1)	33,776	31,431	52,319
Pension and other postretirement non-service credits - net (Note 8)	57,359	24,529	51,242
Other income (Note 17)	51,755	46,884	22,746
Other expense (Note 17)	(53,694)	(12,990)	(15,292)
Total	89,196	89,854	111,015
INTEREST EXPENSE
Interest charges	233,452	220,174	231,391
Allowance for borrowed funds used during construction (Note 1)	(18,530)	(18,528)	(25,180)
Total	214,922	201,646	206,211
INCOME BEFORE INCOME TAXES	676,285	575,192	734,572
Income tax benefit	88,764	(9,572)	144,814
NET INCOME	587,521	584,764	589,758
Less: Net income attributable to noncontrolling interests (Note 18)	19,493	19,493	19,493
NET INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 568,028	$ 565,271	$ 570,265