CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
PROPERTY, PLANT AND EQUIPMENT (Notes 1, 7 and 10)
Plant in service and held for future use	$ 21,688,661	$ 20,837,885
Accumulated depreciation and amortization	(7,504,603)	(7,110,310)
Net	14,184,058	13,727,575
Construction work in progress	1,329,478	937,384
Palo Verde sale leaseback, net of accumulated depreciation	94,166	98,036
Intangible assets, net of accumulated amortization	273,693	282,570
Nuclear fuel, net of accumulated amortization	106,039	113,645
Total property, plant and equipment	15,987,434	15,159,210
INVESTMENTS AND OTHER ASSETS
Nuclear decommissioning trust (Notes 13 and 19)	1,294,757	1,138,435
Other special use funds (Notes 13 and 19)	358,410	254,509
Assets from risk management activities (Note 16)	46,908	1,818
Other assets	97,884	91,104
Total investments and other assets	1,797,959	1,485,866
CURRENT ASSETS
Cash and cash equivalents	9,969	59,968
Customer and other receivables	391,923	313,576
Accrued unbilled revenues	133,980	132,197
Allowance for doubtful accounts (Note 2)	(25,354)	(19,782)
Materials and supplies (at average cost)	349,135	314,745
Fossil fuel (at average cost)	18,032	19,552
Income tax receivable (Note 5)	7,514	6,792
Assets from risk management activities (Note 16)	63,481	2,931
Deferred fuel and purchased power regulatory asset (Note 4)	388,148	175,835
Other regulatory assets (Note 4)	130,376	115,878
Other current assets	83,896	76,627
Total current assets	1,551,100	1,198,319
DEFERRED DEBITS
Regulatory assets (Notes 1, 4 and 5)	1,192,987	1,133,987
Operating lease right-of-use assets (Note 9)	890,057	505,064
Assets for pension and other postretirement benefits (Note 8)	545,723	502,992
Other	37,962	34,983
Total deferred debits	2,666,729	2,177,026
Total Assets	22,003,222	20,020,421
EQUITY
Retained earnings	3,264,719	3,025,106
Accumulated other comprehensive loss	(54,861)	(62,796)
Total shareholders’ equity	5,906,200	5,633,503
Noncontrolling interests (Note 18)	115,260	119,290
Total equity	6,021,460	5,752,793
LONG-TERM DEBT LESS CURRENT MATURITIES (Note 7)	6,913,735	6,314,266
CURRENT LIABILITIES
Short-term borrowings (Note 6)	292,000	169,000
Accounts payable	393,083	318,585
Accrued taxes	168,645	159,551
Accrued interest	57,332	56,962
Common dividends payable	95,988	93,531
Customer deposits	42,293	48,340
Liabilities from risk management activities (Note 16)	4,373	7,557
Liabilities for asset retirements (Note 12)	4,473	15,586
Operating lease liabilities (Note 9)	100,443	74,785
Regulatory liabilities (Note 4)	296,271	229,088
Other current liabilities	151,968	187,448
Total current liabilities	1,756,869	1,360,433
DEFERRED CREDITS AND OTHER
Deferred income taxes (Note 5)	2,311,862	2,135,403
Regulatory liabilities (Notes 1, 4, 5 and 8)	2,499,213	2,450,169
Liabilities for asset retirements (Note 12)	762,909	689,497
Liabilities for pension benefits (Note 8)	152,865	166,484
Liabilities from risk management activities (Note 16)	0	11,062
Customer advances	257,151	221,032
Coal mine reclamation	174,616	170,097
Deferred investment tax credit	186,570	191,372
Unrecognized tax benefits (Note 5)	4,657	5,834
Operating lease liabilities (Note 9)	728,401	361,336
Other	232,914	190,643
Total deferred credits and other	7,311,158	6,592,929
COMMITMENTS AND CONTINGENCIES (SEE NOTES)
Total Liabilities and Equity	22,003,222	20,020,421
Arizona Public Service Company
PROPERTY, PLANT AND EQUIPMENT (Notes 1, 7 and 10)
Plant in service and held for future use	21,685,200	20,834,424
Accumulated depreciation and amortization	(7,501,317)	(7,107,058)
Net	14,183,883	13,727,366
Construction work in progress	1,327,721	937,384
Palo Verde sale leaseback, net of accumulated depreciation	94,166	98,036
Intangible assets, net of accumulated amortization	273,537	282,415
Nuclear fuel, net of accumulated amortization	106,039	113,645
Total property, plant and equipment	15,985,346	15,158,846
INVESTMENTS AND OTHER ASSETS
Nuclear decommissioning trust (Notes 13 and 19)	1,294,757	1,138,435
Other special use funds (Notes 13 and 19)	358,410	254,509
Assets from risk management activities (Note 16)	46,908	1,818
Other assets	42,440	44,192
Total investments and other assets	1,742,515	1,438,954
CURRENT ASSETS
Cash and cash equivalents	9,374	57,310
Customer and other receivables	390,533	312,644
Accrued unbilled revenues	133,980	132,197
Allowance for doubtful accounts (Note 2)	(25,354)	(19,782)
Materials and supplies (at average cost)	349,135	314,745
Fossil fuel (at average cost)	18,032	19,552
Income tax receivable (Note 5)	10,756	0
Assets from risk management activities (Note 16)	63,481	2,931
Deferred fuel and purchased power regulatory asset (Note 4)	388,148	175,835
Other regulatory assets (Note 4)	130,376	115,878
Other current assets	57,729	47,593
Total current assets	1,526,190	1,158,903
DEFERRED DEBITS
Regulatory assets (Notes 1, 4 and 5)	1,192,987	1,133,987
Operating lease right-of-use assets (Note 9)	888,207	503,475
Assets for pension and other postretirement benefits (Note 8)	537,092	495,673
Other	37,319	34,413
Total deferred debits	2,655,605	2,167,548
Total Assets	21,909,656	19,924,251
EQUITY
Common stock	178,162	178,162
Additional paid-in capital	3,021,696	2,871,696
Retained earnings	3,470,235	3,216,955
Accumulated other comprehensive loss	(34,880)	(40,918)
Total shareholders’ equity	6,635,213	6,225,895
Noncontrolling interests (Note 18)	115,260	119,290
Total equity	6,750,473	6,345,185
LONG-TERM DEBT LESS CURRENT MATURITIES (Note 7)	6,266,693	5,817,945
Total capitalization	13,017,166	12,163,130
CURRENT LIABILITIES
Short-term borrowings (Note 6)	278,700	0
Accounts payable	389,365	311,699
Accrued taxes	152,012	148,970
Accrued interest	56,622	56,322
Common dividends payable	96,000	93,500
Customer deposits	42,293	48,340
Liabilities from risk management activities (Note 16)	4,373	7,557
Liabilities for asset retirements (Note 12)	4,473	15,586
Operating lease liabilities (Note 9)	100,199	74,695
Regulatory liabilities (Note 4)	296,271	229,088
Other current liabilities	145,286	190,420
Total current liabilities	1,565,594	1,176,177
DEFERRED CREDITS AND OTHER
Deferred income taxes (Note 5)	2,331,701	2,143,673
Regulatory liabilities (Notes 1, 4, 5 and 8)	2,499,213	2,450,169
Liabilities for asset retirements (Note 12)	762,909	689,497
Liabilities for pension benefits (Note 8)	138,328	148,943
Liabilities from risk management activities (Note 16)	0	11,062
Customer advances	257,151	221,032
Coal mine reclamation	174,616	170,097
Deferred investment tax credit	186,570	191,372
Unrecognized tax benefits (Note 5)	37,423	39,410
Operating lease liabilities (Note 9)	726,572	359,653
Other	212,413	160,036
Total deferred credits and other	7,326,896	6,584,944
COMMITMENTS AND CONTINGENCIES (SEE NOTES)
Total Liabilities and Equity	$ 21,909,656	$ 19,924,251