Jointly-Owned Facilities (Details) - Arizona Public Service Company $ in Thousands	Dec. 31, 2023 USD ($)
Palo Verde Units 1 and 3
Interests in jointly-owned facilities
Percent Owned	29.10%
Plant in Service	$ 1,990,237
Accumulated Depreciation	1,087,614
Construction Work in Progress	$ 21,442
Palo Verde Unit 2
Interests in jointly-owned facilities
Percent Owned	16.80%
Plant in Service	$ 681,483
Accumulated Depreciation	387,485
Construction Work in Progress	$ 12,700
Palo Verde Common
Interests in jointly-owned facilities
Percent Owned	28.00%
Plant in Service	$ 857,807
Accumulated Depreciation	356,962
Construction Work in Progress	65,911
Palo Verde Sale Leaseback
Interests in jointly-owned facilities
Plant in Service	351,050
Accumulated Depreciation	264,624
Construction Work in Progress	$ 0
Four Corners Generating Station
Interests in jointly-owned facilities
Percent Owned	63.00%
Plant in Service	$ 1,748,436
Accumulated Depreciation	659,780
Construction Work in Progress	$ 29,586
Cholla Common Facilities
Interests in jointly-owned facilities
Percent Owned	50.50%
Plant in Service	$ 250,994
Accumulated Depreciation	167,357
Construction Work in Progress	$ 7,487
ANPP 500kV System
Interests in jointly-owned facilities
Percent Owned	33.40%
Plant in Service	$ 136,145
Accumulated Depreciation	58,252
Construction Work in Progress	$ 4,801
Navajo Southern System
Interests in jointly-owned facilities
Percent Owned	25.20%
Plant in Service	$ 87,185
Accumulated Depreciation	36,743
Construction Work in Progress	$ 550
Palo Verde — Yuma 500kV System
Interests in jointly-owned facilities
Percent Owned	25.30%
Plant in Service	$ 24,057
Accumulated Depreciation	7,912
Construction Work in Progress	$ 432
Four Corners Switchyards
Interests in jointly-owned facilities
Percent Owned	57.50%
Plant in Service	$ 84,279
Accumulated Depreciation	21,918
Construction Work in Progress	$ 161
Phoenix — Mead System
Interests in jointly-owned facilities
Percent Owned	17.10%
Plant in Service	$ 39,772
Accumulated Depreciation	20,679
Construction Work in Progress	$ 257
Palo Verde — Rudd 500kV System
Interests in jointly-owned facilities
Percent Owned	50.00%
Plant in Service	$ 95,736
Accumulated Depreciation	32,665
Construction Work in Progress	$ 731
Morgan — Pinnacle Peak System
Interests in jointly-owned facilities
Percent Owned	63.20%
Plant in Service	$ 117,080
Accumulated Depreciation	26,990
Construction Work in Progress	$ 229
Round Valley System
Interests in jointly-owned facilities
Percent Owned	50.00%
Plant in Service	$ 548
Accumulated Depreciation	205
Construction Work in Progress	$ 0
Palo Verde — Morgan System
Interests in jointly-owned facilities
Percent Owned	87.50%
Plant in Service	$ 268,629
Accumulated Depreciation	40,962
Construction Work in Progress	$ 8,053
Hassayampa — North Gila System
Interests in jointly-owned facilities
Percent Owned	80.00%
Plant in Service	$ 151,684
Accumulated Depreciation	24,618
Construction Work in Progress	$ 0
Cholla 500kV Switchyard
Interests in jointly-owned facilities
Percent Owned	85.70%
Plant in Service	$ 8,445
Accumulated Depreciation	2,760
Construction Work in Progress	$ 0
Saguaro 500kV Switchyard
Interests in jointly-owned facilities
Percent Owned	60.00%
Plant in Service	$ 21,627
Accumulated Depreciation	14,060
Construction Work in Progress	$ 17
Kyrene — Knox System
Interests in jointly-owned facilities
Percent Owned	50.00%
Plant in Service	$ 578
Accumulated Depreciation	340
Construction Work in Progress	$ 0
Agua Fria Switchyard
Interests in jointly-owned facilities
Percent Owned	10.00%
Plant in Service	$ 0
Accumulated Depreciation	0
Construction Work in Progress	$ 77