Jointly-Owned Facilities (Details) - Arizona Public Service Company $ in Thousands	Dec. 31, 2024 USD ($)
Palo Verde Units 1 and 3
Interests in jointly-owned facilities
Percent Owned	29.10%
Plant in Service	$ 2,010,346
Accumulated Depreciation	1,081,321
Construction Work in Progress	$ 20,694
Palo Verde Unit 2
Interests in jointly-owned facilities
Percent Owned	16.80%
Plant in Service	$ 709,414
Accumulated Depreciation	397,235
Construction Work in Progress	$ 9,076
Palo Verde Common
Interests in jointly-owned facilities
Percent Owned	28.00%
Plant in Service	$ 898,401
Accumulated Depreciation	366,027
Construction Work in Progress	47,962
Palo Verde Sale Leaseback
Interests in jointly-owned facilities
Plant in Service	351,050
Accumulated Depreciation	268,494
Construction Work in Progress	$ 0
Four Corners Generating Station
Interests in jointly-owned facilities
Percent Owned	63.00%
Plant in Service	$ 1,848,412
Accumulated Depreciation	705,667
Construction Work in Progress	$ 56,226
Cholla Common Facilities
Interests in jointly-owned facilities
Percent Owned	50.50%
Plant in Service	$ 301,035
Accumulated Depreciation	231,170
Construction Work in Progress	$ 1,743
Arizona Nuclear Power Project 500kV System
Interests in jointly-owned facilities
Percent Owned	33.30%
Plant in Service	$ 134,713
Accumulated Depreciation	60,174
Construction Work in Progress	$ 7,174
Navajo Southern System
Interests in jointly-owned facilities
Percent Owned	24.70%
Plant in Service	$ 88,528
Accumulated Depreciation	38,797
Construction Work in Progress	$ 626
Palo Verde — Yuma 500kV System
Interests in jointly-owned facilities
Percent Owned	25.50%
Plant in Service	$ 24,260
Accumulated Depreciation	8,120
Construction Work in Progress	$ 142
Four Corners Switchyards
Interests in jointly-owned facilities
Percent Owned	58.00%
Plant in Service	$ 84,367
Accumulated Depreciation	23,886
Construction Work in Progress	$ 309
Phoenix — Mead System
Interests in jointly-owned facilities
Percent Owned	17.10%
Plant in Service	$ 39,788
Accumulated Depreciation	21,173
Construction Work in Progress	$ 330
Palo Verde — Rudd 500kV System
Interests in jointly-owned facilities
Percent Owned	50.00%
Plant in Service	$ 95,785
Accumulated Depreciation	34,254
Construction Work in Progress	$ 1,808
Morgan — Pinnacle Peak System
Interests in jointly-owned facilities
Percent Owned	63.20%
Plant in Service	$ 117,500
Accumulated Depreciation	29,013
Construction Work in Progress	$ 287
Round Valley System
Interests in jointly-owned facilities
Percent Owned	50.00%
Plant in Service	$ 548
Accumulated Depreciation	213
Construction Work in Progress	$ 0
Palo Verde — Morgan System
Interests in jointly-owned facilities
Percent Owned	87.50%
Plant in Service	$ 266,547
Accumulated Depreciation	46,327
Construction Work in Progress	$ 208
Hassayampa — North Gila System
Interests in jointly-owned facilities
Percent Owned	80.00%
Plant in Service	$ 154,330
Accumulated Depreciation	27,739
Construction Work in Progress	$ 0
Cholla 500kV Switchyard
Interests in jointly-owned facilities
Percent Owned	85.70%
Plant in Service	$ 8,454
Accumulated Depreciation	2,859
Construction Work in Progress	$ 35
Saguaro 500kV Switchyard
Interests in jointly-owned facilities
Percent Owned	60.00%
Plant in Service	$ 29,850
Accumulated Depreciation	15,768
Construction Work in Progress	$ 101
Kyrene — Knox System
Interests in jointly-owned facilities
Percent Owned	50.00%
Plant in Service	$ 578
Accumulated Depreciation	349
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	$ 82