Asset Retirement Obligations - Narrative (Details) - APS $ in Millions	6 Months Ended
	Jun. 30, 2024 USD ($)
Cholla
Schedule of Asset Retirement Obligations [Line Items]
Asset retirement obligation, period increase	$ 63
Four Corners Coal-Fired Power Plant
Schedule of Asset Retirement Obligations [Line Items]
Asset retirement obligation, period increase	82
Navajo Coal-Fired Power Plant
Schedule of Asset Retirement Obligations [Line Items]
Asset retirement obligation, period increase	8
Palo Verde Nuclear Plant
Schedule of Asset Retirement Obligations [Line Items]
Asset retirement obligation, period increase	$ 1