Asset Retirement Obligations - SPPC - Asset Retirement Obligation by Type (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Asset Retirement Obligations By Type [Line Items]
Asset retirement obligations	$ 1,550	$ 1,428	$ 1,328
Other
Asset Retirement Obligations By Type [Line Items]
Asset retirement obligations	122	116
SPPC
Asset Retirement Obligations By Type [Line Items]
Asset retirement obligations	11	12	$ 11
SPPC | Asbestos
Asset Retirement Obligations By Type [Line Items]
Asset retirement obligations	5	5
SPPC | Evaporative ponds and dry ash landfills
Asset Retirement Obligations By Type [Line Items]
Asset retirement obligations	2	3
SPPC | Solar-powered generating facilities
Asset Retirement Obligations By Type [Line Items]
Asset retirement obligations	1	1
SPPC | Other
Asset Retirement Obligations By Type [Line Items]
Asset retirement obligations	$ 3	$ 3