Income Taxes - SPPC - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities	$ 1,323	$ 1,349
Other	741	686
Total deferred income tax assets	3,159	3,159
Property-related items	(12,244)	(11,814)
Regulatory assets	(898)	(764)
Other	(510)	(478)
Total deferred income tax liabilities	(15,650)	(15,933)
Net deferred income tax liability	(12,678)	(12,938)
SPPC
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities	63	64
Operating and finance leases	26	27
Customer advances	17	14
Derivative contracts and unamortized contract values	6	8
Other	6	6
Total deferred income tax assets	118	119
Property-related items	(387)	(379)
Regulatory assets	(135)	(94)
Operating and finance leases	(25)	(27)
Other	(16)	(21)
Total deferred income tax liabilities	(563)	(521)
Net deferred income tax liability	$ (445)	$ (402)