Supplemental Cash Flow Disclosures - SPPC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Condensed Cash Flow Statements, Captions [Line Items]
Interest paid, net of amounts capitalized	$ 2,304	$ 2,109	$ 2,071
Income taxes paid (refunded)	(1,501)	(1,370)	(1,863)
Accruals related to property, plant and equipment additions	1,337	1,494	1,049
SPPC
Condensed Cash Flow Statements, Captions [Line Items]
Interest paid, net of amounts capitalized	72	49	45
Income taxes paid (refunded)	66	56	(1)
Accruals related to property, plant and equipment additions	$ 133	$ 51	$ 57