Supplemental Cash Flow Disclosures - SPPC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents	$ 1,096	$ 1,290
Restricted cash and cash equivalents	127	140
Total cash and cash equivalents and restricted cash and cash equivalents	1,244	1,445	$ 1,268	$ 883
Interest paid, net of amounts capitalized	2,041	1,855	1,723
Income taxes received, net	(1,309)	(1,361)	(850)
Accrued capital expenditures	834	801	888
SPPC
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents	10	19
Restricted cash and cash equivalents	6	7
Total cash and cash equivalents and restricted cash and cash equivalents	16	26	32	$ 76
Interest paid, net of amounts capitalized	41	42	41
Income taxes received, net	(3)	2	37
Accrued capital expenditures	$ 27	$ 17	$ 18