Related Party Transactions - SPPC (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Related Party Transaction [Line Items]
Revenues	$ 25,920,000,000	$ 25,602,000,000	$ 26,337,000,000
Accounts payable	2,928,000,000	3,175,000,000
Other current liabilities	2,109,000,000	1,551,000,000
Related party, cash received (paid) for income taxes	1,580,000,000	1,479,000,000	1,961,000,000
SPPC
Related Party Transaction [Line Items]
Revenues	1,262,000,000	1,431,000,000	1,193,000,000
Trade receivables, net	138,000,000	180,000,000
Accounts payable	410,000,000	228,000,000
Other current liabilities	50,000,000	46,000,000
Income tax receivable (payable), related parties current	(3,000,000)	4,000,000
Related party, cash received (paid) for income taxes	(65,000,000)	(55,000,000)	1,000,000
SPPC | NV Energy
Related Party Transaction [Line Items]
Related party amounts of transaction	5,000,000	5,000,000	5,000,000
Expense reimbursement	3,000,000	1,000,000	1,000,000
SPPC | NPC
Related Party Transaction [Line Items]
Related party amounts of transaction	31,000,000	28,000,000	25,000,000
Expense reimbursement	19,000,000	19,000,000	16,000,000
SPPC | Intercompany administrative services agreement
Related Party Transaction [Line Items]
Related party amounts of transaction	45,000,000	27,000,000	23,000,000
SPPC | Electricity services
Related Party Transaction [Line Items]
Purchases from related party	188,000,000	230,000,000	362,000,000
SPPC | Related party | NV Energy
Related Party Transaction [Line Items]
Trade receivables, net	0	0
Other current liabilities	54,000,000	24,000,000
SPPC | Related party | NPC
Related Party Transaction [Line Items]
Trade receivables, net	65,000,000	20,000,000
Other current liabilities	0	0
SPPC | Related party | Electricity services
Related Party Transaction [Line Items]
Revenues	29,000,000	70,000,000	$ 86,000,000
Trade receivables, net	1,000,000	1,000,000
Accounts payable	$ 7,000,000	$ 10,000,000