Related Party Transactions - SPPC (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Nov. 30, 2022
Related Party Transaction [Line Items]
Revenues	$ 25,602,000,000	$ 26,337,000,000	$ 25,150,000,000
Accounts payable	3,175,000,000	2,679,000,000
Other current liabilities	1,551,000,000	1,677,000,000
Related party, cash received (paid) for income taxes	1,479,000,000	1,961,000,000	1,441,000,000
SPPC
Related Party Transaction [Line Items]
Revenues	1,431,000,000	1,193,000,000	965,000,000
Trade receivables, net	180,000,000	175,000,000
Accounts payable	228,000,000	224,000,000
Other current liabilities	61,000,000	61,000,000
Notes payable to affiliates	0	70,000,000
Income tax receivable (payable), related parties current	(4,000,000)	11,000,000
Related party, cash received (paid) for income taxes	(55,000,000)	1,000,000	3,000,000
SPPC | NV Energy
Related Party Transaction [Line Items]
Related party amounts of transaction	5,000,000	5,000,000	5,000,000
Expense reimbursement	1,000,000	1,000,000	0
SPPC | NPC
Related Party Transaction [Line Items]
Related party amounts of transaction	28,000,000	25,000,000	25,000,000
Expense reimbursement	19,000,000	16,000,000	15,000,000
SPPC | Intercompany administrative services agreement
Related Party Transaction [Line Items]
Related party amounts of transaction	27,000,000	23,000,000	14,000,000
SPPC | Electricity services
Related Party Transaction [Line Items]
Purchases from related party	230,000,000	362,000,000	179,000,000
SPPC | Related party | NV Energy
Related Party Transaction [Line Items]
Trade receivables, net	0	0
Other current liabilities	24,000,000	47,000,000
Notes payable to affiliates	0	70,000,000		$ 100,000,000
SPPC | Related party | NPC
Related Party Transaction [Line Items]
Trade receivables, net	20,000,000	0
Accounts payable	0	33,000,000
SPPC | Related party | Electricity services
Related Party Transaction [Line Items]
Revenues	70,000,000	86,000,000	$ 43,000,000
Trade receivables, net	1,000,000	5,000,000
Accounts payable	$ 10,000,000	$ 41,000,000