Summary of Significant Accounting Policies - Cash and Restricted Cash (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Restricted Cash and Cash Equivalents
Money market funds	$ 101	$ 199
Cash and cash equivalents	193	345
Short-term restricted cash	$ 40	$ 35
Restricted Cash, Current, Statement of Financial Position Flag	Other current assets	Other current assets
Long-term restricted cash	$ 451	$ 152
Restricted Cash, Noncurrent, Statement of Financial Position Flag	Other long-term assets	Other long-term assets
Total cash, cash equivalents and restricted cash	$ 684	$ 532	$ 917	$ 394
SCE
Restricted Cash and Cash Equivalents
Money market funds	0	78
Cash and cash equivalents	78	214
Short-term restricted cash	$ 36	$ 33
Restricted Cash, Current, Statement of Financial Position Flag	Other current assets	Other current assets
Long-term restricted cash	$ 451	$ 151
Restricted Cash, Noncurrent, Statement of Financial Position Flag	Other long-term assets	Other long-term assets
Total cash, cash equivalents and restricted cash	$ 565	$ 398	$ 766	$ 280