Summary of Significant Accounting Policies - Cash and Restricted Cash (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024	Dec. 31, 2023
Restricted Cash and Cash Equivalents
Cash and cash equivalents	$ 1,318	$ 193
Restricted Cash, Current, Statement of Financial Position [Extensible Enumeration]	Other current assets
Restricted Cash, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other long-term assets
Total cash, cash equivalents, and restricted cash	$ 1,908	684	$ 1,287	$ 532
Edison International
Restricted Cash and Cash Equivalents
Cash and cash equivalents	1,318	193
Short-term restricted cash	60	40
Long-term restricted cash	530	451
Total cash, cash equivalents, and restricted cash	1,908	684
SCE
Restricted Cash and Cash Equivalents
Cash and cash equivalents	1,094	78
Short-term restricted cash	58	36
Long-term restricted cash	530	451
Total cash, cash equivalents, and restricted cash	$ 1,682	$ 565	$ 1,142	$ 398