Investments (Trust Value) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Fair Value
Fair Value	$ 4,870	$ 4,833
Repurchase agreements
Fair Value
Fair Value	37	138
SCE
Fair Value
Amortized Cost	2,555	2,494
Fair Value	4,870	4,833
SCE | Stocks
Fair Value
Fair Value	1,972	1,908
SCE | Municipal bonds
Fair Value
Amortized Cost	875	1,013
SCE | U.S. government and agency securities
Fair Value
Amortized Cost	1,095	740
SCE | Corporate bonds
Fair Value
Amortized Cost	386	460
Fair Value	446
SCE | Short-term investments and receivables/payables
Fair Value
Amortized Cost	199	281
SCE | Fair Value, Measurements, Recurring
Fair Value
Fair Value	4,889	5,039
SCE | Fair Value, Measurements, Recurring | Municipal bonds
Fair Value
Fair Value	1,033	1,218
SCE | Fair Value, Measurements, Recurring | U.S. government and agency securities
Fair Value
Fair Value	1,212	864
SCE | Fair Value, Measurements, Recurring | Corporate bonds
Fair Value
Fair Value		550
SCE | Fair Value, Measurements, Recurring | Short-term investments and receivables/payables
Fair Value
Fair Value	$ 207	$ 293