Investments (Trust Value) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Fair Value
Fair Value	$ 4,527	$ 4,870
Repurchase agreements
Fair Value
Fair Value	11	37
SCE
Fair Value
Amortized Cost	2,444	2,555
Fair Value	4,527	4,870
SCE | Municipal bonds
Fair Value
Amortized Cost	872	875
SCE | Government and agency securities
Fair Value
Amortized Cost	1,023	1,095
SCE | Corporate bonds
Fair Value
Amortized Cost	415	386
SCE | Short-term investments and receivables/payables
Fair Value
Amortized Cost	134	199
SCE | Fair Value, Measurements, Recurring
Fair Value
Fair Value	4,549	4,889
SCE | Fair Value, Measurements, Recurring | Stocks
Fair Value
Fair Value	1,879	1,972
SCE | Fair Value, Measurements, Recurring | Municipal bonds
Fair Value
Fair Value	955	1,033
SCE | Fair Value, Measurements, Recurring | Government and agency securities
Fair Value
Fair Value	1,092	1,212
SCE | Fair Value, Measurements, Recurring | Corporate bonds
Fair Value
Fair Value	458	446
SCE | Fair Value, Measurements, Recurring | Short-term investments and receivables/payables
Fair Value
Fair Value	$ 143	$ 207