Regulatory Assets and Liabilities (Schedule of Regulatory Assets) (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Regulatory Assets [Line Items]
Current regulatory assets	$ 1,692	$ 1,009
Long-term regulatory assets	6,528	6,088
Southern California Edison
Regulatory Assets [Line Items]
Current regulatory assets	1,692	1,009
Long-term regulatory assets	6,528	6,088
Total regulatory assets	8,220	7,097
Southern California Edison | Regulatory balancing and memorandum accounts
Regulatory Assets [Line Items]
Current regulatory assets	1,443	798
Long-term regulatory assets	1,331	981
Southern California Edison | Power contracts
Regulatory Assets [Line Items]
Current regulatory assets	228	189
Long-term regulatory assets	361	434
Southern California Edison | Other
Regulatory Assets [Line Items]
Current regulatory assets	21	22
Long-term regulatory assets	34	62
Southern California Edison | Deferred income taxes, net of liabilities
Regulatory Assets [Line Items]
Long-term regulatory assets	4,231	4,026
Southern California Edison | Pensions and other postretirement benefits
Regulatory Assets [Line Items]
Long-term regulatory assets	83	87
Southern California Edison | Unamortized investments, net of accumulated amortization
Regulatory Assets [Line Items]
Long-term regulatory assets	117	119
Southern California Edison | Unamortized loss on reacquired debt
Regulatory Assets [Line Items]
Long-term regulatory assets	138	142
Southern California Edison | Environmental remediation
Regulatory Assets [Line Items]
Long-term regulatory assets	$ 233	$ 237