Regulatory Assets and Liabilities (Schedule of Regulatory Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Regulatory Assets [Line Items]
Current regulatory assets	$ 350	$ 560
Long-term regulatory assets	7,455	7,512
SCE
Regulatory Assets [Line Items]
Current regulatory assets	350	560
Long-term regulatory assets	7,455	7,512
Total regulatory assets	7,805	8,072
SCE | Regulatory balancing accounts
Regulatory Assets [Line Items]
Current regulatory assets	135	382
Long-term regulatory assets	66	36
SCE | Energy derivatives
Regulatory Assets [Line Items]
Current regulatory assets	150	159
Long-term regulatory assets	947	1,027
SCE | Unamortized investments, net
Regulatory Assets [Line Items]
Current regulatory assets	49	0
Long-term regulatory assets	80	182
SCE | Other
Regulatory Assets [Line Items]
Current regulatory assets	16	19
Long-term regulatory assets	7	288
SCE | Deferred income taxes, net
Regulatory Assets [Line Items]
Long-term regulatory assets	4,478	3,757
SCE | Pensions and other postretirement benefits
Regulatory Assets [Line Items]
Long-term regulatory assets	710	849
SCE | San Onofre
Regulatory Assets [Line Items]
Long-term regulatory assets	857	1,043
SCE | Unamortized loss on reacquired debt
Regulatory Assets [Line Items]
Long-term regulatory assets	184	201
SCE | Environmental remediation
Regulatory Assets [Line Items]
Long-term regulatory assets	$ 126	$ 129