Regulatory Assets and Liabilities (Schedule of Regulatory Liabilities) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Regulatory Liabilities [Line Items]
Current regulatory liabilities	$ 1,030	$ 1,128
Long-term regulatory liabilities	6,020	5,676
Southern California Edison
Regulatory Liabilities [Line Items]
Current regulatory liabilities	1,030	1,128
Long-term regulatory liabilities	6,020	5,676
Total regulatory liabilities	7,050	6,804
Southern California Edison | Regulatory balancing accounts
Regulatory Liabilities [Line Items]
Current regulatory liabilities	999	1,106
Long-term regulatory liabilities	1,348	1,314
Southern California Edison | Other
Regulatory Liabilities [Line Items]
Current regulatory liabilities	31	22
Long-term regulatory liabilities	61	79
Southern California Edison | Costs of removal
Regulatory Liabilities [Line Items]
Long-term regulatory liabilities	2,842	2,781
Southern California Edison | Recoveries in excess of ARO liabilities
Regulatory Liabilities [Line Items]
Long-term regulatory liabilities	$ 1,769	$ 1,502