Regulatory Assets and Liabilities (Schedule of Regulatory Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Regulatory Liabilities [Line Items]
Current regulatory liabilities	$ 756	$ 1,128
Long-term regulatory liabilities	5,726	5,676
SCE
Regulatory Liabilities [Line Items]
Current regulatory liabilities	756	1,128
Long-term regulatory liabilities	5,726	5,676
Total regulatory liabilities	6,482	6,804
SCE | Regulatory balancing accounts
Regulatory Liabilities [Line Items]
Current regulatory liabilities	736	1,106
Long-term regulatory liabilities	1,180	1,314
SCE | Other
Regulatory Liabilities [Line Items]
Current regulatory liabilities	20	22
Long-term regulatory liabilities	60	79
SCE | Costs of removal
Regulatory Liabilities [Line Items]
Long-term regulatory liabilities	2,847	2,781
SCE | Recoveries in excess of ARO liabilities
Regulatory Liabilities [Line Items]
Long-term regulatory liabilities	$ 1,639	$ 1,502