Regulatory Assets and Liabilities (Details) - USD ($) $ in Millions			12 Months Ended
		Feb. 01, 2012	Dec. 31, 2015	Dec. 31, 2014
Regulatory Assets
Regulatory Assets, Current			$ 560	$ 1,254
Regulatory Asset, Long-term			7,512	7,612
Regulatory Liabilities
Regulatory Liabilities, Current			1,128	401
Regulatory Liabilities, Long-term			$ 5,676	5,889
Southern California Edison
Regulatory Assets and Liabilities
Regulatory assets, energy derivatives, low range of contract expiration (in years)			2 years
Regulatory assets, energy derivatives, high range of contract expiration (in years)			45 years
Regulatory assets related to deferred income taxes, recovery period, low range (in years)			1 year
Regulatory assets related to deferred income taxes, recovery period, high range (in years)			60 years
Low end of the range of remaining original amortization (in years)			1 year
High end of the range of remaining original amortization (in years)			35 years
Regulatory Assets
Regulatory Assets, Current			$ 560	1,254
Regulatory Asset, Long-term			7,512	7,612
Total Regulatory Assets			8,072	8,866
Regulatory Liabilities
Regulatory Liabilities, Current			1,128	401
Regulatory Liabilities, Long-term			5,676	5,889
Total Regulatory Liabilities			6,804	6,290
Southern California Edison | FERC-Approved Settlement Agreements
Regulatory Liabilities
Litigation Settlement, Amount			219
Litigation Settlement, Amount Subject to Shareholder Incentive			15
Southern California Edison | Regulatory balancing accounts
Regulatory Assets
Regulatory Assets, Current			382	1,088
Regulatory Asset, Long-term			36	44
Southern California Edison | Pensions and other postretirement benefits
Regulatory Assets
Regulatory Asset, Long-term			849	1,218
Southern California Edison | Environmental remediation
Regulatory Assets
Regulatory Asset, Long-term			129	107
Southern California Edison | Energy derivatives
Regulatory Assets
Regulatory Assets, Current			159	159
Regulatory Asset, Long-term			1,027	850
Southern California Edison | Other
Regulatory Assets
Regulatory Assets, Current			19	7
Regulatory Asset, Long-term			288	244
Regulatory Liabilities
Regulatory Liabilities, Current			22	21
Regulatory Liabilities, Long-term			79	24
Southern California Edison | Deferred income taxes, net
Regulatory Assets
Regulatory Asset, Long-term			$ 3,757	$ 3,405
Southern California Edison | Unamortized investments, net
Regulatory Assets and Liabilities
Return rate earned on assets included in rate base (as a percent)			7.90%	7.90%
Regulatory Assets
Regulatory Asset, Long-term			$ 182	$ 255
Southern California Edison | San Onofre
Regulatory Assets
Regulatory Asset, Long-term			1,043	1,288
Southern California Edison | Unamortized loss on reacquired debt
Regulatory Assets
Regulatory Asset, Long-term			201	201
Southern California Edison | Regulatory balancing accounts
Regulatory Liabilities
Regulatory Liabilities, Current			1,106	380
Regulatory Liabilities, Long-term			1,314	1,083
Southern California Edison | Costs of removal
Regulatory Liabilities
Regulatory Liabilities, Long-term			2,781	2,826
Southern California Edison | Recoveries in excess of ARO liabilities1
Regulatory Liabilities
Regulatory Liabilities, Long-term	[1]		$ 1,502	$ 1,956
Legacy Meters | Southern California Edison | Unamortized investments, net
Regulatory Assets and Liabilities
Return rate earned on assets included in rate base (as a percent)			6.46%	6.46%
San Onofre | Southern California Edison
Regulatory Assets and Liabilities
Return rate earned on assets included in rate base (as a percent)			2.62%
Period for rate recovery		10 years

[1] Represents the cumulative differences between ARO expenses and amounts collected in rates primarily for the decommissioning of the SCE's nuclear generation facilities. Decommissioning costs recovered through rates are primarily placed in nuclear decommissioning trusts. This regulatory liability also represents the deferral of realized and unrealized gains and losses on the nuclear decommissioning trust investments (see Note 9).