Debt and Credit Agreements (Details) (USD $) In Millions, unless otherwise specified											6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 Southern California Edison	Dec. 31, 2012 Southern California Edison	Mar. 31, 2013 Southern California Edison First and refunding mortgage bonds	Jun. 30, 2013 Southern California Edison Revolving credit facility maturing in May 2017	Jun. 30, 2013 Edison International Parent and Other Revolving credit facility maturing in May 2017	Dec. 31, 2012 Edison International Parent and Other Revolving credit facility maturing in May 2017	Jun. 30, 2013 Commercial paper Southern California Edison Revolving credit facility maturing in May 2017	Dec. 31, 2012 Commercial paper Southern California Edison Revolving credit facility maturing in May 2017	Jun. 30, 2013 Letters of credit Southern California Edison Revolving credit facility maturing in May 2017	Jul. 18, 2013 Subsequent Event Southern California Edison Revolving credit facility maturing in May 2017	Jul. 18, 2013 Subsequent Event Southern California Edison Credit facility maturing in July 2018	Jul. 18, 2013 Subsequent Event Edison International Parent and Other Revolving credit facility maturing in May 2017	Jul. 18, 2013 Subsequent Event Edison International Parent and Other Credit facility maturing in July 2018
Debt Instrument [Line Items]
Issuance of debt					$ 400
Stated interest rate (as a percent)					3.90%
Outstanding borrowings						828				175
Weighted average interest rate (as a percent)							1.48%		0.27%	0.37%
Commitment						2,750	1,250					150	2,600	68	1,182
Outstanding letters of credit											96
Letters of credit expiration period											12 months
Short-term debt	$ 853	$ 175	$ 828	$ 175			$ 25	$ 0