Debt and Credit Agreements (Details) (USD $)												3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Revolving credit facility maturing in May 2017	Mar. 31, 2013 Southern California Edison	Dec. 31, 2012 Southern California Edison	Mar. 31, 2013 Southern California Edison First and refunding mortgage bonds	Mar. 31, 2013 Southern California Edison Revolving credit facility maturing in May 2017	Mar. 31, 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	Mar. 31, 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	Mar. 31, 2013 Letters of credit Southern California Edison Revolving credit facility maturing in May 2017
Debt Instrument [Line Items]
Issuance of debt						$ 400,000,000
Stated interest rate (as a percent)						3.90%
Outstanding borrowings							404,000,000
Weighted average interest rate (as a percent)								1.485%		0.32%	0.37%
Commitment			1,250,000,000				2,750,000,000
Outstanding letters of credit												121,000,000
Letters of credit expiration period												12 months
Short-term debt	$ 420,000,000	$ 175,000,000		$ 404,000,000	$ 175,000,000			$ 16,000,000	$ 0		$ 175,000,000