Debt and Credit Agreements (Details) (USD $) In Millions, unless otherwise specified														9 Months Ended	1 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Southern California Edison	Dec. 31, 2012 Southern California Edison	Mar. 31, 2013 Southern California Edison 3.90% First and refunding mortgage bonds due 2043	Jul. 18, 2013 Southern California Edison Revolving credit facility	Jul. 18, 2013 Southern California Edison Credit facility maturing in July 2018	Sep. 30, 2013 Edison International Parent and Other Revolving credit facility	Jul. 18, 2013 Edison International Parent and Other Revolving credit facility	Dec. 31, 2012 Edison International Parent and Other Revolving credit facility	Jul. 18, 2013 Edison International Parent and Other Credit facility maturing in July 2018	Sep. 30, 2013 Commercial paper Southern California Edison Revolving credit facility	Dec. 31, 2012 Commercial paper Southern California Edison Revolving credit facility	Sep. 30, 2013 Letters of credit Southern California Edison Revolving credit facility	Oct. 31, 2013 Subsequent Event Southern California Edison First and refunding mortgage bonds	Oct. 31, 2013 Subsequent Event Southern California Edison 3.50% First and refunding mortgage bonds due 2023	Oct. 31, 2013 Subsequent Event Southern California Edison 4.65% First and refunding mortgage bonds due 2043	Oct. 31, 2013 Subsequent Event Southern California Edison Floating rate bonds due 2014
Debt Instrument [Line Items]
Issuance of debt					$ 400											$ 600	$ 800	$ 200
Stated interest rate (as a percent)					3.90%											3.50%	4.65%
Extinguishment of Debt, Amount															800
Outstanding borrowings												1,350	175
Weighted average interest rate (as a percent)								1.46%				0.25%	0.37%
Commitment						150	2,600	1,250	68		1,182	2,750
Outstanding letters of credit														140
Letters of credit expiration period														12 months
Short-term debt	$ 1,528	$ 175	$ 1,354	$ 175				$ 174		$ 0