Schedule II - Valuation and Qualifying Accounts (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Movement in Valuation and Qualifying Accounts
Balance at Beginning of Period	$ 79.6		$ 89.9		$ 56.0
Charged to Costs and Expenses	93.2		50.2		42.0
Charged to Other Accounts	0		0		24.5
Deductions	46.7	[1]	60.5	[1]	32.6	[1]
Balance at End of Period	126.1		79.6		89.9
Retirement liabilities for EME employees	2,614		2,715
Deferred tax assets, loss and credit carryforwards	1,515		689
Deferred tax assets, valuation allowance	1,017		0
Allowance For Uncollectible Accounts From Customers
Movement in Valuation and Qualifying Accounts
Balance at Beginning of Period	42.0		36.1		33.9
Charged to Costs and Expenses	34.6		31.0		27.0
Charged to Other Accounts	0		0		0
Deductions	30.0		25.1		24.8
Balance at End of Period	46.6		42.0		36.1
Allowance For Uncollectible Accounts From Others
Movement in Valuation and Qualifying Accounts
Balance at Beginning of Period	37.6		53.8		22.1
Charged to Costs and Expenses	58.6		19.2		15.0
Charged to Other Accounts	0		0		24.5	[2]
Deductions	16.7		35.4	[2]	7.8
Balance at End of Period	79.5		37.6		53.8
Tax Valuation Allowance
Movement in Valuation and Qualifying Accounts
Balance at Beginning of Period	0
Charged to Costs and Expenses	0
Charged to Other Accounts	1,016.5	[3]
Deductions	0
Balance at End of Period	1,016.5
Edison Mission Energy
Movement in Valuation and Qualifying Accounts
Deferred tax assets, valuation allowance	1,017
Southern California Edison
Movement in Valuation and Qualifying Accounts
Balance at Beginning of Period	75.0		85.5		52.9
Charged to Costs and Expenses	46.6		49.9		41.8
Charged to Other Accounts	0		0		22.8
Deductions	46.7	[1]	60.4	[1]	32.0	[1]
Balance at End of Period	74.9		75.0		85.5
Retirement liabilities for EME employees	2,245		2,461
Deferred tax assets, loss and credit carryforwards	125		15
Deferred tax assets, valuation allowance	0		0
Write-off on termination of agreement			23
Southern California Edison | Allowance For Uncollectible Accounts From Customers
Movement in Valuation and Qualifying Accounts
Balance at Beginning of Period	42.0		36.1		33.9
Charged to Costs and Expenses	34.6		31.0		27.0
Charged to Other Accounts	0		0		0
Deductions	30.0		25.1		24.8
Balance at End of Period	46.6		42.0		36.1
Southern California Edison | Allowance For Uncollectible Accounts From Others
Movement in Valuation and Qualifying Accounts
Balance at Beginning of Period	33.0		49.4		19.0
Charged to Costs and Expenses	12.0		18.9		14.8
Charged to Other Accounts	0		0		22.8	[2]
Deductions	16.7		35.3	[2]	7.2
Balance at End of Period	28.3		33.0		49.4
Pension Plans
Movement in Valuation and Qualifying Accounts
Retirement liabilities for EME employees	1,387		1,329
Deconsolidated charges recorded in other comprehensive income	34	[4]	0	[4]
Pension Plans | Edison Mission Energy
Movement in Valuation and Qualifying Accounts
Retirement liabilities for EME employees	80
Deconsolidated charges recorded in other comprehensive income	34
Pension Plans | Southern California Edison
Movement in Valuation and Qualifying Accounts
Retirement liabilities for EME employees	1,108		1,135
Deconsolidated charges recorded in other comprehensive income	0	[4]	0	[4]
Plan Support Agreement
Movement in Valuation and Qualifying Accounts
Net receivable under plan support agreement	$ 46

[1] Accounts written off, net.

[2] In 2010, SCE recorded a reserve against an uncollectible receivable related to contract termination negotiations. During 2011, the $23 million was written-off.

[3] Edison International recorded deferred tax assets of $1.5 billion related to net operating losses and tax carryforwards that pertain to Edison International's consolidated or combined federal and state tax returns, including EME. Edison International continues to consolidate EME for federal and certain combined state tax returns. Under federal and state tax regulations, a tax deconsolidation of EME in future periods, as expected through the bankruptcy proceeding, would result in EME retaining a portion of such carryforward benefits and reducing the amounts that Edison International would be eligible to use in future periods. As a result of the expected future tax deconsolidation and separation of EME from Edison International, Edison International has recorded a valuation allowance of $1.0 billion based on the estimated amount of such benefits as of December 31, 2012, as calculated under the applicable federal and state tax regulations.

[4] The retirement plan liabilities of EME have been deconsolidated as a result of the bankruptcy filing by EME, except for qualified pension plans that Edison International is jointly liable with EME under the Internal Revenue Code. See Note 17 for further information.