Variable Interest Entities (Details) - Southern California Edison - Variable Interest Entity, Not Primary Beneficiary	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($) $ / shares MW	Jun. 30, 2014 USD ($) MW	Jun. 30, 2015 USD ($) $ / shares MW	Jun. 30, 2014 USD ($) MW	Dec. 31, 2014 USD ($)
SCE Power Purchase Contracts
Details of projects or entities
Power generating capacity (in megawatts) | MW	4,125	5,341	4,125	5,341
Payments to unconsolidated VIEs for power purchase contracts	$ 78,000,000	$ 93,000,000	$ 181,000,000	$ 207,000,000
SCE Trust I
Unconsolidated Trust
Dividend income	6,000,000	6,000,000	13,000,000	13,000,000
Dividend distributions	6,000,000	6,000,000	$ 13,000,000	13,000,000
SCE Trust I | Trust Securities
Unconsolidated Trust
Security dividend rate, (as a percent)			5.625%
Liquidation preference	$ 475,000,000		$ 475,000,000		$ 475,000,000
Liquidation value (in dollars per share) | $ / shares	$ 25		$ 25
Common stock	$ 10,000		$ 10,000		10,000
SCE Trust I | Series F Preferred Stock
Unconsolidated Trust
Liquidation preference	$ 475,000,000		$ 475,000,000		475,000,000
Liquidation value (in dollars per share) | $ / shares	$ 2,500		$ 2,500
SCE Trust II
Unconsolidated Trust
Dividend income	$ 5,000,000	5,000,000	$ 10,000,000	10,000,000
Dividend distributions	5,000,000	5,000,000	$ 10,000,000	10,000,000
SCE Trust II | Trust Securities
Unconsolidated Trust
Security dividend rate, (as a percent)			5.10%
Liquidation preference	$ 400,000,000		$ 400,000,000		400,000,000
Liquidation value (in dollars per share) | $ / shares	$ 25		$ 25
Common stock	$ 10,000		$ 10,000		10,000
SCE Trust II | Series G Preferred Stock
Unconsolidated Trust
Liquidation preference	$ 400,000,000		$ 400,000,000		$ 400,000,000
Liquidation value (in dollars per share) | $ / shares	$ 2,500		$ 2,500
SCE Trust III
Unconsolidated Trust
Dividend income	$ 4,000,000	4,000,000	$ 8,000,000	5,000,000
Dividend distributions	4,000,000	$ 4,000,000	$ 8,000,000	$ 5,000,000
SCE Trust III | Trust Securities
Unconsolidated Trust
Security dividend rate, (as a percent)			5.75%
Liquidation preference	$ 275,000,000		$ 275,000,000
Liquidation value (in dollars per share) | $ / shares	$ 25		$ 25
Common stock	$ 10,000		$ 10,000
SCE Trust III | Series H Preferred Stock
Unconsolidated Trust
Liquidation preference	$ 275,000,000		$ 275,000,000
Liquidation value (in dollars per share) | $ / shares	$ 2,500		$ 2,500