Variable Interest Entities (Details) - Southern California Edison	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares MW	Dec. 31, 2014 USD ($) $ / shares MW
Series G Preferred Stock
Unconsolidated Trust
Security dividend rate, (as a percent)	5.10%
Series H Preferred Stock
Unconsolidated Trust
Security dividend rate, (as a percent)	5.75%
Series J Preferred Stock
Unconsolidated Trust
Security dividend rate, (as a percent)	5.375%
Liquidation preference	$ 325,000,000
Series F Preferred Stock
Unconsolidated Trust
Security dividend rate, (as a percent)	5.625%
Variable Interest Entity, Not Primary Beneficiary | SCE Power Purchase Contracts
Details of projects or entities
Power generating capacity for majority interest (in megawatts) | MW	4,062	5,641
Payments to unconsolidated VIEs for power purchase contracts	$ 640,000,000	$ 739,000,000
Variable Interest Entity, Not Primary Beneficiary | SCE Trust I
Unconsolidated Trust
Common stock	$ 10,000	$ 10,000
Variable Interest Entity, Not Primary Beneficiary | SCE Trust I | Trust Securities
Unconsolidated Trust
Security dividend rate, (as a percent)	5.625%	5.625%
Liquidation preference	$ 475,000,000	$ 475,000,000
Liquidation value (in dollars per share) | $ / shares	$ 25	$ 25
Variable Interest Entity, Not Primary Beneficiary | SCE Trust I | Series F Preferred Stock
Unconsolidated Trust
Security dividend rate, (as a percent)	5.625%	5.625%
Liquidation preference	$ 475,000,000	$ 475,000,000
Liquidation value (in dollars per share) | $ / shares	$ 2,500	$ 2,500
Variable Interest Entity, Not Primary Beneficiary | SCE Trust II
Unconsolidated Trust
Common stock	$ 10,000	$ 10,000
Variable Interest Entity, Not Primary Beneficiary | SCE Trust II | Trust Securities
Unconsolidated Trust
Security dividend rate, (as a percent)	5.10%	5.10%
Liquidation preference	$ 400,000,000	$ 400,000,000
Liquidation value (in dollars per share) | $ / shares	$ 25	$ 25
Variable Interest Entity, Not Primary Beneficiary | SCE Trust II | Series G Preferred Stock
Unconsolidated Trust
Security dividend rate, (as a percent)	5.10%	5.10%
Liquidation preference	$ 400,000,000	$ 400,000,000
Liquidation value (in dollars per share) | $ / shares	$ 2,500	$ 2,500
Variable Interest Entity, Not Primary Beneficiary | SCE Trust III
Unconsolidated Trust
Common stock	$ 10,000	$ 10,000
Variable Interest Entity, Not Primary Beneficiary | SCE Trust III | Trust Securities
Unconsolidated Trust
Security dividend rate, (as a percent)	5.75%	5.75%
Liquidation preference	$ 275,000,000	$ 275,000,000
Liquidation value (in dollars per share) | $ / shares	$ 25	$ 25
Variable Interest Entity, Not Primary Beneficiary | SCE Trust III | Series H Preferred Stock
Unconsolidated Trust
Security dividend rate, (as a percent)	5.75%	5.75%
Liquidation preference	$ 275,000,000	$ 275,000,000
Liquidation value (in dollars per share) | $ / shares	$ 2,500	$ 2,500
Variable Interest Entity, Not Primary Beneficiary | SCE Trust IV
Unconsolidated Trust
Common stock	$ 10,000
Variable Interest Entity, Not Primary Beneficiary | SCE Trust IV | Trust Securities
Unconsolidated Trust
Security dividend rate, (as a percent)	5.375%
Liquidation preference	$ 325,000,000
Liquidation value (in dollars per share) | $ / shares	$ 25
Variable Interest Entity, Not Primary Beneficiary | SCE Trust IV | Series J Preferred Stock
Unconsolidated Trust
Security dividend rate, (as a percent)	5.375%
Liquidation preference	$ 325,000,000
Liquidation value (in dollars per share) | $ / shares	$ 2,500