Variable Interest Entities (Variable Interest in VIEs that are not Consolidated) (Details) - SCE	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares MW	Dec. 31, 2015 USD ($) $ / shares MW
Series F Preferred Stock
Unconsolidated Trust
Security dividend rate, (as a percent)	5.625%
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%
Series K Preferred Stock
Unconsolidated Trust
Security dividend rate, (as a percent)	5.45%
Variable Interest Entity, Not Primary Beneficiary | SCE Power Purchase Contracts
Details of projects or entities
Power generating capacity for majority interest (in megawatts) | MW	4,353	4,062
Payments to unconsolidated VIEs for power purchase contracts	$ 788,000,000	$ 640,000,000
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%
Liquidation preference	$ 475,000,000	$ 475,000,000
Liquidation value (in dollars per share) | $ / shares	$ 25	$ 25
Common stock	$ 10,000
Variable Interest Entity, Not Primary Beneficiary | SCE Trust I | Series F Preferred Stock
Unconsolidated Trust
Security dividend rate, (as a percent)	5.625%
Liquidation preference	$ 475,000,000	$ 475,000,000
Liquidation value (in dollars per share) | $ / shares	$ 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%
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%
Liquidation preference	$ 400,000,000	$ 400,000,000
Liquidation value (in dollars per share) | $ / shares	$ 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%
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%
Liquidation preference	$ 275,000,000	$ 275,000,000
Liquidation value (in dollars per share) | $ / shares	$ 2,500
Variable Interest Entity, Not Primary Beneficiary | SCE Trust IV
Unconsolidated Trust
Common stock	$ 10,000	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	$ 325,000,000
Liquidation value (in dollars per share) | $ / shares	$ 25	$ 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	$ 325,000,000
Liquidation value (in dollars per share) | $ / shares	$ 2,500
Variable Interest Entity, Not Primary Beneficiary | SCE Trust V
Unconsolidated Trust
Common stock	$ 10,000
Variable Interest Entity, Not Primary Beneficiary | SCE Trust V | Trust Securities
Unconsolidated Trust
Security dividend rate, (as a percent)	5.45%
Liquidation preference	$ 300,000,000
Liquidation value (in dollars per share) | $ / shares	$ 25
Common stock	$ 10,000
Variable Interest Entity, Not Primary Beneficiary | SCE Trust V | Series K Preferred Stock
Unconsolidated Trust
Security dividend rate, (as a percent)	5.45%
Liquidation preference	$ 300,000,000
Liquidation value (in dollars per share) | $ / shares	$ 2,500