Variable Interest Entities (Details) - Southern California Edison	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2016 USD ($) $ / shares MW	Mar. 31, 2016 $ / shares	Jun. 30, 2015 USD ($) MW	Jun. 30, 2016 USD ($) $ / shares MW	Jun. 30, 2015 USD ($) MW	Dec. 31, 2015 USD ($) $ / shares
Series K Preferred Stock
Unconsolidated Trust
Security dividend rate, (as a percent)		5.45%
Liquidation value (in dollars per share) | $ / shares		$ 2,500
Variable Interest Entity, Not Primary Beneficiary | SCE Power Purchase Contracts
Details of projects or entities
Power generating capacity (in megawatts) | MW	4,349		4,125	4,349	4,125
Payments to unconsolidated VIEs for power purchase contracts	$ 92,000,000		$ 78,000,000	$ 219,000,000	$ 181,000,000
Variable Interest Entity, Not Primary Beneficiary | SCE Trust I
Unconsolidated Trust
Common stock	10,000			10,000		$ 10,000
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
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		$ 475,000,000
Liquidation value (in dollars per share) | $ / shares	$ 25			$ 25		$ 25
Common stock	$ 10,000			$ 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%		5.625%
Liquidation preference	$ 475,000,000			$ 475,000,000		$ 475,000,000
Liquidation value (in dollars per share) | $ / shares	$ 2,500			$ 2,500		$ 2,500
Variable Interest Entity, Not Primary Beneficiary | SCE Trust II
Unconsolidated Trust
Common stock	$ 10,000			$ 10,000		$ 10,000
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
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		$ 400,000,000
Liquidation value (in dollars per share) | $ / shares	$ 25			$ 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		$ 400,000,000
Liquidation value (in dollars per share) | $ / shares	$ 2,500			$ 2,500		$ 2,500
Variable Interest Entity, Not Primary Beneficiary | SCE Trust III
Unconsolidated Trust
Common stock	$ 10,000			$ 10,000		$ 10,000
Dividend income	4,000,000		4,000,000	8,000,000	8,000,000
Dividend distributions	4,000,000		$ 4,000,000	$ 8,000,000	$ 8,000,000
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		$ 275,000,000
Liquidation value (in dollars per share) | $ / shares	$ 25			$ 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		$ 275,000,000
Liquidation value (in dollars per share) | $ / shares	$ 2,500			$ 2,500		$ 2,500
Variable Interest Entity, Not Primary Beneficiary | SCE Trust IV
Unconsolidated Trust
Common stock	$ 10,000			$ 10,000		$ 10,000
Dividend income	5,000,000			9,000,000
Dividend distributions	5,000,000			$ 9,000,000
Variable Interest Entity, Not Primary Beneficiary | SCE Trust IV | Trust Securities
Unconsolidated Trust
Security dividend rate, (as a percent)				5.375%		5.375%
Liquidation preference	$ 325,000,000			$ 325,000,000		$ 325,000,000
Liquidation value (in dollars per share) | $ / shares	$ 25			$ 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%		5.375%
Liquidation preference	$ 325,000,000			$ 325,000,000		$ 325,000,000
Liquidation value (in dollars per share) | $ / shares	$ 2,500			$ 2,500		$ 2,500
Variable Interest Entity, Not Primary Beneficiary | SCE Trust V
Unconsolidated Trust
Common stock	$ 10,000			$ 10,000
Dividend income	4,000,000			5,000,000
Dividend distributions	4,000,000			$ 5,000,000
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			$ 300,000,000
Liquidation value (in dollars per share) | $ / shares	$ 25			$ 25
Common stock	$ 10,000			$ 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			$ 300,000,000
Liquidation value (in dollars per share) | $ / shares	$ 2,500			$ 2,500