Variable Interest Entities (Textual) (Details)		1 Months Ended	3 Months Ended			9 Months Ended
	Jul. 27, 2017 USD ($)	Jul. 27, 2017 USD ($)	Sep. 30, 2017 USD ($) $ / shares MW	Jun. 30, 2017 USD ($) $ / shares	Sep. 30, 2016 USD ($) MW	Sep. 30, 2017 USD ($) $ / shares MW	Sep. 30, 2016 USD ($) MW
Variable Interest Entity
Redemption of trust securities						$ 475,000,000	$ 125,000,000
Southern California Edison
Variable Interest Entity
Redemption of trust securities						$ 475,000,000	$ 125,000,000
Southern California Edison | Series F Preferred Stock
Variable Interest Entity
Redemption of trust securities	$ 475,000,000
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | SCE Power Purchase Contracts
Variable Interest Entity
Power generating capacity (in megawatts) | MW			4,858		4,349	4,858	4,349
Payments to unconsolidated VIEs for power purchase contracts			$ 325,000,000		$ 313,000,000	$ 571,000,000	$ 532,000,000
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust I
Variable Interest Entity
Common stock			10,000			$ 10,000
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust I | Trust Securities
Variable Interest Entity
Security dividend rate						5.625%
Liquidation preference			$ 475,000,000			$ 475,000,000
Liquidation value (in dollars per share) | $ / shares			$ 25			$ 25
Common stock			$ 10,000			$ 10,000
Redemption of trust securities		$ 10,000
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust I | Series F Preferred Stock
Variable Interest Entity
Security dividend rate						5.625%
Liquidation preference			$ 475,000,000			$ 475,000,000
Liquidation value (in dollars per share) | $ / shares			$ 2,500			$ 2,500
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust II
Variable Interest Entity
Common stock			$ 10,000			$ 10,000
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust II | Trust Securities
Variable Interest Entity
Security dividend rate						5.10%
Liquidation preference			$ 400,000,000			$ 400,000,000
Liquidation value (in dollars per share) | $ / shares			$ 25			$ 25
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust II | Series G Preferred Stock
Variable Interest Entity
Security dividend rate						5.10%
Liquidation preference			$ 400,000,000			$ 400,000,000
Liquidation value (in dollars per share) | $ / shares			$ 2,500			$ 2,500
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust III
Variable Interest Entity
Common stock			$ 10,000			$ 10,000
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust III | Trust Securities
Variable Interest Entity
Security dividend rate						5.75%
Liquidation preference			$ 275,000,000			$ 275,000,000
Liquidation value (in dollars per share) | $ / shares			$ 25			$ 25
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust III | Series H Preferred Stock
Variable Interest Entity
Security dividend rate						5.75%
Liquidation preference			$ 275,000,000			$ 275,000,000
Liquidation value (in dollars per share) | $ / shares			$ 2,500			$ 2,500
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust IV
Variable Interest Entity
Common stock			$ 10,000			$ 10,000
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust IV | Trust Securities
Variable Interest Entity
Security dividend rate						5.375%
Liquidation preference			$ 325,000,000			$ 325,000,000
Liquidation value (in dollars per share) | $ / shares			$ 25			$ 25
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust IV | Series J Preferred Stock
Variable Interest Entity
Security dividend rate						5.375%
Liquidation preference			$ 325,000,000			$ 325,000,000
Liquidation value (in dollars per share) | $ / shares			$ 2,500			$ 2,500
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust V
Variable Interest Entity
Common stock			$ 10,000			$ 10,000
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust V | Trust Securities
Variable Interest Entity
Security dividend rate						5.45%
Liquidation preference			$ 300,000,000			$ 300,000,000
Liquidation value (in dollars per share) | $ / shares			$ 25			$ 25
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust V | Series K Preferred Stock
Variable Interest Entity
Security dividend rate						5.45%
Liquidation preference			$ 300,000,000			$ 300,000,000
Liquidation value (in dollars per share) | $ / shares			$ 2,500			$ 2,500
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust VI
Variable Interest Entity
Common stock			$ 10,000			$ 10,000
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust VI | Trust Securities
Variable Interest Entity
Security dividend rate						5.00%
Liquidation preference			$ 475,000,000			$ 475,000,000
Liquidation value (in dollars per share) | $ / shares			$ 25			$ 25
Redemption of trust securities		$ 475,000,000
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust VI | Series K Preferred Stock
Variable Interest Entity
Liquidation preference			$ 475,000,000			$ 475,000,000
Southern California Edison | Variable Interest Entity, Not Primary Beneficiary | Trust VI | Series L Preferred Stock
Variable Interest Entity
Security dividend rate				5.00%		5.00%
Liquidation preference			$ 475,000,000	$ 475,000,000		$ 475,000,000
Liquidation value (in dollars per share) | $ / shares			$ 2,500	$ 2,500		$ 2,500