Compensation and Benefit Plans (Expense Components) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension and Other Postretirement Benefits
Net loss reclassified from other comprehensive loss	$ 0	$ 0	$ 3,000,000
Pension Plans
Pension and Other Postretirement Benefits
Service cost	139,000,000	142,000,000
Interest cost	171,000,000	170,000,000
Other	10,000,000	14,000,000	9,000,000
Postretirement Benefits Other Than Pensions
Pension and Other Postretirement Benefits
Service cost	35,000,000	46,000,000	40,000,000
Interest cost	97,000,000	102,000,000	117,000,000
Expected return on plan assets	(112,000,000)	(116,000,000)	(108,000,000)
Settlement costs	2,000,000	1,000,000	3,000,000
Amortization of prior service cost	(2,000,000)	(12,000,000)	(36,000,000)
Amortization of net loss	0	3,000,000	6,000,000
Expense under accounting standards	20,000,000	24,000,000	22,000,000
SCE | Pension Plans
Pension and Other Postretirement Benefits
Service cost	132,000,000	133,000,000
Interest cost	150,000,000	150,000,000
Net loss reclassified from other comprehensive loss	20,000,000	18,000,000
Other	6,000,000	8,000,000	4,000,000
SCE | Postretirement Benefits Other Than Pensions
Pension and Other Postretirement Benefits
Service cost	34,000,000	46,000,000	40,000,000
Interest cost	97,000,000	102,000,000	117,000,000
Expected return on plan assets	(112,000,000)	(116,000,000)	(108,000,000)
Settlement costs	2,000,000	1,000,000	3,000,000
Amortization of prior service cost	(2,000,000)	(12,000,000)	(35,000,000)
Amortization of net loss	0	2,000,000	5,000,000
Expense under accounting standards	19,000,000	23,000,000	22,000,000
Continuing Operations | Pension Plans
Pension and Other Postretirement Benefits
Service cost	139,000,000	142,000,000	133,000,000
Interest cost	172,000,000	170,000,000	181,000,000
Expected return on plan assets	(220,000,000)	(233,000,000)	(229,000,000)
Settlement costs	0	0	45,000,000
Curtailment gain	0	0	(4,000,000)
Amortization of prior service cost	4,000,000	5,000,000	5,000,000
Amortization of net loss	27,000,000	40,000,000	12,000,000
Expense under accounting standards	122,000,000	124,000,000	143,000,000
Regulatory adjustment (deferred)	(21,000,000)	(6,000,000)	8,000,000
Total expense recognized	101,000,000	118,000,000	151,000,000
Continuing Operations | SCE | Pension Plans
Pension and Other Postretirement Benefits
Service cost	136,000,000	139,000,000	128,000,000
Interest cost	156,000,000	155,000,000	164,000,000
Expected return on plan assets	(205,000,000)	(217,000,000)	(213,000,000)
Settlement costs	0	0	42,000,000
Curtailment gain	0	0	0
Amortization of prior service cost	4,000,000	5,000,000	5,000,000
Amortization of net loss	23,000,000	35,000,000	7,000,000
Expense under accounting standards	114,000,000	117,000,000	133,000,000
Regulatory adjustment (deferred)	(21,000,000)	(6,000,000)	8,000,000
Total expense recognized	$ 93,000,000	$ 111,000,000	$ 141,000,000