Income Taxes (Components of Income Tax Expense (Benefit) by Location) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
Federal	$ (46)	$ 18	$ (99)
State	33	19	20
Total current	(13)	37	(79)
Deferred:
Federal	176	340	454
State	14	109	68
Total deferred	190	449	522
Total continuing operations	177	486	443
Discontinued operations	(11)	(21)	(710)
Total	166	465	(267)
SCE
Current:
Federal	75	72	(89)
State	93	127	101
Total current	168	199	12
Deferred:
Federal	112	298	476
State	(24)	10	(14)
Total deferred	88	308	462
Total continuing operations	256	507	474
Discontinued operations	0	0	0
Total	$ 256	$ 507	$ 474