Leases (Supplemental Balance Sheet Information) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Operating leases:
Operating lease right-of-use assets	$ 933	$ 0
Current portion of operating lease liabilities	157	0
Operating lease liabilities	776	0
Southern California Edison
Operating leases:
Operating lease right-of-use assets	928	0
Current portion of operating lease liabilities	156	0
Operating lease liabilities	772	$ 0
Total operating lease liabilities	928
Finance leases included in:
Utility property, plant and equipment, gross	14
Accumulated depreciation	(4)
Utility property, plant and equipment, net	10
Other current liabilities	1
Other long-term liabilities	9
Total finance lease liabilities	$ 10