Summary of Significant Accounting Policies (Revenue Recognition) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended								12 Months Ended
	May 31, 2019	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Public Utilities, General Disclosures [Line Items]
Net income (loss)										$ 1,405	$ (316)	$ 668
SCE
Public Utilities, General Disclosures [Line Items]
Franchise fees billed to customers										$ 122	133	133
Rate recovery period										24 months
Net income (loss)		$ 224	$ 534	$ 449	$ 323	$ (1,399)	$ 567	$ 327	$ 316	$ 1,530	$ (189)	$ 1,136
California Public Utilities Commission | General Rate Case, 2018 | SCE
Public Utilities, General Disclosures [Line Items]
Reduction in authorized revenue	$ 5,100			289
Approved decision escalate capital additions, year one, percent	2.49%
Approved revenue requirement year one	$ 5,500
Approved revenue requirement year two	$ 5,900
Impact of decision non-core impairment of utility core earnings, net of tax				131
Reduction in revenue				265
Increase in approved revenue				24
Refund to customers				554
Impact of decision non-core impairment of utility property, plant and equipment				170
Impact of decision non-core impairment of utility property, plant and equipment, net of tax				$ 123
FERC | FERC 2018 Settlement Period | SCE
Public Utilities, General Disclosures [Line Items]
Net income (loss)										$ 29