Regulatory Assets and Liabilities (Schedule of Regulatory Liabilities) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Regulatory Liabilities [Line Items]
Current regulatory liabilities	$ 1,010		$ 1,010		$ 1,532
Long-term regulatory liabilities	8,544		8,544		8,329
Deferred tax re-measurement	0	$ 0	69	$ 0
Southern California Edison
Regulatory Liabilities [Line Items]
Current regulatory liabilities	1,010		1,010		1,532
Long-term regulatory liabilities	8,544		8,544		8,329
Total regulatory liabilities	9,554		9,554		9,861
Deferred tax re-measurement	0	$ 0	69	$ 0
Southern California Edison | Regulatory balancing accounts
Regulatory Liabilities [Line Items]
Current regulatory liabilities	957		957		1,080
Long-term regulatory liabilities	1,490		1,490		1,344
Southern California Edison | Energy derivatives
Regulatory Liabilities [Line Items]
Current regulatory liabilities	41		41		158
Southern California Edison | 2018 GRC
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0		0		274
Southern California Edison | Other
Regulatory Liabilities [Line Items]
Current regulatory liabilities	12		12		20
Long-term regulatory liabilities	167		167		125
Southern California Edison | Cost of removal
Regulatory Liabilities [Line Items]
Long-term regulatory liabilities	2,721		2,721		2,769
Southern California Edison | Re-measurement of deferred taxes
Regulatory Liabilities [Line Items]
Long-term regulatory liabilities	2,474		2,474		2,776
Southern California Edison | Recoveries in excess of ARO liabilities
Regulatory Liabilities [Line Items]
Long-term regulatory liabilities	1,494		1,494		1,130
Southern California Edison | Other postretirement benefits
Regulatory Liabilities [Line Items]
Long-term regulatory liabilities	$ 198		$ 198		$ 185