Regulatory Assets and Liabilities (Schedule of Regulatory Liabilities) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Regulatory Liabilities [Line Items]
Current regulatory liabilities	$ 1,295		$ 1,532
Long-term regulatory liabilities	8,588		8,329
Deferred tax re-measurement	69	$ 0
Southern California Edison
Regulatory Liabilities [Line Items]
Current regulatory liabilities	1,295		1,532
Long-term regulatory liabilities	8,588		8,329
Total regulatory liabilities	9,883		9,861
Deferred tax re-measurement	69	$ 0
Southern California Edison | Regulatory balancing accounts
Regulatory Liabilities [Line Items]
Current regulatory liabilities	836		1,080
Long-term regulatory liabilities	1,428		1,344
Southern California Edison | Energy derivatives
Regulatory Liabilities [Line Items]
Current regulatory liabilities	100		158
Southern California Edison | 2018 GRC
Regulatory Liabilities [Line Items]
Current regulatory liabilities	341		274
Southern California Edison | Other
Regulatory Liabilities [Line Items]
Current regulatory liabilities	18		20
Long-term regulatory liabilities	156		125
Southern California Edison | Cost of removal
Regulatory Liabilities [Line Items]
Long-term regulatory liabilities	2,808		2,769
Southern California Edison | Re-measurement of deferred taxes
Regulatory Liabilities [Line Items]
Long-term regulatory liabilities	2,650		2,776
Southern California Edison | Recoveries in excess of ARO liabilities
Regulatory Liabilities [Line Items]
Long-term regulatory liabilities	1,357		1,130
Southern California Edison | Other postretirement benefits
Regulatory Liabilities [Line Items]
Long-term regulatory liabilities	$ 189		$ 185