Regulatory Assets and Liabilities (Schedule of Regulatory Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Regulatory Liabilities [Line Items]
Current regulatory liabilities	$ 972	$ 1,532
Long-term regulatory liabilities	8,385	8,329
SCE
Regulatory Liabilities [Line Items]
Current regulatory liabilities	972	1,532
Long-term regulatory liabilities	8,385	8,329
Total regulatory liabilities	9,357	9,861
SCE | Regulatory balancing and memorandum accounts
Regulatory Liabilities [Line Items]
Current regulatory liabilities	883	1,080
Long-term regulatory liabilities	1,261	1,344
SCE | Energy derivatives
Regulatory Liabilities [Line Items]
Current regulatory liabilities	80	158
SCE | 2018 GRC
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	274
SCE | Other
Regulatory Liabilities [Line Items]
Current regulatory liabilities	9	20
Long-term regulatory liabilities	41	125
SCE | Costs of removal
Regulatory Liabilities [Line Items]
Long-term regulatory liabilities	2,674	2,769
SCE | Re-measurement of deferred taxes
Regulatory Liabilities [Line Items]
Long-term regulatory liabilities	2,424	2,776
SCE | Recoveries in excess of ARO liabilities
Regulatory Liabilities [Line Items]
Long-term regulatory liabilities	1,569	1,130
SCE | Other postretirement benefits
Regulatory Liabilities [Line Items]
Long-term regulatory liabilities	$ 416	$ 185