REGULATORY ASSETS, LIABILITIES, AND BALANCING ACCOUNTS (Long-Term Regulatory Liabilities) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Regulatory Liabilities [Line Items]
Total long-term regulatory liabilities	$ 11,563	$ 11,999
Proceeds received from sale of transmission tower wireless licenses, to be refunded to customers	442
Federal Energy Regulatory Commission
Regulatory Liabilities [Line Items]
Proceeds received from sale of transmission tower wireless licenses, to be refunded to customers	307
California Public Utilities Commission
Regulatory Liabilities [Line Items]
Proceeds received from sale of transmission tower wireless licenses, to be refunded to customers	135
Cost of removal obligations
Regulatory Liabilities [Line Items]
Total long-term regulatory liabilities	7,431	7,306
Recoveries in excess of AROs
Regulatory Liabilities [Line Items]
Total long-term regulatory liabilities	154	388
Public purpose programs
Regulatory Liabilities [Line Items]
Total long-term regulatory liabilities	1,043	946
Employee benefit plans
Regulatory Liabilities [Line Items]
Total long-term regulatory liabilities	1,234	1,229
Transmission tower wireless licenses
Regulatory Liabilities [Line Items]
Total long-term regulatory liabilities	442	446
SFGO sale
Regulatory Liabilities [Line Items]
Total long-term regulatory liabilities	323	343
Other
Regulatory Liabilities [Line Items]
Total long-term regulatory liabilities	$ 936	$ 1,341