GENERAL INFORMATION AND OTHER FINANCIAL DATA - OTHER (EXPENSE) INCOME, NET (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Other Income [Line Items]
Allowance for equity funds used during construction	$ 35	$ 38
Investment (losses) gains, net	(13)	9
Gains (losses) on interest rate and foreign exchange instruments, net	6	(30)
Foreign currency transaction losses, net(2)	(19)	(19)
Non-service component of net periodic benefit credit	41	29
Interest on regulatory balancing accounts, net	1	1
Sundry, net	(13)	7
Total	38	35
San Diego Gas and Electric Company
Other Income [Line Items]
Allowance for equity funds used during construction	21	23
Non-service component of net periodic benefit credit	11	9
Interest on regulatory balancing accounts, net	1	1
Sundry, net	1	2
Total	34	35
Southern California Gas Company
Other Income [Line Items]
Allowance for equity funds used during construction	13	12
Non-service component of net periodic benefit credit	32	28
Sundry, net	(11)	(1)
Total	34	39
IMG
Other Income [Line Items]
Foreign currency transaction losses, net(2)	$ (11)	$ (23)