SIGNIFICANT ACCOUNTING POLICIES AND OTHER FINANCIAL DATA - OTHER (EXPENSE) INCOME, NET (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Other Income [Line Items]
Allowance for equity funds used during construction	$ 133	$ 128	$ 94
Investment gains, net	50	41	61
(Losses) gains on interest rate and foreign exchange instruments, net	(28)	(67)	34
Foreign currency transaction (losses) gains, net	(18)	(25)	21
Non-service component of net periodic benefit cost	(67)	(102)	(132)
Interest on regulatory balancing accounts, net	6	14	14
Sundry, net	(18)	(37)	(15)
Total	58	(48)	77
San Diego Gas and Electric Company [Member]
Other Income [Line Items]
Allowance for equity funds used during construction	81	79	56
Non-service component of net periodic benefit cost	(13)	(20)	(20)
Interest on regulatory balancing accounts, net	6	9	13
Sundry, net	(10)	(16)	(10)
Total	64	52	39
SoCalGas
Other Income [Line Items]
Allowance for equity funds used during construction	48	41	34
Non-service component of net periodic benefit cost	(40)	(54)	(72)
Interest on regulatory balancing accounts, net	0	5	1
Sundry, net	(22)	(20)	(18)
Total	(14)	(28)	(55)
IMG JV
Other Income [Line Items]
Foreign currency transaction (losses) gains, net	$ (23)	$ (42)	$ 30