INCOME TAXES - COMPONENTS OF INCOME TAX EXPENSE (BENEFIT) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Expense (Benefit), Continuing Operations [Abstract]
U.S.	$ 1,461	$ 1,191	$ (102)
Non-U.S.	322	573	580
Pretax income	1,783	1,764	478
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
U.S. federal	0	0	(1)
U.S. state	(22)	(14)	67
Non-U.S.	112	140	127
Total	90	126	193
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
U.S. federal	157	87	(121)
U.S. state	36	21	(183)
Non-U.S.	(34)	84	66
Total	159	192	(238)
Deferred investment tax credits	0	(3)	(4)
Total income tax expense (benefit)	249	315	(49)
San Diego Gas and Electric Company [Member]
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Pretax income	1,014	945	849
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
U.S. federal	121	35	104
U.S. state	34	31	30
Total	155	66	134
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
U.S. federal	11	75	17
U.S. state	25	32	24
Total	36	107	41
Deferred investment tax credits	(1)	(2)	(2)
Total income tax expense (benefit)	190	171	173
Southern California Gas Company [Member]
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Pretax income	601	762	493
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
U.S. federal	163	8	4
U.S. state	45	24	10
Total	208	32	14
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
U.S. federal	(85)	79	78
U.S. state	(28)	10	2
Total	(113)	89	80
Deferred investment tax credits	1	(1)	(2)
Total income tax expense (benefit)	$ 96	$ 120	$ 92