NEW ACCOUNTING STANDARDS - INCOME STATEMENT IMPACT (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Income Statement [Abstract]
Operation and maintenance									$ 3,309	$ 3,096	[1]	$ 2,976	[1]
Other income, net									72	233	[1]	138	[1]
Accounting Standards Update 2017-07 [Member]
Income Statement [Abstract]
Operation and maintenance										3,096		2,976
Other income, net										233		138
Accounting Standards Update 2017-07 [Member] | As previously reported [Member]
Income Statement [Abstract]
Operation and maintenance										3,117		2,970
Other income, net										254		132
Accounting Standards Update 2017-07 [Member] | Effect of adoption [Member]
Income Statement [Abstract]
Operation and maintenance										(21)		6
Other income, net										(21)		6
San Diego Gas and Electric Company [Member]
Income Statement [Abstract]
Utilities Operation and maintenance									1,058	1,024	[1]	1,062	[1]
Operating income	$ 247	$ 300	$ 215	$ 248	$ 256	$ (58)	$ 237	$ 274	1,010	709	[1]	976	[1]
Other income, net									56	70	[1]	64	[1]
San Diego Gas and Electric Company [Member] | Accounting Standards Update 2017-07 [Member]
Income Statement [Abstract]
Utilities Operation and maintenance										1,024		1,062
Operating expenses										3,767		3,277
Operating income										709		976
Other income, net										70		64
San Diego Gas and Electric Company [Member] | Accounting Standards Update 2017-07 [Member] | As previously reported [Member]
Income Statement [Abstract]
Utilities Operation and maintenance										1,020		1,048
Operating expenses										3,763		3,263
Operating income										713		990
Other income, net										66		50
San Diego Gas and Electric Company [Member] | Accounting Standards Update 2017-07 [Member] | Effect of adoption [Member]
Income Statement [Abstract]
Utilities Operation and maintenance										4		14
Operating expenses										4		14
Operating income										(4)		(14)
Other income, net										4		14
Southern California Gas Company [Member]
Income Statement [Abstract]
Utilities Operation and maintenance									1,613	1,474	[1]	1,391	[1]
Operating income	$ 239	$ 5	$ 69	$ 278	$ 230	$ 5	$ 80	$ 312	591	627	[1]	551	[1]
Other income, net									$ 15	31	[1]	38	[1]
Southern California Gas Company [Member] | Accounting Standards Update 2017-07 [Member]
Income Statement [Abstract]
Utilities Operation and maintenance										1,474		1,391
Operating expenses										3,158		2,920
Operating income										627		551
Other income, net										31		38
Southern California Gas Company [Member] | Accounting Standards Update 2017-07 [Member] | As previously reported [Member]
Income Statement [Abstract]
Utilities Operation and maintenance										1,479		1,385
Operating expenses										3,163		2,914
Operating income										622		557
Other income, net										36		32
Southern California Gas Company [Member] | Accounting Standards Update 2017-07 [Member] | Effect of adoption [Member]
Income Statement [Abstract]
Utilities Operation and maintenance										(5)		6
Operating expenses										(5)		6
Operating income										5		(6)
Other income, net										$ (5)		$ 6

[1] As adjusted for the retrospective adoption of ASU 2017-07, which we discuss in Note 2, and a reclassification to conform to current year presentation, which we discuss in Note 1.