NEW ACCOUNTING STANDARDS (Details) - USD ($) $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017		Jun. 30, 2018		Jun. 30, 2017		Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment from change in accounting principle(2)									$ (1)
CASH FLOWS FROM OPERATING ACTIVITIES
Net cash provided by operating activities					$ 1,629		$ 1,889	[1]
CASH FLOWS FROM INVESTING ACTIVITIES
Expenditures for investments and acquisition of businesses, net of cash and cash equivalents acquired					(9,823)		(97)	[1]
Other					30		4	[1]
Net cash used in investing activities					(11,740)		(2,058)	[1]
CASH FLOWS FROM FINANCING ACTIVITIES
Other					(71)		(9)	[1]
Net Cash Provided by (Used in) Financing Activities					10,077		44	[1]
Effect of exchange rate changes on cash, cash equivalents and restricted cash					(3)		10	[1]
(Decrease) increase in cash, cash equivalents and restricted cash					(37)		(115)	[1]
Cash and cash equivalents beginning balance	[2]				288
Cash and cash equivalents ending balance		$ 252			252
Cash, cash equivalents and restricted cash beginning balance					364		425	[1]
Cash, cash equivalents and restricted cash ending balance		327	$ 310	[1]	327		310	[1]
Income Statement [Abstract]
Operation and maintenance		783	748	[3]	1,564		1,467	[3]
Other (expense) income, net		(54)	108	[3]	99		282	[3]
New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2016-18 [Member]
CASH FLOWS FROM INVESTING ACTIVITIES
Increases in restricted cash							0
Decreases in restricted cash							0
Net cash used in investing activities							(2,058)
CASH FLOWS FROM FINANCING ACTIVITIES
Effect of Exchange Rate on Cash and Cash Equivalents							0
Effect of exchange rate changes on cash, cash equivalents and restricted cash							10
(Decrease) increase in cash and cash equivalents							0
(Decrease) increase in cash, cash equivalents and restricted cash							(115)
Cash and cash equivalents beginning balance							0
Cash and cash equivalents ending balance			0				0
Cash, cash equivalents and restricted cash beginning balance							425
Cash, cash equivalents and restricted cash ending balance			310				310
New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2016-01 and 2018-03 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment from change in accounting principle(2)									1
New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2017-07 [Member]
Income Statement [Abstract]
Operation and maintenance			748				1,467
Other (expense) income, net			108				282
New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2017-12 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment from change in accounting principle(2)									$ 3
As previously reported [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2016-18 [Member]
CASH FLOWS FROM INVESTING ACTIVITIES
Increases in restricted cash							(194)
Decreases in restricted cash							185
Net cash used in investing activities							(2,067)
CASH FLOWS FROM FINANCING ACTIVITIES
Effect of Exchange Rate on Cash and Cash Equivalents							8
Effect of exchange rate changes on cash, cash equivalents and restricted cash							0
(Decrease) increase in cash and cash equivalents							(126)
(Decrease) increase in cash, cash equivalents and restricted cash							0
Cash and cash equivalents beginning balance							349
Cash and cash equivalents ending balance			223				223
Cash, cash equivalents and restricted cash beginning balance							0
Cash, cash equivalents and restricted cash ending balance			0				0
As previously reported [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2017-07 [Member]
Income Statement [Abstract]
Operation and maintenance			731				1,445
Other (expense) income, net			91				260
Effect of adoption [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2016-18 [Member]
CASH FLOWS FROM INVESTING ACTIVITIES
Increases in restricted cash							194
Decreases in restricted cash							(185)
Net cash used in investing activities							9
CASH FLOWS FROM FINANCING ACTIVITIES
Effect of Exchange Rate on Cash and Cash Equivalents							(8)
Effect of exchange rate changes on cash, cash equivalents and restricted cash							10
(Decrease) increase in cash and cash equivalents							126
(Decrease) increase in cash, cash equivalents and restricted cash							(115)
Cash and cash equivalents beginning balance							(349)
Cash and cash equivalents ending balance			(223)				(223)
Cash, cash equivalents and restricted cash beginning balance							425
Cash, cash equivalents and restricted cash ending balance			310				310
Effect of adoption [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2017-07 [Member]
Income Statement [Abstract]
Operation and maintenance			17				22
Other (expense) income, net			17				22
San Diego Gas and Electric Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net cash provided by operating activities					644		690	[1]
CASH FLOWS FROM INVESTING ACTIVITIES
Other					6		0	[1]
Net cash used in investing activities					(845)		(732)	[1]
CASH FLOWS FROM FINANCING ACTIVITIES
Net Cash Provided by (Used in) Financing Activities					197		48	[1]
Cash and cash equivalents beginning balance	[2]				12
Cash and cash equivalents ending balance		8			8
Cash, cash equivalents and restricted cash beginning balance					29		20	[1]
Cash, cash equivalents and restricted cash ending balance		25	26	[1]	25		26	[1]
Income Statement [Abstract]
Operation and maintenance		251	241	[3]	499		472	[3]
Total operating expenses		836	821	[3]	1,643		1,604	[3]
Operating income		215	237	[3]	463		511	[3]
Other (expense) income, net		25	19	[3]	53		41	[3]
San Diego Gas and Electric Company [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2016-18 [Member]
CASH FLOWS FROM INVESTING ACTIVITIES
Increases in restricted cash							0
Decreases in restricted cash							0
Net cash used in investing activities							(732)
CASH FLOWS FROM FINANCING ACTIVITIES
(Decrease) increase in cash and cash equivalents							0
(Decrease) increase in cash, cash equivalents and restricted cash							6
Cash and cash equivalents beginning balance							0
Cash and cash equivalents ending balance			0				0
Cash, cash equivalents and restricted cash beginning balance							20
Cash, cash equivalents and restricted cash ending balance			26				26
San Diego Gas and Electric Company [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2017-07 [Member]
Income Statement [Abstract]
Operation and maintenance			241				472
Total operating expenses			821				1,604
Operating income			237				511
Other (expense) income, net			19				41
San Diego Gas and Electric Company [Member] | As previously reported [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2016-18 [Member]
CASH FLOWS FROM INVESTING ACTIVITIES
Increases in restricted cash							(20)
Decreases in restricted cash							18
Net cash used in investing activities							(734)
CASH FLOWS FROM FINANCING ACTIVITIES
(Decrease) increase in cash and cash equivalents							4
(Decrease) increase in cash, cash equivalents and restricted cash							0
Cash and cash equivalents beginning balance							8
Cash and cash equivalents ending balance			12				12
Cash, cash equivalents and restricted cash beginning balance							0
Cash, cash equivalents and restricted cash ending balance			0				0
San Diego Gas and Electric Company [Member] | As previously reported [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2017-07 [Member]
Income Statement [Abstract]
Operation and maintenance			237				464
Total operating expenses			817				1,596
Operating income			241				519
Other (expense) income, net			15				33
San Diego Gas and Electric Company [Member] | Effect of adoption [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2016-18 [Member]
CASH FLOWS FROM INVESTING ACTIVITIES
Increases in restricted cash							20
Decreases in restricted cash							(18)
Net cash used in investing activities							2
CASH FLOWS FROM FINANCING ACTIVITIES
(Decrease) increase in cash and cash equivalents							(4)
(Decrease) increase in cash, cash equivalents and restricted cash							6
Cash and cash equivalents beginning balance							(8)
Cash and cash equivalents ending balance			(12)				(12)
Cash, cash equivalents and restricted cash beginning balance							20
Cash, cash equivalents and restricted cash ending balance			26				26
San Diego Gas and Electric Company [Member] | Effect of adoption [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2017-07 [Member]
Income Statement [Abstract]
Operation and maintenance			4				8
Total operating expenses			4				8
Operating income			(4)				(8)
Other (expense) income, net			4				8
Southern California Gas Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net cash provided by operating activities					749		855	[1]
CASH FLOWS FROM INVESTING ACTIVITIES
Other					4		0	[1]
Net cash used in investing activities					(779)		(766)	[1]
CASH FLOWS FROM FINANCING ACTIVITIES
Net Cash Provided by (Used in) Financing Activities					105		(63)	[1]
(Decrease) increase in cash and cash equivalents					75		26	[1]
Cash and cash equivalents beginning balance					8	[2]	12	[1]
Cash and cash equivalents ending balance		83	38	[1]	83		38	[1]
Income Statement [Abstract]
Operation and maintenance		382	351	[3]	766		707	[3]
Total operating expenses		703	690	[3]	1,551		1,619	[3]
Operating income		69	80	[3]	347		392	[3]
Other (expense) income, net		$ 13	24	[3]	$ 46		38	[3]
Southern California Gas Company [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2017-07 [Member]
Income Statement [Abstract]
Operation and maintenance			351				707
Total operating expenses			690				1,619
Operating income			80				392
Other (expense) income, net			24				38
Southern California Gas Company [Member] | As previously reported [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2017-07 [Member]
Income Statement [Abstract]
Operation and maintenance			336				689
Total operating expenses			675				1,601
Operating income			95				410
Other (expense) income, net			9				20
Southern California Gas Company [Member] | Effect of adoption [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2017-07 [Member]
Income Statement [Abstract]
Operation and maintenance			15				18
Total operating expenses			15				18
Operating income			(15)				(18)
Other (expense) income, net			$ 15				$ 18

[1] As adjusted for the retrospective adoption of ASU 2016-18, which we discuss in Note 2.

[2] Derived from audited financial statements.

[3] 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.