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EMPLOYEE BENEFIT PLANS - NARRATIVE (Details) - USD ($) $ in Millions		12 Months Ended
	Mar. 09, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Dedicated assets in support of certain benefit plans		$ 416	$ 455
Benefit obligation payment for settlement		54
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan amendments		12	1
Plan assets, payment for settlement		394	194
Settlement charges		12	8	$ 0
Increase due to business combination		0	0
Increase in liability due to special termination benefits		0	0
Settlements		394	194	75
Settlement charge			38	16
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan amendments		0	0
Plan assets, payment for settlement		0	0
Settlement charges		0	0	0
Increase due to business combination		21	0
Increase in liability due to special termination benefits		5	18	26
Settlements		0	0
San Diego Gas and Electric Company [Member] \| Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan amendments		8	0
Plan assets, payment for settlement		145	0
Settlement charges		4	0	0
Increase in liability due to special termination benefits		0	0
Settlements		145	0	75
Settlement charge				16
San Diego Gas and Electric Company [Member] \| Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan amendments		0	0
Plan assets, payment for settlement		0	0
Settlement charges		0	0	0
Increase in liability due to special termination benefits		3	0	14
Settlements		0	0
Southern California Gas Company [Member] \| Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, payment for settlement		231	175
Increase in liability due to special termination benefits		0	0
Settlements		231	175
Settlement charge			30
Southern California Gas Company [Member] \| Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, payment for settlement		0	0
Increase in liability due to special termination benefits		2	18	$ 11
Settlements		0	0
Qualified Plan [Member] \| Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, payment for settlement		363
Qualified Plan [Member] \| San Diego Gas and Electric Company [Member] \| Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, payment for settlement		132
Benefit obligation payment for settlement		22
Qualified Plan [Member] \| Southern California Gas Company [Member] \| Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, payment for settlement		231
Benefit obligation payment for settlement		32
Nonqualified Plan [Member] \| Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation payment for settlement		12	$ 8
Nonqualified Plan [Member] \| San Diego Gas and Electric Company [Member] \| Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation payment for settlement		$ 4
Sempra Texas Holdings Corp [Member] \| Sempra Texas Intermediate Holding Company LLC [Member] \| Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Increase due to business combination	$ 21
Sempra Texas Holdings Corp [Member] \| Oncor Electric Delivery Company LLC [Member] \| Sempra Texas Intermediate Holding Company LLC [Member] \| Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Gain (loss) arising during the period	$ 27