GENERAL INFORMATION AND OTHER FINANCIAL DATA - OTHER INTANGIBLE ASSETS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	$ 440		$ 440		$ 250
Accumulated amortization	(58)		(58)		(48)
Net intangible assets	382		382		202
Amortization expense	7	$ 2	10	$ 5
Amortization expense recorded against revenue	3		3
Future amortization expense per year			13
Expected amortization charged against revenue			7
Future amortization expense, per year, next four years			26
Expected amortization expense, recorded in revenue, next four years			13
Renewable energy transmission and consumption permit [Member]
Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	169		169		169
Accumulated amortization	(37)		$ (37)		(32)
Renewable energy transmission and consumption permit [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)			15 years
Renewable energy transmission and consumption permit [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)			19 years
O&M agreement [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)			23 years
Gross intangible assets	66		$ 66		66
Accumulated amortization	(10)		$ (10)		(9)
PPA [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)			14 years
Gross intangible assets	190		$ 190		0
Accumulated amortization	3		3		0
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	15		15		15
Accumulated amortization	(8)		$ (8)		$ (7)
Other [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)			10 years
Sempra Mexico [Member] | PPA [Member]
Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	$ 190		$ 190