SIGNIFICANT ACCOUNTING POLICIES AND OTHER FINANCIAL DATA - WILDFIRE FUND (Details) - USD ($)	1 Months Ended	12 Months Ended
	Jul. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2019
Loss Contingencies [Line Items]
Noncurrent portion of the Wildfire Fund asset		$ 331,000,000	$ 363,000,000	$ 392,000,000
San Diego Gas and Electric Company [Member]
Loss Contingencies [Line Items]
Fire risk mitigation capital improvements	$ 215,000,000
Initial liability cap		1,100,000,000
Initial shareholder contributions					$ 322,500,000
Additional annual contributions, aggregate value		129,000,000
Wildfire fund asset				451,500,000
Annual contributions		$ 12,900,000
Amortization of wildfire fund asset		15 years
Current portion of Wildfire fund		$ 29,000,000	29,000,000	29,000,000
Noncurrent portion of the Wildfire Fund asset		331,000,000	363,000,000	392,000,000
Wildfire fund obligations in current liabilities		13,000,000	13,000,000	13,000,000
Noncurrent Wildfire Fund obligation		64,000,000	75,000,000	86,000,000
Amortization of Wildfire Fund asset		29,000,000	29,000,000	12,000,000
Wildfire Fund asset, impairment losses		3,000,000	0	0
Accretion of Wildfire Fund obligation		2,000,000	$ 2,000,000	$ 1,000,000
Wildfire Fund
Loss Contingencies [Line Items]
Wildfire fund, threshold amount to seek payment	$ 1,000,000,000
Wildfire fund, threshold percentage of equity portion of electric transmission	20.00%
Liquidity fund, maximum borrowing capacity		10,500,000,000
Initial shareholder contributions		7,500,000,000
Additional annual contributions, aggregate value		$ 3,000,000,000
Period of annual contributions		10 years