EMPLOYEE BENEFIT PLANS - PLAN ASSETS (Details)	12 Months Ended
	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	6.75%
Ultra-long duration government securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	5.00%
Return Seeking Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	74.00%
Risk Mitigating Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	26.00%
Other Diversifying Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	2.00%
Domestic Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	33.00%
International Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	22.00%
Long Credit [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	21.00%
Diversified Real Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	10.00%
Return Seeking Credit [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	7.00%
Minimum [Member] | Return Seeking Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	4.00%
Minimum [Member] | Risk Mitigating Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	1.00%
Maximum [Member] | Return Seeking Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	12.00%
Maximum [Member] | Risk Mitigating Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	4.00%
San Diego Gas and Electric Company [Member] | Return Seeking Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	38.00%
San Diego Gas and Electric Company [Member] | Risk Mitigating Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	62.00%
Southern California Gas Company [Member] | Return Seeking Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	30.00%
Asset allocations	38.00%
Southern California Gas Company [Member] | Risk Mitigating Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	70.00%
Asset allocations	62.00%