FAIR VALUE MEASUREMENTS - FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, allowance for credit losses	$ 8
Notes receivable, transaction costs	5
Long term amounts due from unconsolidated affiliates, allowance for credit losses	1	$ 3
Accrued interest receivable	2	3
Unamortized discount (net of premium) and debt issuance costs	260	268	$ 225
Finance lease obligations	1,335	1,330	1,289
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term note receivable	300
Long-term amounts due from unconsolidated affiliates	640	786	742
Long-term amounts due to unconsolidated affiliates	287	275	195
Total long-term debt	20,099	22,259	21,247
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term note receivable	327
Long-term amounts due from unconsolidated affiliates	642	817	759
Long-term amounts due to unconsolidated affiliates	295	266	184
Total long-term debt	22,126	25,478	22,664
Fair Value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term note receivable	0
Long-term amounts due from unconsolidated affiliates	0	0	0
Long-term amounts due to unconsolidated affiliates	0	0	0
Total long-term debt	0	0	0
Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term note receivable	0
Long-term amounts due from unconsolidated affiliates	642	817	759
Long-term amounts due to unconsolidated affiliates	295	266	184
Total long-term debt	22,126	25,478	22,638
Fair Value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term note receivable	327
Long-term amounts due from unconsolidated affiliates	0	0	0
Long-term amounts due to unconsolidated affiliates	0	0	0
Total long-term debt	0	0	26
San Diego Gas and Electric Company [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unamortized discount (net of premium) and debt issuance costs	61	52	48
Finance lease obligations	1,274	1,276	1,270
San Diego Gas and Electric Company [Member] | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	6,417	6,253	5,140
San Diego Gas and Electric Company [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	7,236	7,384	5,662
San Diego Gas and Electric Company [Member] | Fair Value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	0	0	0
San Diego Gas and Electric Company [Member] | Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	7,236	7,384	5,662
San Diego Gas and Electric Company [Member] | Fair Value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	0	0	0
SoCalGas
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unamortized discount (net of premium) and debt issuance costs	36	40	34
Finance lease obligations	61	54	19
SoCalGas | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	4,759	4,759	3,809
SoCalGas | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	5,367	5,655	4,189
SoCalGas | Fair Value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	0	0	0
SoCalGas | Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	5,367	5,655	4,189
SoCalGas | Fair Value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	$ 0	$ 0	$ 0