FAIR VALUE MEASUREMENTS - FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term amounts due from unconsolidated affiliates, allowance for credit losses		$ 1
Unamortized transaction costs	$ 5	5
Unamortized discount and debt issuance costs	299	260
Finance lease obligations	1,335	1,335
Allowance for credit losses	7	8
Due from Unconsolidated Affiliates - Current
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest Receivable	1	2
Carrying amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term amounts due from unconsolidated affiliates	626	640
Long-term notes receivable	306	300
Long-term amounts due to unconsolidated affiliate	309	287
Total long-term debt	23,678	20,099
Fair value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term amounts due from unconsolidated affiliates	633	642
Long-term notes receivable	307	327
Long-term amounts due to unconsolidated affiliate	304	295
Total long-term debt	23,608	22,126
Fair value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term amounts due from unconsolidated affiliates	0	0
Long-term notes receivable	0	0
Long-term amounts due to unconsolidated affiliate	0	0
Total long-term debt	0	0
Fair value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term amounts due from unconsolidated affiliates	633	642
Long-term notes receivable	0	0
Long-term amounts due to unconsolidated affiliate	304	295
Total long-term debt	23,608	22,126
Fair value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term amounts due from unconsolidated affiliates	0	0
Long-term notes receivable	307	327
Long-term amounts due to unconsolidated affiliate	0	0
Total long-term debt	0	0
San Diego Gas and Electric Company
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unamortized discount and debt issuance costs	74	61
Finance lease obligations	1,270	1,274
San Diego Gas and Electric Company | Carrying amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	7,600	6,417
San Diego Gas and Electric Company | Fair value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	7,687	7,236
San Diego Gas and Electric Company | Fair value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	0	0
San Diego Gas and Electric Company | Fair value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	7,687	7,236
San Diego Gas and Electric Company | Fair value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	0	0
Southern California Gas Company
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unamortized discount and debt issuance costs	44	36
Finance lease obligations	65	61
Southern California Gas Company | Carrying amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	5,459	4,759
Southern California Gas Company | Fair value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	5,561	5,367
Southern California Gas Company | Fair value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	0	0
Southern California Gas Company | Fair value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	5,561	5,367
Southern California Gas Company | Fair value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	$ 0	$ 0