FAIR VALUE MEASUREMENTS - RECURRING FAIR VALUE MEASURES (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value Measured at Net Asset Value Per Share [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Alternative investment			$ 5
Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	$ 1,004	$ 1,028	1,090
Short-term investments held in Rabbi Trust	81	61	66
Support Agreement, net of related guarantee fees	7	7
Assets fair value disclosure, total	1,332	1,304	1,367
Effect of netting and allocation of collateral			(14)
Support Agreement, net of related guarantee fees		4
Liabilities fair value disclosure, total	221	264	245
Fair Value, Recurring | Short-term investments, primarily cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	3	3	16
Fair Value, Recurring | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	364	364	509
Fair Value, Recurring | Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	56	65	57
Fair Value, Recurring | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	321	326	282
Fair Value, Recurring | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	260	270	226
Fair Value, Recurring | Total debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	637	661	565
Fair Value, Recurring | Interest rate instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	6	1	3
Derivative liability	8	47	28
Fair Value, Recurring | Foreign exchange instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	2	24	21
Derivative liability	1	11	7
Fair Value, Recurring | Commodity contracts not subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	46	4	11
Effect of netting and allocation of collateral	58	21	43
Derivative liability	31	16	17
Fair Value, Recurring | Interest rate and foreign exchange instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	131	128	122
Fair Value, Recurring | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	82	128	108
Effect of netting and allocation of collateral	46	30	25
Derivative liability	50	58	85
Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	419	408	563
Short-term investments held in Rabbi Trust	81	61	66
Support Agreement, net of related guarantee fees	0	0
Assets fair value disclosure, total	601	515	688
Effect of netting and allocation of collateral			(14)
Support Agreement, net of related guarantee fees		0
Liabilities fair value disclosure, total	0	0	0
Fair Value, Recurring | Level 1 | Short-term investments, primarily cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	13	9	14
Fair Value, Recurring | Level 1 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	358	358	503
Fair Value, Recurring | Level 1 | Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	48	41	46
Fair Value, Recurring | Level 1 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
Fair Value, Recurring | Level 1 | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
Fair Value, Recurring | Level 1 | Total debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	48	41	46
Fair Value, Recurring | Level 1 | Interest rate instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0	0
Derivative liability	0	0	0
Fair Value, Recurring | Level 1 | Foreign exchange instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0	0
Derivative liability	0	0	0
Fair Value, Recurring | Level 1 | Commodity contracts not subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0	0
Effect of netting and allocation of collateral	58	21	43
Derivative liability	0	0	0
Fair Value, Recurring | Level 1 | Interest rate and foreign exchange instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	0	0	0
Fair Value, Recurring | Level 1 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	12	6	5
Effect of netting and allocation of collateral	31	19	11
Derivative liability	0	0	14
Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	585	620	527
Short-term investments held in Rabbi Trust	0	0	0
Support Agreement, net of related guarantee fees	0	0
Assets fair value disclosure, total	649	655	578
Effect of netting and allocation of collateral			0
Support Agreement, net of related guarantee fees		0
Liabilities fair value disclosure, total	206	208	178
Fair Value, Recurring | Level 2 | Short-term investments, primarily cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	(10)	(6)	2
Fair Value, Recurring | Level 2 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	6	6	6
Fair Value, Recurring | Level 2 | Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	8	24	11
Fair Value, Recurring | Level 2 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	321	326	282
Fair Value, Recurring | Level 2 | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	260	270	226
Fair Value, Recurring | Level 2 | Total debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	589	620	519
Fair Value, Recurring | Level 2 | Interest rate instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	6	1	3
Derivative liability	8	47	28
Fair Value, Recurring | Level 2 | Foreign exchange instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	2	24	21
Derivative liability	1	11	7
Fair Value, Recurring | Level 2 | Commodity contracts not subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	46	4	11
Effect of netting and allocation of collateral	0	0	0
Derivative liability	31	16	17
Fair Value, Recurring | Level 2 | Interest rate and foreign exchange instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	131	128	122
Fair Value, Recurring | Level 2 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	1	1	8
Effect of netting and allocation of collateral	9	5	8
Derivative liability	35	6	4
Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
Short-term investments held in Rabbi Trust	0	0	0
Support Agreement, net of related guarantee fees	7	7
Assets fair value disclosure, total	82	134	101
Effect of netting and allocation of collateral			0
Support Agreement, net of related guarantee fees		4
Liabilities fair value disclosure, total	15	56	67
Fair Value, Recurring | Level 3 | Short-term investments, primarily cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
Fair Value, Recurring | Level 3 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
Fair Value, Recurring | Level 3 | Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
Fair Value, Recurring | Level 3 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
Fair Value, Recurring | Level 3 | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
Fair Value, Recurring | Level 3 | Total debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
Fair Value, Recurring | Level 3 | Interest rate instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0	0
Derivative liability	0	0	0
Fair Value, Recurring | Level 3 | Foreign exchange instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0	0
Derivative liability	0	0	0
Fair Value, Recurring | Level 3 | Commodity contracts not subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0	0
Effect of netting and allocation of collateral	0	0	0
Derivative liability	0	0	0
Fair Value, Recurring | Level 3 | Interest rate and foreign exchange instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	0	0	0
Fair Value, Recurring | Level 3 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	69	121	95
Effect of netting and allocation of collateral	6	6	6
Derivative liability	15	52	67
San Diego Gas and Electric Company [Member] | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	1,004	1,028	1,090
Assets fair value disclosure, total	1,113	1,178	1,205
Liabilities fair value disclosure, total	15	52	67
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Short-term investments, primarily cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	3	3	16
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	364	364	509
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	56	65	57
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	321	326	282
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	260	270	226
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Total debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	637	661	565
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	81	126	99
Effect of netting and allocation of collateral	28	24	16
Derivative liability	15	52	81
Effect of netting and allocation of collateral			(14)
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	419	408	563
Assets fair value disclosure, total	453	431	574
Liabilities fair value disclosure, total	0	0	0
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 1 | Short-term investments, primarily cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	13	9	14
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 1 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	358	358	503
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 1 | Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	48	41	46
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 1 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 1 | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 1 | Total debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	48	41	46
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 1 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	12	5	1
Effect of netting and allocation of collateral	22	18	10
Derivative liability	0	0	14
Effect of netting and allocation of collateral			(14)
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	585	620	527
Assets fair value disclosure, total	585	620	530
Liabilities fair value disclosure, total	0	0	0
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 2 | Short-term investments, primarily cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	(10)	(6)	2
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 2 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	6	6	6
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 2 | Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	8	24	11
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 2 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	321	326	282
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 2 | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	260	270	226
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 2 | Total debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	589	620	519
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 2 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0	3
Effect of netting and allocation of collateral	0	0	0
Derivative liability	0	0	0
Effect of netting and allocation of collateral			0
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
Assets fair value disclosure, total	75	127	101
Liabilities fair value disclosure, total	15	52	67
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 3 | Short-term investments, primarily cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 3 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 3 | Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 3 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 3 | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 3 | Total debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0	0
San Diego Gas and Electric Company [Member] | Fair Value, Recurring | Level 3 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	69	121	95
Effect of netting and allocation of collateral	6	6	6
Derivative liability	15	52	67
Effect of netting and allocation of collateral			0
SoCalGas | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value disclosure, total	19	8	18
Liabilities fair value disclosure, total	35	6	4
SoCalGas | Fair Value, Recurring | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Effect of netting and allocation of collateral	18	6	9
Derivative liability	35	6	4
Derivative Asset, Fair Value, Gross Asset	1	2	9
SoCalGas | Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value disclosure, total	9	2	5
Liabilities fair value disclosure, total	0	0	0
SoCalGas | Fair Value, Recurring | Level 1 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Effect of netting and allocation of collateral	9	1	1
Derivative liability	0	0	0
Derivative Asset, Fair Value, Gross Asset	0	1	4
SoCalGas | Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value disclosure, total	10	6	13
Liabilities fair value disclosure, total	35	6	4
SoCalGas | Fair Value, Recurring | Level 2 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Effect of netting and allocation of collateral	9	5	8
Derivative liability	35	6	4
Derivative Asset, Fair Value, Gross Asset	1	1	5
SoCalGas | Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value disclosure, total	0	0	0
Liabilities fair value disclosure, total	0	0	0
SoCalGas | Fair Value, Recurring | Level 3 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Effect of netting and allocation of collateral	0	0	0
Derivative liability	0	0	0
Derivative Asset, Fair Value, Gross Asset	$ 0	$ 0	$ 0