INCOME TAXES - DEFERRED INCOME TAXES (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred income tax assets:
Less: valuation allowances	$ 174	$ 144
Deferred income taxes assets, noncurrent	136	155
Deferred income tax liabilities, noncurrent	2,871	2,577
Sempra Energy Consolidated [Member]
Deferred income tax liabilities:
Differences in financial and tax bases of fixed assets, investments and other assets	4,891	4,052
U.S. state and non-U.S. withholding tax on repatriation of foreign earnings	46	153
Regulatory balancing accounts	587	468
Right-of-use assets – operating leases	144	131
Property taxes	51	44
Other deferred income tax liabilities	40	93
Total deferred income tax liabilities	5,759	4,941
Deferred income tax assets:
Tax credits	1,161	1,136
Net operating losses	1,299	911
Postretirement benefits	162	200
Compensation-related items	169	161
Operating lease liabilities	125	131
Other deferred income tax assets	152	72
Accrued expenses not yet deductible	130	52
Deferred income tax assets before valuation allowances	3,198	2,663
Less: valuation allowances	174	144
Total deferred income tax assets	3,024	2,519
Net deferred income tax liability	2,735	2,422
Deferred income taxes assets, noncurrent	136	155
Deferred income tax liabilities, noncurrent	2,871	2,577
San Diego Gas and Electric Company [Member]
Deferred income tax liabilities:
Differences in financial and tax bases of fixed assets, investments and other assets	1,833	1,735
Regulatory balancing accounts	224	141
Right-of-use assets – operating leases	28	32
Property taxes	34	30
Other deferred income tax liabilities	2	14
Total deferred income tax liabilities	2,121	1,952
Deferred income tax assets:
Tax credits	5	6
Postretirement benefits	14	37
Compensation-related items	12	6
Operating lease liabilities	28	32
Bad debt allowance	18	3
Other deferred income tax assets	3	4
State income taxes	8	7
Accrued expenses not yet deductible	14	9
Total deferred income tax assets	102	104
Net deferred income tax liability	2,019	1,848
Deferred income tax liabilities, noncurrent	2,019	1,848
Southern California Gas Company [Member]
Deferred income tax liabilities:
Differences in financial and tax bases of fixed assets, investments and other assets	1,322	1,246
Regulatory balancing accounts	362	327
Right-of-use assets – operating leases	21	22
Property taxes	17	14
Other deferred income tax liabilities	1	1
Total deferred income tax liabilities	1,723	1,610
Deferred income tax assets:
Tax credits	3	3
Postretirement benefits	123	120
Compensation-related items	36	25
Operating lease liabilities	21	22
Bad debt allowance	15	1
Other deferred income tax assets	15	13
State income taxes	11	8
Accrued expenses not yet deductible	93	15
Total deferred income tax assets	317	207
Net deferred income tax liability	1,406	1,403
Deferred income tax liabilities, noncurrent	$ 1,406	$ 1,403