SIGNIFICANT ACCOUNTING POLICIES AND OTHER FINANCIAL DATA - INVENTORIES (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Inventory [Line Items]
Natural gas	$ 118	$ 110
LNG	7	9
Materials and supplies	183	158
Inventories	308	277
SDG&E [Member]
Inventory [Line Items]
Natural gas	0	1
LNG	0	0
Materials and supplies	104	93
Inventories	104	94
SoCalGas [Member]
Inventory [Line Items]
Natural gas	94	90
LNG	0	0
Materials and supplies	59	46
Inventories	$ 153	$ 136

Energy related inventory, Liquefied Natural Gas.

No definition available.

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Balance Type:	debit
Period Type:	instant

- Definition

Energy related inventory, materials and supplies.

+ References

No definition available.

+ Details

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Namespace Prefix:	sre_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of natural gas in storage, which is a mixture of gases (liquefied or otherwise), used for fuel and manufacturing purposes, which is ready for sale.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.6(a))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121566466&loc=d3e6676-107765

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.6(a))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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- Details

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