EMPLOYEE BENEFIT PLANS - PLAN ASSETS (Details)	12 Months Ended
Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	7.00%
Domestic Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	35.00%
International Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	24.00%
Long Credit [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	18.00%
Ultra-long duration government securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	8.00%
Defined Benefit Plan, Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	5.00%
Return Seeking Credit [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	5.00%
Real Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	5.00%
Return Seeking Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	74.00%
Risk Mitigating Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	26.00%
Minimum [Member] \| Return Seeking Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	5.00%
Minimum [Member] \| Risk Mitigating Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	1.00%
Maximum [Member] \| Return Seeking Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	9.00%
Maximum [Member] \| Risk Mitigating Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	4.00%
San Diego Gas and Electric Company [Member] \| Return Seeking Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	38.00%
San Diego Gas and Electric Company [Member] \| Risk Mitigating Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	62.00%
Southern California Gas Company [Member] \| Return Seeking Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	25.00%
Asset allocations	38.00%
Southern California Gas Company [Member] \| Risk Mitigating Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted plan asset allocations	75.00%
Asset allocations	62.00%

Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(3)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- 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

Name:	us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=118257860&loc=d3e4179-114921

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of actual investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=sre_DomesticEquityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=sre_InternationalEquityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=sre_LongCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=sre_LonggovernmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_DefinedBenefitPlanRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=sre_HighYieldCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=sre_RealAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=sre_ReturnSeekingAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=sre_RiskMitigatingAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=sre_SanDiegoGasAndElectricCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=sre_SouthernCaliforniaGasCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: