XML 94 R76.htm IDEA: XBRL DOCUMENT v3.25.0.1

Summary of Significant Accounting Policies (Narrative II) (Details) $ in Millions	3 Months Ended		12 Months Ended
	Sep. 30, 2024 CAD ($)	Sep. 30, 2024 USD ($)	Dec. 31, 2024 CAD ($) Item	Dec. 31, 2024 USD ($) Item	Dec. 31, 2023 CAD ($)	Aug. 05, 2024 CAD ($)	Dec. 31, 2022 CAD ($)
Asset Impairment Charges
Impairment charge			$ 225,000,000		$ 0
Goodwill
Goodwill			5,858,000,000		5,871,000,000		$ 6,012,000,000
Goodwill impairment charge			$ 214,000,000		0
Lease, Practical Expedient, Lessor Single Lease Component [true false]			true
New Mexico Gas Company [Member]
Goodwill
Goodwill						$ 366,000,000
Goodwill impairment charge	$ 210,000,000	$ 155	$ 210,000,000	$ 155
Goodwill impairment charge, net of tax	198,000,000	$ 146	198,000,000	$ 146
Various Canadian And US Government Agencies [Member]
Goodwill
Amount received from government funds			$ 47,000,000		$ 7,000,000
Government Assistance Asset Increase Noncurrent Statement Of Financial Position Extensible Enumeration			Property, Plant and Equipment, Net	Property, Plant and Equipment, Net	Property, Plant and Equipment, Net
Natural Resources Canada Smart Renewables & Electrification Pathways [Member]
Goodwill
Number of battery storage systems funded for construction | Item			3	3
Percent under grant for claims of eligible project costs			33.00%	33.00%
Maximum project costs eligible under grant for claims			$ 109,000,000
Amount received from government funds			$ 26,000,000
Government Assistance Asset Increase Noncurrent Statement Of Financial Position Extensible Enumeration			Property, Plant and Equipment, Net	Property, Plant and Equipment, Net	Property, Plant and Equipment, Net
Long-Lived Assets
Asset Impairment Charges
Impairment charge			$ 11,000,000		$ 0
Certain Long Lived Assets
Asset Impairment Charges
Impairment charge			19,000,000
Asset Impairment Charges, net of tax			14,000,000
Included In Other Income, Net
Asset Impairment Charges
Impairment charge			8,000,000
Equity Method Investments
Asset Impairment Charges
Impairment charge			0		0
Financial Assets
Asset Impairment Charges
Impairment charge			0		$ 0
NMGC
Goodwill
Goodwill	303,000,000		$ 303,000,000
Goodwill impairment charge	$ 210,000,000

X

- Definition

Amount of write-down of assets, net of tax, recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

No definition available.

+ Details

Name:	ema_AssetImpairmentChargesNetOfTax
Namespace Prefix:	ema_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Maximum project costs eligible under grant for claims.

+ References

No definition available.

+ Details

Name:	ema_MaximumProjectCostsEligibleUnderGrantForClaims
Namespace Prefix:	ema_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Number of battery storage systems funded for construction.

+ References

No definition available.

+ Details

Name:	ema_NumberOfBatteryStorageSystemsFundedForConstruction
Namespace Prefix:	ema_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Percent under grant for claims of eligible project costs.

+ References

No definition available.

+ Details

Name:	ema_PercentUnderGrantForClaimsOfEligibleProjectCosts
Namespace Prefix:	ema_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482130/360-10-45-4

+ Details

Name:	us-gaap_AssetImpairmentCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- References

No definition available.

+ Details

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

X

- Definition

Amount, after accumulated impairment loss, of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 49
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482785/280-10-55-49

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 24
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482548/350-20-55-24

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 100
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-100

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 852
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481372/852-10-55-10

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(15))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482598/350-20-45-1

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(10)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

+ Details

Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- References

No definition available.

+ Details

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

X

- Definition

Amount of impairment loss from asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 24
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482548/350-20-55-24

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-2

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 100
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-100

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482598/350-20-45-2

+ Details

Name:	us-gaap_GoodwillImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount, after tax, of impairment loss from asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

+ References

No definition available.

+ Details

Name:	us-gaap_GoodwillImpairmentLossNetOfTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of increase in asset from government assistance, classified as noncurrent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 832
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483507/832-10-50-3

+ Details

Name:	us-gaap_GovernmentAssistanceAssetIncreaseNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Indicates line item in statement of financial position that includes increase in asset from government assistance, classified as noncurrent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 832
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483507/832-10-50-3

+ Details

Name:	us-gaap_GovernmentAssistanceAssetIncreaseNoncurrentStatementOfFinancialPositionExtensibleEnumeration
Namespace Prefix:	us-gaap_
Data Type:	enum2:enumerationSetItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Indicates (true false) whether practical expedient is elected to account for lease component and nonlease component as single lease component.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 3A
-Subparagraph (a)
-SubTopic 30
-Topic 842
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479773/842-30-50-3A

+ Details

Name:	us-gaap_LeasePracticalExpedientLessorSingleLeaseComponent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=ema_NewMexicoGasCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_GovernmentAssistanceTypeAxis=ema_VariousCanadianAndUsGovernmentAgenciesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_GovernmentAssistanceTypeAxis=ema_NaturalResourcesCanadaSmartRenewablesElectrificationPathwaysMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByAssetClassAxis=ema_LongLivedAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByAssetClassAxis=ema_CertainLongLivedAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByAssetClassAxis=ema_IncludedInOtherIncomeNetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_EquityMethodInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByAssetClassAxis=ema_FinancialAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ConsolidatedEntitiesAxis=ema_NmgcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: