Amortization And Financing Costs

No definition available.

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

- Definition

Amount Requested To Defer Operating Costs Incurred From Storm Restoration

+ References

No definition available.

+ Details

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

- Definition

Collection Period Of Amortization And Financing Costs

+ References

No definition available.

+ Details

Name:	ema_CollectionPeriodOfAmortizationAndFinancingCosts
Namespace Prefix:	ema_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Compliance Costs Accrued

+ References

No definition available.

+ Details

Name:	ema_ComplianceCostsAccrued
Namespace Prefix:	ema_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Costs not recoverable for rate approval

+ References

No definition available.

+ Details

Name:	ema_CostsNotRecoverableForRateApproval
Namespace Prefix:	ema_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Costs not recoverable for rate approval net of tax

+ References

No definition available.

+ Details

Name:	ema_CostsNotRecoverableForRateApprovalNetOfTax
Namespace Prefix:	ema_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Credits Purchased From Provincial Auctions

+ References

No definition available.

+ Details

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

- Definition

The duration period applicable to the existing commitments related to energy delivery over a number of years.

+ References

No definition available.

+ Details

Name:	ema_EnergyDeliveryCommitmentsAndContractsTerm
Namespace Prefix:	ema_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Equity ratio

+ References

No definition available.

+ Details

Name:	ema_EquityRatio
Namespace Prefix:	ema_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Estimate of possible percentage of receiving deliveries

+ References

No definition available.

+ Details

Name:	ema_EstimateOfPossiblePercentageOfReceivingDeliveries
Namespace Prefix:	ema_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The length of a long pipe, underground, for conveying oil, gas, etc. over long distances.

+ References

No definition available.

+ Details

Name:	ema_LengthOfPipeline
Namespace Prefix:	ema_
Data Type:	dtr-types:lengthItemType
Balance Type:	na
Period Type:	instant

- Definition

Monthly Holdback Amount

+ References

No definition available.

+ Details

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

- Definition

Number of pipelines

+ References

No definition available.

+ Details

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

- Definition

Percent of contracted annual amount

+ References

No definition available.

+ Details

Name:	ema_PercentOfContractedAnnualAmount
Namespace Prefix:	ema_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Requested Approval For Sale Of Regulatory Assets

+ References

No definition available.

+ Details

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

- Definition

Amount of contractual obligation to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

No definition available.

+ Details

Name:	us-gaap_ContractualObligationDueInNextTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of contractual obligation to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

No definition available.

+ Details

Name:	us-gaap_ContractualObligationDueInSecondYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of capitalized storm costs of a regulated entity that are expected to be recoverable through rate adjustments within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 980
-SubTopic 340
-Name Accounting Standards Codification
-Section 25
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482000/980-340-25-1

+ Details

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

- Definition

Fuel costs incurred that are directly related to goods produced and sold and services rendered during the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(a),(d))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

+ Details

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

- Definition

The increase (decrease) during the reporting period in the value of other assets that are created when regulatory agencies permits public utilities to defer costs to the balance sheet.

+ References

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

+ Details

Name:	us-gaap_IncreaseDecreaseInOtherRegulatoryAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount charged against operating income increasing loss contingency liability, after adjustments to reduce previously estimated charges.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483076/450-20-50-1

+ Details

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

- Definition

Amount of noncurrent assets classified as other.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(17))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

+ Details

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

- Definition

Percentage of public utility's approved return on equity.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesApprovedReturnOnEquityPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types: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_PublicUtilitiesGeneralDisclosuresLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Period end amount of property, plant and equipment (PPE) related to transmission and distribution owned by public utility.

+ References

No definition available.

+ Details

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

- Definition

Percentage of public utility's requested equity to capital, including debt and equity.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesRequestedEquityCapitalStructurePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of public utility's amended requested rate increase (decrease) with regulatory agency.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesRequestedRateIncreaseDecreaseAmendedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period.

+ References

+ Details

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

- Definition

The amount for the individual regulatory liability as itemized in a table of regulatory liabilities as of the end of the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 980
-SubTopic 405
-Name Accounting Standards Codification
-Section 25
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481854/980-405-25-1

+ Details

Name:	us-gaap_RegulatoryLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Remaining recovery period of regulatory assets for which no return on investment during recovery period is provided, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 980
-SubTopic 340
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481878/980-340-50-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 980
-SubTopic 340
-Section 55
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481849/980-340-55-2

+ Details

Name:	us-gaap_RemainingRecoveryPeriodOfRegulatoryAssetsForWhichNoReturnOnInvestmentDuringRecoveryPeriodIsProvided1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

A noncash adjustment to the provision established for storm damage by an oil, gas, or utility company.

+ References

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

+ Details

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

- Definition

Amount of operating expense for depreciation and amortization of regulated operation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

+ Details

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

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ema_CanadianElectricUtilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_RegulatoryAssetAxis=ema_NovaScotiaCapAndTradeCapAndTradeProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
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:	srt_StatementScenarioAxis=us-gaap_ScenarioPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryLiabilityAxis=us-gaap_RevenueSubjectToRefundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryAgencyAxis=ema_UtilityAndReviewBoardMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=ema_NspMaritimeLinkIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

Regulatory Assets and Liabilities - Canada Electric Utilities (Narrative) (Details) $ in Millions					3 Months Ended	12 Months Ended			24 Months Ended
	Jan. 29, 2024 CAD ($)	Dec. 01, 2023 CAD ($)	Oct. 31, 2023 CAD ($)	Aug. 15, 2021	Jun. 30, 2023 CAD ($)	Dec. 31, 2024	Dec. 31, 2023 CAD ($) km	Dec. 31, 2022 CAD ($)	Dec. 31, 2023 CAD ($) km	Dec. 21, 2023 CAD ($)	Mar. 31, 2023 CAD ($)	Feb. 28, 2022 CAD ($)
Public Utilities, General Disclosures [Line Items]
Regulatory Liabilities							$ 1,772	$ 2,273	$ 1,772
Utilities Operating Expense, Depreciation and Amortization							1,049	952
Contractual Obligation, to be Paid, Year One							2,698		2,698
Contractual Obligation, to be Paid, Year Two							1,217		1,217
Regulatory Assets							3,105	3,620	3,105
Non-current assets							11,396	11,850	$ 11,396
Canadian Electric Utilities \| Operating
Public Utilities, General Disclosures [Line Items]
Utilities Operating Expense, Depreciation and Amortization							276	259
NSPI
Public Utilities, General Disclosures [Line Items]
Storm cost							$ 10
NSPI \| Canadian Electric Utilities
Public Utilities, General Disclosures [Line Items]
Recovery Period							3 years		3 years
NSPI \| Canadian Electric Utilities \| Operating
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amended, Percentage							6.90%
Storm cost							$ 31
Deferred storm rider							$ 21		$ 21
NSPI \| Canadian Electric Utilities \| Operating \| Nova Scotia Cap-and-Trade ("Cap-and-Trade") Program
Public Utilities, General Disclosures [Line Items]
Gas costs								166
Credits purchased from provincial auctions								$ 6
Compliance costs accrued											$ (166)
NSPI \| Canadian Electric Utilities \| Operating \| Subsequent Event [Member]
Public Utilities, General Disclosures [Line Items]
Requested approval for sale of regulatory assets	$ 117
Amortization and financing costs	$ 117
Collection period of amortization and financing costs	10 years
NSPI \| Range, Minimum \| Canadian Electric Utilities \| Operating
Public Utilities, General Disclosures [Line Items]
Approved regulated return on equity							8.75%	8.75%
NSPI \| Range, Maximum \| Canadian Electric Utilities \| Operating
Public Utilities, General Disclosures [Line Items]
Approved regulated return on equity							9.25%	9.25%
Regulated common equity component							40.00%
NSPI \| Scenario Plan \| Canadian Electric Utilities \| Operating
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amended, Percentage						6.50%
NSPI \| NSPI FAM \| Canadian Electric Utilities \| Operating
Public Utilities, General Disclosures [Line Items]
Increase to regulatory assets					$ 51
NSPI \| UARB \| Canadian Electric Utilities \| Operating
Public Utilities, General Disclosures [Line Items]
Amount requested to defer operating costs incurred from storm restoration			$ 24
Non-current assets							$ 24		24
NSPI \| UARB \| Canadian Electric Utilities \| Operating \| NSP Maritime Link Inc.
Public Utilities, General Disclosures [Line Items]
Holdback payable							$ 4	$ 8	$ 12
Estimate of possible percentage of receiving deliveries							90.00%		90.00%
Monthly holdback amount		$ 4						$ 2
Percent of contracted annual amount							10.00%		10.00%
Emera Newfoundland and Labrador Holdings Inc. \| Canadian Electric Utilities \| Operating \| NSP Maritime Link Inc.
Public Utilities, General Disclosures [Line Items]
Public Utilities, Equipment, Transmission and Distribution							$ 1,800		$ 1,800
Number of pipelines							2
Length Of Pipeline \| km							170		170
Regulatory Liabilities												$ 1,800
Costs not recoverable for rate approval												9
Costs not recoverable for rate approval net of tax												$ 7
Holdback payable							$ 4
Contractual Obligation, to be Paid, Year One							$ 164		$ 164	$ 164
Energy Delivery Commitments and Contracts, Term				35 years
Emera Newfoundland and Labrador Holdings Inc. \| Range, Minimum \| Canadian Electric Utilities \| Operating \| NSP Maritime Link Inc.
Public Utilities, General Disclosures [Line Items]
Approved regulated return on equity							8.75%
Emera Newfoundland and Labrador Holdings Inc. \| Range, Maximum \| Canadian Electric Utilities \| Operating \| NSP Maritime Link Inc.
Public Utilities, General Disclosures [Line Items]
Approved regulated return on equity							9.25%
Equity ratio							30.00%		30.00%