XML 175 R157.htm IDEA: XBRL DOCUMENT
v3.21.1

Commitments and Contingencies (Guarantees and Letters of Credit) (Details) $ in Millions, $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2020 CAD ($) | Dec. 31, 2020 USD ($) | Dec. 31, 2019 CAD ($) | Dec. 31, 2019 USD ($)
Guarantor Obligations [Line Items] |  |  |  |
Letters of Credit Outstanding, Amount | $ 4 |  | $ 3 |
Nova Scotia Power Inc. [Member] |  |  |  |
Guarantor Obligations [Line Items] |  |  |  |
Guaranty Liabilities |  | $ 18 |  |
Letters of Credit Outstanding, Amount | $ 63 |  | $ 52 |
Guarantor Obligations, Term | The expiry date of this letter of credit was extended to June 2021 |  |  |
Emera Inc. |  |  |  |
Guarantor Obligations [Line Items] |  |  |  |
Guaranty Liabilities |  | 35 |  |
Guarantor Obligations, Origin and Purpose | relating to outstanding notes of GBPC |  |  |
Guarantor Obligations, Term | The guarantee for the notes will expire in May 2023 |  |  |
Payment Guarantee | SeaCoast Gas Transmission, LLC |  |  |  |
Guarantor Obligations [Line Items] |  |  |  |
Letters of Credit Outstanding, Amount |  | 27 |  |
Guarantor Obligations, Maximum Exposure, Undiscounted |  | 45 |  |
Surety Bonds |  |  |  |
Guarantor Obligations [Line Items] |  |  |  |
Letters of Credit Outstanding, Amount |  | $ 55 |  | $ 82

X
- 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_GuaranteeObligationsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=121555522&loc=d3e12069-110248 + Details
Name: | us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Describes how and under what circumstances or in connection with which transaction the guarantee or each group of similar guarantees was given and the objective of the guarantee. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=121555522&loc=d3e12069-110248 + Details
Name: | us-gaap_GuaranteeObligationsOriginAndPurpose
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Describe the approximate term of the guarantee or each group of similar guarantees. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=121555522&loc=d3e12069-110248 + Details
Name: | us-gaap_GuaranteeObligationsTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition This item represents a non-contingent liability for the fair value of an obligation to stand ready to perform over the term of a guaranty issued in the event that specified triggering events or conditions occur. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.15) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.15) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 25 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=121555860&loc=d3e11019-110243 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 25 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=121555860&loc=d3e11049-110243 + Details
Name: | us-gaap_GuarantyLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The total amount of the contingent obligation under letters of credit outstanding as of the reporting date. + References No definition available. + Details
Name: | us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=ema_NovaScotiaPowerIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=srt_ParentCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_PaymentGuaranteeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=ema_SeacoastGasTransmissionLlcMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_SuretyBondMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |