XML 100 R83.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Segment Information (Reportable Segments) (Details) - CAD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | $ 6,226 | $ 4,277 |
Allowance for Funds Used During Construction, Investing Activities | 16 | 35 |
Regulated Fuel Adjustment | 59 | 61 |
Depreciation, Depletion and Amortization | 856 | 588 |
Interest Expense | 705 | 598 |
Internally Allocated Interest | 0 | 0 |
Income (Loss) from Equity Method Investments | 124 | 100 |
Income tax expense (recovery) | 520 | (22) |
Net Income (Loss) Attributable to Parent | 266 | 227 |
Segment Reporting Information, Additional Information [Abstract] |  |  |
Capital expenditures | 1,522 | 1,069 |
Assets, Total | 28,771 | 29,221 |
Goodwill | 5,805 | 6,213 | $ 264
Investments subject to significant influence | 1,215 | 947 |
All External Customers [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 6,226 | 4,276 |
Internal Customers [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 0 | 1 |
Intersegment Eliminations [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | (58) | (36) |
Allowance for Funds Used During Construction, Investing Activities | 0 | 0 |
Regulated Fuel Adjustment | 0 | 0 |
Depreciation, Depletion and Amortization | 0 | 0 |
Interest Expense | 0 | 0 |
Internally Allocated Interest | 0 | 0 |
Income (Loss) from Equity Method Investments | 0 | 0 |
Income tax expense (recovery) | 0 | 0 |
Net Income (Loss) Attributable to Parent | 0 | 0 |
Segment Reporting Information, Additional Information [Abstract] |  |  |
Capital expenditures | 0 | 0 |
Assets, Total | (86) | (113) |
Goodwill | 0 |  |
Investments subject to significant influence | 0 |  |
Intersegment Eliminations [Member] | All External Customers [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 0 | 0 |
Intersegment Eliminations [Member] | Internal Customers [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | (58) | (36) |
Emera Florida And New Mexico Segment [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 3,623 | 1,839 |
Allowance for Funds Used During Construction, Investing Activities | 5 | 28 |
Regulated Fuel Adjustment | 0 | 0 |
Depreciation, Depletion and Amortization | 500 | 243 |
Interest Expense | 248 | 125 |
Internally Allocated Interest | 0 | 0 |
Income (Loss) from Equity Method Investments | 0 | 0 |
Income tax expense (recovery) | 529 | 100 |
Net Income (Loss) Attributable to Parent | 99 | 172 |
Segment Reporting Information, Additional Information [Abstract] |  |  |
Capital expenditures | 910 | 547 |
Assets, Total | 17,216 | 18,016 |
Goodwill | 5,566 | 5,957 |
Investments subject to significant influence | 0 | 0 |
Emera Florida And New Mexico Segment [Member] | All External Customers [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 3,623 | 1,839 |
Emera Florida And New Mexico Segment [Member] | Internal Customers [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 0 | 0 |
Nova Scotia Power Inc Segment [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 1,338 | 1,356 |
Allowance for Funds Used During Construction, Investing Activities | 8 | 6 |
Regulated Fuel Adjustment | 59 | 61 |
Depreciation, Depletion and Amortization | 207 | 197 |
Interest Expense | 134 | 127 |
Internally Allocated Interest | 0 | 0 |
Income (Loss) from Equity Method Investments | 0 | 0 |
Income tax expense (recovery) | 0 | 12 |
Net Income (Loss) Attributable to Parent | 129 | 130 |
Segment Reporting Information, Additional Information [Abstract] |  |  |
Capital expenditures | 385 | 304 |
Assets, Total | 4,979 | 4,776 |
Goodwill | 0 | 0 |
Investments subject to significant influence | 0 | 0 |
Nova Scotia Power Inc Segment [Member] | All External Customers [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 1,335 | 1,354 |
Nova Scotia Power Inc Segment [Member] | Internal Customers [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 3 | 2 |
Emera Maine Segment [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 297 | 297 |
Allowance for Funds Used During Construction, Investing Activities | 3 | 1 |
Regulated Fuel Adjustment | 0 | 0 |
Depreciation, Depletion and Amortization | 47 | 51 |
Interest Expense | 20 | 19 |
Internally Allocated Interest | 0 | 0 |
Income (Loss) from Equity Method Investments | 1 | 0 |
Income tax expense (recovery) | 27 | 23 |
Net Income (Loss) Attributable to Parent | 46 | 47 |
Segment Reporting Information, Additional Information [Abstract] |  |  |
Capital expenditures | 82 | 85 |
Assets, Total | 1,505 | 1,543 |
Goodwill | 143 | 154 |
Investments subject to significant influence | 13 | 13 |
Emera Maine Segment [Member] | All External Customers [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 297 | 297 |
Emera Maine Segment [Member] | Internal Customers [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 0 | 0 |
Emera Caribbean Segment [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 434 | 419 |
Allowance for Funds Used During Construction, Investing Activities | 0 | 0 |
Regulated Fuel Adjustment | 0 | 0 |
Depreciation, Depletion and Amortization | 51 | 48 |
Interest Expense | 25 | 15 |
Internally Allocated Interest | 0 | 0 |
Income (Loss) from Equity Method Investments | 3 | 3 |
Income tax expense (recovery) | 0 | 14 |
Net Income (Loss) Attributable to Parent | 31 | 100 |
Segment Reporting Information, Additional Information [Abstract] |  |  |
Capital expenditures | 72 | 87 |
Assets, Total | 1,251 | 1,331 |
Goodwill | 96 | 102 |
Investments subject to significant influence | 39 | 39 |
Emera Caribbean Segment [Member] | All External Customers [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 434 | 419 |
Emera Caribbean Segment [Member] | Internal Customers [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 0 | 0 |
Emera Energy Segment [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 465 | 309 |
Allowance for Funds Used During Construction, Investing Activities | 0 | 0 |
Regulated Fuel Adjustment | 0 | 0 |
Depreciation, Depletion and Amortization | 48 | 45 |
Interest Expense | 2 | 1 |
Internally Allocated Interest | (24) | (24) |
Income (Loss) from Equity Method Investments | 24 | 11 |
Income tax expense (recovery) | 18 | (53) |
Net Income (Loss) Attributable to Parent | 93 | (110) |
Segment Reporting Information, Additional Information [Abstract] |  |  |
Capital expenditures | 47 | 39 |
Assets, Total | 1,575 | 1,702 |
Goodwill | 0 | 0 |
Investments subject to significant influence | 0 | 0 |
Emera Energy Segment [Member] | All External Customers [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 451 | 298 |
Emera Energy Segment [Member] | Internal Customers [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 14 | 11 |
Corporate and Other [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 127 | 93 |
Allowance for Funds Used During Construction, Investing Activities | 0 | 0 |
Regulated Fuel Adjustment | 0 | 0 |
Depreciation, Depletion and Amortization | 3 | 4 |
Interest Expense | 276 | 311 |
Internally Allocated Interest | 24 | 24 |
Income (Loss) from Equity Method Investments | 96 | 86 |
Income tax expense (recovery) | (54) | (118) |
Net Income (Loss) Attributable to Parent | (132) | (112) |
Segment Reporting Information, Additional Information [Abstract] |  |  |
Capital expenditures | 26 | 7 |
Assets, Total | 2,331 | 1,966 |
Goodwill | 0 | 0 |
Investments subject to significant influence | 1,163 | 895 |
Amortization Related to Unregulated Long Term Debt | 24 | 13 |
Corporate and Other [Member] | All External Customers [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | 86 | 69 |
Corporate and Other [Member] | Internal Customers [Member] |  |  |
Segment Reporting Information, Profit (Loss) [Abstract] |  |  |
Revenues, Total | $ 41 | $ 24 |

X
- Definition Amortization Related to Unregulated Long Term Debt. + References No definition available. + Details
Name: | ema_AmortizationRelatedToUnregulatedLongTermDebt
Namespace Prefix: | ema_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of interest expense allocated between segments. + References No definition available. + Details
Name: | ema_InternallyAllocatedInterest
Namespace Prefix: | ema_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The regulated fuel adjustment related to the fuel adjustment mechanism ("FAM"). + References No definition available. + Details
Name: | ema_RegulatedFuelAdjustment
Namespace Prefix: | ema_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Cash inflow due to change during the period in the allowance for other funds used during construction classified as an investing activity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6500269&loc=d3e45485-110386 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585 + Details
Name: | us-gaap_AllowanceForFundsUsedDuringConstructionInvestingActivities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(12)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(11)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_Assets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 + Details
Name: | us-gaap_DepreciationDepletionAndAmortization
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975 + Details
Name: | us-gaap_Goodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(12)) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(10)) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=66022249&loc=d3e33749-111570 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(13)(f)) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 + Details
Name: | us-gaap_IncomeLossFromEquityMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a),(b) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(h)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_IncomeTaxExpenseBenefit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of the cost of borrowed funds accounted for as interest expense. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.9) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 + Details
Name: | us-gaap_InterestExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Total investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(22)) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(18)) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(20)) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
Name: | us-gaap_NetIncomeLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585 + Details
Name: | us-gaap_PaymentsToAcquireProductiveAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
Name: | us-gaap_Revenues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_SegmentReportingInformationAdditionalInformationAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_SegmentReportingInformationProfitLossAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_MajorCustomersAxis=ema_AllExternalCustomersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=ema_InternalCustomersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConsolidationItemsAxis=us-gaap_IntersegmentEliminationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=ema_EmeraFloridaAndNewMexicoSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=ema_NovaScotiaPowerIncSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=ema_EmeraMaineSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=ema_EmeraCaribbeanSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=ema_EmeraEnergySegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=us-gaap_CorporateAndOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |