Segment Information (Reportable Segments) (Details) - CAD CAD in Millions	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	CAD 4,277	CAD 2,789
Allowance for Funds Used During Construction, Investing Activities	35	6
Regulated Fuel Adjustment	61	42
Depreciation, Depletion and Amortization	588	340
Interest Expense	600	222
Investment Income, Interest	2	6
Internally Allocated Interest	0	0
Income (Loss) from Equity Method Investments	100	108
Income tax expense (recovery)	(22)	93
Net Income (Loss) Attributable to Parent	255	427
Segment Reporting Information, Additional Information [Abstract]
Capital expenditures	487	487
Assets, Total	29,221	12,039
Goodwill	6,213	264	CAD 222
Investments subject to significant influence	947	1,145
All External Customers [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	4,276	2,787
Internal Customers [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	1	2
Intersegment Eliminations [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	(36)	(44)
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
Investment Income, Interest	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	(113)	(225)
Goodwill	0	0
Investments subject to significant influence	0	0
Intersegment Eliminations [Member] \| All External Customers [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	(2)	(2)
Intersegment Eliminations [Member] \| Internal Customers [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	(34)	(42)
Emera Florida And New Mexico Segment [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	1,839	0
Allowance for Funds Used During Construction, Investing Activities	28	0
Regulated Fuel Adjustment	0	0
Depreciation, Depletion and Amortization	243	0
Interest Expense	125	0
Investment Income, Interest	0	0
Internally Allocated Interest	0	0
Income (Loss) from Equity Method Investments	0	0
Income tax expense (recovery)	100	0
Net Income (Loss) Attributable to Parent	172	0
Segment Reporting Information, Additional Information [Abstract]
Capital expenditures	0	0
Assets, Total	18,016	0
Goodwill	5,957	0
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	1,839	0
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	1,356	1,417
Allowance for Funds Used During Construction, Investing Activities	6	4
Regulated Fuel Adjustment	61	42
Depreciation, Depletion and Amortization	197	206
Interest Expense	127	129
Investment Income, Interest	0	5
Internally Allocated Interest	0	0
Income (Loss) from Equity Method Investments	0	0
Income tax expense (recovery)	12	23
Net Income (Loss) Attributable to Parent	130	130
Segment Reporting Information, Additional Information [Abstract]
Capital expenditures	271	271
Assets, Total	4,776	4,721
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	1,356	1,417
Nova Scotia Power Inc Segment [Member] \| Internal Customers [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	0	0
Emera Maine Segment [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	297	284
Allowance for Funds Used During Construction, Investing Activities	1	2
Regulated Fuel Adjustment	0	0
Depreciation, Depletion and Amortization	51	47
Interest Expense	19	19
Investment Income, Interest	0	0
Internally Allocated Interest	0	0
Income (Loss) from Equity Method Investments	0	0
Income tax expense (recovery)	23	27
Net Income (Loss) Attributable to Parent	47	45
Segment Reporting Information, Additional Information [Abstract]
Capital expenditures	65	65
Assets, Total	1,543	1,558
Goodwill	154	158
Investments subject to significant influence	13	12
Emera Maine Segment [Member] \| All External Customers [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	297	284
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	419	450
Allowance for Funds Used During Construction, Investing Activities	0	0
Regulated Fuel Adjustment	0	0
Depreciation, Depletion and Amortization	48	44
Interest Expense	15	14
Investment Income, Interest	0	0
Internally Allocated Interest	0	0
Income (Loss) from Equity Method Investments	3	3
Income tax expense (recovery)	14	3
Net Income (Loss) Attributable to Parent	100	41
Segment Reporting Information, Additional Information [Abstract]
Capital expenditures	44	44
Assets, Total	1,331	1,403
Goodwill	102	106
Investments subject to significant influence	39	39
Emera Caribbean Segment [Member] \| All External Customers [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	419	442
Emera Caribbean Segment [Member] \| Internal Customers [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	0	8
Emera Energy Segment [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	309	590
Allowance for Funds Used During Construction, Investing Activities	0	0
Regulated Fuel Adjustment	0	0
Depreciation, Depletion and Amortization	45	41
Interest Expense	2	1
Investment Income, Interest	1	1
Internally Allocated Interest	(24)	(18)
Income (Loss) from Equity Method Investments	11	21
Income tax expense (recovery)	(53)	50
Net Income (Loss) Attributable to Parent	(110)	99
Segment Reporting Information, Additional Information [Abstract]
Capital expenditures	98	98
Assets, Total	1,702	1,919
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	298	578
Emera Energy Segment [Member] \| Internal Customers [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	11	12
Corporate and Other [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	93	92
Allowance for Funds Used During Construction, Investing Activities	0	0
Regulated Fuel Adjustment	0	0
Depreciation, Depletion and Amortization	4	2
Interest Expense	312	59
Investment Income, Interest	1	0
Internally Allocated Interest	24	18
Income (Loss) from Equity Method Investments	86	84
Income tax expense (recovery)	(118)	(10)
Net Income (Loss) Attributable to Parent	(112)	82
Segment Reporting Information, Additional Information [Abstract]
Capital expenditures	9	9
Assets, Total	1,966	2,663
Goodwill	0	0
Investments subject to significant influence	895	1,094
Amortization Related to Unregulated Long Term Debt	13
Corporate and Other [Member] \| All External Customers [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	69	68
Corporate and Other [Member] \| Internal Customers [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues, Total	CAD 24	CAD 24

Amortization Related to Unregulated Long Term Debt.

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Amount of interest expense allocated between segments.

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The regulated fuel adjustment related to the fuel adjustment mechanism ("FAM").

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Cash inflow due to change during the period in the allowance for other funds used during construction classified as an investing activity.

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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.

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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.

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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.

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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.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the cost of borrowed funds accounted for as interest expense.

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Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.

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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.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets.

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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).

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