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Regulatory Assets and Liabilities (Emera Maine ) (Details) $ in Millions, $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2018 | Dec. 31, 2017 CAD ($) km | Dec. 31, 2016 USD ($) | Dec. 31, 2016 CAD ($)
Public Utilities, General Disclosures [Line Items] |  |  |  |
Regulatory Assets |  | $ 1,376 |  | $ 1,322
Emera Maine [Member] | Maine Public Utilities Commission (MPUC) [Member] | Electric Distribution [Member] |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |
Public Utilities, Approved Return on Equity, Percentage |  |  | 9.00% |
Public Utilities, Approved Equity Capital Structure, Percentage |  |  | 49.00% |
Public Utilities, Approved Rate Increase (Decrease), Percentage |  |  | 3.75% |
Public Utilities, Approved Rate Increase (Decrease), Amount |  |  | $ 4 |
Bangor Hydro District [Member] | Federal Energy Regulatory Commission (FERC) [Member] | Electric Transmission [Member] |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |
Public Utilities, Approved Return on Equity, Percentage |  | 10.57% | 10.57% |
Bangor Hydro District [Member] | Minimum [Member] | Federal Energy Regulatory Commission (FERC) [Member] | ISO-New England (ISO-NE) [Member] | Electric Transmission [Member] |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |
Public Utilities, Approved Return on Equity, Percentage |  | 11.07% | 11.07% |
Bangor Hydro District [Member] | Maximum [Member] | Federal Energy Regulatory Commission (FERC) [Member] | ISO-New England (ISO-NE) [Member] | Electric Transmission [Member] |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |
Public Utilities, Approved Return on Equity, Percentage |  | 11.74% | 11.74% |
Maine Public Service District [Member] | Federal Energy Regulatory Commission (FERC) [Member] | Electric Transmission [Member] |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |
Public Utilities, Approved Return on Equity, Percentage |  | 9.60% | 10.20% |
Barbados Light & Power Company Limited [Member] |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |
Public Utilities, Approved Return on Equity, Percentage |  | 10.00% | 10.00% |
Dominica Electricity Services Ltd. [Member] |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |
Public Utilities, Approved Return on Equity, Percentage |  | 15.00% | 15.00% |
Grand Bahama Power Company Limited [Member] |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |
Public Utilities, Approved Return on Equity, Percentage | 8.50% | 8.80% | 8.80% |
Brunswick Pipeline [Member] |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |
Length Of Pipeline | km |  | 145 |  |

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