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Consolidated Balance Sheets - HECO (Parenthetical) - USD ($) $ in Thousands | Dec. 31, 2017 | Dec. 31, 2016
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Hawaiian Electric Company, Inc. and Subsidiaries |  |
Accumulated depreciation on other property, plant and equipment | $ 1,251 | $ 1,232

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- Definition Amount of accumulated depreciation of long-lived, physical assets used to produce goods and services and not intended for resale, classified as other. + References No definition available. + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- Details
Name: | dei_LegalEntityAxis=he_HawaiianElectricCompanyAndSubsidiariesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |