Name:	he_FDICInsuranceAssessment
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Represents the rate used to determine the prepaid risk-based assessments for financial institutions in the highest risk category.

No definition available.

Name:	he_PrepaidAssessmentRateForFinancialInstitutionsInHighestRiskCategory
Namespace Prefix:	he_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the rate used to determine the prepaid risk-based assessments for financial institutions in the lowest risk category.

No definition available.

Name:	he_PrepaidAssessmentRateForFinancialInstitutionsInLowestRiskCategory
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Data Type:	num:percentItemType
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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.

No definition available.

Name:	us-gaap_LossContingenciesLineItems
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Data Type:	xbrli:stringItemType
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Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Unused amount of commitments to extend credit to customers.

No definition available.

Name:	us-gaap_UnusedCommitmentsToExtendCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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