Name:	he_AggregateOfPowerPurchaseCapacityExcludingAgreementWithSmallerIndependentPowerProducers
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Data Type:	dtr-types:powerItemType
Balance Type:	na
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Aggregate Of Power Purchase Capacity Increases From Initial Capacity

No definition available.

Name:	he_AggregateOfPowerPurchaseCapacityIncreasesFromInitialCapacity
Namespace Prefix:	he_
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Long-term Contract For Purchase Of Electric Power, Maximum Power Volume Delivered

No definition available.

Name:	he_LongTermContractForPurchaseOfElectricPowerMaximumPowerVolumeDelivered
Namespace Prefix:	he_
Data Type:	dtr-types:powerItemType
Balance Type:	na
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Long-term Contract For Purchase Of Electric Power, Total Contracted Battery Energy Storage System Capacity

No definition available.

Name:	he_LongTermContractForPurchaseOfElectricPowerTotalContractedBatteryEnergyStorageSystemCapacity
Namespace Prefix:	he_
Data Type:	dtr-types:powerItemType
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Long-term Contract For Purchase Of Electric Power, Total Contracted PV Capacity

No definition available.

Name:	he_LongTermContractForPurchaseOfElectricPowerTotalContractedPVCapacity
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Long Term Purchase Commitment, Battery Volume Generated

No definition available.

Name:	he_LongTermPurchaseCommitmentBatteryVolumeGenerated
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Long Term Purchase Commitment, Extension Period

No definition available.

Name:	he_LongTermPurchaseCommitmentExtensionPeriod
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Long-Term Purchase Commitment, Minimum Power Volume Required

No definition available.

Name:	he_LongTermPurchaseCommitmentMinimumPowerVolumeRequired
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Long-Term Purchase Commitment, Power Purchase Price Increase, Percent

No definition available.

Name:	he_LongTermPurchaseCommitmentPowerPurchasePriceIncreasePercent
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Long Term Purchase Commitment, Volume Generated

No definition available.

Name:	he_LongTermPurchaseCommitmentVolumeGenerated
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Long Term Purchase Commitments, Number Of Projects

No definition available.

Name:	he_LongTermPurchaseCommitmentsNumberOfProjects
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Represents the number of firm power purchase agreements entered into, by the company.

No definition available.

Name:	he_NumberOfPowerPurchaseAgreements
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Power Purchase Agreement, Firm Capacity Volume

No definition available.

Name:	he_PowerPurchaseAgreementFirmCapacityVolume
Namespace Prefix:	he_
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Balance Type:	na
Period Type:	duration

-- None. No documentation exists for this element. --

No definition available.

Name:	he_RegulatoryProjectsAndLegalObligationsLineItems
Namespace Prefix:	he_
Data Type:	xbrli:stringItemType
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Utilities Expected Fixed Capacity Charges, After Five Through Fifteen Years

No definition available.

Name:	he_UtilitiesExpectedFixedCapacityChargesAfterFiveThroughFifteenYears
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Utilities Expected Fixed Capacity Charges, Year Five

No definition available.

Name:	he_UtilitiesExpectedFixedCapacityChargesYearFive
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Utilities Expected Fixed Capacity Charges, Year Four

No definition available.

Name:	he_UtilitiesExpectedFixedCapacityChargesYearFour
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Utilities Expected Fixed Capacity Charges, Year One

No definition available.

Name:	he_UtilitiesExpectedFixedCapacityChargesYearOne
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Utilities Expected Fixed Capacity Charges, Year Three

No definition available.

Name:	he_UtilitiesExpectedFixedCapacityChargesYearThree
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Utilities Expected Fixed Capacity Charges, Year Two

No definition available.

Name:	he_UtilitiesExpectedFixedCapacityChargesYearTwo
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Estimated annual cost to purchase electricity under a long-term contract from a production plant constructed and financed by a public utility district, cooperative, or other organization.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 10.D)
-URI https://asc.fasb.org/extlink&oid=122136240&loc=d3e659339-123030

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Period covered by the long-term purchase commitment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	us-gaap_LongtermPurchaseCommitmentPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
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Period Type:	duration

Amount of operating expense for purchased power of regulated operation.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(b))
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

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Data Type:	xbrli:monetaryItemType
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Data Type:	na
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Data Type:	na
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Data Type:	na
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Data Type:	na
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