Public Utilities, Amortization Period For State Investment Tax Credit

No definition available.

Name:	he_PublicUtilitiesAmortizationPeriodForStateInvestmentTaxCredit
Namespace Prefix:	he_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Public Utilities, Interim General Rate Increase, Common Equity Capitalization

+ References

No definition available.

+ Details

Name:	he_PublicUtilitiesInterimGeneralRateIncreaseCommonEquityCapitalization
Namespace Prefix:	he_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Public Utilities, Interim General Rate Increase, Effective Interest Rate Of Return

+ References

No definition available.

+ Details

Name:	he_PublicUtilitiesInterimGeneralRateIncreaseEffectiveInterestRateOfReturn
Namespace Prefix:	he_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Public Utilities, Stipulated Return On Average Common Equity Rate

+ References

No definition available.

+ Details

Name:	he_PublicUtilitiesStipulatedReturnOnAverageCommonEquityRate
Namespace Prefix:	he_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Public Utility, General Rate Increase, Maximum Exposure Cap

+ References

No definition available.

+ Details

Name:	he_PublicUtilityGeneralRateIncreaseMaximumExposureCap
Namespace Prefix:	he_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Public Utility, General Rate Increase, Risk Sharing Percentage, Ratepayer

+ References

No definition available.

+ Details

Name:	he_PublicUtilityGeneralRateIncreaseRiskSharingPercentageRatepayer
Namespace Prefix:	he_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

Name:	he_RegulatoryProjectsAndLegalObligationsLineItems
Namespace Prefix:	he_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 340
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382

+ Details

Name:	us-gaap_RegulatoryAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	dei_LegalEntityAxis=he_HawaiianElectricParentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=he_HawaiiElectricLightCompanyIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

Electric utility segment - Most recent rate proceedings (Details) - USD ($) $ in Thousands	Oct. 22, 2020	Nov. 13, 2019	Mar. 31, 2021	Dec. 31, 2020
Regulatory Projects and Legal Obligations [Line Items]
Regulatory assets			$ 773,426	$ 766,708
Hawaiian Electric (parent only)
Regulatory Projects and Legal Obligations [Line Items]
Common equity capitalization rate	58.00%
Stipulated ROACE rate	9.50%
Effective interest rate of return	7.37%
Hawaii Electric Light
Regulatory Projects and Legal Obligations [Line Items]
Common equity capitalization rate		58.00%
Stipulated ROACE rate		9.50%
Effective interest rate of return		7.52%
Amortization period for state investment tax credit		10 years
Risk sharing percentage, ratepayer		98.00%
Maximum exposure cap		$ 600
Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory Projects and Legal Obligations [Line Items]
Regulatory assets			$ 22,200