XML 54 R38.htm IDEA: XBRL DOCUMENT
v3.21.1

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 |

X
- Definition Public Utilities, Amortization Period For State Investment Tax Credit + References No definition available. + Details
Name: | he_PublicUtilitiesAmortizationPeriodForStateInvestmentTaxCredit
Namespace Prefix: | he_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- 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

X
- 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

X
- 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

X
- 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

X
- 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

X
- 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

X
- 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

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

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

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