Financing Receivable, Conversion Of Debt

No definition available.

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

- Definition

Represents the minimum benchmark percentage of loan to appraisal ratio which mortgage insurance is required as per the policy of the reporting entity.

+ References

No definition available.

+ Details

Name:	he_MinimumBenchmarkPercentageOfLoanToAppraisalRatioWhichMortgageInsuranceIsRequired
Namespace Prefix:	he_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

This element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. This item represents other bank borrowings as of the balance sheet date, including securities sold under agreements to repurchase and advances from the Federal Home Loan Bank.

+ References

No definition available.

+ Details

Name:	he_OtherBankBorrowings
Namespace Prefix:	he_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 470
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478878/942-470-45-1

+ Details

Name:	us-gaap_AdvancesFromFederalHomeLoanBanks
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph c
-Publisher SEC

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-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of impairment loss from asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
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+ Details

Name:	us-gaap_GoodwillImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Unused amount of commitments to extend credit to customers.

+ References

No definition available.

+ Details

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

- Details

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

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_FederalReserveBankAdvancesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Bank segment - Narrative (Details) - USD ($)	3 Months Ended			9 Months Ended
Bank segment - Narrative (Details) - USD ($)	Sep. 30, 2024	Jun. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Allowance for credit losses
Goodwill impairment				$ 82,190,000	$ 0
Other bank borrowings	$ 520,000,000			520,000,000		$ 750,000,000
American Savings Bank (ASB)
Allowance for credit losses
Goodwill impairment	0	$ 82,200,000	$ 0	$ 82,190,000	0
Minimum benchmark percentage of loan to appraisal ratio which mortgage insurance is required				80.00%
Unused line and letters of credits	1,800,000,000			$ 1,800,000,000
Advances from the FHLB	520,000,000.0			520,000,000.0		200,000,000.0
American Savings Bank (ASB) \| Federal Reserve Bank Advances
Allowance for credit losses
Other bank borrowings	$ 0			0		$ 550,000,000.0
Home equity line of credit
Allowance for credit losses
Conversion of debt				18,100,000	20,400,000
Commercial
Allowance for credit losses
Conversion of debt				2,600,000	6,100,000
Consumer
Allowance for credit losses
Conversion of debt				$ 500,000	$ 1,100,000