Unfunded commitments to fund the company's LIHTC Investment Program, Proportional Amortization Method, Elected, Commitment Other accounts receivable, net Accounts and Other Receivables, Net, Current Adjustments to reconcile net income (loss) to net cash provided by operating activities Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Repayment of long-term debt Repayments of Long-Term Debt Collateral [Domain] Collateral Held [Domain] Valuation allowance Valuation allowance, beginning balance Valuation allowance, ending balance Valuation Allowance for Impairment of Recognized Servicing Assets, Balance Cover page. Cover [Abstract] Net increase in cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Gain on sale of loans, net Gain (Loss) on Sales of Loans, Net Weighted average discount rate Measurement Input, Discount Rate [Member] Percent of return on equity Public Utility, Decoupling Order, Performance Incentive Mechanism, Generation-Caused System Average Interruption, Maximum Penalty, Percent Of Return On Equity Public Utility, Decoupling Order, Performance Incentive Mechanism, Generation-Caused System Average Interruption, Maximum Penalty, Percent Of Return On Equity Current Financial Asset, 1 to 29 Days Past Due [Member] Condensed Income Statements, Captions [Line Items] Condensed Income Statements, Captions [Line Items] Trading Symbol(s) Trading Symbol Income tax benefit from compensation expense Income tax benefit (expense) Share-Based Payment Arrangement, Expense, Tax Benefit Total capitalization Capitalization, Long-Term Debt and Equity Common stock dividends (in dollars per share) Common Stock, Dividends, Per Share, Declared Loans held for sale, at lower of cost or fair value Financing Receivable, Held-for-Sale, Not Part of Disposal Group, after Valuation Allowance Bank interest and dividend income Bank Interest And Dividend Income [Member] Bank Interest And Dividend Income [Member] Interest Rate Reduction (in percent) Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification Hawaiian Electric Facility Hawaiian Electric Facility [Member] Hawaiian Electric Facility 2025 ARA revenues Public Utilities, Annual Revenue Adjustment, Revenues Public Utilities, Annual Revenue Adjustment, Revenues Decrease (increase) in accounts receivable Increase (Decrease) in Accounts Receivable Basis of presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Expected funding amount Unusual Or Infrequent Item, Humanitarian Aid, Expected Funding Amount Unusual Or Infrequent Item, Humanitarian Aid, Expected Funding Amount Fair value measurements Fair Value Disclosures [Text Block] 2025 ARA revenues Public Utility, Annual Incremental Rate Adjustment Mechanism Adjusted Revenue Public Utility, Annual Incremental Rate Adjustment Mechanism Adjusted Revenue Net unrealized gains (losses) on available-for-sale investment securities arising during the period, net of taxes of $13,470, $(13,918), $7,878 and $(11,860), respectively OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Management Audit savings commitment Public Utilities, Annual Revenue Adjustment, Management Audit Savings Commitment Public Utilities, Annual Revenue Adjustment, Management Audit Savings Commitment Financial Asset, Period Past Due [Axis] Financial Asset, Aging [Axis] Other borrowings Other Borrowings Net gains (losses) recognized in the Statement of Income Derivative, Gain (Loss) on Derivative, Net Schedule of Collateral-Dependent Loans Financing Receivable, Allowance for Credit Loss [Table Text Block] Decrease in defined benefit pension and other postretirement benefit plans liability Decrease in defined benefit pension and other postretirement benefit plans liability Increase (Decrease) in Obligation, Pension and Other Postretirement Benefits Kapolei Energy Storage Kapolei Energy Storage [Member] Kapolei Energy Storage Financing Receivable, Past Due [Table] Financing Receivable, Past Due [Table] Schedule of Long-Term Incentive Plan Assumptions Schedule Of Share-based Payment Award, Equity Instruments Other Than Options, Valuation Assumptions [Table Text Block] Schedule Of Share-based Payment Award, Equity Instruments Other Than Options, Valuation Assumptions Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Net interest income Interest Income (Expense), Operating Right-of-use assets - finance lease Financing lease right-of-use assets Finance Lease, Right-of-Use Asset, before Accumulated Amortization Share-based Payment Arrangement, Option, Exercise Price Range [Table] Share-Based Payment Arrangement, Option, Exercise Price Range [Table] Annual change in accrued RBA balance through September 30, 2024 (and associated revenue taxes) Public Utility, Increase (Decrease) In Accrued Earnings Sharing Credits To Be Refunded Public Utility, Increase (Decrease) In Accrued Earnings Sharing Credits To Be Refunded Total other long-term assets Assets Noncurrent Excluding Property, Plant and Equipment, Net The carrying value of assets which are intended to be held for a period exceeding one year, excluding property, plant and equipment. Number of pending claims Loss Contingency, Pending Claims, Number HEI Facility HEI Facility [Member] HEI Facility Common stock issued (gross) for director and executive/management compensation (financing) Stock Issued During Period Value Director and Officer Compensatory Plans Value of stock issued during the period from director and officer compensatory plans in noncash transactions. Cash flows from financing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Estimated fair value of noncash contributions in aid of construction (investing) Noncash or Part Noncash Increases Property, Plant and Equipment Contributions in Aid of Construction Noncash (or part noncash) increases in property, plant and equipment due to noncash contributions in aid of construction. Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Plan Name [Domain] Plan Name [Domain] Financing Receivable, Nonaccrual [Table] Financing Receivable, Nonaccrual [Table] Available-for-sale Available-for-sale Securities, Debt Securities, Fair Value [Abstract] Available-for-sale Securities, Debt Securities, Fair Value [Abstract] Other Other Assets, Noncurrent Prior Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year Regulatory assets Regulatory assets Regulatory Asset Research and development tax credits Deferred Tax Assets, Tax Credit Carryforwards, Research Corporate bonds Corporate Bond Securities [Member] Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Held-to-maturity investment securities, at amortized cost Held-to-maturity, at amortized cost (fair value of $1,086,205 and $1,103,668, at September 30, 2024 and December 31, 2023, respectively) Held-to-maturity investment securities, at amortized cost Debt Securities, Held-to-Maturity, Excluding Accrued Interest, after Allowance for Credit Loss Net cash provided by (used in) operating activities Net cash provided by (used in) operating activities Net Cash Provided by (Used in) Operating Activities Interest and dividends payable Interest and preferred dividends payable Interest and Dividends Payable Including Dividends on Preferred Stock of Subsidiaries Sum of the carrying values as of the balance sheet date of (a) interest payable on all forms of debt, including trade payables, that has been incurred, and (b) dividends declared but unpaid on equity securities issued by the entity and outstanding (also includes dividends collected on behalf of another owner of securities that are being held by the entity). This includes dividends on preferred stock of subsidiaries. Schedule of Accumulated Other Comprehensive Income Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Financing Receivable, Nonaccrual [Line Items] Financing Receivable, Nonaccrual [Line Items] Project [Domain] Project [Domain] Net periodic pension/benefit cost (return) Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Total amortized cost Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Amortized Cost Other IPPs Other Independent Power Producers [Member] Represents information pertaining to other independent power producers. Bank fees Bank Fees [Member] Bank Fees [Member] Measurement Frequency [Axis] Measurement Frequency [Axis] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Insurance reimbursement receivable Insurance Reimbursement Receivable Insurance Reimbursement Receivable Preferred stock of subsidiaries - not subject to mandatory redemption Cumulative preferred stock — not subject to mandatory redemption Temporary Equity, Carrying Amount, Including Portion Attributable to Noncontrolling Interests Electric energy sales - large light and power Electric Energy Sales, Large Light And Power [Member] Electric Energy Sales, Large Light And Power [Member] Payment delay Payment Deferral [Member] Entity Small Business Entity Small Business Less accumulated depreciation Public Utilities, Property, Plant and Equipment, Accumulated Depreciation Converted to term loans Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan Significant unobservable inputs (Level 3) Fair Value, Inputs, Level 3 [Member] Share-based compensation Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Valuation allowances and reserves Accrual for Environmental Loss Contingencies Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Measurement Inputs and Valuation Techniques [Table] Interpolated RPS rate goal, after year three (in dollars per MWh) Public Utilities, RPS-A Performance Incentive Mechanism, Reward Threshold, Interpolated RPS Rate Goal, After Year Three Public Utilities, RPS-A Performance Incentive Mechanism, Reward Threshold, Interpolated RPS Rate Goal, After Year Three Noninterest expense Noninterest Expense [Abstract] Retention for property damages Loss Contingency, Property Insurance Policy Limit, Retention For Generation Assets Loss Contingency, Property Insurance Policy Limit, Retention For Generation Assets Maximum power volume to be delivered (in megawatts) Long-term Contract For Purchase Of Electric Power, Maximum Power Volume Delivered Long-term Contract For Purchase Of Electric Power, Maximum Power Volume Delivered Revolving Financing Receivable, Excluding Accrued Interest, Revolving Credit Facility [Domain] Credit Facility [Domain] Settlement payments reserved Litigation Settlement, Amount Awarded To Other Party, Reserved To Resolve Claims By Nonparticipating Plaintiffs Litigation Settlement, Amount Awarded To Other Party, Reserved To Resolve Claims By Nonparticipating Plaintiffs Number of claim forms Humanitarian Aid Fund, Number Of Death Related Claim Forms Humanitarian Aid Fund, Number Of Death Related Claim Forms Total Financing Receivable, Excluding Accrued Interest, Modified, after 12 Months Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Accounts and Financing Receivables [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Mortgage service fees Fees and Commissions, Mortgage Banking and Servicing Goodwill Goodwill Residential land Residential Land [Member] Residential Land Withheld shares for employee taxes on vested share-based compensation Payment, Tax Withholding, Share-Based Payment Arrangement Increase in wildfire tort-related claims Increase (Decrease) In Loss Contingency Liability Increase (Decrease) In Loss Contingency Liability Income taxes refunded (including refundable credits) Proceeds from Income Tax Refunds Call center performance, maximum penalty percentage Public Utility, Decoupling Order, Call Center Performance, Maximum Penalty, Percent Public Utility, Decoupling Order, Call Center Performance, Maximum Penalty, Percent Target performance historical measurement period (in years) Public Utility, Decoupling Order, Performance Incentive Mechanism, Generation-Caused System Average Interruption, Target Performance Historical Measurement Period Public Utility, Decoupling Order, Performance Incentive Mechanism, Generation-Caused System Average Interruption, Target Performance Historical Measurement Period Other Other Assets, Miscellaneous Deposit liabilities—interest-bearing Interest-Bearing Deposit Liabilities Entity Information [Line Items] Entity Information [Line Items] Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-Sale [Table] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Depreciation of property, plant and equipment Depreciation of property, plant and equipment Depreciation Fair value Derivative, Fair Value, Net Other Proceeds from (Payments for) Other Financing Activities Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc. Comprehensive Income (Loss), Net of Tax, Attributable to Parent Pension benefits Pension Plan [Member] Amortized cost Amortized cost Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, after Allowance for Credit Loss Schedule of Contractual Maturities of Available-for-Sale Securities Investments Classified by Contractual Maturity Date [Table Text Block] Award Type [Axis] Award Type [Axis] Corporate bonds Corporate Debt Securities [Member] Consumer mortgage loans collateralized by residential real estate property in foreclosure process Financial Receivables, Loans Collateralized By Real Estate In Foreclosure Financial Receivables, Loans Collateralized By Real Estate In Foreclosure Property, plant and equipment, net of accumulated depreciation of $3,457,283 and $3,317,759 at September 30, 2024 and December 31, 2023, respectively Total property, plant and equipment, net Premises and equipment, net Property, Plant and Equipment, Net Total liabilities Total liabilities Liabilities Electric energy sales - commercial Electric Energy Sales, Commercial [Member] Electric Energy Sales, Commercial [Member] Deferred payments Line Of Credit, Periodic Payment, Deferred Line Of Credit, Periodic Payment, Deferred Savings commitment liability, annual rate Public Utilities, Savings Commitment Liability, Annual Rate Public Utilities, Savings Commitment Liability, Annual Rate Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Less than 12 months, fair value Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value Revolving Credit Facility Revolving Credit Facility [Member] Reclassification Out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Other assets Other Assets [Abstract] Total revenues from other sources Revenue Not from Contract with Customer Current portion of operating lease liabilities Current portion of operating lease liabilities Operating Lease, Liability, Current Excess liability insurance Loss Contingency, Excess Liability Insurance Loss Contingency, Excess Liability Insurance Offsetting Liabilities [Line Items] Offsetting Liabilities [Line Items] Due after ten years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10 Cash and due from banks Cash and Due from Banks Financial Asset, Period Past Due [Domain] Financial Asset, Aging [Domain] Waena Switchyard/Synchronous Project Waena Switchyard/Synchronous Project [Member] Waena Switchyard/Synchronous Project Total Maui windstorm and wildfires related expenses Loss from Catastrophes Due after one year through five years Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Materials and supplies, at average cost Inventory, Raw Materials and Supplies, Gross Mortgage-backed securities Mortgage-backed securities — issued or guaranteed by U.S. Government agencies or sponsored agencies Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member] Credit agreement Debt Instrument [Line Items] Other Total other assets Other Assets Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Mortgage-servicing rights Servicing asset - beginning balance Servicing asset - ending balance Mortgage servicing rights Servicing Asset at Amortized Cost Common stock, no par value, authorized 200,000,000 shares; issued and outstanding: 172,465,608 shares and 110,151,798 shares at September 30, 2024 and December 31, 2023, respectively Common Stocks, Including Additional Paid in Capital, Net of Discount Basis of presentation Basis of Accounting, Policy [Policy Text Block] Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Derivative liabilities Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral [Abstract] Statements of Equity Statements of Income Data Balance Sheets Data Condensed Financial Statements, Captions [Line Items] AOCI Attributable to Parent, Net of Tax [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] Consumer loans Consumer Loan [Member] Total shareholders’ equity Beginning balance Ending balance Common stock equity Equity, Attributable to Parent Public utilities, electric grid project, approved funds Public Utilities, Electric Grid Project, Approved Funds Public Utilities, Electric Grid Project, Approved Funds Environmental Remediation Contingency [Axis] Environmental Remediation Contingency [Axis] Due in one year or less Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Regulatory liability, amortization period (in years) Regulatory Liability, Amortization Period Spectrum Oceanic LLC Spectrum Oceanic LLC [Member] Spectrum Oceanic LLC Litigation Case [Axis] Litigation Case [Axis] Purchased power Utilities Operating Expense, Purchased Power Cash flows from investing activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Current year Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year Mortgage-backed securities — issued or guaranteed by U.S. Government agencies or sponsored agencies Debt Securities, Available-for-Sale, Maturity, without Single Maturity Date, Amortized Cost Defined contribution plan, expenses recognized Defined Contribution Plan, Cost Number of physical injury related claim forms Humanitarian Aid Fund, Number Of Physical Injury Related Claim Forms Humanitarian Aid Fund, Number Of Physical Injury Related Claim Forms Accounts payable Accounts Payable Mahipapa Mahipapa, LLC [Member] Mahipapa Doubtful Doubtful [Member] Residential 1-4 family Residential 1-4 Family [Member] Residential 1-4 Family Sale of Stock [Domain] Sale of Stock [Domain] Document Fiscal Period Focus Document Fiscal Period Focus Net unrealized gains (losses) on securities AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member] Insurance receivable Loss Contingency, Receivable Assets Assets Assets [Abstract] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Proceeds from sale of commercial loans Proceeds From Sale Of Commercial Loans Proceeds From Sale Of Commercial Loans Document Type Document Type Derivative Contract [Domain] Derivative Contract [Domain] Advance payments by borrowers Advance Payments by Borrowers for Taxes and Insurance Payment award, high end of range Share-based Compensation by Share-based Payment Award Payout High End of Range Represents the high end of range of payout depending on achievement of the goals. Decrease in fuel oil stock Decrease in fuel oil stock Increase (Decrease) in Fuel Inventories Schedule of Segment Financial Information Schedule of Segment Reporting Information, by Segment [Table Text Block] Derivative liabilities, statement of financial position Derivative Liability, Statement of Financial Position [Extensible Enumeration] Tort-Related Legal Claims Tort-Related Legal Claims [Member] Tort-Related Legal Claims Schedule of Defined Benefit Plans Disclosures [Table] Defined Benefit Plan [Table] ABL Credit Facility Agreement ABL Credit Facility Agreement [Member] ABL Credit Facility Agreement Payments of obligations under finance leases Payments For Finance Lease Obligations Payments For Finance Lease Obligations 60-89 days past due 60-89 days past due Financial Asset, 60 to 89 Days Past Due [Member] Weighted average measurement input Servicing Asset, Measurement Input Hawaiian Electric Parent Company [Member] Schedule of Condensed Consolidating Statement of Cash Flows Condensed Cash Flow Statement [Table Text Block] Available-for-sale Debt Securities, Available-for-Sale [Abstract] Accounts payable Accounts Payable, Current Maximum penalty, percent of ROE Public Utility, Decoupling Order, Performance Incentive Mechanism, Service Reliability, Maximum Penalty, Percent Of Return On Equity Public Utility, Decoupling Order, Performance Incentive Mechanism, Service Reliability, Maximum Penalty, Percent Of Return On Equity Environmental remediation expense Environmental Remediation Expense, before Recovery Income (loss) before income taxes Income (loss) before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Conversion of debt Financing Receivable, Conversion Of Debt Financing Receivable, Conversion Of Debt Suspension Of Disconnections Suspension Of Disconnections [Member] Suspension Of Disconnections Miscellaneous liability insurance, retention amount Loss Contingency, Miscellaneous Professional Liability Insurance, Retention Amount Loss Contingency, Miscellaneous Professional Liability Insurance, Retention Amount Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Number of settlement agreements Loss Contingency, Claims Settled, Number Goodwill impairment Goodwill, Impairment Loss Amortization of unrealized holding losses on held-to-maturity securities Accumulated Gain (Loss), Net, Cash Flow Hedge, Held-To-Maturity, Parent [Member] Accumulated Gain (Loss), Net, Cash Flow Hedge, Held-To-Maturity, Parent Credit facility period Line of Credit Facility, Expiration Period Subsequent Event Type [Domain] Subsequent Event Type [Domain] Common stock dividends Payments of Ordinary Dividends, Common Stock Due in one year or less Debt Securities, Held-to-Maturity, Amortized Cost Excluding Accrued Interest, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Year One Amortization of net prior period gain Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Diluted earnings (loss) per common share (in dollars per share) Earnings Per Share, Diluted Counterparty Name [Domain] Counterparty Name [Domain] Interest expense, net—other than on deposit liabilities and other bank borrowings Interest expense Interest Expense On Other Than Deposits And Bank Borrowings The amount of interest expense, other than on deposit liabilities and other bank borrowings. Purchase of stock from Federal Home Loan Bank Payments to Acquire Federal Home Loan Bank Stock Schedule of Net Annual Incremental Amounts Proposed to be Collected (Refunded) Schedule Of Annual Decoupling Filings [Table Text Block] Schedule of Annual Decoupling Filings [Table Text Block] Retirement Benefits [Abstract] Retirement Benefits [Abstract] Preferred stock, issued shares (in shares) Preferred Stock, Shares Issued Regulatory Projects and Legal Obligations [Line Items] Regulatory Projects and Legal Obligations [Line Items] -- None. No documentation exists for this element. -- Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Mortgage revenue bonds Mortgage revenue bonds Asset-Backed Securities [Member] Fuel oil Utilities Operating Expense, Fuel Used Decrease in accounts receivable and unbilled revenues, net Increase (Decrease) in Receivables Fair value of vested stock Fair value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Net income (loss) Net income (loss) Total reclassifications Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Indemnification Agreement Indemnification Agreement [Member] Income tax expense (benefit) Income taxes (benefit) Income Tax Expense (Benefit) Interest cost Defined Benefit Plan, Interest Cost Incentives accrued Public Utility, Incentives Accrued Public Utility, Incentives Accrued Repayment of other bank borrowings Repayments of Other Bank Borrowings Repayments of Other Bank Borrowings Notional amount Derivative, Notional Amount Unused line and letters of credits Unused Commitments to Extend Credit Derivative assets Derivative Asset Accrued estimated rewards Public Utilities, Renewable Portfolio Standard Performance Incentive Mechanism, Accrued Estimated Rewards Public Utilities, Renewable Portfolio Standard Performance Incentive Mechanism, Accrued Estimated Rewards Tax Year 2016 To 2018 Tax Year 2016 To 2018 [Member] Tax Year 2016 To 2018 Weighted average period for recognition of unrecognized compensation cost (in years) Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Miscellaneous professional liability Loss Contingency, Miscellaneous Professional Liability Insurance Loss Contingency, Miscellaneous Professional Liability Insurance Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Charge offs one years prior of origination year Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff Interest expense Interest Expense, Operating and Nonoperating [Abstract] Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Principal repayments on available-for-sale investment securities Proceeds From Principal Repayments On Investment And Mortgage Related Securities, Available For Sale Proceeds From Principal Repayments On Investment And Mortgage Related Securities, Available For Sale Total interest expense Total interest expense Interest Expense, Operating and Nonoperating Deposit liabilities - time certificates Deposits, Fair Value Disclosure Grant-date fair value (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award Fair Value Assumptions Grant Date Fair Value Represents the estimated fair value at grant date for nonvested equity-based awards on other than stock (or unit) option plans. Other Other Operating Activities, Cash Flow Statement MPIR requested amount Public Utilities, Solar Project, Major Project Interim Recovery Requested Amount Public Utilities, Solar Project, Major Project Interim Recovery Requested Amount Premium on capital stock Additional paid-in capital Additional Paid in Capital Short-term Debt, Type [Domain] Short-Term Debt, Type [Domain] Business assets Business Assets [Member] Business Assets Reclassifications out of accumulated other comprehensive income/(loss) Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Legal Entity [Axis] Legal Entity [Axis] Interest and dividends on investment securities Interest and Dividend Income, Securities, Operating Regulatory Asset [Axis] Regulatory Asset [Axis] Utility property, plant and equipment Public Utilities, Property, Plant and Equipment, Net [Abstract] ERP/EAM project service period (in years) Public Utility, ERP/EAM Project Service Period Public Utility, ERP/EAM Project Service Period Directors and officers liability insurance, retention Loss Contingency, Directors And Officers Liability Insurance, Retention Amount Loss Contingency, Directors And Officers Liability Insurance, Retention Amount Schedule of Condensed Consolidating Statements of Income Schedule of Statements of Income Data Condensed Income Statement [Table Text Block] Equity in earnings of subsidiaries Equity in Earnings of Subsidiaries Represents the amount of equity in earnings of subsidiaries. Unrealized gains (losses) on derivatives Net realized gains on derivatives qualifying as cash flow hedges Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] U.S. Treasury and federal agency obligations US Government Agencies Debt Securities [Member] Total annual maximum penalty Public Utilities, Interconnection Approval, Performance Incentive Mechanism, Annual Maximum Penalty Public Utilities, Interconnection Approval, Performance Incentive Mechanism, Annual Maximum Penalty Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Entity Address, State or Province Entity Address, State or Province Commercial construction Commercial Construction Loan [Member] Commercial Construction Loan Retirement defined benefits credit—other than service costs Retirement defined benefits credit (expense)—other than service costs Less / Add back: Retirement defined benefits credit—other than service costs Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component Regulatory revenue Regulatory Revenue [Member] Regulatory Revenue [Member] Excess liability insurance, retention amount Loss Contingency, Excess Liability Insurance, Retention Amount Loss Contingency, Excess Liability Insurance, Retention Amount Three years before current year Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year EPRM approved projects, capital costs Public Utilities, Exceptional Project Recovery Mechanism, Capital Costs Public Utilities, Exceptional Project Recovery Mechanism, Capital Costs Retirement benefits Defined Benefit Plan Disclosure [Line Items] Other subsidiaries Other Subsidiaries [Member] Other Subsidiaries Financial Instruments [Domain] Financial Instruments [Domain] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] ERP/EAM Implementation Project ERP/EAM Implementation Project [Member] ERP/EAM Implementation Project [Member] Renewable energy generation project, incurred cost Public Utilities, Renewable Energy Generation Project, Incurred Cost Public Utilities, Renewable Energy Generation Project, Incurred Cost Outstanding, beginning of period (in dollars per share) Outstanding, end of period (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Liabilities and shareholders’ equity Capitalization and liabilities Liabilities and shareholder’s equity Liabilities and Equity [Abstract] Defined benefit pension and other postretirement benefit plans liability Liability, Defined Benefit Plan Schedule of Components of Net Periodic Benefit Cost for Consolidated HEI Schedule of Net Benefit Costs [Table Text Block] Charge offs more than five years prior of origination year Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff Preferred stock, no par value (in dollars per share) Preferred Stock, No Par Value Lawsuit claim filed Loss Contingency, New Claims Filed, Number Commercial construction Construction Loans [Member] Number of cases filed by subrogation insurers Loss Contingency, Number of Plaintiffs 12 months or longer, amount Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Fair Value, by Balance Sheet or Off Balance Sheet Grouping [Table] Fair Value, by Balance Sheet or Off Balance Sheet Grouping [Table] Fair value disclosures related to financial assets (as defined) and financial liabilities (as defined) whether contained in the entity's balance sheet or held off-balance sheet. Disclosures contained in this table include the carrying (reported) amount, the portion of the financial instrument (as defined) at fair value, portion at other than fair value, estimate of fair value, and the change in fair value during the period. Offsetting Liabilities [Table] Offsetting Liabilities [Table] Estimated fair value Estimate of Fair Value Measurement [Member] Asset derivatives Derivative Asset, Subject to Master Netting Arrangement, before Offset of Collateral Deferral treatment approved by the PUC Loss Contingencies, Incremental Non-Labor Expenses, Deferred Accounting Treatment Loss Contingencies, Incremental Non-Labor Expenses, Deferred Accounting Treatment Percentage sharing for any further difference Public Utilities, Earnings Sharing Mechanism, Percentage Sharing For Any Further Difference Public Utilities, Earnings Sharing Mechanism, Percentage Sharing For Any Further Difference Number of defendants Loss Contingency, Number of Defendants Operating lease right-of-use assets Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Income tax credits, net Deferred Tax Assets, Additional Tax Credit Carryforwards, Research Deferred Tax Assets, Additional Tax Credit Carryforwards, Research Short-term Debt, Type [Axis] Short-Term Debt, Type [Axis] Multi-year rate period (in years) Public Utilities, Annual Revenue Adjustment Mechanism, Multi-Year Rate Period Public Utilities, Annual Revenue Adjustment Mechanism, Multi-Year Rate Period Fee income on deposit liabilities Deposit Account [Member] Amortization of prior service credit and net gains recognized during the period in net periodic benefit cost Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member] Subsequent Event Subsequent Event [Member] Amount capitalized Servicing Asset At Amortized Value, Amount Capitalized Servicing Asset At Amortized Value, Amount Capitalized Expenses Costs and Expenses [Abstract] Waena Battery Energy Storage System Project Waena Battery Energy Storage System Project [Member] Waena Battery Energy Storage System Project Unrealized interest rate hedging losses arising during the period, net of taxes of $(291), $(185), $(24) and $(237), respectively Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Granted (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Gain on sale of mortgage loans Gain (Loss) on Sale of Mortgage Loans Weighted-average number of common shares outstanding: Earnings Per Share, Basic, Other Disclosure [Abstract] Segments [Domain] Segments [Domain] Interest and dividend income Interest and Dividend Income, Operating [Abstract] Shares available for future issuance (in shares) Share Based Compensation Arrangement, Number of Shares that could be Issued Upon Vesting of Restricted Stock Units and Long Term Incentive Plans Represents the number of authorized but unissued shares that could be issued under the equity-based compensation plan. Equity and Incentive Plan Equity and Incentive Plan [Member] Represents Equity and Incentive Plan (EIP) as awarded by a company to their employees as a form of incentive compensation. Additional accrued investigation and estimated cleanup costs Reserve For Additional Investigation And Estimated Clean up Costs Represents the amount of additional accrued investigation and estimated cleanup costs. Draw down of debt Proceeds from Lines of Credit Number of share issuable upon vesting and achievement of performance goals (in shares) Share-based Compensation Number of Shares that could be Issued upon Vesting and Achievement of Performance Goals Represents the number of shares that could be issued upon vesting of share-based payment awards and achievement of performance goals. Capitalization Capitalization Stockholder's Equity and Long Term Debt Noncurrent [Abstract] -- None. No documentation exists for this element. -- Interest on deposit liabilities Interest Expense, Deposits Other expense Other Noninterest Expense Taxes, other than income taxes Utilities Operating Expense Other Taxes Discloses the amount of operating expense for the period related to taxes other than income taxes. Interest and fees on loans Interest and Fee Income, Loans and Leases Regulatory liability for O&M expense reductions Public Utility, ERP/EAM Regulatory Liability For Operation And Maintenance Expense Reductions Public Utility, ERP/EAM Regulatory Liability For Operation And Maintenance Expense Reductions Less than 12 months, number of issues Held-To-Maturity Securities, Less Than 12 Months, Number Of Issues Held-To-Maturity Securities, Less Than 12 Months, Number Of Issues Shareholder Derivative Actions, District Of Hawaii Shareholder Derivative Actions, District Of Hawaii [Member] Shareholder Derivative Actions, District Of Hawaii Public utilities in regulatory assets Public Utilities In Regulatory Assets Public Utilities In Regulatory Assets AES Hawaii AES Hawaiian Inc [Member] Represents an independent power producer (IPP) with whom the entity has entered into a power purchase agreement. Local Phone Number Local Phone Number Changes in Carrying Value of MSRs Servicing Asset [Abstract] PCB Contamination PCB Contamination [Member] PCB Contamination [Member] Provision Financing Receivable, Excluding Accrued Interest, Credit Loss Expense (Reversal) Interest expense and other charges, net Interest expense and other charges, net Interest Expense And Other Charges Interest expense and other charges during the period. Four years before current year Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year Residential 1-4 family Residential 1 to 4 Family Portfolio Segment [Member] Portfolio segment of the company's total financing receivables related to residential 1-4 family financing receivables. Changes in assets and liabilities Increase (Decrease) in Operating Capital [Abstract] Long-term Incentive Plan Long-term Incentive Plan [Member] Represents Long-term incentive plan (LTIP) as awarded by a company to their employees as a form of incentive compensation. Increase above target (cancelled) (in shares) Share-based Compensation Arrangement by Share-based Payment Award Equity Instruments Other than Options Increase Above Target in Period (Cancelled) Share-based Compensation Arrangement by Share-based Payment Award Equity Instruments Other than Options Increase Above Target in Period (Cancelled) 25 basis points adverse rate change Sensitivity Analysis Of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 25 Basis Points Adverse Change In Discount Rate Sensitivity Analysis Of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 25 Basis Points Adverse Change In Discount Rate Occupancy Occupancy, Net Litigation settlement, fee expense accrued Litigation Settlement, Fee Expense Accrued Litigation Settlement, Fee Expense Accrued Deferred credits and other liabilities Liabilities, Other than Long-Term Debt, Noncurrent [Abstract] Available-for-sale investment securities, at fair value Available-for-sale investment securities, at fair value Available-for-sale investment securities Debt Securities, Available-for-Sale, Excluding Accrued Interest Unusual or Infrequent Item, or Both [Axis] Unusual or Infrequent Item, or Both [Axis] With a related ACL Financing Receivable, Nonaccrual, With Allowance Financing Receivable, Nonaccrual, With Allowance Fuel oil stock, at average cost Energy Related Inventory Debt Disclosure [Abstract] Debt Disclosure [Abstract] Additional paid-in capital Adjustments to Additional Paid in Capital, Other Common stock Common Stock [Member] Schedule of Condensed Financial Statements [Table] Condensed Financial Statements [Table] Future O&M expense reductions Public Utility, ERP/EAM System, Future Operation And Maintenance Expense Reductions Public Utility, ERP/EAM System, Future Operation And Maintenance Expense Reductions Line of credit facility Line of Credit [Member] Grid Modernization Strategy Phase 1 Project Grid Modernization Strategy Phase 1 Project [Member] Grid Modernization Strategy Phase 1 Project [Member] Segment Reporting [Abstract] Segment Reporting [Abstract] Operating income (loss) Operating Income (Loss) [Abstract] Entity Central Index Key Entity Central Index Key Due in one year or less Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Equity Method Investments and Joint Ventures [Abstract] Allowance for credit losses: Financing Receivable, Allowance for Credit Loss [Roll Forward] Beginning balance Ending balance Off-Balance-Sheet, Credit Loss, Liability Shareholders' equity Equity [Text Block] Financial Instrument [Axis] Financial Instrument [Axis] Segment financial information Segment Reporting Disclosure [Text Block] Current portion of long-term debt, net Current portion of long-term debt Long-Term Debt, Current Maturities Due after one year through five years Debt Securities, Held-to-Maturity, Amortized Cost Excluding Accrued Interest, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year One through Five Services Professional Fees Measurement Basis [Axis] Measurement Basis [Axis] Derivative, gain (loss), statement of income or comprehensive income Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Loans, net Loans Receivable, Fair Value Disclosure Total weighted-average grant-date fair value of shares granted (at target performance levels) (in millions) Share Based Compensation Arrangement by Share Based Payment Award Equity Instruments Other than Options Grants in Period Total Fair Value Represents the total weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). Wildfire tort-related claims Loss Contingency, Loss in Period Schedule of Condensed Consolidating Statement of Comprehensive Income Schedule of Condensed Consolidating Statements of Comprehensive Income [Table Text Block] Tabular disclosure of condensed consolidating comprehensive income. Consolidated Entities [Axis] Consolidated Entities [Axis] City Area Code City Area Code Current liabilities Liabilities, Current [Abstract] Net decrease in short-term borrowings with original maturities of three months or less Net decrease in short-term borrowings from non-affiliates and affiliates with original maturities of three months or less Proceeds from (Repayments of) Short-Term Debt, Maturing in Three Months or Less Utility property, plant and equipment, net Public Utilities, Property, Plant and Equipment, Net COVID-19 COVID-19 [Member] COVID-19 Derivative assets Derivative Asset, Subject to Master Netting Arrangement, before Offset of Collateral [Abstract] Credit agreement, remaining borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Charge-offs Total Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff Long-term debt, net Long-term debt, net Long-Term Debt, Excluding Current Maturities Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Key Assumptions Used in Estimating fair Value Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Bank-owned life insurance Bank Owned Life Insurance Subsequent Event Type [Axis] Subsequent Event Type [Axis] Hawaiian Electric Company, Inc. and Subsidiaries Hawaiian Electric Consolidated Hawaiian Electric Company and Subsidiaries [Member] Represents Hawaiian Electric Company, Inc, and Subsidiaries. Public utilities, project cost recovery cap Public Utilities, Project Cost Recovery Cap Public Utilities, Project Cost Recovery Cap Minimum power volume required (in megawatts) Long-Term Purchase Commitment, Minimum Power Volume Required Long-Term Purchase Commitment, Minimum Power Volume Required Equity [Abstract] Equity [Abstract] Fair value Debt Securities, Available-for-Sale, Fair Value, Fiscal Year Maturity [Abstract] Retained earnings (deficit) Retained Earnings (Accumulated Deficit) Schedule of Reclassification out of AOCI Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Amortization of unrealized holding losses on held-to-maturity securities, net of taxes OCI, Debt Securities, Available-for-Sale, Transfer to Held-to-Maturity, Adjustment from AOCI for Amortization of Gain (Loss), Tax Mortgage-backed securities — issued or guaranteed by U.S. Government agencies or sponsored agencies Debt Securities, Held-to-Maturity, Maturity, without Single Maturity Date, Fair Value Contributions to low income housing investments Payments for Affordable Housing Programs Hawaii Electric Light Company, Inc Hawaii Electric Light Hawaii Electric Light Company, Inc [Member] Hawaii Electric Light Company, Inc [Member] Supplemental Cash Flow Elements [Abstract] Supplemental Cash Flow Elements [Abstract] Additional tax benefit Deferred Income Taxes and Tax Credits Amount agreed to contribute Litigation Settlement, Amount Awarded to Other Party Operating lease liabilities Operating Lease, Liability Residential land Residential Land Portfolio Segment [Member] Portfolio segment of the company's total financing receivables related to residential land receivables. Regulatory assets Regulatory Asset, Current Decrease (increase) in regulatory assets Decrease (increase) in regulatory assets Increase (Decrease) in Other Regulatory Assets Common stock dividends Common stock dividends Dividends, Common Stock, Cash Amendment Flag Amendment Flag Carrying or notional amount Reported Value Measurement [Member] Amortization Servicing Asset at Amortized Cost, Amortization Gross unrealized losses, less than 12 months, number of issues Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions Recovery of deferral costs period (in years) Recovery Of Deferral Costs, CARES Act, Period Recovery Of Deferral Costs, CARES Act, Period Commercial loans Commercial Loan [Member] Servicing Asset at Amortized Cost [Line Items] Servicing Asset at Amortized Cost [Line Items] Increase above target (cancelled) (in dollars per share) Share Based Compensation Arrangement by Share based Payment Award, Equity Instruments Other than Options, Increase Above Target (Cancelled) in Period, Weighted Average Grant Date Fair Value Share Based Compensation Arrangement by Share based Payment Award, Equity Instruments Other than Options, Increase Above Target (Cancelled) in Period, Weighted Average Grant Date Fair Value Recoveries Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery Cash flows Cash Flow, Supplemental Disclosures [Text Block] Substandard Substandard [Member] Due in one year or less Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One Sale of stock, number of shares issued (in shares) Sale of Stock, Number of Shares Issued in Transaction Credit agreements and changes in debt Debt Disclosure [Text Block] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Collateral [Axis] Collateral Held [Axis] Condensed Income Statement [Table] Condensed Income Statement [Table] Condensed Cash Flow Statements, Captions [Line Items] Condensed Cash Flow Statements, Captions [Line Items] Proceeds from issuance of short-term debt Proceeds from Short-Term Debt Entity Address, Postal Zip Code Entity Address, Postal Zip Code Interest rate swap Interest Rate Swap [Member] Minimum benchmark percentage of loan to appraisal ratio which mortgage insurance is required Minimum Benchmark Percentage Of Loan To Appraisal Ratio Which Mortgage Insurance Is Required Represents the minimum benchmark percentage of loan to appraisal ratio which mortgage insurance is required as per the policy of the reporting entity. Long-term Purchase Commitment [Table] Long-Term Purchase Commitment [Table] Number of power purchase agreements (PPAs) (in agreements) Number of Power Purchase Agreements Represents the number of firm power purchase agreements entered into, by the company. Potential total annual maximum reward Public Utilities, Interconnection Approval Performance Incentive Mechanism, Annual Maximum Reward Public Utilities, Interconnection Approval Performance Incentive Mechanism, Annual Maximum Reward Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Other Other Payments for (Proceeds from) Other Investing Activities Provision for credit losses Financing Receivable, Credit Loss, Expense (Reversal) EPRM approved projects Public Utilities, Exceptional Project Recovery Mechanism, Number Of Projects Approved Public Utilities, Exceptional Project Recovery Mechanism, Number Of Projects Approved Forfeited (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Other liabilities Other Liabilities [Abstract] Regulatory Projects and Legal Obligations [Table] Public Utilities General Disclosures [Table] Honolulu Generating Units 8 and 9 Honolulu Generating Units 8 and 9 [Member] Honolulu Generating Units 8 and 9 Accrued expenses Accrued Liabilities Fair Value Measurement [Domain] Fair Value Measurement [Domain] Other-than-temporary impairment Servicing Asset at Amortized Cost, Other than Temporary Impairments Increase in accounts payable Increase (Decrease) in Accounts Payable Bank Subsidiary [Abstract] Bank Subsidiary [Abstract] Bank Subsidiary [Abstract] Environmental Remediation Contingency [Domain] Environmental Remediation Contingency [Domain] Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Public utilities, grid services procurement performance incentive mechanism, accrued estimated rewards Public Utilities, Grid Services Procurement Performance Incentive Mechanism, Accrued Estimated Rewards Public Utilities, Grid Services Procurement Performance Incentive Mechanism, Accrued Estimated Rewards Payments of obligations under finance leases Finance Lease, Principal Payments Other amortization Other amortization Amortization Net income (loss) for common stock Net income (loss) for common stock Net losses incurred Net Income (Loss) Available to Common Stockholders, Basic Interpolated RPS rate goal, year three (in dollars per MWh) Public Utilities, RPS-A Performance Incentive Mechanism, Reward Threshold, Interpolated RPS Rate Goal, Year Three Public Utilities, RPS-A Performance Incentive Mechanism, Reward Threshold, Interpolated RPS Rate Goal, Year Three Purchase of loans held for investment Payment for Acquisition, Loan, Held-for-Investment ERP/EAM project service, savings over 12 years Public Utility, ERP/EAM Required Pass-through Savings Over 12 Years Public Utility, ERP/EAM Required Pass-through Savings Over 12 Years Total assets Total assets Assets Nonutility property, plant and equipment, less accumulated depreciation of $42 and $40 as of September 30, 2024 and December 31, 2023, respectively Nonutility property, plant and equipment, less accumulated depreciation Non-Utilities, Property, Plant And Equipment, Net Non-Utilities, Property, Plant And Equipment, Net Reclassification adjustment for net unrealized losses included in net income, tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax Capital expenditures Payments to Acquire Property, Plant, and Equipment Other Other Liabilities, Noncurrent Number of extension options Line Of Credit Facility, Number Of Extension Options Line Of Credit Facility, Number Of Extension Options Commitments and contingencies (Notes 2, 4 and 5) Commitments and contingencies (Notes 2 and 4) Commitments and Contingencies Weighted average prepayment speed Measurement Input, Prepayment Rate [Member] Net unrealized losses on securities AOCI, Debt Securities, Available-for-Sale, Adjustment, after Tax Climate Adaptation Transmission And Distribution Resilience Program Climate Adaptation Transmission And Distribution Resilience Program [Member] Climate Adaptation Transmission And Distribution Resilience Program Mortgage banking income Mortgage Banking [Member] Advances to affiliates Advances to Affiliate Fair value measurements on a recurring basis Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Without a related ACL Financing Receivable, Nonaccrual, No Allowance Other Total other liabilities Other Liabilities Derivative Financial Instruments Not Designated as Hedging Instruments Not Designated as Hedging Instrument [Member] Other long-term assets Long-Term Investments [Abstract] Amortized cost> 90 days and accruing Financing Receivable, 90 Days or More Past Due, Still Accruing Due after one year through five years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five West Loch PV Project West Loch PV Project [Member] West Loch PV Project [Member] Debt Instrument [Axis] Debt Instrument [Axis] Net income (loss) Net income (loss) Net Income (Loss) Attributable to Parent Noninterest income Revenues from contracts with customers Revenue from Contract with Customer, Including Assessed Tax Schedule of Carrying or Notional Amount, Fair Value and Placement in the Fair Value Hierarchy of the Company’s Financial Instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Two years before current year Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year Accumulated amortization Servicing Asset, Accumulated Amortization Servicing Asset, Accumulated Amortization Gross unrealized gains Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain Total Financing Receivable, Nonaccrual Other sales Other Sales [Member] Other Sales Due after ten years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 10 Waena Switchyard/Synchronous Condenser Project Waena Switchyard/Synchronous Condenser Project [Member] Waena Switchyard/Synchronous Condenser Project Residential construction Residential Construction Portfolio Segment [Member] Portfolio segment of the company's total financing receivables related to residential construction. Preferred stock dividends of subsidiaries Noncontrolling Interest in Net Income (Loss) Preferred Unit Holders, Redeemable Entity File Number Entity File Number Federal Reserve Bank Advances Federal Reserve Bank Advances [Member] Insurance recoveries Insurance recovery Insurance Recoveries Consolidated Entities [Domain] Consolidated Entities [Domain] Income Statement [Abstract] Income Statement [Abstract] Entity Address, Address Line One Entity Address, Address Line One Entity Address, Address Line Two Entity Address, Address Line Two Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Home equity line of credit Home Equity Loan [Member] Mortgage-backed securities — issued or guaranteed by U.S. Government agencies or sponsored agencies Debt Securities, Available-for-Sale, Maturity, without Single Maturity Date, Fair Value Total Maui windstorm and wildfires related expenses, net of insurance recoveries and approved deferral treatment Loss Contingencies, Net Of Recoveries And Reclassifications Of Payments Loss Contingencies, Net Of Recoveries And Reclassifications Of Payments Dividend reinvestment and stock purchase plan (in shares) Stock Issued During Period, Shares, Dividend Reinvestment Plan And Employee Stock Purchase Plans Stock Issued During Period, Shares, Dividend Reinvestment Plan And Employee Stock Purchase Plans Timing of Transfer of Good or Service [Domain] Timing of Transfer of Good or Service [Domain] Estimated fair value of financial instruments Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Proceeds from repayments or maturities of held-to-maturity investment securities Proceeds from Sale and Maturity of Held-to-Maturity Securities Extension period Line Of Credit Facility, Extension Period Line Of Credit Facility, Extension Period Share-based expenses and other, net Stock Issued During Period Value Expenses And Other, Net Stock Issued During Period Value Expenses And Other, Net Document Quarterly Report Document Quarterly Report Financial liabilities Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Reclassification adjustment to net income, net of taxes of $(18), $(17), $(52) and $(50), respectively Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Consumer Consumer Portfolio Segment [Member] Due after one year through five years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five Litigation Case [Domain] Litigation Case [Domain] Schedule of Loan Modification Financing Receivable, Modified [Table Text Block] Accumulated other comprehensive loss, net of tax benefits Accumulated other comprehensive income, net of taxes-retirement benefit plans Accumulated other comprehensive loss, net of tax benefits Accumulated Other Comprehensive Income (Loss), Net of Tax Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Restricted cash Less: Restricted cash Restricted Cash and Cash Equivalents Advances from the FHLB Advance from Federal Home Loan Bank Discount rate Litigation Settlement, Discount Rate Litigation Settlement, Discount Rate Proceeds from sale of residential loans Proceeds from Sale, Loan, Mortgage, Held-for-Sale Related Party, Type [Axis] Related and Nonrelated Parties [Axis] Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Net unrealized gains (losses) on available-for-sale investment securities arising during the period, tax OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, Tax Contributions expected to be paid in current year Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year Net 2025 ARA revenues Public Utilities, Annual Revenue Adjustment, Net Incremental Revenues Public Utilities, Annual Revenue Adjustment, Net Incremental Revenues Total contracted battery energy storage system capacity Long-term Contract For Purchase Of Electric Power, Total Contracted Battery Energy Storage System Capacity Long-term Contract For Purchase Of Electric Power, Total Contracted Battery Energy Storage System Capacity Net decrease in other bank borrowings with original maturities of three months or less Proceeds From (Payments For) Other Bank Borrowings The amount of cash inflows/outflows resulting from other bank borrowings. Gross unrealized losses, less than 12 months, amount Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Entity Filer Category Entity Filer Category Provision Off-Balance-Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal) Loss Contingencies [Line Items] Loss Contingencies [Line Items] Condensed Balance Sheet Statement [Table] Condensed Balance Sheet Statement [Table] Electric utility segment Electric Utility Subsidiary [Text Block] Electric Utility Subsidiary Total contracted PV capacity (in megawatts) Long-term Contract For Purchase Of Electric Power, Total Contracted PV Capacity Long-term Contract For Purchase Of Electric Power, Total Contracted PV Capacity Committed contribution to humanitarian fund Humanitarian Aid Fund, Committed Contribution Humanitarian Aid Fund, Committed Contribution Condensed Balance Sheet Statements, Captions [Line Items] Condensed Balance Sheet Statements, Captions [Line Items] Gross unrealized losses Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Charge offs three years prior of origination year Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff Weighted-average grant-date fair value per share Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract] Schedule of Credit Risk Profile Based on Payment Activity for Loans Financing Receivable, Past Due [Table Text Block] Loan Restructuring Modification [Axis] Loan Restructuring Modification [Axis] Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Other Other Liabilities, Current Provision Valuation Allowance for Impairment of Recognized Servicing Assets, Additions (Deductions) for Expenses (Recoveries) Schedule of Notional and Fair Value of Derivatives Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Segment financial information Segment Reporting Information [Line Items] 25 basis points adverse rate change Sensitivity Analysis Of Fair Value, Transferor's Interests In Transferred Financial Assets, Impact Of 25 Basis Point Adverse Change In Prepayment Speed The hypothetical financial impact of a 25 basis point adverse change of prepayment speed on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date. Variable Interest Entity, Primary Beneficiary Variable Interest Entity, Primary Beneficiary [Member] Major Vendor [Domain] Major Vendor [Domain] Name and description of the vendor that account for major purchases of the entity. Derivative instrument Derivative [Line Items] Schedule of Share-Based Compensation Expense and Related Income Tax Benefit Share-Based Payment Arrangement, Cost by Plan [Table Text Block] Environmental loss contingency, statement of financial position, not disclosed Environmental Loss Contingency, Statement Of Financial Position, Extensible Enumeration, Not Disclosed Flag Environmental Loss Contingency, Statement Of Financial Position, Extensible Enumeration, Not Disclosed Flag Derivative [Table] Derivative [Table] Income Tax Contingency [Table] Income Tax Contingency [Table] LTIP linked to TRS Long-term Incentive Plan Linked to Total Return to Shareholders [Member] Represents Long-term incentive plan (LTIP) as awarded by a company to their employees based on total return to shareholders (TRS). Incremental expenses Unusual or Infrequent Item, or Both, Loss, Gross Liability derivatives Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral Increase in regulatory liabilities Increase in regulatory liabilities Increase (Decrease) in Regulatory Liabilities Change in other assets and liabilities Increase (Decrease) in Other Operating Assets and Liabilities, Net Failure to meet RPS targets, penalty rate (in dollars per MWh) Public Utilities, RPS-A Performance Incentive Mechanism, Failure To Meet RPS Targets, Penalty Rate Public Utilities, RPS-A Performance Incentive Mechanism, Failure To Meet RPS Targets, Penalty Rate American Savings Bank (ASB) American Savings Bank FSB [Member] American Savings Bank FSB Schofield Generation Station Schofield Generation Station [Member] Schofield Generation Station [Member] Nonemployee Director Stock Plan Nonemployee Director Stock Plan [Member] Nonemployee Director Stock Plan [Member] Fees from other financial services Financial Service [Member] Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Net periodic pension/benefit cost (return) (adjusted for impact of PUC D&Os) Defined Benefit Plan, Net Periodic Benefit Cost Adjusted for Impact of Public Utilities Commission Decisions and Orders Represents the total amount of net periodic benefit cost adjusted for impact of Public Utilities Commission's decisions and orders. Pass Pass [Member] Shares available for future grant (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Operating lease liabilities Operating lease liabilities Operating Lease, Liability, Noncurrent Fair Value Measurement Inputs and Valuation Techniques [Line Items] Fair Value Measurement Inputs and Valuation Techniques [Line Items] Accrued interest receivable Interest Receivable Other Product and Service, Other [Member] Electric energy sales - other Electric Energy Sales, Other [Member] Electric Energy Sales, Other [Member] Number of kilovolts Number Of Kilovolts Number Of Kilovolts Wildfire tort-related claims Loss From Catastrophes, Wildfire Tort-Related Claims [Member] Loss From Catastrophes, Wildfire Tort-Related Claims Service cost Defined Benefit Plan, Service Cost Entity Tax Identification Number Entity Tax Identification Number Waiawa UFLS Project Waiawa UFLS Project [Member] Waiawa UFLS Project Retirement Plan Type [Axis] Retirement Plan Type [Axis] Collateral pledged Collateral Pledged [Member] Held-to-maturity Held-to-Maturity, Debt Securities, Amortized Cost [Abstract] Held-to-Maturity, Debt Securities, Amortized Cost [Abstract] Service reliability, estimated penalties Public Utility, Decoupling Order, Performance Incentive Mechanism, Service Reliability, Estimated Penalties Public Utility, Decoupling Order, Performance Incentive Mechanism, Service Reliability, Estimated Penalties Sale of stock, received on transaction Sale of Stock, Consideration Received on Transaction Maui windstorm and wildfires Unusual or Infrequent Items, or Both, Disclosure [Text Block] Schedule of Derivative Financial Instruments Schedule of Derivative Instruments [Table Text Block] Taxes accrued, including revenue taxes Taxes accrued, including revenue taxes Taxes Payable, Current Impact of PUC D&Os Defined Benefit Plan, Impact of Public Utilities Commission Decisions and Orders Represents the impact of Public Utilities Commission's decisions and orders on net periodic benefit cost. Plan Name [Axis] Plan Name [Axis] Land Public Utilities, Property, Plant and Equipment, Land Equity Components [Axis] Equity Components [Axis] Renewable energy generation project, approved funds Public Utilities, Renewable Energy Generation Project, Approved Funds Public Utilities, Renewable Energy Generation Project, Approved Funds Adjustments to fair value of loans held for sale Loans Receivable Held for Sale Amount Fair Value Adjustments Represents the amount of fair value adjustments in loans held for sale. Change in prepaid and accrued income taxes, tax credits and utility revenue taxes Change in prepaid and accrued income taxes, tax credits and revenue taxes Increase (Decrease) in Prepaid and Accrued Income Taxes and Utility Revenue, Taxes The net changes in cash flows resulting from changes in prepaid and accrued income taxes and utility revenue taxes. Low-income housing investments Equity Investments, Affordable Housing Program Equity Investments, Affordable Housing Program Insurance Claims, Legal-Related Recoveries Insurance Claims, Legal-Related Recoveries [Member] Insurance Claims, Legal-Related Recoveries Beginning balance Ending balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Total expenses Total expenses Costs and Expenses Regulatory Projects and Legal Obligations [Table] Regulatory Projects and Legal Obligations [Table] Discloses the components of regulatory projects and legal obligations. Supplemental disclosures of noncash activities Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Net incremental amount to be collected under the RBA rate tariffs Public Utility, Net Receivable Under Tariff Public Utility, Net Receivable Under Tariff Credit risk profile by internally assigned grade for loans Financing Receivable, Credit Quality Indicator [Line Items] Wildfire tort-related claims (Note 2) Settlement accrual, current liability Loss Contingency, Accrual, Current Residential loan Residential Mortgage [Member] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Wildfire tort-related claims Settlement accrual Loss Contingency Accrual Total amortized cost Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date Accrued interest Financing Receivable, Allowance for Credit Loss, Writeoff Cash, cash equivalents and restricted cash, beginning of period Cash, cash equivalents and restricted cash, end of period Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Annual payment Long-term Contract For Purchase Of Electric Power, Total Annual Payment Long-term Contract For Purchase Of Electric Power, Total Annual Payment Unrecognized share based compensation Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Held-to-maturity Held-to-maturity Securities, Debt Securities, Fair Value [Abstract] Held-to-maturity Securities, Debt Securities, Fair Value [Abstract] Current assets Assets, Current [Abstract] Bank-owned life insurance Bank Owned Life Insurance Income [Member] Bank Owned Life Insurance Income [Member] Consolidation Items [Axis] Consolidation Items [Axis] Pending adjusted amount Public Utility, Decoupling Order, Performance Incentive Mechanism, Generation-Caused System Average Interruption, Maximum Penalty, Pending Adjusted Amount Public Utility, Decoupling Order, Performance Incentive Mechanism, Generation-Caused System Average Interruption, Maximum Penalty, Pending Adjusted Amount Shareholder Derivative Actions, Northern District Of California Shareholder Derivative Actions, Northern District Of California [Member] Shareholder Derivative Actions, Northern District Of California Legal expenses Loss From Catastrophes, Legal Expenses [Member] Loss From Catastrophes, Legal Expenses Product and Service [Domain] Product and Service [Domain] Vested (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Incremental PIMs (net) Public Utilities, Decoupling Filing, Performance Incentive Mechanism, Net Public Utilities, Decoupling Filing, Performance Incentive Mechanism, Net Due after five years through ten years Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Prepayment rate: Fair Value Inputs, Prepayment Rate [Abstract] Fair Value Inputs, Prepayment Rate [Abstract] Name of each exchange on which registered Security Exchange Name Financing Receivable, Credit Quality Indicator [Table] Financing Receivable, Credit Quality Indicator [Table] Automatic extension expiration period Line Of Credit Facility, Automatic Extension Expiration Period Line Of Credit Facility, Automatic Extension Expiration Period Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Member] Potential total annual maximum reward Public Utilities, Advanced Metering Infrastructure Utilization Performance Incentive Mechanism, Annual Maximum Reward Public Utilities, Advanced Metering Infrastructure Utilization Performance Incentive Mechanism, Annual Maximum Reward Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Expected payments for remainder of fiscal year Defined Benefit Plan, Expected Future Benefit Payment, Remainder of Fiscal Year Commercial real estate Commercial Real Estate Portfolio Segment [Member] Hawaiian Electric, Parent Hawaiian Electric, Parent [Member] Hawaiian Electric, Parent [Member] Compensation and employee benefits Labor and Related Expense Short-term borrowings Short-Term Debt Less than 12 months, amount Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Stock in Federal Home Loan Bank Investment in Federal Home Loan Bank Stock, Fair Value Disclosure Schedule of the Book Value and Aggregate Fair Value by Major Security Type Debt Securities, Available-for-Sale [Table Text Block] Fair value measurements on a nonrecurring basis Fair Value, Nonrecurring [Member] Right-of-use assets obtained in exchange for finance lease obligations (financing) Right-of-Use Asset Obtained in Exchange for Finance Lease Liability Gain on sale of real estate Less: Gain on sale of real estate Gain (Loss) on Sale of Properties Common stock, shares issued (in shares) Beginning balance (in shares) Ending balance (in shares) Common Stock, Shares, Issued Provision for credit losses Off-Balance Sheet And Financing Receivable, Credit Loss, Liability, Credit Loss Expense (Reversal) Off-Balance Sheet And Financing Receivable, Credit Loss, Liability, Credit Loss Expense (Reversal) Entity [Domain] Entity [Domain] Credit agreement Line of Credit Facility, Maximum Borrowing Capacity Wind IPPs Wind Independent Power Producers [Member] Wind Independent Power Producers [Member] Approved return on equity, percentage Public Utilities, Approved Return on Equity, Percentage Directors and officers liability insurance Loss Contingency, Directors And Officers Liability Insurance Loss Contingency, Directors And Officers Liability Insurance Gross carrying amount Servicing Asset Gross unrealized losses, 12 months or more, amount Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss Charge offs two years prior of origination year Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff Schedule of Allowance for Credit Losses Financing Receivable, Current, Allowance for Credit Loss [Table Text Block] Derivative liabilities Derivative Liability Schedule of Long-Term Incentive Plan (LTIP) Linked to Total Return to Shareholders Schedule of Share Based Compensation, Long term Incentive Plan Linked to Total Return to Shareholders [Table Text Block] Schedule of Share Based Compensation, Long term Incentive Plan Linked to Total Return to Shareholders Number of mortgage loans repurchased Number Of Mortgage Loans Repurchased Number Of Mortgage Loans Repurchased Combination payment delay & term extension Combination Payment Delay And Term Extension [Member] Combination Payment Delay And Term Extension Interest on other borrowings Interest Expense, Borrowings Property, plant and equipment, accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Accounts receivable and unbilled revenues, net Accounts Receivable, after Allowance for Credit Loss Public utilities retained percentage Public Utilities, Retained Percentage Of Savings Public Utilities, Retained Percentage Of Savings Investment securities Debt Securities, Trading, and Equity Securities, FV-NI [Abstract] Common stock, authorized shares (in shares) Common Stock, Shares Authorized Total Total Total financing receivables Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process Consolidating adjustments Consolidation, Eliminations [Member] LTIP awards linked to other performance conditions Long-term Incentive Plan Awards Linked to Other Performance Conditions [Member] Represents Long-term incentive plan (LTIP) as awarded by a company to their employees based on other performance conditions. Other comprehensive income (loss), net of taxes: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Unpaid principal balance Fair Value Inputs, Unpaid Principal Balance, Asset Fair Value Inputs, Unpaid Principal Balance, Asset Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Schedule of Supplemental Disclosures of Cash and Noncash Activity Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Amortization of net actuarial (gain)/losses Defined Benefit Plan, Amortization of Gain (Loss) Hedging Designation [Domain] Hedging Designation [Domain] Servicing contracts Servicing Contracts [Member] Deferred income tax benefit Deferred income tax benefit Deferred Income Tax Expense (Benefit) Retirement benefits expense Pension and Other Postretirement Benefits Cost (Reversal of Cost) Other comprehensive income (loss), net of taxes Other comprehensive income (loss), net of tax benefits Other comprehensive loss, net of taxes Current period other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Fair value measurements on a recurring basis Fair Value, Recurring [Member] Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] Customer accounts receivable, net Accounts Receivable, after Allowance for Credit Loss, Current Proceeds from issuance of other bank borrowings Proceeds from Other Debt Gross unrealized losses, 12 months or longer, fair value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer Dividend reinvestment and stock purchase plan Stock Issued During Period, Value, Dividend Reinvestment Plan And Employee Stock Purchase Plans Stock Issued During Period, Value, Dividend Reinvestment Plan And Employee Stock Purchase Plans Discount rate: Fair Value Inputs, Discount Rate [Abstract] Fair Value Inputs, Discount Rate [Abstract] Impairment charges Asset Impairment Charges Long-term debt, net—other than bank Long-Term Debt Unrealized interest rate hedging arising during the period, tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax Loans held for investment Collateral-dependent loans, amortized cost Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss Mortgage-backed securities — issued or guaranteed by U.S. Government agencies or sponsored agencies Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, without Single Maturity Date Held-to-maturity Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss [Abstract] 50 basis points adverse rate change Sensitivity Analysis Of Fair Value, Transferor's Interests In Transferred Financial Assets, Impact Of 50 Basis Point Adverse Change On Prepayment Speed Sensitivity Analysis Of Fair Value, Transferor's Interests In Transferred Financial Assets, Impact Of 50 Basis Point Adverse Change On Prepayment Speed Investment in wholly owned subsidiaries, at equity Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Weighted average note rate Measurement Input, Note Interest Rate [Member] Measurement Input, Note Interest Rate [Member] Earnings sharing mechanism, actual return on equity, dead band percentage above or below target Public Utilities, Earnings Sharing Mechanism, Actual Return On Equity, Dead Band Percentage Above Or Below Target Public Utilities, Earnings Sharing Mechanism, Actual Return On Equity, Dead Band Percentage Above Or Below Target Vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Schedule of Condensed Consolidating Balance Sheet Schedule of Balance Sheets Data Condensed Balance Sheet [Table Text Block] Risk-free interest rate Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Interest paid to non-affiliates, net of amounts capitalized Interest Paid to Non Affiliates The amount of cash paid for interest of non-affiliates during the period. Common stock, no par value (in dollars per share) Common Stock, No Par Value Project [Axis] Project [Axis] Liabilities Liabilities [Abstract] Revenues Revenues [Abstract] Preferred stock dividends of subsidiaries Preferred stock dividends of Hawaiian Electric Preferred Stock Dividends, Income Statement Impact 12 months or longer: fair value Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value Fair value measurements Fair Value Measurement, Policy [Policy Text Block] Unamortized tax credits Unamortized tax credits Accumulated Deferred Investment Tax Credit Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes of $462, $163, $781 and $458, respectively Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes Other Comprehensive Income, Reclassification Adjustment for Impact of Decision and Orders of the P U C Included in Regulatory Assets, Net of Tax Reclassification adjustments on pension and post retirement benefits for the accounting impact of the decisions issued by the Public Utilities Commission, net of income taxes. Current Fiscal Year End Date Current Fiscal Year End Date Interest rate lock commitments Interest Rate Lock Commitments [Member] Credit Facilities Credit Facilities [Member] Credit Facilities Retirement benefit plans Accumulated Other Comprehensive Income (Loss) Defined Benefit Pension and Other Postretirement Plans Net of Tax Adjusted for Regulatory Impacts The total of net (gain) loss, prior service cost (credit), and transition assets (obligations), as well as minimum pension liability if still remaining, included in accumulated other comprehensive income associated with a defined benefit pension or other postretirement plan(s) because they have yet to be recognized as components of net periodic benefit cost. This amount is adjusted for regulatory rate making impacts. Regulatory Asset [Domain] Regulatory Asset [Domain] Other income, net Other Income, Net [Member] Other Income, Net [Member] Stock in Federal Home Loan Bank, at cost Federal Home Loan Bank Stock Shares granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period Award Type [Domain] Award Type [Domain] Loan Restructuring Modification [Domain] Loan Restructuring Modification [Domain] Other Other Sundry Liabilities Services/goods transferred over time Transferred over Time [Member] Deferred tax asset Deferred Income Tax Assets, Net Defined benefit pension liability Defined benefit pension and other postretirement benefit plans liability Liability, Defined Benefit Plan, Noncurrent Regulatory liabilities Regulatory liabilities Regulatory Liability, Noncurrent Premium on capital stock Additional Paid-in Capital [Member] Equipment Equipment Expense Number of extended transmission lines Public Utilities, Renewable Energy Generation Project, Number Of Extended Transmission Lines Public Utilities, Renewable Energy Generation Project, Number Of Extended Transmission Lines Finance lease liabilities Finance lease liabilities Finance Lease, Liability, Noncurrent Natural Disasters and Other Casualty Events Natural Disasters and Other Casualty Events [Member] Schedule of Components of Loans Receivable Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Decrease (increase) in accrued unbilled revenues Increase (Decrease) in Contract with Customer, Asset Retirement benefits Retirement Benefits [Text Block] Target deadband period (in months) Public Utility, Decoupling Order, Performance Incentive Mechanism, Generation-Caused System Average Interruption, Target Deadband Period Public Utility, Decoupling Order, Performance Incentive Mechanism, Generation-Caused System Average Interruption, Target Deadband Period 50 basis points adverse rate change Sensitivity Analysis Of Fair Value, Transferor's Interests In Transferred Financial Assets, Impact Of 50 Basis Points Adverse Change In Discount Rate Sensitivity Analysis Of Fair Value, Transferor's Interests In Transferred Financial Assets, Impact Of 50 Basis Points Adverse Change In Discount Rate Charge offs four years prior of origination year Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff Molokai New Energy Partners Molokai New Energy Partners [Member] Molokai New Energy Partners Recent accounting pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Accrued unbilled revenues, net Unbilled Receivables, Current Total Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount Notice period, pre-cursor to citizen's suit Notice Period, Pre-Cursor To Citizen's Suit Notice Period, Pre-Cursor To Citizen's Suit James Campbell Company James Campbell Company [Member] James Campbell Company Number of incentive earned power purchase agreements Number Of Incentive Earned Power Purchase Agreements Number Of Incentive Earned Power Purchase Agreements Service reliability, pending adjusted maximum penalty amount Public Utility, Decoupling Order, Performance Incentive Mechanism, Service Reliability, Maximum Penalty, Pending Adjusted Amount Public Utility, Decoupling Order, Performance Incentive Mechanism, Service Reliability, Maximum Penalty, Pending Adjusted Amount Entity Interactive Data Current Entity Interactive Data Current Advanced (to) from affiliates Proceeds From (Payments For) Contributions From Affiliates Proceeds From (Payments For) Contributions From Affiliates Income taxes paid (including refundable credits) Income Taxes Paid Interpolated RPS rate goal, year one and two (in dollars per MWh) Public Utilities, RPS-A Performance Incentive Mechanism, Reward Threshold, Interpolated RPS Rate Goal, Year One And Two Public Utilities, RPS-A Performance Incentive Mechanism, Reward Threshold, Interpolated RPS Rate Goal, Year One And Two Retirement benefit plans: Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent [Abstract] Schedule of Assets Measured at Fair Value on a Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Electric utility subsidiary [Abstract] Electric Utility Subsidiary [Abstract] Electric utility subsidiary [Abstract] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Net unrealized gains (losses) on available-for-sale investment securities: Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent [Abstract] Allowance for loan commitments: Off-Balance-Sheet, Credit Loss, Liability [Roll Forward] Share-based compensation expense Share-Based Payment Arrangement, Noncash Expense Bank segment Bank Subsidiary [Text Block] This element encapsulates disclosures pertaining to banking subsidiary. Retirement benefit plans Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Net decrease (increase) in loans held for investment Payments for (Proceeds from) Loans Receivable Supplemental disclosures of cash flow information Supplemental Cash Flow Information [Abstract] Real estate Real Estate Portfolio Segment [Member] Real Estate Portfolio Segment Total noninterest income Noninterest income Noninterest Income Schedule of Derivative Financial Instruments and Net Gain or Loss Derivative Instruments, Gain (Loss) [Table Text Block] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Net carrying amount Servicing Asset, Net Servicing Asset, Net Decrease (increase) in materials and supplies Increase (Decrease) in Raw Materials, Packaging Materials and Supplies Inventories Stage 1 And 2 Renewable PPAs Stage 1 And 2 Renewable PPAs [Member] Stage 1 And 2 Renewable PPAs Effective income tax, percent Effective Income Tax Rate Reconciliation, Percent Schedule of Credit Risk Profile by Internally Assigned Grade for Loans Financing Receivable Credit Quality Indicators [Table Text Block] Total operating income (loss) Operating income - bank Operating Income (Loss) Redemption of stock from Federal Home Loan Bank Proceeds from Sale of Federal Home Loan Bank Stock Deposit liabilities Deposits Performance incentive mechanism, maximum reward Public Utilities, Low-to-Moderate Income Energy Efficiency Performance Incentive Mechanism, Maximum Reward Public Utilities, Low-to-Moderate Income Energy Efficiency Performance Incentive Mechanism, Maximum Reward Total liabilities and shareholders’ equity Liabilities and Equity Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Number of deferred payments Line Of Credit, Number Of Deferred Periodic Payments Line Of Credit, Number Of Deferred Periodic Payments Hedging Designation [Axis] Hedging Designation [Axis] Future cost avoidance related to capital cost and tax costs Public Utility, ERP/EAM System, Future Cost Avoidance Related To Capital Cost And Tax Cost Public Utility, ERP/EAM System, Future Cost Avoidance Related To Capital Cost And Tax Cost Commercial real estate Commercial Real Estate [Member] Interest income Investment Income, Interest Right-of-use assets obtained in exchange for operating lease obligations (investing) Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Award performance period (in years) Share-based Compensation Arrangement by Share-based Payment Award, Award Performance Period Share-based Compensation Arrangement by Share-based Payment Award, Award Performance Period Measurement Input Type [Axis] Measurement Input Type [Axis] Construction in progress Public Utilities, Property, Plant and Equipment, Construction Work in Progress Plant and equipment Public Utilities Property Plant and Equipment Transmission Distribution Generation and Other Period end amount of property, plant and equipment (PPE) related to transmission, distribution, generation and other owned by public utility. Obligations to fund low income housing investments (investing) Affordable Housing Program Assessments Accumulated other comprehensive income (loss) AOCI AOCI Attributable to Parent [Member] Expected life in years Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term Product and Service [Axis] Product and Service [Axis] Statement [Line Items] Statement [Line Items] Measurement Input Type [Domain] Measurement Input Type [Domain] MPIR and EPRM requested amount Public Utilities, Solar Project, Major Project Interim Recovery And Exceptional Project Recovery Mechanism Requested Amount Public Utilities, Solar Project, Major Project Interim Recovery And Exceptional Project Recovery Mechanism Requested Amount Maui Windstorm and Wildfires Loss from Catastrophes [Member] Schedule of Changes in Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Condensed Cash Flow Statement [Table] Condensed Cash Flow Statement [Table] Fee income on other financial products Financial Service, Other [Member] Reportable Legal Entities Reportable Legal Entities [Member] Maui Wildfire Negligence Maui Wildfire Negligence [Member] Maui Wildfire Negligence Financing Receivable, Modified [Line Items] Financing Receivable, Modified [Line Items] Due after five years through ten years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Number of generating units converting to synchronous condensers Public Utilities, Renewable Energy Generation Project, Number Of Generating Units Converting To Synchronous Condensers Public Utilities, Renewable Energy Generation Project, Number Of Generating Units Converting To Synchronous Condensers Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Bad debt expense Accounts Receivable, Credit Loss Expense (Reversal) Residential real estate property Residential Real Estate [Member] Segments [Axis] Segments [Axis] Tax Period [Axis] Tax Period [Axis] 12 months or longer, number of issues Held-To-Maturity Securities, More Than 12 Months, Number Of Issues Held-To-Maturity Securities, More Than 12 Months, Number Of Issues Regulatory asset amortization period Regulatory Asset, Amortization Period Derivative Instrument [Axis] Derivative Instrument [Axis] Home equity line of credit Home Equity Line of Credit [Member] Condensed Statement of Comprehensive Income [Table] Condensed Statement of Comprehensive Income [Table] Schedule of Statements of Comprehensive Income Data Comprehensive Income (Loss) [Table Text Block] Performance incentive mechanism, accrued award Public Utilities, Low-to-Moderate Income Energy Efficiency Performance Incentive Mechanism, Accrued Award Public Utilities, Low-to-Moderate Income Energy Efficiency Performance Incentive Mechanism, Accrued Award PUC proposal period (in days) Public Utilities Pilot Process Proposal Period Public Utilities Pilot Process Proposal Period Power purchase agreement Power Purchase Agreement [Abstract] -- None. No documentation exists for this element. -- Schedule of Variable Interest Entities [Table] Variable Interest Entity [Table] Shareholders’ equity Equity, Attributable to Parent [Abstract] Gross unrealized losses, less than 12 months, fair value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months Hawaiian Electric Company Subsidiaries [Member] Noninterest income Noninterest Income [Abstract] Derivative asset, statement of financial position Derivative Asset, Statement of Financial Position [Extensible Enumeration] Adjustment for amortization of prior service credit and net gains recognized during the period in net periodic benefit cost, net of taxes of $(431), $(153), $(740) and $(397), respectively Adjustment for amortization of prior service credit and net gains recognized during the period in net periodic benefit cost, net of taxes of $(462), $(190), $(813) and $(516), respectively Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit) Recognized In Net Periodic Benefit Cost, Reclassification Adjustment From AOCI, Net Of Tax Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit) Recognized In Net Periodic Benefit Cost, Reclassification Adjustment From AOCI, Net Of Tax Term extension Extended Maturity [Member] Condensed Statement of Income Captions [Line Items] Condensed Statement of Income Captions [Line Items] Finance lease liabilities Finance Lease, Liability Gross unrealized losses Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Entities [Table] Entities [Table] Loans held for investment, net Loans held for investment, net Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss Other benefits Other Postretirement Benefits Plan [Member] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Hamakua Energy Hamakua Energy, LLC [Member] Represents an independent power producer (IPP) with whom the entity has entered into a power purchase agreement. Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table Text Block] Number of financial institutions with extended termination date Number Of Financial Institutions With Extended Termination Date Number Of Financial Institutions With Extended Termination Date Gross unrealized gains Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax State refundable credit State Refundable Credit State Refundable Credit Data processing Information Technology and Data Processing Other operation and maintenance Utilities Operating Expense, Maintenance and Operations Other Interest rate swap (Other segment) Other Operating Segment [Member] Allowance for equity funds used during construction Allowance for equity funds used during construction Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity Related Party, Type [Domain] Related and Nonrelated Parties [Domain] Cashier’s checks Cashier Checks Cashier's check is a check drawn directly on a customer's account, making the bank the primary obligor, and assuring firm that the amount will be paid. Maui Electric Maui Electric Company Limited [Member] Maui Electric Company Limited [Member] Financing Receivable, Modified [Table] Financing Receivable, Modified [Table] Number of performance incentive mechanisms Public Utilities, Number Of Performance Incentive Mechanisms Public Utilities, Number Of Performance Incentive Mechanisms Long-term Purchase Commitment [Line Items] Long-Term Purchase Commitment [Line Items] Mortgage servicing rights SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward] Customer dividend, negative adjustment percentage Public Utilities, Customer Dividend, Negative Adjustment Percentage Public Utilities, Customer Dividend, Negative Adjustment Percentage Other bank noninterest income Other Bank Noninterest Income [Member] Other Bank Noninterest Income [Member] Schedule of Long-Term Incentive Plan (LTIP) Linked to Other Performance Conditions Schedule of Share Based Compensation, Long term Incentive Plan Linked to Other Performance Conditions Activity [Table Text Block] Tabular disclosure of the number and weighted-average grant date fair value of shares that were outstanding at the beginning and end of the year, and the number of Long-Term Incentive Plan awards that were granted, vested, or forfeited during the year that were linked to other performance conditions. Deferred income taxes Deferred income taxes Deferred Income Tax Liabilities, Net Loans originated, held for sale Payment for Origination and Purchase, Loan, Held-for-Sale Expected volatility Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate Schedule of Restricted Stock Units Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block] Kapolei Petroleum Contamination Kapolei Petroleum Contamination [Member] Kapolei Petroleum Contamination Allowance for borrowed funds used during construction Interest Costs Capitalized Adjustment Kalaeloa Kalaeloa Partners L P [Member] Represents an independent power producer (IPP) with whom the entity has entered into a power purchase agreement. Property insurance policy limit Loss Contingency, Property Insurance Policy Limit Loss Contingency, Property Insurance Policy Limit Preferred stock, authorized shares (in shares) Preferred Stock, Shares Authorized Share-based expenses and other, net and Common stock offering (in shares) Stock Issued During Period, Shares, New Issues Gross unrealized losses, 12 months or longer, number of issues Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions Public utilities, modified pilot process proposal period (in days) Public Utilities, Modified Pilot Process Proposal Period Public Utilities, Modified Pilot Process Proposal Period Entity Emerging Growth Company Entity Emerging Growth Company Bank Banking Segment [Member] Represents information about the banking business segment of the company. Increase in accounts, interest and dividends payable Increase (Decrease) in Accounts Payable and Interest and Dividends Payable The increase (decrease) during the reporting period in accounts, interest and dividends payable. Prior year deferred cost recovery approved Public Utilities, Pilot Update, Prior Year Deferred Cost Recovery Approved Public Utilities, Pilot Update, Prior Year Deferred Cost Recovery Approved Range of expected volatility for Peer Group, minimum rate Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum Number of years for which regulatory asset/liability for each utility will be amortized, beginning with respective utility's next rate case (in years) Defined Benefit Plan, Number of Years Regulatory Assets or Liability will be Amortized for Each Utility which Start from Respective Utilities Next Rate Case Represents the number of years for which regulatory asset/liability for each utilities will be amortized, beginning with the respective utility's next rate case. Solar IPPs Solar Independent Power Producer [Member] Solar Independent Power Producer [Member] Equity Component [Domain] Equity Component [Domain] Net interest income after provision for credit losses Interest Income (Expense), after Provision for Loan Loss Interest and dividend income Interest and dividend income Interest and Dividend Income, Operating Derivatives qualifying as cash flow hedges: Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent [Abstract] Entity Shell Company Entity Shell Company Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Valuation allowance for mortgage servicing rights Valuation Allowance for Impairment of Recognized Servicing Assets [Roll Forward] Dead band percentage above or below the target Public Utility, Decoupling Order, Performance Incentive Mechanism, Call Center Performance, Dead Band Percentage Above Or Below Target Public Utility, Decoupling Order, Performance Incentive Mechanism, Call Center Performance, Dead Band Percentage Above Or Below Target 30-59 days past due 30-59 days past due Financial Asset, 30 to 59 Days Past Due [Member] Wildfire tort-related claims (Note 2) Settlement accrual, non-current liabilities Loss Contingency, Accrual, Noncurrent Statement [Table] Statement [Table] Major Vendor [Axis] Major Vendor [Axis] Vendor that is considered major by the entity. Electric energy sales - residential Electric Energy Sales, Residential [Member] Electric Energy Sales, Residential [Member] Measurement Frequency [Domain] Measurement Frequency [Domain] Counterparty Name [Axis] Counterparty Name [Axis] Schedule of Purchases From All IPPs Schedule of Variable Interest Entities [Table Text Block] Consolidation Items [Domain] Consolidation Items [Domain] Charge offs current fiscal year of origination Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year, Writeoff Accumulated depreciation on other property, plant and equipment Property, Plant and Equipment, Other, Accumulated Depreciation Schedule of Condensed Consolidating Statement of Changes in Common Stock Equity Schedule of Condensed Consolidating Statements of Changes in Common Stock Equity [Table Text Block] Tabular disclosure of changes in condensed consolidating common stock equity. Principal payments received Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Credit risk profile based on payment activity for loans Credit risk profile based on nonaccrual loans Financing Receivable, Past Due [Line Items] Quoted prices in active markets for identical assets (Level 1) Fair Value, Inputs, Level 1 [Member] One year before current year Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year Total current assets Assets, Current Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Available-for-sale Available-for-Sale Securities, Debt Maturities [Abstract] Tax Period [Domain] Tax Period [Domain] Hu Honua Bioenergy, LLC Hu Honua Bioenergy, LLC [Member] Hu Honua Bioenergy, LLC [Member] Transfer of retail repurchase agreements to deposit liabilities (financing) Domestic Deposit Liabilities, Retail Domestic Deposit Liabilities, Retail Unusual or Infrequent Items, or Both [Abstract] % of total class of loans Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage Financial assets Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Contributions made to defined benefit plans Defined Benefit Plan, Plan Assets, Contributions by Employer Short-term borrowings from non-affiliates Other Short-Term Borrowings Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Number of projects Public Utilities, Exceptional Project Recovery Mechanism, Number Of Projects Public Utilities, Exceptional Project Recovery Mechanism, Number Of Projects Due after five years through ten years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Decrease (increase) in materials and supplies Increase (Decrease) in Materials and Supplies Accumulated other comprehensive loss, net of tax benefits Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Income taxes Income Tax Disclosure [Text Block] Number of financial institutions Number Of Financial Institutions Represents the number of financial institutions with which the entity entered into a revolving Non Collateralized credit agreement with a letter of credit sub-facility. Asset impairment Intangible And Tangible Asset Impairment (Excluding Goodwill) Intangible And Tangible Asset Impairment (Excluding Goodwill) Residential construction Residential Construction Loan [Member] Residential Construction Loan Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Loans transferred from held for investment to held for sale (investing) Financing Receivable, Reclassification to Held-for-Sale Unrealized gain (loss) included in other comprehensive income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss) Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities HPOWER Hpower [Member] Represents an independent power producer (IPP) with whom the entity has entered into a power purchase agreement. Adjustment for amortization of prior service credit and net gains recognized during the period in net periodic benefit cost, tax Adjustment for amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, tax Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit) Recognized In Net Periodic Benefit Cost, Reclassification Adjustment From AOCI Tax Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit) Recognized In Net Periodic Benefit Cost, Reclassification Adjustment From AOCI Tax Credit Facility [Axis] Credit Facility [Axis] Long-term debt, net Long-Term Debt, Fair Value Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Entity Registrant Name Entity Registrant Name Defined Benefit Plan Defined Benefit Plan, Plan Amendment [Abstract] Services/goods transferred at a point in time Transferred at Point in Time [Member] Cash flows from operating activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Axis] Unusual or Infrequent Item, or Both [Domain] Unusual or Infrequent Item, or Both [Domain] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Subrogation Insurers Subrogation Insurers [Member] Subrogation Insurers Net decrease in deposit liabilities Increase (Decrease) in Deposits Affiliated Entity Affiliated Entity [Member] Significant  other observable  inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Amortization of unrealized holding losses on held-to-maturity securities, net of taxes of $1,231, $1,354, $3,565 and $4,050, respectively OCI, Debt Securities, Available-for-Sale, Transfer to Held-to-Maturity, Adjustment from AOCI for Amortization of Gain (Loss), after Tax Expenses Utilities Operating Expense [Abstract] Schedule of Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Common stock offering Issuance of common stock, net of expenses Stock Issued During Period, Value, New Issues Preferred stock dividends of subsidiaries Payments of Ordinary Dividends, Noncontrolling Interest Title of 12(b) Security Title of 12(b) Security Common stock ($6 2/3 par value, authorized 50,000,000 shares; outstanding 17,854,278 shares at September 30, 2024 and December 31, 2023) Common stock Common Stock, Value, Issued Total past due Financial Asset, Past Due [Member] Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Schedule of Windstorm and Wildfire Expenses Schedule of Unusual or Infrequent Items, or Both [Table Text Block] Regulatory assets Regulatory Asset, Noncurrent Total deferred credits and other liabilities Liabilities, Other than Long-Term Debt, Noncurrent Depreciation Utilities Operating Expense, Depreciation and Amortization Interest-bearing deposits Interest-Bearing Deposits in Banks and Other Financial Institutions Due after ten years Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10 Regulatory liabilities Regulatory Liability, Current Interest Rate Reduction Contractual Interest Rate Reduction [Member] Other long-term assets Assets Noncurrent Excluding Property Plant and Equipment Net [Abstract] -- None. No documentation exists for this element. -- Preferred stock, no par value, authorized 10,000,000 shares; issued: none Preferred Stock, Value, Issued Regulatory liabilities Regulatory Liability Forward commitments Forward Contracts [Member] Puna Geothermal Venture Puna Geothermal Venture [Member] Puna Geothermal Venture [Member] Other expense Loss From Catastrophes, Other Expense [Member] Loss From Catastrophes, Other Expense Basic earnings (loss) per common share (in dollars per share) Earnings Per Share, Basic Office supplies, printing and postage Supplies Printing and Postage Expense The aggregate amount of expenses directly related to the office supplies, printing and postage. Net proceeds from issuance of common stock Proceeds from issuance of common stock Proceeds from Issuance of Common Stock Measurement period for total return to shareholders (in years) Share-based Compensation Arrangement by Share-based Payment Award Equity Instruments Other than Option Period Used for Calculation of Total Return to Shareholders Represents the number of years used in the calculation of total return to shareholders. Propose pilots annual cap Public Utilities, Pilot Process Annual Cap Public Utilities, Pilot Process Annual Cap Unpaid invoices and accruals for capital expenditures, balance, end of period (investing) Capital Expenditures Incurred but Not yet Paid Interconnection approval PIM, accrued estimated rewards Public Utilities, Interconnection Approval Performance Incentive Mechanism, Accrued Estimated Rewards Public Utilities, Interconnection Approval Performance Incentive Mechanism, Accrued Estimated Rewards Proceeds from sale of loans, held for sale Proceeds from Sale, Loan, Held-for-Sale Total current liabilities Liabilities, Current EPRM requested amount Public Utilities, Solar Project, Exceptional Project Recovery Mechanism Requested Amount Public Utilities, Solar Project, Exceptional Project Recovery Mechanism Requested Amount Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period U.S. Treasury and federal agency obligations US Treasury and Government [Member] Over-Allotment Option Over-Allotment Option [Member] Installment payments Litigation Settlement, Amount Awarded To Other Party, Number Of Installments Litigation Settlement, Amount Awarded To Other Party, Number Of Installments Held-to-maturity investment securities Held-to-maturity investment securities Debt Securities, Held-to-Maturity, Fair Value Mortgage revenue bonds, measurement input Asset Backed Securities, Measurement Input Asset Backed Securities, Measurement Input Public Utilities, General Disclosures [Line Items] Public Utilities, General Disclosures [Line Items] Marketing Marketing Expense Allowance for credit losses Financing Receivable, Allowance for Credit Loss [Line Items] County Of Maui County Of Maui [Member] County Of Maui Range of expected volatility for Peer Group, maximum rate Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum Repayment of short-term debt Repayments of Short-Term Debt Revenues Revenues Revenues Revenues Revenues Total fair value Debt Securities, Held-to-Maturity, Maturity, Allocated and Single Maturity Date, Fair Value Share-based compensation Share-Based Payment Arrangement [Text Block] Less: Deferred fees and discounts Financing Receivable, Unamortized Loan Cost (Fee) and Purchase Premium (Discount) Preferred stock dividends of Hawaiian Electric and subsidiaries Payments of Ordinary Dividends, Preferred Stock and Preference Stock Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, tax Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, tax Other Comprehensive Income, Reclassification Adjustment for Impact of Decision and Orders of the P U C Included in Regulatory Assets, Tax The amount of income taxes on the reclassification adjustments on pension and post retirement benefits for the accounting impact of the decisions issued by the Public Utilities Commission. Research and development tax credit that are proposed to be disallowed Deferred Tax Assets, Tax Credit Carryforward, Proposed Disallowance Deferred Tax Assets, Tax Credit Carryforward, Proposed Disallowance Entity Address, City or Town Entity Address, City or Town Proceeds from issuance of long-term debt Proceeds from issuance of long-term debt Proceeds from Issuance of Long-Term Debt Number of lawyers representing individual plaintiffs Loss Contingency, Number Of Lawyers Representing Plaintiffs Loss Contingency, Number Of Lawyers Representing Plaintiffs Allowance for credit losses Beginning balance Ending balance Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest Share-based compensation expense (benefit) Share-Based Payment Arrangement, Expense Decoupling order, service reliability performance, historical measurement period (in years) Public Utility, Decoupling Order, Performance Incentive Mechanism, Service Reliability, Target Performance Historical Measurement Period Public Utility, Decoupling Order, Performance Incentive Mechanism, Service Reliability, Target Performance Historical Measurement Period Property, plant and equipment Public Utilities, Property, Plant and Equipment [Abstract] Cash contributions by the employer to defined contribution plan Defined Contribution Plan, Employer Discretionary Contribution Amount Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Loss Contingencies [Table] Loss Contingencies [Table] Schedule of Amortized Intangible Assets Schedule of Finite-Lived Intangible Assets [Table Text Block] Real estate loans Real Estate Loan [Member] Earnings sharing mechanism, actual earning, above or below dead band Public Utilities, Earnings Sharing Mechanism, Actual Earnings, Above Or Below Dead Band Public Utilities, Earnings Sharing Mechanism, Actual Earnings, Above Or Below Dead Band Current Financial Asset, Not Past Due [Member] Deposit liabilities—noninterest-bearing Noninterest-Bearing Deposit Liabilities Due after five years through ten years Debt Securities, Held-to-Maturity, Amortized Cost Excluding Accrued Interest, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year 5 through 10 Financing Receivable, Allowance for Credit Loss [Table] Financing Receivable, Allowance for Credit Loss [Table] Commercial Commercial Portfolio Segment [Member] Revenues Revenue from Contract with Customer [Text Block] Document Fiscal Year Focus Document Fiscal Year Focus Total fair value Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Fair Value Total Defendants Hawaiian Electric Company, Inc And Other Defendants [Member] Hawaiian Electric Company, Inc And Other Defendants Schedule of Credit Risk Profile Based on Nonaccrual Loans, Accruing Loans 90 days or More Past Due Financing Receivable, Nonaccrual [Table Text Block] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Call center performance, pending adjusted maximum penalty Public Utility, Decoupling Order, Call Center Performance, Maximum Penalty, Pending Adjusted Amount Public Utility, Decoupling Order, Call Center Performance, Maximum Penalty, Pending Adjusted Amount Project costs incurred Public Utilities, Project Costs Incurred Public Utilities, Project Costs Incurred Document Period End Date Document Period End Date Sale of Stock [Axis] Sale of Stock [Axis] Percentage sharing between customers and utilities Public Utilities, Earnings Sharing Mechanism, Sharing Between Customers And Utilities, Percentage Public Utilities, Earnings Sharing Mechanism, Sharing Between Customers And Utilities, Percentage Outstanding, beginning of period (in shares) Outstanding, end of period (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Payment award, low end of range Share-based Compensation by Share-based Payment Award Payout, Low of Range Represents the low end of range of payout depending on achievement of the goals. Project period Public Utilities, Electric Grid Project, Period Public Utilities, Electric Grid Project, Period Expected beneficiary amount Unusual Or Infrequent Item, Humanitarian Aid, Expected Beneficiary Amount Unusual Or Infrequent Item, Humanitarian Aid, Expected Beneficiary Amount Special Mention Special Mention [Member] Electric utility Electric Utility Segment [Member] Represents information about the electric utility business segment of the company. Certain subsidiaries of the company are regulated operating public utilities engaged in the production, purchase, transmission, distribution and sale of electricity. Amortized  cost Debt Securities, Available-for-Sale, Amortized Cost, Fiscal Year Maturity [Abstract] Target performance period (in months) Public Utility, Decoupling Order, Performance Incentive Mechanism, Generation-Caused System Average Interruption, Target Performance Period Public Utility, Decoupling Order, Performance Incentive Mechanism, Generation-Caused System Average Interruption, Target Performance Period Prepayments and other Prepaid Expense and Other Assets, Current Reclassifications Reclassification, Comparability Adjustment [Policy Text Block] Document Transition Report Document Transition Report Purchase obligation Purchase Obligation Schedule of Common Stock Granted to Nonemployee Directors Share-Based Payment Arrangement, Nonemployee Director Award Plan, Activity [Table Text Block] Accrued earned rewards, net of penalties Public Utilities, Accrued Earned Rewards, Net Of Penalties Public Utilities, Accrued Earned Rewards, Net Of Penalties Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Entity Current Reporting Status Entity Current Reporting Status Retained earnings Retained Earnings [Member] Servicing Asset at Amortized Cost [Table] Servicing Asset at Amortized Cost [Table] Schedule of Allowance for Loan Commitments Off-Balance Sheet, Credit Loss, Liability [Table Text Block] Off-Balance Sheet, Credit Loss, Liability Greater than 89 days past due 90 days or more past due Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Number of IPPs (in entities) Variable Interest Entity Number Of Consolidated VIEs Variable Interest Entity Number Of Consolidated VIEs Weighted average Financing Receivable, Modified, Weighted Average Term Increase from Modification Restricted stock units Restricted Stock Units (RSUs) [Member] Due after ten years Debt Securities, Held-to-Maturity, Amortized Cost Excluding Accrued Interest, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year 10 Increase (decrease) in stockholders' equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Other bank borrowings Other bank borrowings Other Bank Borrowings 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. Noninterest expense Noninterest expense Noninterest Expense Impact of D&Os of the PUC included in regulatory assets Accumulated Defined Benefit Plans Adjustment, Impact Of Decision And Orders Of The Public Utility Commission Included In Regulatory Assets [Member] Accumulated Defined Benefit Plans Adjustment, Impact Of Decision And Orders Of The Public Utility Commission Included In Regulatory Assets [Member] Estimated capital costs Public Utilities, Exceptional Project Recovery Mechanism, Estimated Capital Costs Public Utilities, Exceptional Project Recovery Mechanism, Estimated Capital Costs Letter of Credit Letter of Credit [Member]