Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Trading Arrangement: Trading Arrangement [Axis] Maximum Maximum [Member] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Short-term Debt, Type [Axis] Short-Term Debt, Type [Axis] Title of 12(b) Security Title of 12(b) Security Carrying or notional amount Reported Value Measurement [Member] Subsequent Event Subsequent Event [Member] Weighted average interest rate (as percent) Debt, Weighted Average Interest Rate Adjustment to Compensation, Amount Adjustment to Compensation Amount Segment Reporting [Abstract] Segment Reporting [Abstract] Retirement benefits Retirement Benefits [Text Block] Wildfire tort-related claims Loss Contingency Accrual Change in defined benefit pension and other postretirement benefit plans asset/liability Change in defined benefit pension and other postretirement benefit plans asset/liability Increase (Decrease) in Obligation, Pension and Other Postretirement Benefits Unusual or Infrequent Item, or Both [Axis] Unusual or Infrequent Item, or Both [Axis] Consolidated Entities [Axis] Consolidated Entities [Axis] Hawaiian Electric Facility Hawaiian Electric Facility [Member] Hawaiian Electric Facility Project [Axis] Project [Axis] 2026 ARA revenues Public Utilities, Annual Revenue Adjustment, Revenues Public Utilities, Annual Revenue Adjustment, Revenues Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Allowance for equity funds used during construction 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 Management Audit savings commitment Public Utilities, Annual Revenue Adjustment, Management Audit Savings Commitment Public Utilities, Annual Revenue Adjustment, Management Audit Savings Commitment Kapolei Energy Storage Kapolei Energy Storage [Member] Kapolei Energy Storage 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 Other amortization Amortization 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. Consolidated Entities [Domain] Consolidated Entities [Domain] HEI Facility HEI Facility [Member] HEI Facility Common stock issued (gross) for nonemployee 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. 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. Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Member] Noncurrent liabilities: Liabilities, Noncurrent [Abstract] 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 HEI 2.48%-6.10% senior notes due 2028-2052 Senior Notes Due 2028 to 2052 [Member] Senior Notes Due 2028 to 2052 Retirement Benefits [Abstract] Retirement Benefits [Abstract] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Total capitalization Capitalization, Long-Term Debt and Equity Number of reportable segments Number of Reportable Segments Total current liabilities Liabilities, Current Short-term Debt, Type [Domain] Short-Term Debt, Type [Domain] Entity Address, City or Town Entity Address, City or Town Other IPPs Other Independent Power Producers [Member] Represents information pertaining to other independent power producers. Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Share-based compensation Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Insurance reimbursement receivable Insurance Reimbursement Receivable Insurance Reimbursement Receivable Electric energy sales - large light and power Electric Energy Sales, Large Light And Power [Member] Electric Energy Sales, Large Light And Power [Member] Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Significant  other observable  inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Hawaiian Electric Parent Company [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Additional paid-in capital Additional paid-in capital Adjustments to Additional Paid in Capital, Other Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] HEI consolidated and Hawaiian Electric consolidated Hawaiian Electric Industries, Inc. And Hawaiian Electric Company, Inc. And Subsidiaries [Member] Hawaiian Electric Industries, Inc. And Hawaiian Electric Company, Inc. And Subsidiaries 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 Schedule of Segment Financial Information Segment Reporting [Table Text Block] Deferred credits and other liabilities Liabilities, Other than Long-Term Debt, Noncurrent [Abstract] Pretax impairment charge Impairment of Long-Lived Assets to be Disposed of Related Party, Type [Axis] Related and Nonrelated Parties [Axis] Other comprehensive loss, net of tax benefits Other comprehensive loss, net of tax benefits Other comprehensive loss, net of tax benefits Current period other comprehensive loss Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent 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 gas turbines acquired Public Utilities, Number Of Gas Turbines Acquired Public Utilities, Number Of Gas Turbines Acquired Supplemental disclosures of noncash activities Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Document Period End Date Document Period End Date Decrease in wildfire-related claims Increase (Decrease) In Loss Contingency Liability Increase (Decrease) In Loss Contingency Liability Liabilities held for sale Liabilities held for sale-current Disposal Group, Including Discontinued Operation, Liabilities, Current Debt assumed by buyer - sale of a subsidiary (financing) Debt Assumed By Buyer From Sale Of Subsidiaries Debt Assumed By Buyer From Sale Of Subsidiaries Consolidating adjustments Consolidation, Eliminations [Member] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Weighted-average number of common shares outstanding: Earnings Per Share, Basic, Other Disclosure [Abstract] Cash flows Cash Flow, Supplemental Disclosures [Text Block] Federal income tax, net Income Tax Paid, Federal, after Refund Received 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 Accumulated other comprehensive income, net of taxes Accumulated other comprehensive income, net of taxes-retirement benefit plans Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Consolidation Items [Domain] Consolidation Items [Domain] Current portion of operating lease liabilities Current portion of operating lease liabilities Operating Lease, Liability, Current Document Fiscal Period Focus Document Fiscal Period Focus Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Total liabilities Liabilities Trading Symbol(s) Trading Symbol Electric energy sales - commercial Electric Energy Sales, Commercial [Member] Electric Energy Sales, Commercial [Member] Capital expenditures Capital expenditures Payments to Acquire Property, Plant, and Equipment Savings commitment liability, annual rate Public Utilities, Savings Commitment Liability, Annual Rate Public Utilities, Savings Commitment Liability, Annual Rate Company Selected Measure Name Company Selected Measure Name Preferred stock dividends of subsidiaries Payments of Ordinary Dividends, Noncontrolling Interest Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Expenses Utilities Operating Expense [Abstract] Schedule of Condensed Consolidating Statement of Cash Flows Condensed Cash Flow Statement [Table Text Block] Common stock, no par value, authorized 400,000,000 shares; issued and outstanding: 172,728,004 shares and 172,620,476 shares at June 30, 2026 and December 31, 2025, respectively Common Stocks, Including Additional Paid in Capital, Net of Discount Excess liability insurance Loss Contingency, Excess Liability Insurance Loss Contingency, Excess Liability Insurance Credit Facility [Domain] Credit Facility [Domain] Loss on sale of a subsidiary and impairment loss on assets held for sale Loss on sale of a subsidiary and impairment loss on assets held for sale Gain (Loss) on Sale of Assets and Asset Impairment Charges Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Disposal Group Name [Domain] Disposal Group Name [Domain] Line of Credit Facility [Table] Line of Credit Facility [Table] Total Maui windstorm and wildfires related expenses Loss from Catastrophes Share-based Payment Arrangement, Option, Exercise Price Range [Table] Share-Based Payment Arrangement, Option, Exercise Price Range [Table] Entities [Table] Entities [Table] Schedule of Discontinued Operations Disposal Groups, Including Discontinued Operations [Table Text Block] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Change in other assets and liabilities Change in other assets and liabilities Increase (Decrease) in Other Operating Assets and Liabilities, Net Public utilities, electric grid project, approved funds Public Utilities, Electric Grid Project, Approved Funds Public Utilities, Electric Grid Project, Approved Funds Award Timing Predetermined Award Timing Predetermined [Flag] Project [Domain] Project [Domain] Utility property, plant and equipment, net Public Utilities, Property, Plant and Equipment, Net Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Quoted prices in active markets for identical assets (Level 1) Fair Value, Inputs, Level 1 [Member] Effective income tax, percent Effective Income Tax Rate Reconciliation, Percent Mahipapa Mahipapa, LLC [Member] Mahipapa Net effect of potentially dilutive shares (share-based compensation programs) (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Net income Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Long-term debt, net Long-Term Debt, Fair Value Depreciation of property, plant and equipment Depreciation Plan Name [Domain] Plan Name [Domain] 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. Mahipapa Non-Recourse Loans Mahipapa Non-Recourse Loans [Member] Mahipapa Non-Recourse Loans Operating lease right-of-use assets Operating lease right-of-use assets Operating Lease, Right-of-Use Asset HEI revolving credit facility SOFR + 2.50%, due 2030 Revolving Credit Facility At 2.50% Due 2030 [Member] Revolving Credit Facility At 2.50% Due 2030 Tort-Related Legal Claims Tort-Related Legal Claims [Member] Tort-Related Legal Claims Operating income (loss) Operating Income (Loss) [Abstract] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] ABL Facility ABL Credit Facility Agreement ABL Credit Facility Agreement [Member] ABL Credit Facility Agreement Common stock dividends Payments of Ordinary Dividends, Common Stock Expiration Date Trading Arrangement Expiration Date Less: Restricted cash Restricted Cash and Cash Equivalent Money market mutual funds Cash and Cash Equivalents, Fair Value Disclosure Affiliated Entity Affiliated Entity [Member] Unamortized tax credits Unamortized tax credits Accumulated Deferred Investment Tax Credit Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Proceeds from capital contribution from parent Proceeds from capital contribution from parent Proceeds from Issuance of Common Stock 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 Incremental Pilot Process cost recovery Public Utilities, Decoupling Filing, Pilot Process Cost Recovery Public Utilities, Decoupling Filing, Pilot Process Cost Recovery Unrecognized share based compensation Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Segments [Domain] Segments [Domain] Increase in regulatory liabilities Increase in regulatory liabilities Increase (Decrease) in Regulatory Liabilities Credit agreements and long-term debt Debt Disclosure [Text Block] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Incremental ARA revenues Public Utilities, Annual Incremental Rate Adjustment Mechanism Adjusted Revenue Public Utilities, Annual Incremental Rate Adjustment Mechanism Adjusted Revenue Long-term debt, net Disposal Group, Including Discontinued Operation, Long-Term Debt, Net, Current Disposal Group, Including Discontinued Operation, Long-Term Debt, Net, Current PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Recovery of COVID-19 related costs Public Utilities, Annual Revenue Adjustment, COVID-19 Related Cost Recovery Public Utilities, Annual Revenue Adjustment, COVID-19 Related Cost Recovery 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] Total expenses Total expenses Costs and Expenses Investment in wholly owned subsidiaries, at equity Investments In And Advance To Affiliates, Subsidiaries, Associates, And Joint Ventures, Current Investments In And Advance To Affiliates, Subsidiaries, Associates, And Joint Ventures, Current Stated interest rate (as percent) Debt Instrument, Interest Rate, Stated Percentage Common stock dividends Common stock dividends Dividends, Common Stock, Cash Total shareholders’ equity Beginning balance Ending balance Common stock equity Equity, Attributable to Parent Regulatory Projects and Legal Obligations [Line Items] Regulatory Projects and Legal Obligations [Line Items] -- None. No documentation exists for this element. -- Number of contracts entered Number Of Purchase Contracts Number Of Purchase Contracts Defined benefit pension and other postretirement benefit plans asset Defined benefit pension and other postretirement benefit plans asset Assets for Plan Benefits, Defined Benefit Plan Maui Windstorm and Wildfires Loss from Catastrophes [Member] Assets Assets [Abstract] Property insurance coverage Loss Contingency, Property Insurance Coverage Loss Contingency, Property Insurance Coverage Insider Trading Policies and Procedures [Line Items] Decrease in wildfire tort-related claims Increase (Decrease) In Wilfire Tort-Related Claims Increase (Decrease) In Wilfire Tort-Related Claims Interest and dividends payable Interest and preferred dividends payable Interest and Dividends Payable Including Dividends on Preferred Stock of Subsidiaries, Current 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. Prepayments and other Prepaid Expense and Other Assets, Current Deferred income tax expense (benefit) Deferred income tax expense (benefit) Deferred Income Tax Expense (Benefit) Regulatory assets Regulatory Asset, Current Miscellaneous professional liability Loss Contingency, Miscellaneous Professional Liability Insurance Loss Contingency, Miscellaneous Professional Liability Insurance Number of operating segments Number of Operating Segments Entity Central Index Key Entity Central Index Key Property, plant and equipment, accumulated depreciation Property, Plant, and Equipment, Accumulated Depreciation, Depletion, and Amortization Equity [Abstract] Equity [Abstract] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] First settlement payment Payments for Legal Settlements 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. Ownership [Axis] Ownership [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Investment, Name [Axis] Investment, Name [Axis] Finance lease liabilities Finance lease liabilities Finance Lease, Liability, Noncurrent Settlement payment Increase (Decrease) In Settlement Payment Increase (Decrease) In Settlement Payment Line of credit facility basis point spread (as percent) Debt Instrument, Basis Spread on Variable Rate Allowance for borrowed funds used during construction Interest Costs Capitalized Adjustment Directors and officers liability insurance, retention Loss Contingency, Directors And Officers Liability Insurance, Retention Amount Loss Contingency, Directors And Officers Liability Insurance, Retention Amount Accumulated other comprehensive income Accumulated other comprehensive income AOCI AOCI Attributable to Parent [Member] Equity in earnings of subsidiaries Equity in Earnings of Subsidiaries Represents the amount of equity in earnings of subsidiaries. All Individuals All Individuals [Member] Weighted average period for recognition of unrecognized compensation cost (in years) Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition 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 Total noncurrent assets Assets, Noncurrent Statement [Line Items] Statement [Line Items] Total assets Total assets Assets Defined Benefit Plan [Table] Defined Benefit Plan [Table] Other subsidiaries Other Subsidiaries [Member] Other Subsidiaries Performance incentive mechanism, (penalties) rewards Public Utilities, Performance Incentive, Mechanism, (Penalties) Rewards Public Utilities, Performance Incentive, Mechanism, (Penalties) Rewards 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] Reportable Legal Entities Reportable Legal Entities [Member] Renewable energy generation project, incurred cost Public Utilities, Renewable Energy Generation Project, Incurred Cost Public Utilities, Renewable Energy Generation Project, Incurred Cost Operating Segments Operating Segments [Member] Interest expense, net (Note 2) Interest expense, net Interest Expense, Nonoperating 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. Share-based compensation Share-Based Payment Arrangement [Text Block] Adjustments amount Insurance Recoveries, Adjustments Related To Costs No Longer Probable Adjustments To Insurance Recoveries Deferral treatment approved by the PUC Loss Contingencies, Incremental Non-Labor Expenses, Deferred Accounting Treatment Loss Contingencies, Incremental Non-Labor Expenses, Deferred Accounting Treatment PEO PEO [Member] 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 Other Other Liabilities, Noncurrent Waiau Repower Project Waiau Repower Project [Member] Waiau Repower Project Retirement Plan Type [Axis] Retirement Plan Type [Axis] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Insurance recoveries Insurance Recoveries, Including Adjustment Of Costs No Longer Probable Insurance Recoveries, Including Adjustment Of Costs No Longer Probable Retained earnings (deficit) Retained earnings Retained Earnings [Member] Operating lease liabilities Operating lease liabilities Operating Lease, Liability, Noncurrent 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 Money market mutual funds Money Market Funds [Member] Revolving Credit Facility Revolving Credit Facility [Member] Fair value measurements Fair Value Measurement, Policy [Policy Text Block] Increase (decrease) in stockholders' equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] 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] Diluted earnings per common share (in dollars per share) Earnings Per Share, Diluted 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 Waena Battery Energy Storage System Project Waena Battery Energy Storage System Project [Member] Waena Battery Energy Storage System Project Litigation Case [Domain] Litigation Case [Domain] Ownership [Domain] Ownership [Domain] 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. Long-term Purchase Commitment [Line Items] Long-Term Purchase Commitment [Line Items] Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Undrawn Line of Credit Facility, Remaining Borrowing Capacity 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. -- Assets held for sale Assets held for sale-current Disposal Group, Including Discontinued Operation, Assets, Current Financial assets Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Term Loan Term Loan [Member] Term Loan Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] 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. Net income for common stock Net Income (Loss) Available To Common Stockholders Net Income (Loss) Available To Common Stockholders Shareholder Derivative Actions, District of Hawaii Shareholder Derivative Actions, District Of Hawaii [Member] Shareholder Derivative Actions, District Of Hawaii Public utilities, renewable energy generation project, estimated annual flooding percentage (as percent) Public Utilities, Renewable Energy Generation Project, Estimated Annual Flooding Percentage Public Utilities, Renewable Energy Generation Project, Estimated Annual Flooding Percentage Property, plant and equipment, net of accumulated depreciation Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Current Cash flows from operating activities Cash Provided by (Used in) Operating Activity, Continuing Operation [Abstract] Operating income (loss) Operating Income (Loss) Accordion feature, increase limit Line of Credit Facility, Accordion Feature, Increase Limit Line of Credit Facility, Accordion Feature, Increase Limit PCB Contamination PCB Contamination [Member] PCB Contamination [Member] 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. Preferred stock dividends of subsidiaries Noncontrolling Interest in Net Income (Loss) Preferred Unit Holders, Redeemable 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. Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Service cost Defined Benefit Plan, Service Cost Litigation settlement, fee expense accrued Litigation Settlement, Fee Expense Accrued Litigation Settlement, Fee Expense Accrued Common stock, shares issued (in shares) Beginning balance (in shares) Ending balance (in shares) Common Stock, Shares, Issued Entity Information [Line Items] Entity Information [Line Items] Increase in accounts receivable Increase (Decrease) in Accounts Receivable Product and Service [Domain] Product and Service [Domain] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] ASB Hawaii, Inc ASB Hawaii, Inc [Member] ASB Hawaii, Inc Deferred income taxes Deferred Income Tax Liabilities, Net Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Defined contribution plan, expenses recognized Defined Contribution Plan, Cost Reclassifications out of accumulated other comprehensive income/(loss) Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Termination Date Trading Arrangement Termination Date Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Plaintiffs that initially opted out and have no signed individual release agreements Litigation Settlement, Claimants That Initially Opted Out And Have Not Signed Release Agreements, Number Litigation Settlement, Claimants That Initially Opted Out And Have Not Signed Release Agreements, Number Other Other Liabilities, Current Fair Value as of Grant Date Award Grant Date Fair Value Renewable energy (in megawatts) Public Utilities, Power Of Renewable Energy Public Utilities, Power Of Renewable Energy Target reduction risk, period Public Utilities, Wildfire Mitigation Plan, Target Reduction Risk, Period Public Utilities, Wildfire Mitigation Plan, Target Reduction Risk, Period Total weighted-average grant-date fair value of shares granted 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). Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Arrangement Duration Trading Arrangement Duration 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. Consolidation Items [Axis] Consolidation Items [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Revenues Revenues Revenues Revenues Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Noncash capital distribution to parent and noncash transfer of operating liabilities from the parent Noncash Capital Distribution To Parent And Noncash Transfer Of Operating Liabilities From Parent Noncash Capital Distribution To Parent And Noncash Transfer Of Operating Liabilities From Parent Environmental Remediation Contingency [Axis] Environmental Remediation Contingency [Axis] Award Type [Domain] Award Type [Domain] Fair value measurements Fair Value Disclosures [Text Block] Insurance recovery related to wildfire tort-related claim Loss Contingency, Insurance Recovery, Catastrophe Loss Contingency, Insurance Recovery, Catastrophe Expected life in years Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term Minority ownership percentage Subsidiary, Ownership Percentage, Noncontrolling Owner 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 Retirement defined benefits credit—other than service costs Retirement defined benefits credit (expense)—other than service costs Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component Schedule of Windstorm and Wildfire Expenses Schedule of Unusual or Infrequent Items, or Both [Table Text Block] Hawaii Electric Light Hawaii Electric Light Company, Inc [Member] Hawaii Electric Light Company, Inc [Member] Legal Entity [Axis] Legal Entity [Axis] Deferred to a regulatory asset Insurance Recoveries, Deferred Regulatory Asset Adjustments Insurance Recoveries, Deferred Regulatory Asset Adjustments Premium on capital stock Premium On Capital Stock Premium On Capital Stock Cash, cash equivalents and restricted cash, beginning of period Cash, cash equivalents and restricted cash, end of period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Schedule of Reclassification out of AOCI Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Non-NEOs Non-NEOs [Member] Adjustment of costs no longer probable Insurance Recoveries, Adjustment Of Costs No Longer Probable Insurance Recoveries, Adjustment Of Costs No Longer Probable Membership interest Equity Method Investment, Ownership Percentage Investment, Name [Domain] Investment, Name [Domain] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Statistical Measurement [Axis] Statistical Measurement [Axis] Award Type [Axis] Award Type [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] 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. Retained earnings (deficit) Retained earnings Retained Earnings (Accumulated Deficit) Product and Service [Axis] Product and Service [Axis] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Pension benefits Pension Plan [Member] Common stock Common Stock [Member] Reclassification Out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Shares granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period EPRM approved projects Public Utilities, Exceptional Project Recovery Mechanism, Number Of Projects Approved Public Utilities, Exceptional Project Recovery Mechanism, Number Of Projects Approved Natural Disasters and Other Casualty Events Natural Disasters and Other Casualty Events [Member] Regulatory Projects and Legal Obligations [Table] Public Utilities General Disclosures [Table] Utility property, plant and equipment Public Utilities, Property, Plant and Equipment, Net [Abstract] Total liabilities and shareholders’ equity Liabilities and Equity Employee Stock Option Share-Based Payment Arrangement, Option [Member] Segments [Axis] Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Related Party, Type [Domain] Related and Nonrelated Parties [Domain] Tabular List, Table Tabular List [Table Text Block] Additional paid-in capital Additional Paid in Capital Name Awards Close in Time to MNPI Disclosures, Individual Name Nonutility property, plant and equipment, less accumulated depreciation of $1 as of June 30, 2026 and December 31, 2025 Nonutility property, plant and equipment, less accumulated depreciation Non-Utilities, Property, Plant And Equipment, Net Non-Utilities, Property, Plant And Equipment, Net GLST1, LLC GLST1, LLC [Member] GLST1, LLC Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Noncurrent assets: Assets, Noncurrent [Abstract] Materials and supplies, at average cost Inventory, Raw Materials and Supplies, Gross Climate Adaptation Transmission and Distribution Resilience Program Climate Adaptation Transmission And Distribution Resilience Program [Member] Climate Adaptation Transmission And Distribution Resilience Program Preferred stock, no par value, authorized 10,000,000 shares; issued: none Preferred Stock, Value, Issued Number of subrogation insurers Number Of Subrogation Insurers Number Of Subrogation Insurers Adjustment to Compensation: Adjustment to Compensation [Axis] Number of existing turbines being replaced Public Utilities, Number Of Replaced Turbines Public Utilities, Number Of Replaced Turbines Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Interest on finance lease obligations Interest Paid, Excluding Capitalized Interest, Operating Activity Increase in fuel oil stock Increase in fuel oil stock Increase (Decrease) in Fuel Inventories Credit Facility [Axis] Credit Facility [Axis] Name Measure Name Pay vs Performance Disclosure [Line Items] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Other Other Operating Segment [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Other sales Other Sales [Member] Other Sales Premium on capital stock Other Additional Capital [Member] Additional paid-in capital Additional Paid-in Capital [Member] Total revenues from other sources Revenue Not from Contract with Customer Name Trading Arrangement, Individual Name Cash and cash equivalents Cash and cash equivalents, end of period Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Cash and Cash Equivalent Number of settlement agreements Loss Contingency, Claims Settled, Number Company Selected Measure Amount Company Selected Measure Amount Total Maui windstorm and wildfires related items, net Loss Contingencies, Net Of Recoveries And Reclassifications Of Payments Loss Contingencies, Net Of Recoveries And Reclassifications Of Payments Stage 1 and Stage 2 Renewable P P Stage1 And2 Renewable P P [Member] Stage1 And2 Renewable P P Depreciation and amortization Depreciation, Depletion and Amortization Accretion expense Loss Contingencies, Accretion Expense Loss Contingencies, Accretion Expense Right-of-use assets obtained in exchange for finance lease obligations (financing) Right-of-Use Asset Obtained in Exchange for Finance Lease Liability Non-PEO NEO Non-PEO NEO [Member] Share-based expenses and other, net Stock Issued During Period Value Expenses And Other, Net Stock Issued During Period Value Expenses And Other, Net Condensed Cash Flow Statement [Table] Condensed Cash Flow Statement [Table] Expected payments for remainder of fiscal year Defined Benefit Plan, Expected Future Benefit Payment, Remainder of Fiscal Year Increase in regulatory assets Increase in regulatory assets Increase (Decrease) in Other Regulatory Assets Purchase obligation Purchase Obligation Award Timing Method Award Timing Method [Text Block] Other Product and Service, Other [Member] Net decrease in cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] 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 Property Insurer Litigation Property Insurer Litigation [Member] Property Insurer Litigation Amortization of net actuarial (gain)/losses Defined Benefit Plan, Amortization of Gain (Loss) Net income Net income attributable to Hawaiian Electric Net Income (Loss) Attributable to Parent Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Bridge Loan Bridge Loan [Member] Discount rate Litigation Settlement, Discount Rate Litigation Settlement, Discount Rate Authorized ROE Public Utilities, Approved Return on Equity, Percentage Restatement Determination Date: Restatement Determination Date [Axis] Schedule of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Net 2026 ARA revenues Public Utilities, Annual Revenue Adjustment, Net Incremental Revenues Public Utilities, Annual Revenue Adjustment, Net Incremental Revenues Amount awarded Litigation Settlement, Amount Awarded to Other Party Total contracted battery energy storage system capacity (in megawatts) 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 Decrease (increase) in accounts receivable and unbilled revenues, net Increase (Decrease) in Receivables Condensed Balance Sheet Statements, Captions [Line Items] Condensed Balance Sheet Statements, Captions [Line Items] Condensed Income Statements, Captions [Line Items] Condensed Income Statements, Captions [Line Items] Lawsuit claim filed Loss Contingency, New Claims Filed, Number Schedule of Common Stock Granted to Non-employee Directors Share-Based Payment Arrangement, Nonemployee Director Award Plan, Activity [Table Text Block] Revenues Revenues [Abstract] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] 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 Statistical Measurement [Domain] Statistical Measurement [Domain] Committed contribution to humanitarian fund Humanitarian Aid Fund, Committed Contribution Humanitarian Aid Fund, Committed Contribution Unusual or Infrequent Items, or Both [Abstract] Less accumulated depreciation Public Utilities, Property, Plant and Equipment, Accumulated Depreciation Document Fiscal Year Focus Document Fiscal Year Focus Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Capital distribution to parent (financing) Proceeds From Distribution To Parent Proceeds From Distribution To Parent Common stock ($6 2/3 par value, authorized 50,000,000 shares; outstanding 17,854,278 shares at June 30, 2026 and December 31, 2025) Common Stock, Value, Issued Withheld shares for employee taxes on vested share-based compensation Payment, Tax Withholding, Share-Based Payment Arrangement Public Utilities, General Disclosures [Line Items] Public Utilities, General Disclosures [Line Items] Schedule of Long-Term Debt Schedule of Long-Term Debt Instruments [Table Text Block] Services/goods transferred over time Transferred over Time [Member] Line of Credit Line of Credit [Member] Restatement Determination Date Restatement Determination Date Investment in unconsolidated affiliate Investment in unconsolidated affiliate Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets EPRM approved recovery amount Public Utilities, Exceptional Project Recovery Mechanism, Approved Recovery Amount Public Utilities, Exceptional Project Recovery Mechanism, Approved Recovery Amount Major Vendor [Domain] Major Vendor [Domain] Name and description of the vendor that account for major purchases of the entity. Maui windstorm and wildfires Unusual or Infrequent Items, or Both, Disclosure [Text Block] Other long-term assets Long-Term Investments [Abstract] Regulatory liabilities Regulatory liabilities Regulatory Liability, Noncurrent Amendment Flag Amendment Flag Current liabilities Liabilities, Current [Abstract] Bad debt expense Accounts Receivable, Credit Loss Expense (Reversal) Payments of obligations under finance leases Finance Lease, Principal Payments 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). Disposal Group Classification [Axis] Disposal Group Classification [Axis] Public utilities, renewable firm generation capacity (in megawatts) Public Utilities, Renewable Firm Generation Capacity Public Utilities, Renewable Firm Generation Capacity Number of defendants Loss Contingency, Number of Defendants Right-of-use assets - finance lease Finance Lease, Right-of-Use Asset, before Accumulated Amortization American Savings Bank (ASB) American Savings Bank FSB [Member] American Savings Bank FSB Nonemployee Director Stock Plan Nonemployee Director Stock Plan [Member] Nonemployee Director Stock Plan [Member] Disposal Group, Held-for-Sale, Not Discontinued Operations Disposal Group, Held-for-Sale, Not Discontinued Operations [Member] Timing of Transfer of Good or Service [Domain] Timing of Transfer of Good or Service [Domain] 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. Total noncurrent liabilities Liabilities, Noncurrent Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Property, plant and equipment Property, Plant, and Equipment [Abstract] Electric energy sales - other Electric Energy Sales, Other [Member] Electric Energy Sales, Other [Member] Entity Address, State or Province Entity Address, State or Province PEO Total Compensation Amount PEO Total Compensation Amount Land Public Utilities, Property, Plant and Equipment, Land Capital expenditures Segment Reporting, Long-Lived Asset, Expenditure for Addition Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] Weighted-average number of common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Regulatory assets Regulatory Asset, Noncurrent Defined Benefit Plan Defined Benefit Plan, Plan Amendment [Abstract] Environmental Remediation Contingency [Domain] Environmental Remediation Contingency [Domain] 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. Revenues from contracts with customers Revenue from Contract with Customer, Including Assessed Tax Renewable energy generation project, approved funds Public Utilities, Renewable Energy Generation Project, Approved Funds Public Utilities, Renewable Energy Generation Project, Approved Funds Schedule of Supplemental Disclosures of Cash and Noncash Activity Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Retirement benefits Defined Benefit Plan Disclosure [Line Items] Insurance Claims, Legal-Related Recoveries Insurance Claims, Legal-Related Recoveries [Member] Insurance Claims, Legal-Related Recoveries Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Basis of presentation Basis of Accounting, Policy [Policy Text Block] Preferred stock dividends of Hawaiian Electric and subsidiaries Payments of Ordinary Dividends, Preferred Stock and Preference Stock Net income for common stock Net income for common stock Net Income (Loss) Available to Common Stockholders, Basic Other accounts receivable, net Accounts and Other Receivables, Net, Current Regulatory Projects and Legal Obligations [Table] Regulatory Projects and Legal Obligations [Table] Discloses the components of regulatory projects and legal obligations. Capacity Credit agreement Line of Credit Facility, Maximum Borrowing Capacity Net incremental amount to be collected under the RBA rate tariffs Public Utility, Net Receivable Under Tariff Public Utility, Net Receivable Under Tariff Public utilities, renewable energy generation project, revised estimated cost Public Utilities, Renewable Energy Generation Project, Revised Estimated Cost Public Utilities, Renewable Energy Generation Project, Revised Estimated Cost Current portion of long-term debt, net Current portion of long-term debt, net Less current portion long-term debt, net of unamortized debt issuance cost Long-Term Debt, Current Maturities Return of Enterprise Resource Planning benefit liability Public Utilities, Annual Revenue Adjustment, Return Of Enterprise Resource Planning Benefit Liability Public Utilities, Annual Revenue Adjustment, Return Of Enterprise Resource Planning Benefit Liability Recent accounting pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Unpaid invoices and accruals for capital expenditures, balance, end of period (investing) Capital Expenditures Incurred but Not yet Paid Number of financial institutions Number Of Financial Institutions Forming Syndicate Number Of Financial Institutions Forming Syndicate Litigation Case [Axis] Litigation Case [Axis] Unrealized interest rate hedging loss, tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax Cash contributions by the employer to defined contribution plan Defined Contribution Plan, Employer Discretionary Contribution Amount Long-term debt, net Long-term debt, net Long-Term Debt Changes in assets and liabilities Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Net cash used in investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Decrease (increase) in accrued unbilled revenues Increase (Decrease) in Contract with Customer, Asset Regulatory assets Regulatory Asset Shareholder Derivative Actions, Northern District of California Shareholder Derivative Actions, Northern District Of California [Member] Shareholder Derivative Actions, Northern District Of California Shareholders' equity Equity [Text Block] Expenses Costs and Expenses [Abstract] Name of each exchange on which registered Security Exchange Name Legal expenses Loss From Catastrophes, Legal Expenses [Member] Loss From Catastrophes, Legal Expenses Incremental PIMs (net) Public Utilities, Decoupling Filing, Performance Incentive Mechanism, Net Public Utilities, Decoupling Filing, Performance Incentive Mechanism, Net Schedule of Condensed Consolidating Balance Sheet Condensed Balance Sheet [Table Text Block] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Name Outstanding Recovery, Individual Name Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Incremental MPIR/EPRM revenue adjustment Public Utilities, Incremental Major Project Interim Recovery And Exceptional Project Recovery Mechanism Adjustment Public Utilities, Incremental Major Project Interim Recovery And Exceptional Project Recovery Mechanism Adjustment Depreciation Utilities Operating Expense, Depreciation and Amortization Hawaiian Electric Hawaiian Electric, Parent [Member] Hawaiian Electric, Parent [Member] Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Purchased power Utilities Operating Expense, Purchased Power Retirement benefits expense Pension and Other Postretirement Benefits Cost (Reversal of Cost) Retirement benefit plans Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Aggregate principal amount, issued Long-Term Debt, Gross Condensed Income Statement [Table] Condensed Income Statement [Table] Wind IPPs Wind Independent Power Producers [Member] Wind Independent Power Producers [Member] Directors and officers liability insurance Loss Contingency, Directors And Officers Liability Insurance Loss Contingency, Directors And Officers Liability Insurance Issuance of common stock, net of expenses Stock Issued During Period Value Dividend Reinvestment and Stock Purchase Plan Stock Issued During Period Value Dividend Reinvestment and Stock Purchase Plan 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 Interest and dividend income Investment Income, Interest and Dividend Compensation Amount Outstanding Recovery Compensation Amount Individual: Individual [Axis] Weighted-average shares assuming dilution (in shares) Weighted Average Number of Shares Outstanding, Diluted Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Entity Emerging Growth Company Entity Emerging Growth Company Defined benefit pension liability Liability, Defined Benefit Plan, Noncurrent Underlying Security Market Price Change Underlying Security Market Price Change, Percent Regulatory Asset [Axis] Regulatory Asset [Axis] 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. Short-term borrowings, net Short-Term Debt Contributions made to defined benefit plans Defined Benefit Plan, Plan Assets, Contributions by Employer Condensed Balance Sheet Statement [Table] Condensed Balance Sheet Statement [Table] Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Reduction of long-term debt from funds previously transferred for repayment (financing) Decrease In Long-Term Debt From Previous Repayments Decrease In Long-Term Debt From Previous Repayments Public utilities, commitment cost, maximum percentage increase (as percent) Public Utilities, Renewable Energy Generation Project, Commitment Cost, Maximum Percentage Increase Public Utilities, Renewable Energy Generation Project, Commitment Cost, Maximum Percentage Increase Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] 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 All Executive Categories All Executive Categories [Member] Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] 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, Tax Credits, And Utility Revenue, Taxes The net changes in cash flows resulting from changes in prepaid and accrued income taxes and utility revenue taxes. Other comprehensive loss, net of tax benefits: Other comprehensive loss, net of tax benefits: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Schedule of Components of Net Periodic Benefit Cost for Consolidated HEI Schedule of Net Benefit Costs [Table Text Block] Shareholder Derivative Actions Shareholder Derivative Actions [Member] Shareholder Derivative Actions Actual return on equity, dead band percentage, above target Public Utilities, Earnings Share Mechanism, Actual Return On Equity, Dead Band Percentage, Above Target Percent Public Utilities, Earnings Share Mechanism, Actual Return On Equity, Dead Band Percentage, Above Target Percent Public utilities, renewable energy generation project, estimated cost Public Utilities, Renewable Energy Generation Project, Estimated Cost Public Utilities, Renewable Energy Generation Project, Estimated Cost Securities Action Securities Action [Member] Securities Action Wildfire tort-related claims Wildfire tort-related claims Loss Contingency, Accrual, Noncurrent 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 Debt Disclosure [Abstract] Debt Disclosure [Abstract] Capital distribution from former unconsolidated affiliate (financing) Proceeds From Distribution From Affiliates Proceeds From Distribution From Affiliates Segment financial information Segment Reporting [Text Block] Minimum Minimum [Member] Unsecured revolving line of credit Unsecured Revolving Line of Credit [Member] Unsecured Revolving Line of Credit Interest 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. Schedule of Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Current liabilities: Liabilities [Abstract] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Axis] Accrued unbilled revenues, net Unbilled Receivables, Current Reclassification adjustment for impact of D&Os of the PUC included in regulatory accounts, net of taxes of $152, $167, $303 and $335, respectively Reclassification adjustment for impact of D&Os of the PUC included in regulatory accounts, net of taxes of $152, $167, $303 and $335, respectively Reclassification adjustment for impact of D&Os of the PUC included in regulatory accounts, 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. Net periodic pension/benefit cost (return) Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Other assets Disposal Group, Including Discontinued Operation, Other Assets, Current Common stock, authorized shares (in shares) Common Stock, Shares Authorized Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Schedule of Restricted Stock Units Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block] Exercise Price Award Exercise Price Segment financial information Segment Reporting [Line Items] Document Quarterly Report Document Quarterly Report Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Accounts receivable and unbilled revenues, net Accounts Receivable, after Allowance for Credit Loss Repayment of long-term debt Repayment of long-term debt Repayments of Long-Term Debt Statements of Equity Condensed Financial Statements, Captions [Line Items] Less unamortized debt issuance costs Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Molokai New Energy Partners Molokai New Energy Partners [Member] Molokai New Energy Partners Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Equity method investments Equity Method Investments Equity Component [Domain] Equity Component [Domain] Advances to affiliates Proceeds From (Payments For) Contributions From Affiliates Proceeds From (Payments For) Contributions From Affiliates Adoption Date Trading Arrangement Adoption Date Counterparty Name [Domain] Counterparty Name [Domain] Electric utility subsidiary [Abstract] Electric Utility Subsidiary [Abstract] Electric utility subsidiary [Abstract] Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Risk-free interest rate Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Other Proceeds from (Payment for) Other Financing Activity Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Unusual or Infrequent Item, or Both [Domain] Unusual or Infrequent Item, or Both [Domain] Schedule of Credit Agreements Schedule of Line of Credit Facilities [Table Text Block] Contributions expected to be paid in current year Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year Letter of Credit Letter of Credit [Member] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Restricted stock units Restricted Stock Units (RSUs) [Member] All Adjustments to Compensation All Adjustments to Compensation [Member] All other Segment Reporting, Reconciling Item, Corporate Nonsegment [Member] Other Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Other Item Net cash provided by (used in) operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Shareholders’ equity Equity, Attributable to Parent [Abstract] Income Statement [Abstract] Income Statement [Abstract] Proposed re-basing, remaining implemented in second year of MRP2 Public Utilities, Increase In Proposed Re-Basing, Remaining Implemented In Second Year Public Utilities, Increase In Proposed Re-Basing, Remaining Implemented In Second Year Document Transition Report Document Transition Report Public utilities, increase in proposed re-basing Public Utilities, Increase In Proposed Re-Basing Public Utility, Increase In Proposed Re-Basing Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] City Area Code City Area Code 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 Amortization of net gains recognized during the period in net periodic benefit cost Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member] 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. Defined benefit pension liability Liability, Defined Benefit Pension Plan, Noncurrent Name Forgone Recovery, Individual Name Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] 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 Entity [Domain] Entity [Domain] Valuation allowances and reserves Accrual for Environmental Loss Contingencies Tax expense Tax Adjustments, Settlements, and Unusual Provisions Preferred stock, issued shares (in shares) Preferred Stock, Shares Issued Condensed Cash Flow Statements, Captions [Line Items] Condensed Cash Flow Statements, Captions [Line Items] Maui Wildfire Negligence Maui Wildfire Negligence [Member] Maui Wildfire Negligence Share-based expenses and other, net (in shares) Stock Issued During Period, Shares, New Issues Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Wildfire Mitigation Plan (WMP) (to be determined by the PUC) Wildfire Mitigation Plan [Member] Wildfire Mitigation Plan Share-based compensation expense Share-Based Payment Arrangement, Expense Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement Inputs and Valuation Techniques [Line Items] Fair Value Measurement Inputs and Valuation Techniques [Line Items] 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 Subsequent Event Type [Domain] Subsequent Event Type [Domain] Taxes accrued, including revenue taxes Taxes accrued, including revenue taxes Taxes Payable, Current 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 Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Entity Current Reporting Status Entity Current Reporting Status Net cash used in financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Total Shareholder Return Amount Total Shareholder Return Amount Power purchase agreement Power Purchase Agreement [Abstract] -- None. No documentation exists for this element. -- Other liabilities Disposal Group, Including Discontinued Operation, Other Liabilities, Current Capital contribution from parent of a membership interest in a former unconsolidated affiliate (financing) Proceeds from Contributions from Affiliates Approved funds, net of other existing project costs Public Utilities, Approved Funds, Net Of Other Existing Project Costs Public Utilities, Approved Funds, Net Of Other Existing Project Costs Net increase in short-term borrowings from affiliate Proceeds from (Repayments of) Short-Term Debt, Maturing in Three Months or Less Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Adjustment for amortization of net gains recognized during the period in net periodic benefit cost, net of taxes of $(158), $(175), $(317) and $(351), respectively Adjustment for amortization of net gains recognized during the period in net periodic benefit cost, net of taxes of $(167), $(184), $(335) and $(368), respectively Adjustment for amortization of net gains recognized during the period in net periodic benefit cost, net of taxes 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 Other operation and maintenance Utilities Operating Expense, Maintenance and Operations Adjustments to reconcile net income to net cash provided by (used in) operating activities Adjustments to reconcile net income to net cash provided by operating activities Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Property, plant and equipment, net of accumulated depreciation of $3,626,536 and $3,518,501 at June 30, 2026 and December 31, 2025, respectively Total property, plant and equipment, net Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization Interest cost Defined Benefit Plan, Interest Cost State of Hawaii income tax, net (including refundable credits) Income Tax Paid, State and Local, after Refund Received Number of fuel-flexible combustion turbines Public Utilities, Number Of Fuel-Flexible Combustion Turbines Public Utilities, Number Of Fuel-Flexible Combustion Turbines Hamakua Energy Hamakua Energy, LLC [Member] Represents an independent power producer (IPP) with whom the entity has entered into a power purchase agreement. Underlying Securities Award Underlying Securities Amount State refundable credit State Refundable Credit State Refundable Credit Estimated fair value Estimate of Fair Value Measurement [Member] Revenues Revenue from Contract with Customer [Text Block] Accumulated depreciation on other property, plant and equipment Property, Plant, and Equipment, Other, Accumulated Depreciation Other, net Other Payment for (Proceeds from) Other Investing Activity Schedule of Condensed Consolidating Statements of Income Condensed Income Statement [Table Text Block] Shares available for future grant (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Segment Reporting [Table] Segment Reporting [Table] Maui Electric Maui Electric Company Limited [Member] Maui Electric Company Limited [Member] Cash flows from investing activities Cash Provided by (Used in) Investing Activity, Continuing Operation [Abstract] Condensed Statement of Comprehensive Income [Table] Condensed Statement of Comprehensive Income [Table] Other Other Assets, Current All Trading Arrangements All Trading Arrangements [Member] Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Reclassification adjustment to net income, tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax Current Fiscal Year End Date Current Fiscal Year End Date Customer dividend, negative adjustment percentage Public Utilities, Customer Dividend, Negative Adjustment Percentage Public Utilities, Customer Dividend, Negative Adjustment Percentage Hawaiian Electric Industries, Inc., Hawaiian Electric Company, Inc., and Maui Electric Company, Limited Hawaiian Electric Industries, Inc., Hawaiian Electric Company, Inc., and Maui Electric Company, Limited [Member] Hawaiian Electric Industries, Inc., Hawaiian Electric Company, Inc., and Maui Electric Company, Limited 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. Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Entity File Number Entity File Number Kalaeloa Partners, L.P. Kalaeloa Partners L P [Member] Represents an independent power producer (IPP) with whom the entity has entered into a power purchase agreement. Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Measure: Measure [Axis] Schedule of Purchases From All IPPs Schedule of Variable Interest Entities [Table Text Block] Proceeds from sale of subsidiaries Proceeds from Divestiture of Interest in Subsidiaries and Affiliates Increase in materials and supplies Increase (Decrease) in Raw Materials, Packaging Materials and Supplies Inventories Equity Components [Axis] Equity Components [Axis] Risk mitigation strategies, period of implementation Risk Mitigation Strategies, Period Of Implementation Risk Mitigation Strategies, Period Of Implementation Entity Interactive Data Current Entity Interactive Data Current 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. Proceeds from contributions from parent Capital contribution from parent related to first installment payment of the Wildfire tort-related claim liability (financing) Proceeds from Contributions from Parent Entity Small Business Entity Small Business Comprehensive income attributable to Hawaiian Electric Industries, Inc. Comprehensive Income (Loss), Net of Tax, Attributable to Parent Number of putative actions dismissed Number Of Putative Actions Dismissed Number Of Putative Actions Dismissed 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] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Other Other Assets, Noncurrent Cash flows from financing activities Cash Provided by (Used in) Financing Activity, Continuing Operation [Abstract] Document Type Document Type Maui Windstorm And Wildfires Hawaiian Electric Plaintiffs Maui Windstorm And Wildfires, Hawaiian Electric Plaintiffs [Member] Maui Windstorm And Wildfires, Hawaiian Electric Plaintiffs Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Local Phone Number Local Phone Number Other benefits Other Postretirement Benefits Plan [Member] 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] Approved funds with inflationary adjustment Public Utilities, Renewable Energy Generation Project, Approved Funds With Inflationary Adjustment Public Utilities, Renewable Energy Generation Project, Approved Funds With Inflationary Adjustment Public utilities, approved estimated capital costs (as percent) Public Utilities, Approved Equity Capital Structure, Percentage Income before income taxes Income (loss) before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest 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. Commitments and contingencies (Notes 2 and 4) Commitments and contingencies (Notes 2 and 4) Commitments and Contingencies Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Income Tax Contingency [Table] Income Tax Contingency [Table] Executive Category: Executive Category [Axis] Long-term Purchase Commitment [Table] Long-Term Purchase Commitment [Table] Counterparty Name [Axis] Counterparty Name [Axis] Liabilities and shareholders’ equity Capitalization and liabilities Liabilities and Equity [Abstract] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Variable Interest Entity [Table] Variable Interest Entity [Table] Increase in materials and supplies Increase (Decrease) in Materials and Supplies Supplemental disclosures of cash flow information Supplemental Cash Flow Information [Abstract] Reclassification adjustment to net income, net of taxes of $(19), $(18), $(37) and $(35), respectively Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Number of projects Public Utilities, Exceptional Project Recovery Mechanism, Number Of Projects Public Utilities, Exceptional Project Recovery Mechanism, Number Of Projects PEO Name PEO Name Condensed Statement of Income Captions [Line Items] Condensed Statement of Income Captions [Line Items] Short-term borrowings from affiliate Other Short-Term Borrowings Unrealized gains (losses) on derivatives Net realized gains on derivatives qualifying as cash flow hedges Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Financial liabilities Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Unrealized interest rate hedging loss, net of taxes of nil, $(80), nil and $(215), respectively Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Income tax benefit from compensation expense Income tax benefit Share-Based Payment Arrangement, Expense, Tax Benefit Preferred stock dividends of subsidiaries Preferred stock dividends of Hawaiian Electric Preferred Stock Dividends, Income Statement Impact HPOWER Hpower [Member] Represents an independent power producer (IPP) with whom the entity has entered into a power purchase agreement. Increase in accounts payable Increase (Decrease) in Accounts Payable Adjustment for amortization of prior service credit and net gains recognized during the period in net periodic benefit cost, tax Adjustment for amortization of net gains 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 Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Restricted cash Restricted Cash and Cash Equivalent, Current Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Basis of presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Debt Instrument [Axis] Debt Instrument [Axis] Share-based compensation expense Share-Based Payment Arrangement, Noncash Expense Disposal Group Name [Axis] Disposal Group Name [Axis] Basic earnings per common share (in dollars per share) Earnings Per Share, Basic Total current assets Assets, Current Insider Trading Arrangements [Line Items] Long-term debt, net Long-term debt, net Long-Term Debt, Excluding Current Maturities Customer accounts receivable, net Accounts Receivable, after Allowance for Credit Loss, Current Special purpose revenue bonds and unsecured senior notes Special Purpose Revenue Bonds And Senior Notes [Member] Special purpose revenue bonds and Senior Notes, net of unamortized debt issuance costs Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Expected volatility Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate Fuel oil Utilities Operating Expense, Fuel Used Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover page. Cover [Abstract] Schedule of Condensed Financial Statements [Table] Condensed Financial Statements [Table] Fuel oil stock, at average cost Energy Related Inventory Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Measurement Inputs and Valuation Techniques [Table] Other long-term assets Assets Noncurrent Excluding Property Plant and Equipment Net [Abstract] -- None. No documentation exists for this element. -- Advances to affiliates Advances to Affiliate Derivatives qualified as cash flow hedges: Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent [Abstract] Equity Awards Adjustments Equity Awards Adjustments [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 Regulatory Asset [Domain] Regulatory Asset [Domain] 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. Estimated fair value of financial instruments Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Construction in progress Public Utilities, Property, Plant and Equipment, Construction Work in Progress Plan Name [Axis] Plan Name [Axis] Wildfire tort-related claims Wildfire tort-related claims Loss Contingency Accrual, Loss (Reversal of Loss) Settlement remeasurement Loss Contingencies, Settlement Remeasurement Loss Contingencies, Settlement Remeasurement Schedule of Share-Based Compensation Expense and Related Income Tax Benefit Share-Based Payment Arrangement, Cost by Plan [Table Text Block] Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Installment payments Litigation Settlement, Amount Awarded To Other Party, Number Of Installments Litigation Settlement, Amount Awarded To Other Party, Number Of Installments Insurance recoveries Insurance Recoveries, Including Adjustment Of Wildfire Tort-Related Claims Insurance Recoveries, Including Adjustment Of Wildfire Tort-Related Claims Preferred stock, authorized shares (in shares) Preferred Stock, Shares Authorized Reclassification adjustment for impact of D&Os of the PUC included in regulatory accounts, tax Reclassification adjustment for impact of D&Os of the PUC included in regulatory accounts, 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. Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Property, plant and equipment Public Utilities, Property, Plant and Equipment [Abstract] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Actual return on equity, dead band percentage, below target Public Utilities, Earnings Share Mechanism, Actual Return On Equity, Dead Band Percentage, Below Target Percent Public Utilities, Earnings Share Mechanism, Actual Return On Equity, Dead Band Percentage, Below Target Percent Income taxes Income Tax Disclosure [Text Block] Accounts payable Accounts Payable, Current Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] 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 Retirement Plan Type [Domain] Retirement Plan Type [Domain] Entity Filer Category Entity Filer Category Supplemental Cash Flow Elements [Abstract] Supplemental Cash Flow Elements [Abstract] Wildfire Mitigation Plan (WMP) Wildfire Mitigation Plan (WMP) [Member] Wildfire Mitigation Plan (WMP) Total Defendants Hawaiian Electric Company, Inc And Other Defendants [Member] Hawaiian Electric Company, Inc And Other Defendants Borrowing from HEI - standing commitment letter Standing Commitment Letter [Member] Standing Commitment Letter Proposed re-basing, first year of MRP2 Public Utilities, Increase In Proposed Re-Basing, First Year Public Utilities, Increase In Proposed Re-Basing, First Year Retirement benefit plans: Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent [Abstract] Project costs incurred Public Utilities, Project Costs Incurred Public Utilities, Project Costs Incurred 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 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 (in years) Public Utilities, Electric Grid Project, Period Public Utilities, Electric Grid Project, Period Entity Address, Address Line Two Entity Address, Address Line Two Net income Net income Total reclassifications Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Current assets Assets, Current [Abstract] 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. Insurance recoveries Insurance Recoveries Senior Notes Senior Notes [Member] Entity Address, Address Line One Entity Address, Address Line One Right-of-use assets obtained in exchange for operating lease obligations (investing) Right-of-Use Asset Obtained in Exchange for Operating Lease Liability 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 Outstanding Line of Credit Facility, Fair Value of Amount Outstanding Income tax expense Income tax expense (benefit) Income Tax Expense (Benefit) Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Accretion expense Accretion Expense Variable Interest Entity, Primary Beneficiary Variable Interest Entity, Primary Beneficiary [Member] Wildfire related claims Wildfire tort-related claims Loss Contingency, Accrual, Current AOCI Attributable to Parent, Net of Tax [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] Statement [Table] Statement [Table] Regulatory liabilities Regulatory Liability, Current Interest income Interest income Investment Income, Interest Total deferred credits and other liabilities Liabilities, Other than Long-Term Debt, Noncurrent Impact of D&Os of the PUC included in regulatory accounts 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] Percentage of attorney's fees requested of the proceeds Litigation Settlement, Requested Proceeds As Percentage Of Attorney's Fee Litigation Settlement, Requested Proceeds As Percentage Of Attorney's Fee Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Axis] GE Vernova Operations, LLC GE Vernova Operations, LLC [Member] GE Vernova Operations, LLC Loss contingency, damages sought, value Loss Contingency, Damages Sought, Value