Bank Segment Disclosure [Abstract] Bank Segment Disclosure [Abstract] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] American Savings Bank (ASB) American Savings Bank FSB [Member] American Savings Bank FSB Financial Instrument [Axis] Financial Instrument [Axis] Types of Financial Instruments [Domain] Financial Instruments [Domain] Allowance for mortgage-servicing assets – bank Servicing Contracts [Member] Loans receivable Accounts, Notes, Loans and Financing Receivable [Line Items] Mortgage Servicing Rights [Roll Forward] Mortgage Servicing Rights [Roll Forward] Mortgage Servicing Rights [Roll Forward] Beginning balance Servicing Asset at Amortized Cost Amount capitalized Servicing Asset at Amortized Value, Amount Capitalized Servicing Asset at Amortized Value, Amount Capitalized Amortization Servicing Asset at Amortized Cost, Amortization Sale of mortgage servicing rights Servicing Asset at Amortized Cost, Disposals Other-than-temporary impairment Servicing Asset at Amortized Cost, Other than Temporary Impairments Ending balance Valuation Allowance [Roll Forward] Valuation Allowance for Impairment of Recognized Servicing Assets [Roll Forward] Valuation allowance, beginning balance Valuation Allowance for Impairment of Recognized Servicing Assets, Balance Provision (recovery) Valuation Allowance for Impairment of Recognized Servicing Assets, Additions (Deductions) for Expenses (Recoveries) Other-than-temporary impairment Valuation allowance, ending balance Net carrying amount Servicing Asset, Net Servicing Asset, Net Estimated Aggregate Amortization Expenses of Mortgage Servicing Rights [Abstract] Estimated Aggregate Amortization Expenses of Mortgage Servicing Rights [Abstract] Estimated Aggregate Amortization Expenses of Mortgage Servicing Rights [Abstract] 2017 Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months 2018 Finite-Lived Intangible Assets, Amortization Expense, Year Two 2019 Finite-Lived Intangible Assets, Amortization Expense, Year Three 2020 Finite-Lived Intangible Assets, Amortization Expense, Year Four 2021 Finite-Lived Intangible Assets, Amortization Expense, Year Five Related Party Transactions [Abstract] Schedule of Related Party Transactions Schedule of Related Party Transactions [Table Text Block] Other related-party transactions Related Party Transactions Disclosure [Text Block] Statement of Comprehensive Income [Abstract] Net income for common stock Net Income (Loss) Available to Common Stockholders, Basic Other comprehensive income (loss), net of taxes: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] 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] Net unrealized gains (losses) on available-for sale investment securities arising during the period, net of (taxes) benefits of $3,763, $1,541 and $(3,856) for 2016, 2015 and 2014, respectively Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Less: reclassification adjustment for net realized gains included in net income, net of taxes of $238, nil and $1,132 for 2016, 2015 and 2014, respectively Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Derivatives qualified as cash flow hedges: Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent [Abstract] Effective portion of foreign currency hedge net unrealized losses arising during the period, net of tax benefits of $179, nil and nil for 2016, 2015 and 2014, respectively Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax Less: reclassification adjustment to net income, net of (taxes) benefit of $(76), $150 and $150 for 2016, 2015 and 2014, respectively Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Retirement benefit plans: Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent [Abstract] Net gains (losses) arising during the period, net of (taxes) benefits of $27,703, $(3,753) and $149,364 for 2016, 2015 and 2014, respectively Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax Less: amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of tax benefits of $9,267, $14,344 and $7,245 for 2016, 2015 and 2014, respectively Other Comprehensive Income, Reclassification of Defined Benefit Plans Net Gain (Loss), Prior Service Gain (Loss), and Net Transition Asset Obligation Recognized in Net Periodic Benefit Cost, Net of Tax The adjustment out of other comprehensive income for actuarial gains or losses, prior service gains or losses, and net transition asset or obligation recognized as a component of net periodic benefit cost during the period, after tax. Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of (taxes) benefits of $(18,206), $16,011 and $(132,373) for 2016, 2015 and 2014, respectively 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. Other comprehensive income (loss), net of taxes Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Comprehensive income attributable to Hawaiian Electric Company, Inc. Comprehensive Income (Loss), Net of Tax, Attributable to Parent Segment Reporting [Abstract] Schedule of segment financial information Schedule of Segment Reporting Information, by Segment [Table Text Block] Statement of Cash Flows [Abstract] Statement [Table] Statement [Table] Hawaiian Electric Company, Inc. and Subsidiaries Hawaiian Electric Company and Subsidiaries [Member] Represents Hawaiian Electric Company, Inc, and Subsidiaries. Statement [Line Items] Statement [Line Items] Cash flows from operating activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Adjustments to reconcile net income to net cash provided by operating activities Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation of property, plant and equipment Depreciation Other amortization Amortization Impairment of utility assets Asset Impairment Charges Deferred income taxes Deferred Income Tax Expense (Benefit) Income tax credits, net Income Tax Credits and Adjustments Allowance for equity funds used during construction Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity Change in cash overdraft Increase (Decrease) in Outstanding Checks, Operating Activities Other Other Operating Activities, Cash Flow Statement Changes in assets and liabilities Increase (Decrease) in Operating Capital [Abstract] Decrease in accounts receivable Increase (Decrease) in Accounts Receivable Decrease (increase) in accrued unbilled revenues Increase (Decrease) in Unbilled Receivables Decrease in fuel oil stock Increase (Decrease) in Fuel Inventories Decrease (increase) in materials and supplies Increase (Decrease) in Raw Materials, Packaging Materials and Supplies Inventories Increase in regulatory assets Increase (Decrease) in Other Regulatory Assets Decrease in accounts payable Increase (Decrease) in Accounts Payable 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 Increase (Decrease) In Prepaid And Accrued Income Taxes, Tax Credits, And Utility Revenue, Taxes Increase (decrease) in defined benefit pension and other postretirement benefit plans liability Increase (Decrease) in Pension and Postretirement Obligations Change in other assets and liabilities Increase (Decrease) in Other Operating Assets and Liabilities, Net Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations Cash flows from investing activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Capital expenditures Payments to Acquire Property, Plant, and Equipment Contributions in aid of construction Proceeds from Contribution in Aid of Construction Other Payments for (Proceeds from) Other Investing Activities Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations Cash flows from financing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Common stock dividends Payments of Ordinary Dividends, Common Stock Preferred stock dividends of Hawaiian Electric and subsidiaries Payments of Ordinary Dividends, Preferred Stock and Preference Stock Net proceeds from issuance of common stock Proceeds from (Repurchase of) Equity Proceeds from issuance of long-term debt Proceeds from Issuance of Long-term Debt Repayment of long-term debt Repayments of Long-term Debt Other Proceeds from (Payments for) Other Financing Activities Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations Net increase (decrease) in cash and equivalents Net Cash Provided by (Used in) Continuing Operations Cash and cash equivalents, beginning of period Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents, end of period Accounting Policies [Abstract] Tax Credit Carryforward [Table] Tax Credit Carryforward [Table] Variable Interest Entities [Axis] Variable Interest Entities [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Not Primary Beneficiary Variable Interest Entity, Not Primary Beneficiary [Member] Tax Credit Carryforward [Line Items] Tax Credit Carryforward [Line Items] Amortization recognized in the provision for income taxes Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amortization, Amount Tax credits and other tax benefits recognized in the provision for income taxes Effective Income Tax Rate Reconciliation, Tax Credits And Other Adjustments Effective Income Tax Rate Reconciliation, Tax Credits And Other Adjustments Net benefit to income tax expense Income Tax Expense (Benefit) Statement of Stockholders' Equity [Abstract] Common stock dividends (in dollars per share) Common Stock, Dividends, Per Share, Declared Schedule of Financing Receivable, Allowance for Credit Losses [Table] Schedule of Financing Receivable, Allowance for Credit Losses [Table] Portfolio Segment [Axis] Class of Financing Receivable, Type [Axis] Financing Receivable Allowance [Domain] Class of Financing Receivable, Type [Domain] 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. Commercial real estate Commercial Real Estate Portfolio Segment [Member] Home equity line of credit Home Equity Line of Credit [Member] Residential land Residential Land Portfolio Segment [Member] Portfolio segment of the company's total financing receivables related to residential land receivables. Commercial construction Construction Loans [Member] Residential construction Residential Construction Portfolio Segment [Member] Portfolio segment of the company's total financing receivables related to residential construction. Commercial loans Commercial Loan [Member] Consumer loans Consumer Loan [Member] Unallocated Unallocated Financing Receivables [Member] Allowance for loan losses Financing Receivable, Allowance for Credit Losses [Line Items] Allowance for loan losses: Financing Receivable, Allowance for Credit Losses [Roll Forward] Valuation allowance, balance at the beginning of the period Financing Receivable, Allowance for Credit Losses Charge-offs Financing Receivable, Allowance for Credit Losses, Write-downs Recoveries Financing Receivable, Allowance for Credit Losses, Recovery Provision Provision for Loan, Lease, and Other Losses Valuation allowance, balance at the end of the period Ending balance: individually evaluated for impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Ending balance: collectively evaluated for impairment Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment Financing Receivables: Financing Receivable, Net [Abstract] Total financing receivables Financing Receivable, Net Ending balance: individually evaluated for impairment Financing Receivable, Individually Evaluated for Impairment Ending balance: collectively evaluated for impairment Financing Receivable, Collectively Evaluated for Impairment Schedule of Financing Receivables Past Due [Table] Schedule of Financing Receivables Past Due [Table] Credit risk profile based on nonaccrual loans Financing Receivable, Recorded Investment, Past Due [Line Items] Nonaccrual loans Financing Receivable, Recorded Investment, Nonaccrual Status Accruing loans 90 days or more past due Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing Troubled debt restructured loans not included above Financing Receivable, Modifications, Post-Modification Recorded Investment Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract] Unconsolidated variable interest entities Unconsolidated Variable Interest Entities [Text Block] Unconsolidated Variable Interest Entities [Text Block] Compensation and Retirement Disclosure [Abstract] Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Hawaii Electric Light Company, Inc. (HELCO) Subsidiaries Two [Member] This element represents Hawaii Electric Light Company, Inc., an electric utility subsidiary of Hawaiian Electric Company, Inc. Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Defined Benefit Plans and Other Postretirement Benefit Plans [Domain] Defined Benefit Plan and Other Postretirement Benefit Plan [Domain] Pension benefits Pension Plan [Member] Other benefits Other Postretirement Benefit Plan [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Vested percentage of interest of each affected participant after participating employer terminates participation Defined Benefit Plan, Vested Percentage of Interest of Each Affected Participant after Participating Employer Terminates Participation Represents the vested percentage of interest of each affected participant if a participating employer terminates its participation in the plans up to the extent funded. Number of years for which regulatory asset/liability for each utility will be amortized, beginning with respective utility's next rate case 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. Executive life and nonqualified pension plan expenses Executive Life and Defined Benefit Plan Nonqualified Pension Plan Expenses Represents the amount of executive life and nonqualified pension plan expenses, which are not recoverable. Regulatory asset charges pretax Defined Benefit Plan, Accumulated Other Comprehensive Income Regulatory Asset Charges before Tax The pretax net amount of regulatory asset charges, which would otherwise be recorded in accumulated other comprehensive income. Retirement benefits expense Pension and Other Postretirement Benefit Expense Fair value of plan assets, valuation difference amortized in first year (as a percent) Defined Benefit Plan, Plan Assets at Fair Value Percentage of Valuation Difference Amortized in Year One Represents the percentage of valuation difference of plan assets amortized in the first year to determine market related value. Fair value of plan assets, valuation difference amortized in two to five years (as a percent) Defined Benefit Plan, Plan Assets at Fair Value Percentage of Valuation Difference Amortized in Years Two to Five Represents the percentage of valuation difference of plan assets amortized in two to five years to determine market related value. Number of past years for adding or subtracting the unamortized differences from fair value Defined Benefit Plan, Number of Past Years for Adding or Subtracting Unamortized Differences from Fair Value Represents the number of past years for adding or subtracting the unamortized differences from the fair value. Percentage of range around fair value Defined Benefit Plan, Plan Assets at Fair Value Range Around Fair Value Percentage Represents the percentage of the range around the fair value in valuation method. Threshold percentage around fair value Defined Benefit Plan, Plan Assets at Fair Value Threshold Percentage around Fair Value Represents the threshold percentage to measure amounts to be recognized. Expected rate of return on plan assets (as a percent) Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost Expected Rate of Return on Assets for Next Fiscal Year An assumption for the next fiscal year as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation. Discount rate (as a percent) Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate, Including Active Manager Premium Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate, Including Active Manager Premium Actual net return on plan assets (as a percent) Defined Benefit Plan, Actual Return On Assets, Percent Defined Benefit Plan, Actual Return On Assets, Percent Assumed discount rate, active manager premium Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Assumed Discount Rate, Active Manager Premium Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Assumed Discount Rate, Active Manager Premium Assumed health care trend rate for medical in next fiscal year (as a percent) Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Medical Plan in Next Fiscal Year The assumed health care cost trend rate for the next year used to measure the expected cost of benefits covered by the medical plan under the defined benefit plan (gross eligible charges). This is based upon the annual rate of change in the cost of health care benefits currently provided by the postretirement benefit plan, due to factors other than changes in the composition of the plan population by age and dependency status. Assumed health care trend rate for grading down plan in 12 fiscal years thereafter (as a percent) Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Grading Down Plan in Twelve Fiscal Years Thereafter Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Grading Down Plan in Twelve Fiscal Years Thereafter Assumed health care trend rate for dental in next fiscal year (as a percent) Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Dental Plan in Next Fiscal Year The assumed health care cost trend rate for the next year used to measure the expected cost of benefits covered by the dental plan under the defined benefit plan (gross eligible charges). This is based upon the annual rate of change in the cost of health care benefits currently provided by the postretirement benefit plan, due to factors other than changes in the composition of the plan population by age and dependency status. Assumed health care trend rate for vision in next fiscal year (as a percent) Defined Benefit Plan Health Care Cost Trend Rate Assumed for Vision Plan in Next Fiscal Year The assumed health care cost trend rate for the next year used to measure the expected cost of benefits covered by the vision plan under the defined benefit plan (gross eligible charges). This is based upon the annual rate of change in the cost of health care benefits currently provided by the postretirement benefit plan, due to factors other than changes in the composition of the plan population by age and dependency status. Assumed health care trend rate for grading down in 2024 and thereafter (as a percent) Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Grading Down Plan in Nine Fiscal Years Thereafter Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Grading Down Plan in Nine Fiscal Years Thereafter Pension expense Pension Expense Less Public Utilities Commission Impact and Capitalized Amounts The amount of pension benefit costs recognized during the period for defined benefit plans. Pension expense includes the following components: service cost, interest cost, expected return on plan assets, gain (loss) on plan assets, prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments, less the impact of Public Utilities Commission decisions and orders and capitalized amounts. Postretirement benefits other than pension expense Other Postretirement Benefit Expense Effect of one-percentage-point increase in assumed health care cost trend rates that would have increased total service and interest cost Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components Effect of one-percentage-point increase in assumed health care cost trend rates that would have increased the accumulated postretirement benefit obligation (APBO) Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation Effect of one-percentage-point decrease that would have reduced total service and interest cost Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components Effect of one-percentage-point decrease that would have reduced APBO Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation Defined benefit pension plans with accumulated benefit obligations in excess of plan assets Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets [Abstract] Aggregate accumulated benefit obligations Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Accumulated Benefit Obligation Plan assets Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets Defined benefit plans with benefit obligations in excess of plan assets Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets [Abstract] Aggregate projected benefit obligations Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets, Aggregate Benefit Obligation Plan assets Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets Expected cash funding for qualified defined benefit plans Defined Benefit Plan Estimated Future Benefit Funding [Abstract] -- None. No documentation exists for this element. -- Estimate of contributions to postretirement benefit plans in 2015 Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year 2017 Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months 2018 Defined Benefit Plan, Expected Future Benefit Payments, Year Two 2019 Defined Benefit Plan, Expected Future Benefit Payments, Year Three 2020 Defined Benefit Plan, Expected Future Benefit Payments, Year Four 2021 Defined Benefit Plan, Expected Future Benefit Payments, Year Five 2022 through 2025 Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter Maximum percentage of participant deferrals eligible for Employer contribution match, towards defined contribution plan Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay Employer's additional matching contribution on employee deferrals (as a percent) Defined Contribution Plan, Employer Matching Contribution, Percent of Match Defined contribution plan, expenses recognized Defined Contribution Plan, Cost Recognized Cash contributions by the employer to defined contribution plan Defined Contribution Plan, Contributions by Employer Represents the contributions made by the employer in defined contribution plan. Income Tax Disclosure [Abstract] Income Tax Expense (Benefit) [Table] Income Tax Expense (Benefit) [Table] Income Tax Expense (Benefit) [Table] Income Tax Authority [Axis] Income Tax Authority [Axis] Income Tax Authority [Domain] Income Tax Authority [Domain] Federal Tax Authority Domestic Tax Authority [Member] Tax Credit Carryforward [Axis] Tax Credit Carryforward [Axis] Tax Credit Carryforward, Name [Domain] Tax Credit Carryforward, Name [Domain] General Business Tax Credit Carryforward General Business Tax Credit Carryforward [Member] Income Tax Expense (Benefit) [Line Items] Income Tax Expense (Benefit) [Line Items] [Line Items] for Income Tax Expense (Benefit) [Table] Reconciliation percentage of amount of income taxes computed at federal statutory rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Net operating loss Operating Loss Carryforwards Federal general business credit carryforward Tax Credit Carryforward, Amount Unrecognized tax benefits Unrecognized Tax Benefits Credit adjustments to interest expense on income taxes Unrecognized Tax Benefits, Interest on Income Taxes Expense Amount of accrued interest related to uncertain tax positions Unrecognized Tax Benefits, Interest on Income Taxes Accrued Expected increase in depreciation expense Income Tax Expense, Expected Increase In Depreciation Expense, Amount Income Tax Expense, Expected Increase In Depreciation Expense, Amount Renewable energy investment tax credit, percent Income Tax Expense, Tax Credit, Renewable Energy, Investment, Percent Income Tax Expense, Tax Credit, Renewable Energy, Investment, Percent Statement of Financial Position [Abstract] ASSETS Assets [Abstract] Cash and cash equivalents Cash, Cash Equivalents, and Federal Funds Sold Accounts receivable and unbilled revenues, net Accounts Receivable, Net Available-for-sale investment securities Available-for-sale Securities Stock in Federal Home Loan Bank, at cost Federal Home Loan Bank Stock Loans receivable held for investment, net Loans and Leases Receivable, Net Amount Loans held for sale, at lower of cost or fair value Loans Receivable Held-for-sale, Net, Not Part of Disposal Group Property, plant and equipment, net Property, Plant and Equipment, Net [Abstract] Land Land Plant and equipment Machinery and Equipment, Gross Construction in progress Construction in Progress, Gross Property, plant and equipment, gross Property, Plant and Equipment, Gross Less – accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Total property, plant and equipment, net Property, Plant and Equipment, Net Regulatory assets Regulatory Assets Other Other Assets Goodwill Goodwill Total assets Assets LIABILITIES AND SHAREHOLDERS' EQUITY Liabilities and Equity [Abstract] Liabilities Liabilities [Abstract] Accounts payable Accounts Payable Interest and 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. Deposit liabilities Deposits Short-term borrowings—other than bank Other Short-term 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. Long-term debt, net—other than bank Long-term Debt Deferred income taxes Deferred Tax Liabilities, Net Regulatory liabilities Regulatory Liabilities Contributions in aid of construction Contributions in Aid of Construction Defined benefit pension and other postretirement benefit plans liability Pension and Other Postretirement Defined Benefit Plans, Liabilities Other Other Liabilities Total liabilities Liabilities Preferred stock of subsidiaries - not subject to mandatory redemption Temporary Equity, Carrying Amount, Including Portion Attributable to Noncontrolling Interests Commitments and contingencies Commitments and Contingencies Shareholders' equity Stockholders' Equity Attributable to Parent [Abstract] Preferred stock, no par value, authorized 10,000,000 shares; issued: none Preferred Stock, Value, Issued Common stock, no par value, authorized 200,000,000 shares; issued and outstanding: 108,583,413 shares and 107,460,406 shares at December 31, 2016 and 2015, respectively Common Stocks, Including Additional Paid in Capital, Net of Discount Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss, net of tax benefits Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Net unrealized losses on securities Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Unrealized losses on derivatives Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax 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. Accumulated other comprehensive loss, net of tax benefits Accumulated Other Comprehensive Income (Loss), Net of Tax Total shareholders’ equity Stockholders' Equity Attributable to Parent Total capitalization and liabilities Liabilities and Equity Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Equity and Incentive Plan (EIP) 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. Stock Option and Incentive Plan (SOIP) Stock Option and Incentive Plan [Member] Represents Stock Option and Incentive Plan (SOIP) as awarded by a company to their employees as a form of incentive compensation. Nonemployee Director Stock Plan Nonemployee Director Stock Plan [Member] Nonemployee Director Stock Plan [Member] Award Type [Axis] Award Type [Axis] Award Type [Domain] Equity Award [Domain] Stock appreciation rights (SARs) Stock Appreciation Rights (SARs) [Member] Restricted shares Restricted Stock [Member] Long-term incentive plan (LTIP) 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. Stock Compensation Plan Stock Compensation Plan [Member] Restricted stock units Restricted Stock Units (RSUs) [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. Share-based compensation Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Additional shares available for issuance Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Shares remaining available for future issuance 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. Shares that can be issued upon vesting of outstanding units and achievement of performance goals 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. Percentage of award exercisable in installments Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Period during which the award vests and becomes exercisable in installments Share-based Compensation Arrangement by Share-based Payment Award, Exercisable in Installments Period Represents the number of years over which the award vests and becomes exercisable in installments under the plan. Period award expires if not exercised Share Based Compensation Arrangements by Share Based Payment Award, Options, Expiration Term The period of time, from the grant date until the time at which the share-based [option] award expires. The number of equal annual increments for which the awards become unrestricted (in installments) Share-based Compensation Arrangement by Share-based Payment Award, Annual Increments upon which Restricted Awards Become Unrestricted Number The number of annual increments, on the anniversaries of the grant date, upon which restricted awards become unrestricted. Performance period Share-based Compensation Arrangement by Share-based Payment Award, Award Performance Period Share-based Compensation Arrangement by Share-based Payment Award, Award Performance Period Exception to forfeiture, minimum requisite service period Share-based Compensation Arrangement by Share-based Payment Award, Award Exception to Forfeiture Requisite Service Period, Minimum Represents the requisite minimum months of service in the performance period required in order to qualify for the forfeiture exception in the event of death, disability and retirement, on completion of requisite minimum months of service. Shares remaining available for future issuance Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Share-based compensation expense (in dollars) Allocated Share-based Compensation Expense Fair value of vested stock (in dollars) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Income tax benefit (in dollars) Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Unrecognized compensation cost Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Weighted-average period over which unrecognized compensation cost expected to be recognized Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Payout low end of range (as a percent) 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. Payout high end of range (as a percent) 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. Electric utility subsidiary -- None. No documentation exists for this element. -- Concentration Risk [Table] Concentration Risk [Table] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Operating revenues Regulated Operating Revenue, Electric, Non Nuclear [Member] Represents regulated power revenues recognized during the period. Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Customer concentration Customer Concentration Risk [Member] Major Customers [Axis] Customer [Axis] Name of Major Customer [Domain] Customer [Domain] Various federal government agencies Federal Government Agencies [Member] Represents various government agencies. Major customers Concentration Risk [Line Items] Operating revenues percentage Concentration Risk, Percentage Operating revenues amount Concentration Risk Amount Represents the concentration risk amount. Residential loan Residential Mortgage [Member] Proceeds from sale of mortgage loans Proceeds from Sale of Mortgage Loans Held-for-sale Gain on sale of mortgage loans Gain (Loss) on Sale of Mortgage Loans Repurchased mortgage loans Mortgage Loans on Real Estate, Repurchases Mortgage Loans on Real Estate, Repurchases Mortgage servicing fees Fees and Commissions, Mortgage Banking and Servicing Servicing Assets and servicing liabilities, basis spread Risks Inherent in Servicing Assets and Servicing Liabilities, Basis Spread Risks Inherent in Servicing Assets and Servicing Liabilities, Basis Spread Net unrealized gains (losses) on securities arising during the period, taxes Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax Less: reclassification adjustment for net realized gains included in net income, taxes Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax Foreign currency hedge net unrealized loss, tax benefits Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax Less: reclassification adjustment to net income, net of tax benefits of $150, $150 and $150 for 2015, 2014 and 2013, respectively Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax Net gains (losses) arising during the period, tax benefits Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Tax Less: amortization of net loss, prior service gain and transition obligation included in net periodic benefit cost, tax benefits Other Comprehensive Income, Reclassification of Defined Benefit Plans Net Gain (Loss), Prior Service Gain (Loss), and Reclassification of Defined Benefit Plan Net Transition Asset Obligation Recognized in Net Periodic Benefit Cost, Tax Tax effect on adjustment out of other comprehensive income for actuarial gains or losses, prior service gains or losses, and net transition asset or obligation recognized as a component of net periodic benefit cost during the period. Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of (taxes) benefits of ($132,373), $141,777 and ($48,299) for 2015, 2014 and 2013, respectively 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. Adjustments to reconcile net income to net cash provided by operating activities Provision for loan losses Provision for Loan and Lease Losses Loans receivable originated and purchased, held for sale Payments for Origination and Purchases of Loans Held-for-sale Proceeds from sale of loans receivable, held for sale Proceeds from Sale of Loans Held-for-sale Deferred income taxes Share-based compensation expense Share-based Compensation Excess tax benefits from share-based payment arrangements Excess Tax Benefit from Share-based Compensation, Operating Activities Decrease (increase) in accounts receivable and unbilled revenues, net Increase (Decrease) in Receivables Decrease 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. Available-for-sale investment securities purchased Payments to Acquire Available-for-sale Securities Principal repayments on available-for-sale investment securities Proceeds from Principal Repayments on Investment and Mortgage Related Securities The net cash inflow (outflow) resulting from principal repayments on investment and mortgage-related securities. Proceeds from sale of available-for-sale investment securities Proceeds from Sale of Available-for-sale Securities Purchase of stock from Federal Home Loan Bank Payments to Acquire Federal Home Loan Bank Stock Redemption of stock from Federal Home Loan Bank Proceeds from Sale of Federal Home Loan Bank Stock Net increase in loans held for investment Payments for (Proceeds from) Loans and Leases Proceeds from sale of commercial loans Proceeds from Sale of Loans Receivable Proceeds from sale of real estate acquired in settlement of loans Proceeds from Sale of Wholly Owned Real Estate and Real Estate Acquired in Settlement of Loans Proceeds from sale of real estate held for sale Proceeds from Sale of Property Held-for-sale Net increase in deposit liabilities Increase (Decrease) in Deposits Net increase (decrease) in short-term borrowings with original maturities of three months or less Proceeds from (Repayments of) Short-term Debt, Maturing in Three Months or Less Net increase (decrease) in retail repurchase agreements Increase (Decrease) in Retail Repurchase Agreements The decrease in retail repurchase agreements, during the period. Proceeds from other bank borrowings Proceeds from Other Bank Borrowings The amount of cash inflows resulting from other bank borrowings. Repayments of other bank borrowings Repayments of Other Bank Borrowings The amount of cash outflows resulting from repayment of other bank borrowings. Excess tax benefits from share-based payment arrangements Excess Tax Benefit from Share-based Compensation, Financing Activities Preferred stock dividends of subsidiaries Payments of Ordinary Dividends, Noncontrolling Interest Cash and cash equivalents, January 1 Cash and cash equivalents, December 31 Schedule of Condensed Financial Statements [Table] Condensed Financial Statements [Table] Condensed Financial Statements, Captions [Line Items] Condensed Financial Statements, Captions [Line Items] Assets Interest-bearing deposits Interest-bearing Deposits in Banks and Other Financial Institutions Restricted cash Restricted Cash and Cash Equivalents Available-for-sale investment securities, at fair value Stock in Federal Home Loan Bank, at cost Loans receivable held for investment Loans and Leases Receivable, Net of Deferred Income Allowance for loan losses Loans and Leases Receivable, Allowance Total loans, net Deposit liabilities-noninterest-bearing Noninterest-bearing Deposit Liabilities Deposit liabilities-interest-bearing Interest-bearing Deposit Liabilities Other borrowings Other Borrowings Commitments and contingencies Common stock Common Stock, Value, Issued Additional paid in capital Additional Paid in Capital, Common Stock Retirement benefit plans Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax Other assets Other Assets [Abstract] Bank-owned life insurance Bank Owned Life Insurance Premises and equipment, net Prepaid expenses Prepaid Expense Accrued interest receivable Interest Receivable Mortgage servicing rights Low-income housing equity investments Affordable Housing Program Equity Investment Affordable Housing Program Equity Investment Real estate acquired in settlement of loans, net Real Estate Acquired Through Foreclosure Other Other Assets, Miscellaneous Total other assets Other liabilities Other Liabilities [Abstract] Accrued expenses Accrued Liabilities Federal and state income taxes payable Accrued Income Taxes 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. Advance payments by borrowers Advance Payments by Borrowers for Taxes and Insurance Other Other Sundry Liabilities Total other liabilities Effective portion of foreign currency hedge net unrealized losses arising during the period, net of tax benefits of $179, nil and nil for 2016, 2015 and 2014, respectively Less: reclassification adjustment to net income, net of taxes of $110, nil and nil for 2016, 2015 and 2014, respectively Net gains (losses) arising during the period, net of (taxes) benefits of nil, $(59) and $6,164 for 2016, 2015 and 2014, respectively Less: amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of tax benefits of $566, $1,011 and $561 for 2016, 2015 and 2014, respectively Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of (taxes) benefits of $(18,206), $16,011 and $(132,373) for 2016, 2015 and 2014, respectively Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Affiliated Entity Affiliated Entity [Member] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Hawaii Medical Service Association (HMSA) Hawaii Medical Service Association (HMSA) [Member] Hawaii Medical Service Association (HMSA) [Member] Hawaii Dental Service (HDS) Hawaii Dental Service (HDS) [Member] Hawaii Dental Service (HDS) [Member] Related Party Transaction [Axis] Related Party Transaction [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] Gross costs Related Party Expense, Gross [Member] Related Party Expense, Gross [Member] Net expense Related Party Expense, Net [Member] Related Party Expense, Net [Member] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Expenses from related party transactions Related Party Transaction, Expenses from Transactions with Related Party Federal Federal Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal current taxes Current Federal Tax Expense (Benefit) Federal deferred taxes Deferred Federal Income Tax Expense (Benefit) Deferred tax credits, net Deferred Federal Tax Credits, Net The component of income tax expense for the period representing federal tax credits recognized during the period. Federal taxes Federal Income Tax Expense (Benefit), Continuing Operations State State and Local Income Tax Expense (Benefit), Continuing Operations [Abstract] Current Current State and Local Tax Expense (Benefit) Deferred Deferred State and Local Income Tax Expense (Benefit) Deferred tax credits, net Deferred State and Local Tax Credits, Net The component of income tax expense for the period representing state tax credits recognized during the period. State taxes State and Local Income Tax Expense (Benefit), Continuing Operations Federal and state taxes Fair Value Disclosures [Abstract] Fair value measurements Fair Value Disclosures [Text Block] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair value measurements on a recurring basis Fair Value, Measurements, Recurring [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Level 3 Fair Value, Inputs, Level 3 [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Other Other Segments [Member] Bank Banking Segment [Member] Represents information about the banking business segment of the company. Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] Major Types of Debt and Equity Securities [Domain] Mortgage-related securities-FNMA, FHLMC and GNMA Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] U.S. Treasury and federal agency obligations US Treasury and Government [Member] Mortgage revenue bond Asset-backed Securities [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest Rate Lock Commitments Interest Rate Lock Commitments [Member] Forward commitments Forward Contracts [Member] Foreign Exchange Forward Foreign Exchange Forward [Member] Fair value measurements on a recurring and nonrecurring basis Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Money market funds Money Market Funds, at Carrying Value Derivative assets Derivative Asset Derivative liabilities Derivative Liability 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] Balance at December 31, 2015 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Principal payments received Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases 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) Balance at December 31, 2016 Weighted average discount rate Fair Value Inputs, Discount Rate Risks and Uncertainties [Abstract] Percentage of benchmark loan to appraisal ratio in excess of 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. Net unrealized gains (losses) on available-for sale investment securities: Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax [Abstract] Retirement benefit plans: Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract] Accumulated depreciation on other property, plant and equipment Property, Plant and Equipment, Other, Accumulated Depreciation Electric utility subsidiary [Abstract] Electric utility subsidiary [Abstract] HECO Subsidiaries [Member] MECO Subsidiaries Three [Member] This element represents Maui Electric Company, Limited, an electric utility subsidiary of Hawaiian Electric Company, Inc. Other subsidiaries Renewable Hawaii Company [Member] A wholly owned subsidiary of Hawaiian Electric Company, Inc. Consolidating adjustments Consolidation Reclassifications and Eliminations [Member] Reclassifications and eliminating entries used in consolidating a parent entity and its subsidiaries. HECO Consolidated Increase (decrease) in stockholders' equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning Balance Net income for common stock Other comprehensive income (loss), net of tax benefits Issuance of common stock, net of expenses Stock Issued During Period Value Dividend Reinvestment and Stock Purchase Plan The value of stock that is newly issued during the period from a dividend reinvestment and stock purchase plan (DRIP). The DRIP allows the holder of the stock to reinvest dividends paid to them by the entity in stock of the entity and to make optional cash investments in stock of the entity. Common stock dividends Dividends, Common Stock, Cash Ending Balance Condensed Financial Information of Parent Company Only Disclosure [Abstract] SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT Condensed Financial Information of Parent Company Only Disclosure [Text Block] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Capitalized share-based compensation expense Employee Service Share-based Compensation, Allocation of Recognized Period Costs, Capitalized Amount Electric utility segment Electric Utility Subsidiary [Text Block] This element encapsulates disclosures pertaining to electric utility subsidiary. Basis of presentation Use of Estimates, Policy [Policy Text Block] Consolidation Consolidation, Policy [Policy Text Block] Cash and cash equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Equity method Equity Method Investments, Policy [Policy Text Block] Property, plant and equipment Property Plant and Equipment Cost [Policy Text Block] Disclosure of accounting policy for property, plant and equipment cost which may include the basis of such assets, the entities capitalization policy, including its accounting treatment for cost incurred for repairs and maintenance activities (excluding overhauls of generating units), how disposals of such assets are accounted for and how impairment of such assets is assessed and recognized. Depreciation Depreciation, Depletion, and Amortization [Policy Text Block] Leases Lease, Policy [Policy Text Block] Retirement benefits Pension and Other Postretirement Plans, Policy [Policy Text Block] Environmental expenditures Environmental Costs, Policy [Policy Text Block] Financing costs Debt, Policy [Policy Text Block] Income taxes Income Tax, Policy [Policy Text Block] Fair value measurements Fair Value Measurement, Policy [Policy Text Block] Earnings per share (HEI only) Earnings Per Share, Policy [Policy Text Block] Impairment of long-lived assets and long-lived assets to be disposed of Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Recent accounting pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Reclassifications Reclassification, Policy [Policy Text Block] Electric utility Electric Utility [Abstract] -- None. No documentation exists for this element. -- Regulation by the Public Utilities Commission of the State of Hawaii (PUC) Public Utilities, Policy [Policy Text Block] Accounts receivable Receivables, Policy [Policy Text Block] Contributions in aid of construction Contributions in Aid of Construction [Policy Text Block] Describes the entity's methodology for contributions in aid of construction. Electric utility revenues Utility, Revenue and Expense Recognition, Policy [Policy Text Block] Power purchase agreements Power Purchase Agreements [Policy Text Block] Describes the entity's accounting policy for power purchase agreements. Repairs and maintenance costs Repairs and Maintenance Costs [Policy Text Block] Describes the entity's accounting policy for repairs and maintenance costs on overhauls of generating units. Allowance for funds used during construction (AFUDC) Allowance for Funds Used During Construction, Policy [Policy Text Block] Bank Bank [Abstract] -- None. No documentation exists for this element. -- Investment securities Investment, Policy [Policy Text Block] Loans receivable Finance, Loan and Lease Receivables, Held-for-investment, Policy [Policy Text Block] Loans held for sale, gain on sale of loans, and mortgage servicing assets and liabilities Loans Held-for-sale Gain on Sale of Loans and Mortgage Servicing Assets or Liabilities [Policy Text Block] Describes an entity's accounting policy for loans held for sale, gain on sale of loans, and mortgage servicing assets and liabilities. Allowance for loan losses Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block] Nonperforming loans Loans and Leases Receivable, Nonperforming Loan and Lease, Policy [Policy Text Block] Loans modified in a troubled debt restructuring Loans and Leases Receivable, Troubled Debt Restructuring Policy [Policy Text Block] Real estate acquired in settlement of loans Loans and Leases Receivable, Real Estate Acquired Through Foreclosure, Policy [Policy Text Block] Goodwill Goodwill and Intangible Assets, Policy [Policy Text Block] Mortgage banking Loans and Leases Receivable, Mortgage Banking Activities, Policy [Policy Text Block] Tax Credit Investments Investments, Affordable Housing Tax Credits, Policy [Policy Text Block] Investments, Affordable Housing Tax Credits, Policy [Policy Text Block] Hawaiian Electric Industries, Inc. Parent Company [Member] Consolidated subsidiary Consolidated Subsidiary [Member] Consolidated Subsidiary [Member] Management and administrative services Management and Administrative Services [Member] Management and Administrative Services [Member] Borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Obligation to contribute additional capital under the Capital Maintenance Agreement Obligation to Contribute Additional Capital under Capital Maintenance Agreement Represent the amount of maximum obligation to contribute additional capital under the Capital Maintenance Agreement. Reduction in obligation to contribute additional capital under the Capital Maintenance Agreement Remaining Obligation to Contribute Additional Capital under Capital Maintenance Agreement Represent the remaining amount of maximum obligation to contribute additional capital under the Capital Maintenance Agreement. Cash dividends paid Cash Dividends Paid to Parent Company Revenue from related party Revenue from Related Parties Prepaid assessment rate for financial institutions, lowest risk category Prepaid Assessment Rate for Financial Institutions in Lowest Risk Category Represents the rate used to determine the prepaid risk-based assessments for financial institutions in the lowest risk category. Prepaid assessment rate for financial institutions, highest risk category Prepaid Assessment Rate for Financial Institutions in Highest Risk Category Represents the rate used to determine the prepaid risk-based assessments for financial institutions in the highest risk category. Amount charged to subsidiaries for general management and administrative services Related Party Transaction, Amounts of Transaction Due to related parties Due to Related Parties, Current Effective interest rate basis term Debt Instrument Interest Rate Basis Term of Commercial Paper Represents the term of commercial paper, the average effective interest rate of which is used as a basis for calculating the interest rate of the debt instrument. Line of credit facility basis point spread (as a percent) Debt Instrument, Basis Spread on Variable Rate Interest expense, related party Interest Expense, Related Party Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common stock Common Stock [Member] Premium on capital stock Additional Paid-in Capital [Member] Retained earnings Retained Earnings [Member] Accumulated other comprehensive income (loss) AOCI Attributable to Parent [Member] Balance (in shares) Common Stock, Shares, Issued Issuance of common stock, net of expenses Stock Issued During Period, Value, New Issues Issuance of common stock, net of expenses (in shares) Stock Issued During Period, Shares, New Issues Common stock dividends Balance (in shares) Retirement benefits Pension and Other Postretirement Benefits Disclosure [Text Block] Defined Benefit Plan, Asset Categories [Axis] Defined Benefit Plan, Asset Categories [Axis] Plan Asset Categories [Domain] Plan Asset Categories [Domain] Equity Securities, Measured at Fair Value and Net Asset Value Equity Securities, Measured At Fair Value And Net Asset Value [Member] Equity Securities, Measured At Fair Value And Net Asset Value [Member] Equity securities Equity Securities [Member] U.S. Equity Index Fund U.S. Equity Index Fund [Member] U.S. Equity Index Fund [Member] Non-U.S. Equity Funds Non-U.S. Equity Fund [Member] Non-U.S. Equity Fund [Member] Fixed Income Funds, Measured at Fair Value and Net Asset Value Fixed Income Funds, Measured At Fair Value And Net Asset Value [Member] Fixed Income Funds, Measured At Fair Value And Net Asset Value [Member] Total fixed income investments Fixed Income Funds [Member] Cash Equivalents Cash and Cash Equivalents [Member] Fair value measurements on a recurring basis Fair value of plan assets Defined Benefit Plan, Fair Value of Plan Assets NAV of plan assets Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets Cash, receivables and payables, net Defined Benefit Plan, Fair Value Of Plan Assets, Cash, Receivables, And Payables, Net Represents the accounts receivable and payable as categorized in the footnote disclosures to the financial statements. Fair value of plan assets, net Defined Benefit Plan, Assets, Fair Value Disclosure, Net Of Adjustment Defined Benefit Plan, Assets, Fair Value Disclosure, Net Of Adjustment Redemption notice period (in days) Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Redemption Restriction, Period in Effect Redemption frequency, daily Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Redemption Frequency, Percent, Daily Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Redemption Frequency, Percent, Daily Redemption frequency, monthly Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Redemption Frequency, Percent, Monthly Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Redemption Frequency, Percent, Monthly Redemption frequency, quarterly Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Redemption Frequency, Percent, Quarterly Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Redemption Frequency, Percent, Quarterly Share-based Compensation, Restricted Shares [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Outstanding, beginning of period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Increased above target (in shares) Share-based Compensation Arrangement by Share-based Payment Award Equity Instruments Other than Options Cancelled in Period The number of equity-based payment instruments, excluding stock (or unit) options, that were cancelled during the reporting period. Forfeited Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Outstanding, end of period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Outstanding, beginning 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 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 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 Increased above target (in dollars per share) Share Based Compensation Arrangement by Share based Payment Award, Equity Instruments Other than Options, Cancelled in Period, Weighted Average Grant Date Fair Value The weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect during the reporting period as a result of the cancelled in during the period. 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 Outstanding, end of period (in dollars per share) Total weighted-average grant-date fair value 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). Income Tax Contingency [Table] Income Tax Contingency [Table] Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] Changes in total unrecognized tax benefits Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Unrecognized tax benefits, at the beginning of the period Reductions based on tax positions taken during the year Unrecognized Tax Benefits, Decrease Resulting from Current Period Tax Positions Additions for tax positions of prior years Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Settlements Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities Unrecognized tax benefits, at the end of the period Regulatory Capital Requirements [Abstract] Schedule of Restricted Regulatory Assets [Table] Schedule of Restricted Regulatory Assets [Table] Represents the table of regulatory assets which are restricted to transfer without Public Utilities Commission approval. Regulatory restrictions on net assets Schedule of Restricted Regulatory Assets [Line Items] -- None. No documentation exists for this element. -- Restrictions on transfer of net assets to the parent in the form of cash dividends, loans and advances Amount of Restricted Net Assets for Consolidated and Unconsolidated Subsidiaries Amount of net assets available for transfer Amount of Net Assets Available for Transfer Represents the amount of net assets that are available for transfer in the form of dividends to the parent company while maintaining a "well-capitalized" position. Long-term Debt, Unclassified [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Term loan Secured Debt [Member] Senior notes Senior Notes [Member] Line of credit facility Line of Credit [Member] Unsecured Debt Unsecured Debt [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Special purpose revenue bonds issued on behalf of electric utility subsidiaries Bonds Issued on Behalf of Electric Utility Subsidiaries [Member] Represents the information pertaining to special revenue purpose bonds issued on behalf of subsidiaries by the parent company. HEI Term loan LIBOR .75%, due 2017 HEI Term Loan, LIBOR Plus .75% Due 2017 [Member] HEI Term Loan, LIBOR Plus .75% Due 2017 [Member] HEI term loan LIBOR .75%, due 2018 HEI Term Loan, LIBOR Plus .75% Due 2018 [Member] HEI Term Loan, LIBOR Plus .75% Due 2018 [Member] HEI senior note 4.41%, paid 2016 Senior Notes 4.41 Percent Due 2016 [Member] Represents the information pertaining to senior notes, bearing an interest rate of 4.41 percent, due in 2016. HEI senior note 5.67%, due 2021 Senior Notes 5.67 Percent Due 2021 [Member] Represents the information pertaining to senior notes, bearing an interest rate of 5.67 percent, due in 2021. HEI senior note 3.99%, due 2023 Series 2013A Senior Notes 3.99 Percent Due2023 [Member] Represents information pertaining to the Series 2013 A Senior notes, bearing an interest rate of 3.99 percent, which are due in 2023. Bank of American Term Loan Bank Of American Term Loan Expiring March 23, 2018 [Member] Bank Of American Term Loan Expiring March 23, 2018 [Member] Eurodollar Term Loan Eurodollar Term Loan [Member] Eurodollar Term Loan [Member] Senior Notes, 4.41% Senior Notes, 4.41% [Member] Senior Notes, 4.41% [Member] Hawaiian Electric, 5.23%, Series 2015A, due 2045 Hawaiian Electric, Senior Notes Due 2045, 5.23% [Member] Hawaiian Electric, Senior Notes Due 2045, 5.23% [Member] Hawaii Electric Light, 5.23%, Series 2015A, due 2045 Hawaiian Electric Light, Senior Notes Due 2045, 5.23% [Member] Hawaiian Electric Light, Senior Notes Due 2045, 5.23% [Member] 3.25% Refunding Series 2015 SPRBs due 2025 3.25% Refunding Series 2015 SPRBs due 2025 [Member] 3.25% Refunding Series 2015 SPRBs due 2025 [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. HELCO Hawaii Electric Light Company, Inc [Member] Hawaii Electric Light Company, Inc [Member] MECO Maui Electric Company Limited [Member] Maui Electric Company Limited [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] LIBOR London Interbank Offered Rate (LIBOR) [Member] Long-term debt Debt Instrument [Line Items] Total long-term debt Long-term Debt, Gross Less unamortized debt issuance costs Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Long-term debt Aggregate principal payments Long-term Debt, Fiscal Year Maturity [Abstract] 2017 Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months 2018 Long-term Debt, Maturities, Repayments of Principal in Year Two 2019 Long-term Debt, Maturities, Repayments of Principal in Year Three 2020 Long-term Debt, Maturities, Repayments of Principal in Year Four 2021 Long-term Debt, Maturities, Repayments of Principal in Year Five Debt instrument, face amount Debt Instrument, Face Amount Initial interest rate (as a percent) Line Of Credit Facility, Interest Rate For Initial Month Line Of Credit Facility, Interest Rate For Initial Month Subsequent interest rate (as a percent) Line Of Credit Facility, Interest Rate For Subsequent Periods Line Of Credit Facility, Interest Rate For Subsequent Periods Debt instrument, stated interest rate (as a percent) Debt Instrument, Interest Rate, Stated Percentage Advances to affiliates Advances to Affiliate 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). Schedule of Regulatory Assets and Liabilities [Table] Schedule of Regulatory Assets and Liabilities [Table] A table of assets and liabilities that are created when regulatory agencies permit public utilities to defer certain costs and revenues that are included in rate-setting to the balance sheet. Regulatory projects and legal obligations Regulatory Projects and Legal Obligations [Line Items] -- None. No documentation exists for this element. -- Number of orders from regulatory agency Public Utilities Orders from Regulatory Agency Number Public Utilities Orders from Regulatory Agency Number Period to file required plan Public Utilities, Regulatory Filing Period Public Utilities, Regulatory Filing Period Income Statement [Abstract] Revenues Revenues Expenses Utilities Operating Expense [Abstract] Fuel oil Utilities Operating Expense, Fuel Used Purchased power Utilities Operating Expense, Purchased Power Other operation and maintenance Utilities Operating Expense, Maintenance and Operations Depreciation Utilities Operating Expense, Depreciation and Amortization 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. Total expenses Costs and Expenses Operating income Operating Income (Loss) Allowance for equity funds used during construction Interest expense and other charges, net Interest Expense and Other Charges Interest expense and other charges during the period. Allowance for borrowed funds used during construction Interest Costs Capitalized Adjustment Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income taxes Net income Preferred stock dividends of subsidiaries Noncontrolling Interest in Net Income (Loss) Preferred Unit Holders, Redeemable Net income attributable to Hawaiian Electric Net Income (Loss) Attributable to Parent Preferred stock dividends of Hawaiian Electric Preferred Stock Dividends, Income Statement Impact Net income for common stock Supplemental Cash Flow Elements [Abstract] Cash flows Cash Flow, Supplemental Disclosures [Text Block] Condensed Cash Flow Statement [Table] Condensed Cash Flow Statement [Table] Condensed Cash Flow Statement [Line Items] Condensed Cash Flow Statement [Line Items] [Line Items] for Condensed Cash Flow Statement [Table] Supplemental disclosures of cash flow information Supplemental Cash Flow Information [Abstract] Interest paid to non-affiliates Interest Paid to Non Affiliates The amount of cash paid for interest of non-affiliates during the period. Income taxes paid Income Taxes Paid Income taxes refunded Proceeds from Income Tax Refunds Supplemental disclosures of noncash activities Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Unpaid invoices and other Noncash or Part Noncash Increases Property, Plant and Equipment Unpaid Invoices and Other Noncash (or part noncash) increases in property, plant and equipment due to unpaid invoices and other noncash transactions. Common stock dividends reinvested in HEI common stock (financing) Stock Issued During Period, Value, Dividend Reinvestment Plan Loans transferred from held for investment to held for sale (investing) Transfer of Portfolio Loans and Leases to Held-for-sale Real estate acquired in settlement of loans (investing) Noncash or Part Noncash Acquisition of Real Estate in Settlement of Loans The amount of real estate that the entity acquired in settlement of loans in noncash (or part noncash) transactions. Noncash is defined as an information about all investing and financing activities of an enterprise during a period that affect recognized assets or liabilities but that do not result in cash receipts or cash payments during the period. Real estate transferred from property, plant and equipment to other assets held-for-sale (investing) Real Estate Owned, Transfer from Real Estate Owned Obligations to fund low income housing investments, net (operating) Affordable Housing Program Assessments Electric utility property, plant and equipment Noncash or Part Noncash Acquisition, Value of Assets Acquired [Abstract] AFUDC-equity Estimated fair value of noncash contributions in aid of construction 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. Refinancing of long-term debt (financing) Other Significant Noncash Transactions, Refinancing Of Long-term Debt Other Significant Noncash Transactions, Refinancing Of Long-term Debt Advances from Federal Home Loan Bank Advances from Federal Home Loan Banks [Abstract] Weighted-average stated rate Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate of Amounts Due [Abstract] 2017 (as a percent) Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate of Amounts Due within One Year of Balance Sheet Date 2018 (as a percent) Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, One to Two Years from Balance Sheet Date 2019 (as a percent) Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, Two to Three Years from Balance Sheet Date 2020 (as a percent) Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, Three to Four Years from Balance Sheet Date 2021 (as a percent) Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, Four to Five Years from Balance Sheet Date Thereafter (as a percent) Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, after Five Years from Balance Sheet Date Total weighted-average stated rate (as a percent) Federal Home Loan Bank, Advances Maturities Summary, Average Interest Rate The total of weighted average interest rate applicable to the Federal Home Loan Bank advances. Due in Federal Home Loan Bank, Advances, Fiscal Year Maturity [Abstract] 2017 Federal Home Loan Bank, Advances, Maturities Summary, Due in Next Twelve Months 2018 Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Two 2019 Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Three 2020 Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Four 2021 Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Five Thereafter Federal Home Loan Bank, Advances, Maturities Summary, Due after Year Five Total amount due Advances from Federal Home Loan Banks Schedule of Assets Sold under Agreements to Repurchase [Table] Schedule of Assets Sold under Agreements to Repurchase [Table] Securities or Other Assets Sold under Agreements to Repurchase [Axis] Securities or Other Assets Sold under Agreements to Repurchase [Axis] Assets Sold under Agreements to Repurchase, Type [Domain] Assets Sold under Agreements to Repurchase, Type [Domain] Collateralized by mortgage-related securities and federal agency obligations US Government Agencies Debt Securities And Mortgage Backed Securities [Member] US Government Agencies Debt Securities And Mortgage Backed Securities [Member] Identical securities Identical Securities [Member] Represents the information pertaining to identical securities. Securities or Other Assets Sold under Agreements to Repurchase, Maturity Periods [Axis] Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Assets Sold under Agreements to Repurchase, Maturity Period [Domain] Repurchase Agreements and Similar Transactions, Maturity Periods [Domain] Overnight Maturity Overnight [Member] 1 to 29 days Maturity Less than 30 Days [Member] 30 to 90 days Maturity 30 to 90 Days [Member] Over 90 days Maturity Greater than 90 Days [Member] Securities sold under agreements to repurchase Assets Sold under Agreements to Repurchase [Line Items] Repurchase liability Assets Sold under Agreements to Repurchase, Repurchase Liability Weighted-average interest rate Assets Sold under Agreements to Repurchase, Interest Rate Collateralized by mortgage-related securities and federal agency obligations at fair value plus accrued interest Assets Sold Under Agreements To Repurchase Fair Value Plus Accrued Interest Assets Sold Under Agreements To Repurchase Fair Value Plus Accrued Interest Callable quarterly at par until maturity in 2016 Assets Sold under Agreements to Repurchase, Amount Callable Quarterly at Par Until Maturity Assets Sold under Agreements to Repurchase, Amount Callable Quarterly at Par Until Maturity Real estate loans for investors Real Estate Loans Serviced for Investors Real estate loans serviced for investors. Loans pledged as collateral to secure advances from the FHLB of Seattle Loans Pledged as Collateral Loans to directors, executive directors, affiliates and any related interest of such individuals Loan Balances Related to Interest of Individual Directors Executive Officers and Related Interests Represents the amount of Loan balances, which are related to interests of individuals who are directors of bank, executive officers and related interests. Lines of credit closed and repaid, net of new loans and lines of credit to executive directors Debt Instrument, Decrease, Repayments, Net of Increases for Existing Managers Debt Instrument, Decrease, Repayments, Net of Increases for Existing Managers Lines of credit closed and repaid Repayments of Debt Loan balances, related interests of individuals who are directors Loan Balances Related to Interest of Individual Directors Represents the amount of Loan balances, which are related to interests of individuals who are directors of bank. Schedule of future minimum lease payments Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Schedule of earnings per share basic and diluted under two-class method Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of new accounting pronounements Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block] Summary of amounts in income tax expense related to investments in qualifying affordable housing projects Summary Of Amounts In Income Tax Expense, Affordable Housing Projects [Table Text Block] Summary Of Amounts In Income Tax Expense, Affordable Housing Projects [Table Text Block] Quarterly Financial Information Disclosure [Abstract] Schedule of selected quarterly information Quarterly Financial Information [Table Text Block] Document and Entity Information -- None. No documentation exists for this element. -- Entities [Table] Entities [Table] Entity Information [Line Items] Entity Information [Line Items] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Current Fiscal Year End Date Current Fiscal Year End Date Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Entity Filer Category Entity Filer Category Entity Public Float Entity Public Float Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus ASB Hawaii, Inc. ASB Hawaii, Inc. [Member] ASB Hawaii, Inc. [Member] Common stock Common Stock Including Additional Paid in Capital [Member] Condensed Cash Flow Statements, Captions [Line Items] Condensed Cash Flow Statements, Captions [Line Items] Net cash provided by operating activities Cash flows from investing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Investments in subsidiaries Payments to Acquire Interest in Subsidiaries and Affiliates Net increase (decrease) in notes payable to subsidiaries with original maturities of three months or less Proceeds from Repayments of Notes Payable to Subsidiaries Maturing in Three Months or Less Represents the cash outflow associated with notes payable to subsidiaries having initial term of payment within three months. Cash dividends received from subsidiaries Accounts receivable reduction Notes Reduction HEI notes payable increase to ASHI Notes Issued Issuance of common stock: Dividend reinvestment and stock purchase plan Significant group concentrations of credit risk