v3.26.1
Investment Risks - Harbor Short Term Treasury ETF
Jul. 31, 2026
U.S. Treasury Obligations Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] U.S. Treasury Obligations Risk: U.S. Treasury obligations, such as U.S. Treasury bills, are subject to fluctuations in interest rates, which may cause their market value to vary, and may provide lower returns than other securities. In addition, changes in economic conditions, market perceptions, or the financial condition or credit rating of the U.S. government may cause the value of such obligations to decline in value. Although backed by the full faith and credit of the U.S. government, these securities remain subject to market and credit risk.
Credit Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Credit Risk: The issuer or guarantor of a security owned by the Fund could default on its obligation to pay principal or interest or its credit rating could be downgraded.
Inflation Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Inflation Risk: As inflation rises, the value of assets of or income, from the Fund’s investments may be worth less, as inflation decreases the value of payments at future dates. As a result, the real value of the Fund’s portfolio could decline.
Interest Rate Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Interest Rate Risk: As interest rates rise, the values of fixed income securities held by the Fund are likely to decrease and reduce the value of the Fund’s portfolio. Rising interest rates may lead to increased redemptions, increased volatility and decreased liquidity in the fixed income markets, making it more difficult for the Fund to sell its fixed income securities when the Advisor may wish to sell or must sell to meet redemptions. During periods when interest rates are low or there are negative interest rates, the Fund’s yield (and total return) also may be low or the Fund may be unable to maintain positive returns or minimize the volatility of the Fund’s net asset value per share. Changing interest rates may have unpredictable effects on the markets, may result in heightened market volatility and may detract from Fund performance. In addition, changes in monetary policy may exacerbate the risks associated with changing interest rates.
Market Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Market Risk: Securities markets are volatile and can decline significantly in response to adverse market, economic, political, regulatory or other developments, which may lower the value of securities held by the Fund, sometimes rapidly or unpredictably. Events such as war, military conflict, geopolitical disputes, acts of terrorism, social or political unrest, natural disasters, recessions, inflation, rapid interest rate changes, supply chain disruptions, tariffs and other restrictions on trade, sanctions, the spread of infectious illness or other public health threats, or the threat or potential of one or more such events and developments, could also significantly impact the Fund and its investments.
Risks Associated with Exchange-Traded Funds [Member]  
Prospectus [Line Items]  
Risk [Text Block] Risks Associated with Exchange-Traded Funds: As an ETF, the Fund is subject to the following risks:Authorized Participant Concentration/Trading Risk: Only authorized participants (“APs”) may engage in creation or redemption transactions directly with the Fund. The Fund has a limited number of institutions that may act as APs and such APs have no obligation to submit creation or redemption orders. Consequently, there is no assurance that APs will establish or maintain an active trading market for the shares. This risk may be heightened to the extent that securities held by the Fund are traded outside a collateralized settlement system. In that case, APs may be required to post collateral on certain trades on an agency basis (i.e., on behalf of other market participants), which only a limited number of APs may be able to do. In addition, to the extent that APs exit the business or are unable to proceed with creation and/or redemption orders with respect to the Fund and no other AP is able to step forward to create or redeem Creation Units (as defined below), this may result in a significantly diminished trading market for shares, and shares may be more likely to trade at a premium or discount to the Fund’s net asset value and to face trading halts and/or delisting. This risk may be heightened during periods of volatility or market disruptions.Cash Transactions Risk: The Fund may effect some or all of its creations and redemptions for cash rather than in-kind. As a result, an investment in the Fund may be less tax-efficient than an investment in an ETF that effects all of its creations and redemptions in-kind. Because the Fund may effect redemptions for cash, it may be required to sell portfolio securities in order to obtain the cash needed to distribute redemption proceeds. A sale of portfolio securities may result in capital gains or losses and may also result in higher brokerage costs. To the extent costs are not offset by transaction fees charged by the Fund to APs, the costs of cash transactions will be borne by the Fund.Large Shareholder Risk: Certain large shareholders, including APs, may from time to time own a substantial amount of the Fund’s shares. There is no requirement that these shareholders maintain their investment in the Fund. There is a risk that such large shareholders or that the Fund’s shareholders generally may redeem all or a substantial portion of their investments in the Fund in a short period of time, which could have a significant negative impact on the Fund’s NAV, liquidity, and brokerage costs. Large redemptions could also result in tax consequences to shareholders and impact the Fund’s ability to implement its investment strategy. In addition, transactions by large shareholders may account for a large percentage of the trading volume on the listing exchange and may, therefore, have a material upward or downward effect on the market price of the shares.Premium/Discount Risk: The market price of the Fund’s shares will generally fluctuate in accordance with changes in the Fund’s net asset value as well as the relative supply of and demand for shares on the Exchange. The Advisor cannot predict whether shares will trade below, at or above their net asset value because the shares trade on the Exchange at market prices and not at net asset value. Price differences may be due, in large part, to the fact that supply and demand forces at work in the secondary trading market for shares will be closely related, but not identical, to the same forces influencing the prices of the holdings of the Fund trading individually or in the aggregate at any point in time. This may result in the Fund’s shares trading significantly above (premium) or below (discount) the Fund’s net asset value, which will be reflected in the intraday bid/ask spreads and/or the closing price of shares as compared to net asset value. During stressed market conditions, the market for the Fund’s shares may become less liquid in response to deteriorating liquidity in the market for the Fund’s underlying portfolio holdings, which could in turn lead to differences between the market price of the Fund’s shares and their net asset value.
High Portfolio Turnover Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] High Portfolio Turnover Risk: Higher portfolio turnover may adversely affect Fund performance by increasing Fund transaction costs and may lead to the realization and distribution to shareholders of higher capital gains, which may increase a shareholder’s tax liability.
Investment in Other Investment Companies Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Investment in Other Investment Companies Risk: Investments in other investment companies (including money market funds and ETFs) are subject to market and selection risk. In addition, if the Fund acquires shares of investment companies, shareholders bear both their proportionate share of expenses in the Fund and, indirectly, the expenses of the investment companies. The Fund’s investment in shares of ETFs subjects it to the risks of owning the securities underlying the ETF, as well as the same structural risks faced by an investor purchasing shares of the Fund, including premium/discount risk and trading issues risk.
Issuer Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Issuer Risk: An adverse event affecting a particular issuer in which the Fund is invested, such as an unfavorable earnings report, may depress the value of that issuer’s securities, sometimes rapidly or unpredictably.
New Fund Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] New Fund Risk: There can be no assurance that the Fund will grow to or maintain an economically viable size, in which case the Board of Trustees may determine to liquidate the Fund. The Board of Trustees may liquidate the Fund at any time in accordance with the Declaration of Trust and governing law. As a result, the timing of the Fund’s liquidation may not be favorable.
Repurchase Agreements and Reverse Repurchase Agreements Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Repurchase Agreements and Reverse Repurchase Agreements Risk: The Fund may enter into repurchase agreements and reverse repurchase agreements. The Fund may lose money if the counterparty to a repurchase agreement defaults on its obligation to repurchase the securities or if the value of the collateral declines. Reverse repurchase agreements involve borrowing and expose the Fund to counterparty and leverage risk, which could increase the volatility of the Fund’s returns. The Fund could lose money if the counterparty defaults on its obligations under a reverse repurchase agreement or if the value of the collateral, including investments made with the proceeds of the transaction, is less than the value of the securities or the repurchase price.
Securities Lending Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Securities Lending Risk: The Fund may engage in securities lending. Securities lending involves the risk that the Fund may lose money because the borrower of the loaned securities fails to return the securities in a timely manner or at all. The Fund could also lose money in the event of a decline in the value of collateral provided for loaned securities or a decline in the value of any investments made with cash collateral. These events could also trigger adverse tax consequences for the Fund.
Selection Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Selection Risk: The Advisor potentially will be prevented from executing investment decisions at an advantageous time or price as a result of domestic or global market disruptions, particularly disruptions causing heightened market volatility and reduced market liquidity, as well as increased or changing regulations.  Thus, investments that the Advisor believes represent an attractive opportunity or in which the Fund seeks to obtain exposure may be unavailable entirely or in the specific quantities or prices sought by the Advisor and the Fund may need to forgo the investment at the time.
U.S. Government Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] U.S. Government Securities Risk: Securities issued or guaranteed by U.S. government agencies or government-sponsored entities may not be backed by the full faith and credit of the U.S. government. As a result, no assurance can be given that the U.S. government will provide financial support to these securities or issuers (such as securities issued by the Federal National Mortgage Association, or the Federal Home Loan Mortgage Corporation). Although certain government securities are backed by the full faith and credit of the U.S. government (such as securities issued by the Government National Mortgage Association), circumstances could arise that would delay or prevent the payment of interest or principal. It is possible that issuers of U.S. government securities will not have the funds to meet their payment obligations in the future and, in these circumstances, the Fund’s returns may be adversely affected.
Risk Lose Money [Member]  
Prospectus [Line Items]  
Risk [Text Block] This means that you could lose money on your investment in the Fund or the Fund may not perform as well as other possible investments.