Harbor Short Term Treasury ETF S000107033 [Member] NONE or SAME C000277919 [Member] U.S. Treasury Obligations Risk [Member] Credit Risk [Member] Inflation Risk [Member] Interest Rate Risk [Member] Market Risk [Member] Risks Associated with Exchange-Traded Funds [Member] High Portfolio Turnover Risk [Member] Investment in Other Investment Companies Risk [Member] Issuer Risk [Member] New Fund Risk [Member] Repurchase Agreements and Reverse Repurchase Agreements Risk [Member] Securities Lending Risk [Member] Selection Risk [Member] U.S. Government Securities Risk [Member]