| Shareholder Report | 6 Months Ended |
| Nov. 30, 2024 USD ($) Holding |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | aLTSHARES
TRUST |
| Entity Central Index Key | 0001779306 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Nov. 30, 2024 |
| C000229260 | |
| Shareholder Report [Line Items] | |
| Fund Name | AltShares Event-Driven ETF |
| Trading Symbol | EVNT |
| Security Exchange Name | NYSE |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about AltShares Event-Driven ETF for the period of June 1, 2024 to November 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Semi-Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund, including updated performance information, at www.altsharesetfs.com/evnt |
| Additional Information Phone Number | 1-855-955-1607 |
| Additional Information Email | www.altsharesetfs.com/evnt</span>" id="sjs-B19"><span style="box-sizing: border-box; color: rgb(74, 82, 90); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 10.6667px; margin: 0px; overflow: visible; text-align: left;">www.altsharesetfs.com/evnt</span> |
| Additional Information Website | www.altsharesetfs.com/evnt</span>" id="sjs-B20"><span style="box-sizing: border-box; color: rgb(74, 82, 90); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 12.8px; margin: 0px; overflow: visible; text-align: left;">www.altsharesetfs.com/evnt</span> |
| Expenses [Text Block] | What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment) Fund Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Footnote Reference * AltShares Event-Driven ETF $68 1.30% Footnote Description Footnote * Annualized. |
| Expenses Paid, Amount | $ 68 |
| Expense Ratio, Percent | 1.30% |
| AssetsNet | $ 4,942,565 |
| Holdings Count | Holding | 95 |
| InvestmentCompanyPortfolioTurnover | 225% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics Total Net Assets $4,942,565 Number of Portfolio Holdings 95 Portfolio Turnover Rate Footnote Reference ** 225% Footnote Description Footnote ** Not annualized |
| Holdings [Text Block] | Sector Weighting (% of Total Investments) Value Value Technology 21.82% Telecommunication Services 18.04% Consumer, Non-cyclical 16.40% Financials 16.09% Consumer, Cyclical 10.28% Industrials 9.95% Materials 5.03% Utilities 1.56% Energy 0.83% Region Weighting (% of Total Investments) Value Value Americas 92.42% EMEA 7.58% |
| Accountant Change Statement [Text Block] | On November 19, 2024, the Fund’s Board of Trustees, upon recommendation from the Audit Committee, approved and appointed Cohen & Company, Ltd. as the independent registered public accounting firm for the Fund for the fiscal year ending May 31, 2025. Effective November 25, 2024, Ernst & Young LLP (“EY”) ceased to serve as the Fund’s independent registered public accounting firm. During the Fund’s fiscal years ended May 31, 2024 and 2023, and the interim period ended November 25, 2024, there have been no disagreements with EY on any matter of accounting principles or practices, financial statement disclosure, or auditing scope or procedures. |
| Accountant Change Date | Nov. 19, 2024 |
| C000216184 | |
| Shareholder Report [Line Items] | |
| Fund Name | AltShares Merger Arbitrage ETF |
| Trading Symbol | ARB |
| Security Exchange Name | NYSE |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about AltShares Merger Arbitrage ETF for the period of June 1, 2024 to November 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Semi-Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund, including updated performance information, at www.altsharesetfs.com/arb |
| Additional Information Phone Number | 1-855-955-1607 |
| Additional Information Email | www.altsharesetfs.com/arb</span>" id="sjs-B40"><span style="box-sizing: border-box; color: rgb(74, 82, 90); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 10.6667px; margin: 0px; overflow: visible; text-align: left;">www.altsharesetfs.com/arb</span> |
| Additional Information Website | www.altsharesetfs.com/arb</span>" id="sjs-B41"><span style="box-sizing: border-box; color: rgb(74, 82, 90); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 12.8px; margin: 0px; overflow: visible; text-align: left;">www.altsharesetfs.com/arb</span> |
| Expenses [Text Block] | What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment) Fund Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Footnote Reference * AltShares Merger Arbitrage ETF $29 0.56% Footnote Description Footnote * Annualized. |
| Expenses Paid, Amount | $ 29 |
| Expense Ratio, Percent | 0.56% |
| AssetsNet | $ 78,198,007 |
| Holdings Count | Holding | 114 |
| InvestmentCompanyPortfolioTurnover | 219% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics Total Net Assets $78,198,007 Number of Portfolio Holdings 114 Portfolio Turnover Rate Footnote Reference ** 219% Footnote Description Footnote ** Not annualized |
| Holdings [Text Block] | Sector Weighting (% of Total Investments) Value Value Technology 17.83% Telecommunication Services 16.90% Consumer, Non-cyclical 16.80% Financials 16.38% Industrials 9.08% Utilities 7.25% Materials 6.82% Consumer, Cyclical 6.32% Energy 2.62% Region Weighting (% of Total Investments) Value Value Americas 85.37% EMEA 14.63% |
| Accountant Change Statement [Text Block] | On November 19, 2024, the Fund’s Board of Trustees, upon recommendation from the Audit Committee, approved and appointed Cohen & Company, Ltd. as the independent registered public accounting firm for the Fund for the fiscal year ending May 31, 2025. Effective November 25, 2024, Ernst & Young LLP (“EY”) ceased to serve as the Fund’s independent registered public accounting firm. During the Fund’s fiscal years ended May 31, 2024 and 2023, and the interim period ended November 25, 2024, there have been no disagreements with EY on any matter of accounting principles or practices, financial statement disclosure, or auditing scope or procedures. |
| Accountant Change Date | Nov. 19, 2024 |
