| Form N-CSR Cover | 6 Months Ended |
| Sep. 30, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | Blackstone Alternative Investment Funds |
| Entity Central Index Key | 0001557794 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Sep. 30, 2024 |
| Shareholder Report | 6 Months Ended |
| Sep. 30, 2024 USD ($) Holding | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | Blackstone Alternative Investment Funds |
| Entity Central Index Key | 0001557794 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Sep. 30, 2024 |
| C000141764 | |
| Shareholder Report [Line Items] | |
| Fund Name | Blackstone Alternative Multi-Strategy Fund |
| Class Name | Class I |
| Trading Symbol | BXMIX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the Blackstone Alternative Multi-Strategy Fund (the "Fund") for the period of April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Semi-Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at www.bxmix.com |
| Additional Information Phone Number | 1-855-890-7725 |
| Additional Information Website | www.bxmix.com |
| Expenses [Text Block] | What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment) Class Name Cost of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $163 Footnote Reference 3.22% Footnote Reference |
| Expenses Paid, Amount | $ 163 |
| Expense Ratio, Percent | 3.22% |
| AssetsNet | $ 3,661,607,722 |
| Holdings Count | Holding | 4,654 |
| InvestmentCompanyPortfolioTurnover | 195% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) Total Net Assets $3,661,607,722 Total Number of Portfolio Holdings 4,654 Portfolio Turnover Rate Footnote Reference 195% |
| Largest Holdings [Text Block] | Portfolio Composition Percentage of Total Net Assets Common Stock 28.1% Mortgage-Backed Securities Footnote Reference 10.6% Corporate Bonds & Notes 10.5% Investments in Investee Funds 10.1% Asset-Backed Securities 6.3% Bank Debt 4.7% Sovereign Debt 4.7% U.S. Treasury Obligations 1.1% Closed-End Funds 0.9% Warrants 0.1% Preferred Stock 0.1% Convertible Bonds Footnote Reference 0.0% Rights Footnote Reference 0.0% Other Investments Footnote Reference 0.6% Securities Sold Short - Repurchase Agreements 2.0% Other Assets and Liabilities Footnote Reference 49.6% Total 100.0% |
| C000145025 | |
| Shareholder Report [Line Items] | |
| Fund Name | Blackstone Alternative Multi-Strategy Fund |
| Class Name | Class D |
| Trading Symbol | BXMDX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the Blackstone Alternative Multi-Strategy Fund (the "Fund") for the period of April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Semi-Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at www.bxmix.com |
| Additional Information Phone Number | 1-855-890-7725 |
| Additional Information Website | www.bxmix.com |
| Expenses [Text Block] | What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment) Class Name Cost of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class D $177 Footnote Reference 3.49% Footnote Reference |
| Expenses Paid, Amount | $ 177 |
| Expense Ratio, Percent | 3.49% |
| AssetsNet | $ 3,661,607,722 |
| Holdings Count | Holding | 4,654 |
| InvestmentCompanyPortfolioTurnover | 195% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) Total Net Assets $3,661,607,722 Total Number of Portfolio Holdings 4,654 Portfolio Turnover Rate Footnote Reference 195% |
| Largest Holdings [Text Block] | Portfolio Composition Percentage of Total Net Assets Common Stock 28.1% Mortgage-Backed Securities Footnote Reference 10.6% Corporate Bonds & Notes 10.5% Investments in Investee Funds 10.1% Asset-Backed Securities 6.3% Bank Debt 4.7% Sovereign Debt 4.7% U.S. Treasury Obligations 1.1% Closed-End Funds 0.9% Warrants 0.1% Preferred Stock 0.1% Convertible Bonds Footnote Reference 0.0% Rights Footnote Reference 0.0% Other Investments Footnote Reference 0.6% Securities Sold Short - Repurchase Agreements 2.0% Other Assets and Liabilities Footnote Reference 49.6% Total 100.0% |
| C000145027 | |
| Shareholder Report [Line Items] | |
| Fund Name | Blackstone Alternative Multi-Strategy Fund |
| Class Name | Class Y |
| Trading Symbol | BXMYX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the Blackstone Alternative Multi-Strategy Fund (the "Fund") for the period of April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Semi-Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at www.bxmix.com |
| Additional Information Phone Number | 1-855-890-7725 |
| Additional Information Website | www.bxmix.com |
| Expenses [Text Block] | What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment) Class Name Cost of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Y $159 Footnote Reference 3.14% Footnote Reference |
| Expenses Paid, Amount | $ 159 |
| Expense Ratio, Percent | 3.14% |
| AssetsNet | $ 3,661,607,722 |
| Holdings Count | Holding | 4,654 |
| InvestmentCompanyPortfolioTurnover | 195% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) Total Net Assets $3,661,607,722 Total Number of Portfolio Holdings 4,654 Portfolio Turnover Rate Footnote Reference 195% |
| Largest Holdings [Text Block] | Portfolio Composition Percentage of Total Net Assets Common Stock 28.1% Mortgage-Backed Securities Footnote Reference 10.6% Corporate Bonds & Notes 10.5% Investments in Investee Funds 10.1% Asset-Backed Securities 6.3% Bank Debt 4.7% Sovereign Debt 4.7% U.S. Treasury Obligations 1.1% Closed-End Funds 0.9% Warrants 0.1% Preferred Stock 0.1% Convertible Bonds Footnote Reference 0.0% Rights Footnote Reference 0.0% Other Investments Footnote Reference 0.6% Securities Sold Short - Repurchase Agreements 2.0% Other Assets and Liabilities Footnote Reference 49.6% Total 100.0% |
| Shareholder Report, Holdings (Details) | Sep. 30, 2024 |
| C000141764 | AssetCommon Stock | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| C000141764 | AssetMortgage-Backed Securities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.60% |
| C000141764 | AssetCorporate Bonds & Notes | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.50% |
| C000141764 | AssetInvestments in Investee Funds | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.10% |
| C000141764 | AssetAsset-Backed Securities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.30% |
| C000141764 | AssetBank Debt | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.70% |
| C000141764 | AssetSovereign Debt | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.70% |
| C000141764 | AssetU.S. Treasury Obligations | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| C000141764 | AssetExchange-Traded Funds | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000141764 | AssetWarrants | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.10% |
| C000141764 | AssetPreferred Stock | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.10% |
| C000141764 | AssetConvertible Bonds | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| C000141764 | AssetRights | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| C000141764 | AssetOther Investments | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| C000141764 | AssetSecurities Sold Short | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (29.40%) |
| C000141764 | AssetRepurchase Agreements | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2% |
| C000141764 | Asset Other Net Line | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 49.60% |
| C000145025 | AssetCommon Stock | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| C000145025 | AssetMortgage-Backed Securities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.60% |
| C000145025 | AssetCorporate Bonds & Notes | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.50% |
| C000145025 | AssetInvestments in Investee Funds | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.10% |
| C000145025 | AssetAsset-Backed Securities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.30% |
| C000145025 | AssetBank Debt | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.70% |
| C000145025 | AssetSovereign Debt | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.70% |
| C000145025 | AssetU.S. Treasury Obligations | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| C000145025 | AssetExchange-Traded Funds | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000145025 | AssetWarrants | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.10% |
| C000145025 | AssetPreferred Stock | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.10% |
| C000145025 | AssetConvertible Bonds | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| C000145025 | AssetRights | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| C000145025 | AssetOther Investments | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| C000145025 | AssetSecurities Sold Short | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (29.40%) |
| C000145025 | AssetRepurchase Agreements | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2% |
| C000145025 | Asset Other Net Line | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 49.60% |
| C000145027 | AssetCommon Stock | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| C000145027 | AssetMortgage-Backed Securities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.60% |
| C000145027 | AssetCorporate Bonds & Notes | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.50% |
| C000145027 | AssetInvestments in Investee Funds | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.10% |
| C000145027 | AssetAsset-Backed Securities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.30% |
| C000145027 | AssetBank Debt | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.70% |
| C000145027 | AssetSovereign Debt | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.70% |
| C000145027 | AssetU.S. Treasury Obligations | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| C000145027 | AssetExchange-Traded Funds | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000145027 | AssetWarrants | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.10% |
| C000145027 | AssetPreferred Stock | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.10% |
| C000145027 | AssetConvertible Bonds | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| C000145027 | AssetRights | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| C000145027 | AssetOther Investments | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| C000145027 | AssetSecurities Sold Short | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (29.40%) |
| C000145027 | AssetRepurchase Agreements | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2% |
| C000145027 | Asset Other Net Line | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 49.60% |
