| Shareholder Report | 12 Months Ended |
| Oct. 31, 2024 USD ($) Holding |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | NEUBERGER BERMAN ALTERNATIVE FUNDS |
| Entity Central Index Key | 0001317474 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Oct. 31, 2024 |
| C000108850 | |
| Shareholder Report [Line Items] | |
| Fund Name | Long Short Fund |
| Class Name | Class A |
| Trading Symbol | NLSAX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the Fund for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://www.nb.com/en/us/products/mutual-funds/long-short-fund?section=documents fundinfo nb.com |
| Additional Information Phone Number | 800.877.9700 |
| Additional Information Email | fundinfo@nb.com</span>" id="sjs-B19"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 400; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: left;">fundinfo@nb.com</span> |
| Additional Information Website | https://www.nb.com/en/us/products/mutual-funds/long-short-fund?section=documents</span>" id="sjs-B20"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 400; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: left;">https://www.nb.com/en/us/products/mutual-funds/long-short-fund?section=documents</span> |
| Expenses [Text Block] | What were the Fund's costs for the year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $175 1.67% |
| Expenses Paid, Amount | $ 175 |
| Expense Ratio, Percent | 1.67% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? The Fund underperformed the HFRX Equity Hedge Index. In absolute terms, the Fund’s equity long positions positively impacted performance, but this was partly offset by negative impact from its total short positions. Long positions in the Information Technology (IT) and Financials sectors were the largest absolute contributors, whereas short positions in the IT and Consumer Discretionary sectors were the largest absolute detractors. Meanwhile, market hedges detracted on an absolute basis given the up move in the U.S. equity market. Performance Attribution Top Contributors Top Detractors Derivatives Equity Longs – IT, Financials and Communication Services sectors Shorts – Market Hedges Equity Shorts – IT and Consumer Discretionary sectors Index futures, options and swaps related to hedging activities |
| Performance Past Does Not Indicate Future [Text] | The investment return and principal value of an investment will fluctuate so that an investor’s shares, when redeemed, may be worth more or less than their original cost. Results represent the Fund's past performance, which is not a good predictor of how the Fund will perform in the future. Current performance may be lower or higher than the performance data quoted. |
| Line Graph [Table Text Block] | Class A (including sales charge) $15,619 S&P 500 ® HFRX ® 10/31/14 $9,425 $10,000 $10,000 10/31/15 $9,245 $10,520 $9,904 10/31/16 $9,201 $10,994 $9,649 10/31/17 $10,227 $13,593 $10,584 10/31/18 $10,432 $14,591 $10,268 10/31/19 $11,114 $16,681 $10,595 10/31/20 $12,370 $18,301 $10,442 10/31/21 $14,327 $26,155 $12,629 10/31/22 $13,043 $22,334 $12,205 10/31/23 $14,237 $24,599 $12,559 10/31/24 $15,619 $33,950 $14,025 |
| Average Annual Return [Table Text Block] | Name 1 Year 5 Years 10 Years Class A (at NAV) 9.71% 7.04% 5.18% Class A (including sales charge)
3.42% 5.79% 4.56% S&P 500 ® 38.02% 15.27% 13.00% HFRX ® 11.67% 5.77% 3.44% |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or on the redemption of Fund shares. |
| Performance Table Market Index Changed [Text Block] | On July 24, 2024, the Fund began comparing its performance to the S&P 500 Index in order to satisfy a change in regulatory requirements. The HRFX Equity Hedge Index will be maintained as a secondary index as it shows how the Fund’s performance compares to an index with characteristics that are more representative of the Fund's investment strategy than the S&P 500 Index. |
| AssetsNet | $ 6,916,201,295 |
| Holdings Count | Holding | 167 |
| Advisory Fees Paid, Amount | $ 73,174,571 |
| InvestmentCompanyPortfolioTurnover | 48% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics Net Assets $6,916,201,295 Number of Portfolio Holdings 167 Portfolio Turnover Rate 48% Total Investment Advisory Fees Paid $73,174,571 |
| Holdings [Text Block] | Top Ten Short Securities (as a % of Total Investments Footnote Reference Moelis & Co. (0.6%) Interpublic Group of Cos., Inc. (0.6%) CarMax, Inc. (0.6%) Lamar Advertising Co. (0.5%) T. Rowe Price Group, Inc. (0.5%) Dollar General Corp. (0.5%) WW Grainger, Inc. (0.4%) Samsara, Inc. (0.4%) J.M. Smucker Co. (0.4%) FactSet Research Systems, Inc. (0.4%) Footnote Description Footnote Derivatives (other than options purchased), if any, are excluded from this calculation. Portfolio by Investment Type (as a % of Total Net Assets) Name Long Short Common Stocks 88.3% (11.5%) Short-Term Investments 5.2% -% Master Limited Partnerships and Limited Partnerships 2.8% -% Preferred Stocks 0.8% -% Convertible Bonds 0.3% -% Loan Assignments 0.2% -% Corporate Bonds 0.1% -% Other Assets Less Liabilities 13.8%* -% Footnote Reference Total 111.5% (11.5%) Footnote Description Footnote Includes the impact of the Fund's open positions in derivatives (other than options purchased), if any. |
| Largest Holdings [Text Block] | Top Ten Long Securities (as a % of Total Investments Footnote Reference State Street Institutional U.S. Government Money Market Fund 6.0% Microsoft Corp. 5.0% Amazon.com, Inc. 4.5% Apple, Inc. 4.0% Meta Platforms, Inc. 3.7% NVIDIA Corp. 3.6% Alphabet, Inc. 3.2% Salesforce, Inc. 2.7% Fanatics Holdings, Inc. 2.6% McDonald's Corp. 2.5% Footnote Description Footnote Derivatives (other than options purchased), if any, are excluded from this calculation. |
| Material Fund Change [Text Block] | |
| C000108851 | |
| Shareholder Report [Line Items] | |
| Fund Name | Long Short Fund |
| Class Name | Class C |
| Trading Symbol | NLSCX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the Fund for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://www.nb.com/en/us/products/mutual-funds/long-short-fund?section=documents fundinfo nb.com |
| Additional Information Phone Number | 800.877.9700 |
| Additional Information Email | fundinfo@nb.com</span>" id="sjs-B47"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 400; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: left;">fundinfo@nb.com</span> |
| Additional Information Website | https://www.nb.com/en/us/products/mutual-funds/long-short-fund?section=documents</span>" id="sjs-B48"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 400; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: left;">https://www.nb.com/en/us/products/mutual-funds/long-short-fund?section=documents</span> |
| Expenses [Text Block] | What were the Fund's costs for the year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $253 2.42% |
| Expenses Paid, Amount | $ 253 |
| Expense Ratio, Percent | 2.42% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? The Fund underperformed the HFRX Equity Hedge Index. In absolute terms, the Fund’s equity long positions positively impacted performance, but this was partly offset by negative impact from its total short positions. Long positions in the Information Technology (IT) and Financials sectors were the largest absolute contributors, whereas short positions in the IT and Consumer Discretionary sectors were the largest absolute detractors. Meanwhile, market hedges detracted on an absolute basis given the up move in the U.S. equity market. Performance Attribution Top Contributors Top Detractors Derivatives Equity Longs – IT, Financials and Communication Services sectors Shorts – Market Hedges Equity Shorts – IT and Consumer Discretionary sectors Index futures, options and swaps related to hedging activities |
| Performance Past Does Not Indicate Future [Text] | The investment return and principal value of an investment will fluctuate so that an investor’s shares, when redeemed, may be worth more or less than their original cost. Results represent the Fund's past performance, which is not a good predictor of how the Fund will perform in the future. Current performance may be lower or higher than the performance data quoted. |
| Line Graph [Table Text Block] | Class C (including sales charge) $15,379 S&P 500 ® HFRX ® 10/31/14 $10,000 $10,000 $10,000 10/31/15 $9,744 $10,520 $9,904 10/31/16 $9,617 $10,994 $9,649 10/31/17 $10,608 $13,593 $10,584 10/31/18 $10,743 $14,591 $10,268 10/31/19 $11,364 $16,681 $10,595 10/31/20 $12,548 $18,301 $10,442 10/31/21 $14,428 $26,155 $12,629 10/31/22 $13,037 $22,334 $12,205 10/31/23 $14,124 $24,599 $12,559 10/31/24 $15,379 $33,950 $14,025 |
| Average Annual Return [Table Text Block] | Name 1 Year 5 Years 10 Years Class C (at NAV) 8.89% 6.24% 4.40% Class C (including sales charge)
7.89% 6.24% 4.40% S&P 500 ® 38.02% 15.27% 13.00% HFRX ® 11.67% 5.77% 3.44% |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or on the redemption of Fund shares. |
| Performance Table Market Index Changed [Text Block] | On July 24, 2024, the Fund began comparing its performance to the S&P 500 Index in order to satisfy a change in regulatory requirements. The HRFX Equity Hedge Index will be maintained as a secondary index as it shows how the Fund’s performance compares to an index with characteristics that are more representative of the Fund's investment strategy than the S&P 500 Index. |
| AssetsNet | $ 6,916,201,295 |
| Holdings Count | Holding | 167 |
| Advisory Fees Paid, Amount | $ 73,174,571 |
| InvestmentCompanyPortfolioTurnover | 48% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics Net Assets $6,916,201,295 Number of Portfolio Holdings 167 Portfolio Turnover Rate 48% Total Investment Advisory Fees Paid $73,174,571 |
| Holdings [Text Block] | Top Ten Short Securities (as a % of Total Investments Footnote Reference Moelis & Co. (0.6%) Interpublic Group of Cos., Inc. (0.6%) CarMax, Inc. (0.6%) Lamar Advertising Co. (0.5%) T. Rowe Price Group, Inc. (0.5%) Dollar General Corp. (0.5%) WW Grainger, Inc. (0.4%) Samsara, Inc. (0.4%) J.M. Smucker Co. (0.4%) FactSet Research Systems, Inc. (0.4%) Footnote Description Footnote Derivatives (other than options purchased), if any, are excluded from this calculation. Portfolio by Investment Type (as a % of Total Net Assets) Name Long Short Common Stocks 88.3% (11.5%) Short-Term Investments 5.2% -% Master Limited Partnerships and Limited Partnerships 2.8% -% Preferred Stocks 0.8% -% Convertible Bonds 0.3% -% Loan Assignments 0.2% -% Corporate Bonds 0.1% -% Other Assets Less Liabilities 13.8%* -% Footnote Reference Total 111.5% (11.5%) Footnote Description Footnote Includes the impact of the Fund's open positions in derivatives (other than options purchased), if any. |
| Largest Holdings [Text Block] | Top Ten Long Securities (as a % of Total Investments Footnote Reference State Street Institutional U.S. Government Money Market Fund 6.0% Microsoft Corp. 5.0% Amazon.com, Inc. 4.5% Apple, Inc. 4.0% Meta Platforms, Inc. 3.7% NVIDIA Corp. 3.6% Alphabet, Inc. 3.2% Salesforce, Inc. 2.7% Fanatics Holdings, Inc. 2.6% McDonald's Corp. 2.5% Footnote Description Footnote Derivatives (other than options purchased), if any, are excluded from this calculation. |
| Material Fund Change [Text Block] | |
| C000108852 | |
| Shareholder Report [Line Items] | |
| Fund Name | Long Short Fund |
| Class Name | Institutional Class |
| Trading Symbol | NLSIX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the Fund for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://www.nb.com/en/us/products/mutual-funds/long-short-fund?section=documents issdl nb.com |
| Additional Information Phone Number | 800.366.6264 |
| Additional Information Email | issdl@nb.com</span>" id="sjs-B75"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 400; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: left;">issdl@nb.com</span> |
| Additional Information Website | https://www.nb.com/en/us/products/mutual-funds/long-short-fund?section=documents</span>" id="sjs-B76"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 400; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: left;">https://www.nb.com/en/us/products/mutual-funds/long-short-fund?section=documents</span> |
| Expenses [Text Block] | What were the Fund's costs for the year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Institutional Class $138 1.31% |
| Expenses Paid, Amount | $ 138 |
| Expense Ratio, Percent | 1.31% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? The Fund underperformed the HFRX Equity Hedge Index. In absolute terms, the Fund’s equity long positions positively impacted performance, but this was partly offset by negative impact from its total short positions. Long positions in the Information Technology (IT) and Financials sectors were the largest absolute contributors, whereas short positions in the IT and Consumer Discretionary sectors were the largest absolute detractors. Meanwhile, market hedges detracted on an absolute basis given the up move in the U.S. equity market. Performance Attribution Top Contributors Top Detractors Derivatives Equity Longs – IT, Financials and Communication Services sectors Shorts – Market Hedges Equity Shorts – IT and Consumer Discretionary sectors Index futures, options and swaps related to hedging activities |
| Performance Past Does Not Indicate Future [Text] | The investment return and principal value of an investment will fluctuate so that an investor’s shares, when redeemed, may be worth more or less than their original cost. Results represent the Fund's past performance, which is not a good predictor of how the Fund will perform in the future. Current performance may be lower or higher than the performance data quoted. |
| Line Graph [Table Text Block] | Institutional Class $1,719,600 S&P 500 ® HFRX ® 10/31/14 $1,000,000 $1,000,000 $1,000,000 10/31/15 $985,500 $1,052,000 $990,400 10/31/16 $984,100 $1,099,400 $964,900 10/31/17 $1,097,700 $1,359,300 $1,058,400 10/31/18 $1,123,200 $1,459,100 $1,026,800 10/31/19 $1,201,600 $1,668,100 $1,059,500 10/31/20 $1,341,900 $1,830,100 $1,044,200 10/31/21 $1,560,300 $2,615,500 $1,262,900 10/31/22 $1,425,600 $2,233,400 $1,220,500 10/31/23 $1,561,400 $2,459,900 $1,255,900 10/31/24 $1,719,600 $3,395,000 $1,402,500 |
| Average Annual Return [Table Text Block] | Name 1 Year 5 Years 10 Years Institutional Class 10.13% 7.43% 5.57% S&P 500 ® 38.02% 15.27% 13.00% HFRX ® 11.67% 5.77% 3.44% |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or on the redemption of Fund shares. |
| Performance Table Market Index Changed [Text Block] | On July 24, 2024, the Fund began comparing its performance to the S&P 500 Index in order to satisfy a change in regulatory requirements. The HRFX Equity Hedge Index will be maintained as a secondary index as it shows how the Fund’s performance compares to an index with characteristics that are more representative of the Fund's investment strategy than the S&P 500 Index. |
| AssetsNet | $ 6,916,201,295 |
| Holdings Count | Holding | 167 |
| Advisory Fees Paid, Amount | $ 73,174,571 |
| InvestmentCompanyPortfolioTurnover | 48% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics Net Assets $6,916,201,295 Number of Portfolio Holdings 167 Portfolio Turnover Rate 48% Total Investment Advisory Fees Paid $73,174,571 |
| Holdings [Text Block] | Top Ten Short Securities (as a % of Total Investments Footnote Reference Moelis & Co. (0.6%) Interpublic Group of Cos., Inc. (0.6%) CarMax, Inc. (0.6%) Lamar Advertising Co. (0.5%) T. Rowe Price Group, Inc. (0.5%) Dollar General Corp. (0.5%) WW Grainger, Inc. (0.4%) Samsara, Inc. (0.4%) J.M. Smucker Co. (0.4%) FactSet Research Systems, Inc. (0.4%) Footnote Description Footnote Derivatives (other than options purchased), if any, are excluded from this calculation. Portfolio by Investment Type (as a % of Total Net Assets) Name Long Short Common Stocks 88.3% (11.5%) Short-Term Investments 5.2% -% Master Limited Partnerships and Limited Partnerships 2.8% -% Preferred Stocks 0.8% -% Convertible Bonds 0.3% -% Loan Assignments 0.2% -% Corporate Bonds 0.1% -% Other Assets Less Liabilities 13.8%* -% Footnote Reference Total 111.5% (11.5%) Footnote Description Footnote Includes the impact of the Fund's open positions in derivatives (other than options purchased), if any. |
| Largest Holdings [Text Block] | Top Ten Long Securities (as a % of Total Investments Footnote Reference State Street Institutional U.S. Government Money Market Fund 6.0% Microsoft Corp. 5.0% Amazon.com, Inc. 4.5% Apple, Inc. 4.0% Meta Platforms, Inc. 3.7% NVIDIA Corp. 3.6% Alphabet, Inc. 3.2% Salesforce, Inc. 2.7% Fanatics Holdings, Inc. 2.6% McDonald's Corp. 2.5% Footnote Description Footnote Derivatives (other than options purchased), if any, are excluded from this calculation. |
| Material Fund Change [Text Block] | |
