| Shareholder Report | 12 Months Ended |
| Dec. 31, 2024 USD ($) Holding |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | NEUBERGER BERMAN ADVISERS MANAGEMENT TRUST |
| Entity Central Index Key | 0000736913 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Dec. 31, 2024 |
| C000022323 | |
| Shareholder Report [Line Items] | |
| Fund Name | Mid Cap Growth Portfolio |
| Class Name | Class I |
| No Trading Symbol [Flag] | true |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the Fund for the period of January 1, 2024 to December 31, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at www.nb.com/en/us/products/variable-investment-trusts/literature 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 | www.nb.com/en/us/products/variable-investment-trusts/literature</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;">www.nb.com/en/us/products/variable-investment-trusts/literature</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 I $101 0.90% |
| Expenses Paid, Amount | $ 101 |
| Expense Ratio, Percent | 0.90% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? The Fund’s investments in compelling secular growth trends, catalysts and fundamentals drove strong absolute and relative performance versus the Russell Midcap ® Performance Attribution Top Contributors Top Detractors Investments in companies supporting the development and expansion of artificial intelligence, across Information Technology, Industrials and Communication Services sectors Company-specific issues with investments in the Consumer Discretionary, Health Care and Real Estate sectors |
| 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 I $27,182 Russell 3000 ® Russell Midcap ® Russell Midcap ® 12/31/14 $10,000 $10,000 $10,000 $10,000 12/31/15 $10,128 $10,048 $9,980 $9,756 12/31/16 $10,573 $11,327 $10,711 $11,102 12/31/17 $13,246 $13,721 $13,418 $13,158 12/31/18 $12,398 $13,002 $12,780 $11,966 12/31/19 $16,458 $17,035 $17,314 $15,621 12/31/20 $23,038 $20,593 $23,475 $18,292 12/31/21 $26,031 $25,877 $26,463 $22,424 12/31/22 $18,551 $20,907 $19,392 $18,541 12/31/23 $21,918 $26,334 $24,408 $21,735 12/31/24 $27,182 $32,604 $29,803 $25,070 |
| Average Annual Return [Table Text Block] | Name 1 Year 5 Years 10 Years Class I 24.02% 10.56% 10.52% Russell 3000 ® 23.81% 13.86% 12.55% Russell Midcap ® 22.10% 11.47% 11.54% Russell Midcap ® 15.34% 9.92% 9.63% |
| Performance Table Market Index Changed [Text Block] | On July 24, 2024, the Fund began comparing its performance to the Russell 3000 Index in order to satisfy a change in regulatory requirements. The Russell Midcap Growth Index and the Russell Midcap Index will be maintained as additional indices as they show how the Fund’s performance compares to indices with characteristics that are more representative of the Fund’s investment strategy than the Russell 3000 Index. |
| AssetsNet | $ 550,942,888 |
| Holdings Count | Holding | 76 |
| Advisory Fees Paid, Amount | $ 2,738,725 |
| InvestmentCompanyPortfolioTurnover | 96% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics Net Assets $550,942,888 Number of Portfolio Holdings 76 Portfolio Turnover Rate 96% Total Investment Advisory Fees Paid $2,738,725 |
| Holdings [Text Block] | Sector Allocation (as a % of Total Investments Footnote Reference * Information Technology 29.5 % Industrials 17.9 % Financials 15.0 % Consumer Discretionary 14.9 % Health Care 8.2 % Communication Services 6.9 % Utilities 2.2 % Consumer Staples 2.0 % Energy 1.5 % Materials 1.2 % Short-Term Investments 0.7 % Total 100.0% Footnote Description Footnote * Derivatives (other than options purchased), if any, are excluded from this calculation. |
| Largest Holdings [Text Block] | Top Ten Securities (as a % of Total Investments Footnote Reference * Palantir Technologies, Inc. Class A 5.8% AppLovin Corp. Class A 4.0% Axon Enterprise, Inc. 2.8% Trade Desk, Inc. Class A 2.8% ARES Management Corp. Class A 2.8% Datadog, Inc. Class A 2.3% Vistra Corp. 2.2% Deckers Outdoor Corp. 2.1% W.W. Grainger, Inc. 2.1% Tradeweb Markets, Inc. Class A 2.0% Footnote Description Footnote * Derivatives (other than options purchased), if any, are excluded from this calculation. |
| Material Fund Change [Text Block] | |
| C000022324 | |
| Shareholder Report [Line Items] | |
| Fund Name | Mid Cap Growth Portfolio |
| Class Name | Class S |
| No Trading Symbol [Flag] | true |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the Fund for the period of January 1, 2024 to December 31, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at www.nb.com/en/us/products/variable-investment-trusts/literature fundinfo nb.com |
| Additional Information Phone Number | 800.877.9700 |
| Additional Information Email | fundinfo@nb.com</span>" id="sjs-B46"><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 | www.nb.com/en/us/products/variable-investment-trusts/literature</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;">www.nb.com/en/us/products/variable-investment-trusts/literature</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 S $123 1.10% |
| Expenses Paid, Amount | $ 123 |
| Expense Ratio, Percent | 1.10% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? The Fund’s investments in compelling secular growth trends, catalysts and fundamentals drove strong absolute and relative performance versus the Russell Midcap ® Performance Attribution Top Contributors Top Detractors Investments in companies supporting the development and expansion of artificial intelligence, across Information Technology, Industrials and Communication Services sectors Company-specific issues with investments in the Consumer Discretionary, Health Care and Real Estate sectors |
| 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 S $26,544 Russell 3000 ® Russell Midcap ® Russell Midcap ® 12/31/14 $10,000 $10,000 $10,000 $10,000 12/31/15 $10,100 $10,048 $9,980 $9,756 12/31/16 $10,520 $11,327 $10,711 $11,102 12/31/17 $13,104 $13,721 $13,418 $13,158 12/31/18 $12,244 $13,002 $12,780 $11,966 12/31/19 $16,222 $17,035 $17,314 $15,621 12/31/20 $22,663 $20,593 $23,475 $18,292 12/31/21 $25,547 $25,877 $26,463 $22,424 12/31/22 $18,182 $20,907 $19,392 $18,541 12/31/23 $21,448 $26,334 $24,408 $21,735 12/31/24 $26,544 $32,604 $29,803 $25,070 |
| Average Annual Return [Table Text Block] | Name 1 Year 5 Years 10 Years Class S 23.76% 10.35% 10.25% Russell 3000 ® 23.81% 13.86% 12.55% Russell Midcap ® 22.10% 11.47% 11.54% Russell Midcap ® 15.34% 9.92% 9.63% |
| Performance Table Market Index Changed [Text Block] | On July 24, 2024, the Fund began comparing its performance to the Russell 3000 Index in order to satisfy a change in regulatory requirements. The Russell Midcap Growth Index and the Russell Midcap Index will be maintained as additional indices as they show how the Fund’s performance compares to indices with characteristics that are more representative of the Fund’s investment strategy than the Russell 3000 Index. |
| AssetsNet | $ 550,942,888 |
| Holdings Count | Holding | 76 |
| Advisory Fees Paid, Amount | $ 2,738,725 |
| InvestmentCompanyPortfolioTurnover | 96% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics Net Assets $550,942,888 Number of Portfolio Holdings 76 Portfolio Turnover Rate 96% Total Investment Advisory Fees Paid $2,738,725 |
| Holdings [Text Block] | Sector Allocation (as a % of Total Investments Footnote Reference * Information Technology 29.5 % Industrials 17.9 % Financials 15.0 % Consumer Discretionary 14.9 % Health Care 8.2 % Communication Services 6.9 % Utilities 2.2 % Consumer Staples 2.0 % Energy 1.5 % Materials 1.2 % Short-Term Investments 0.7 % Total 100.0% Footnote Description Footnote * Derivatives (other than options purchased), if any, are excluded from this calculation. |
| Largest Holdings [Text Block] | Top Ten Securities (as a % of Total Investments Footnote Reference * Palantir Technologies, Inc. Class A 5.8% AppLovin Corp. Class A 4.0% Axon Enterprise, Inc. 2.8% Trade Desk, Inc. Class A 2.8% ARES Management Corp. Class A 2.8% Datadog, Inc. Class A 2.3% Vistra Corp. 2.2% Deckers Outdoor Corp. 2.1% W.W. Grainger, Inc. 2.1% Tradeweb Markets, Inc. Class A 2.0% Footnote Description Footnote * Derivatives (other than options purchased), if any, are excluded from this calculation. |
| Material Fund Change [Text Block] | |
| C000022322 | |
| Shareholder Report [Line Items] | |
| Fund Name | Short Duration Bond Portfolio |
| Class Name | Class I |
| No Trading Symbol [Flag] | true |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the Fund for the period of January 1, 2024 to December 31, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at www.nb.com/en/us/products/variable-investment-trusts/literature fundinfo nb.com |
| Additional Information Phone Number | 800.877.9700 |
| Additional Information Email | fundinfo@nb.com</span>" id="sjs-B73"><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 | www.nb.com/en/us/products/variable-investment-trusts/literature</span>" id="sjs-B74"><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;">www.nb.com/en/us/products/variable-investment-trusts/literature</span> |
| Expenses Paid, Amount | $ 95 |
| Expense Ratio, Percent | 0.92% |
| 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. |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect any fees and expenses charged by your insurance company under your variable annuity and variable life insurance contracts or by your qualified pension and other retirement plans whose proceeds are invested in the Fund. If such fees and expenses were reflected, returns would be less than those shown. |
| Performance Table Market Index Changed [Text Block] | On July 24, 2024, the Fund began comparing its performance to the Bloomberg U.S. Aggregate Bond Index in order to satisfy a change in regulatory requirements. The Bloomberg 1-3 Year U.S. Government/Credit Bond 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 Bloomberg U.S. Aggregate Bond Index. |
| AssetsNet | $ 79,138,795 |
| Holdings Count | Holding | 333 |
| Advisory Fees Paid, Amount | $ 136,551 |
| InvestmentCompanyPortfolioTurnover | 75% |
| C000022326 | |
| Shareholder Report [Line Items] | |
| Fund Name | Mid Cap Intrinsic Value Portfolio |
| Class Name | Class I |
| No Trading Symbol [Flag] | true |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the Fund for the period of January 1, 2024 to December 31, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at www.nb.com/en/us/products/variable-investment-trusts/literature fundinfo nb.com |
| Additional Information Phone Number | 800.877.9700 |
| Additional Information Email | fundinfo@nb.com</span>" id="sjs-B93"><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 | www.nb.com/en/us/products/variable-investment-trusts/literature</span>" id="sjs-B94"><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;">www.nb.com/en/us/products/variable-investment-trusts/literature</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 I $110 1.05% |
| Expenses Paid, Amount | $ 110 |
| Expense Ratio, Percent | 1.05% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? 2024 was a tumultuous year with several performance reversals, and the Fund finished behind the Russell Midcap Value ® Performance Attribution Top Contributors Top Detractors Investments in Information Technology and Utilities sectors Limited exposure to Real Estate versus the Index Investments in the Consumer Discretionary and Consumer Staples sectors Underweight in Financials versus the Index |
| 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 I $17,332 Russell 3000 ® Russell Midcap ® Russell Midcap ® 12/31/14 $10,000 $10,000 $10,000 $10,000 12/31/15 $9,166 $10,048 $9,522 $9,756 12/31/16 $10,648 $11,327 $11,426 $11,102 12/31/17 $12,430 $13,721 $12,951 $13,158 12/31/18 $10,532 $13,002 $11,359 $11,966 12/31/19 $12,295 $17,035 $14,433 $15,621 12/31/20 $11,973 $20,593 $15,150 $18,292 12/31/21 $15,900 $25,877 $19,443 $22,424 12/31/22 $14,349 $20,907 $17,104 $18,541 12/31/23 $15,927 $26,334 $19,278 $21,735 12/31/24 $17,332 $32,604 $21,798 $25,070 |
| Average Annual Return [Table Text Block] | Name 1 Year 5 Years 10 Years Class I 8.82% 7.11% 5.65% Russell 3000 ® 23.81% 13.86% 12.55% Russell Midcap ® 13.07% 8.59% 8.10% Russell Midcap ® 15.34% 9.92% 9.63% |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect any fees and expenses charged by your insurance company under your variable annuity and variable life insurance contracts or by your qualified pension and other retirement plans whose proceeds are invested in the Fund. If such fees and expenses were reflected, returns would be less than those shown. |
| Performance Table Market Index Changed [Text Block] | On July 24, 2024, the Fund began comparing its performance to the Russell 3000 Index in order to satisfy a change in regulatory requirements. The Russell Midcap Value Index and the Russell Midcap Index will be maintained as additional indices as they show how the Fund’s performance compares to indices with characteristics that are more representative of the Fund’s investment strategy than the Russell 3000 Index. |
| AssetsNet | $ 125,026,263 |
| Holdings Count | Holding | 72 |
| Advisory Fees Paid, Amount | $ 679,824 |
| InvestmentCompanyPortfolioTurnover | 21% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics Net Assets $125,026,263 Number of Portfolio Holdings 72 Portfolio Turnover Rate 21% Total Investment Advisory Fees Paid $679,824 |
| Holdings [Text Block] | Sector Allocation (as a % of Total Investments Footnote Reference * Information Technology 26.0 % Industrials 21.2 % Consumer Discretionary 9.7 % Financials 9.1 % Utilities 8.2 % Energy 8.1 % Health Care 6.2 % Consumer Staples 3.7 % Materials 3.6 % Real Estate 2.5 % Communication Services 1.4 % Short-Term Investments 0.3 % Total 100.0% Footnote Description Footnote * Derivatives (other than options purchased), if any, are excluded from this calculation. |
| Largest Holdings [Text Block] | Top Ten Securities (as a % of Total Investments Footnote Reference * Vistra Corp. 2.6% Ciena Corp. 2.5% CenterPoint Energy, Inc. 2.3% Pure Storage, Inc. Class A 2.3% Wix.com Ltd. 2.3% Williams Cos., Inc. 2.3% Hewlett Packard Enterprise Co. 2.2% Gates Industrial Corp. PLC 2.2% Aptiv PLC 2.2% Teledyne Technologies, Inc. 2.2% Footnote Description Footnote * Derivatives (other than options purchased), if any, are excluded from this calculation. |
| Material Fund Change [Text Block] | |
| C000022327 | |
| Shareholder Report [Line Items] | |
| Fund Name | Mid Cap Intrinsic Value Portfolio |
| Class Name | Class S |
| No Trading Symbol [Flag] | true |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the Fund for the period of January 1, 2024 to December 31, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at www.nb.com/en/us/products/variable-investment-trusts/literature fundinfo nb.com |
| Additional Information Phone Number | 800.877.9700 |
| Additional Information Email | fundinfo@nb.com</span>" id="sjs-B121"><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 | www.nb.com/en/us/products/variable-investment-trusts/literature</span>" id="sjs-B122"><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;">www.nb.com/en/us/products/variable-investment-trusts/literature</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 S $130 1.25% |
| Expenses Paid, Amount | $ 130 |
| Expense Ratio, Percent | 1.25% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? 2024 was a tumultuous year with several performance reversals, and the Fund finished behind the Russell Midcap Value ® Performance Attribution Top Contributors Top Detractors Investments in Information Technology and Utilities sectors Limited exposure to Real Estate versus the Index Investments in the Consumer Discretionary and Consumer Staples sectors Underweight in Financials versus the Index |
| 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 S $16,943 Russell 3000 ® Russell Midcap ® Russell Midcap ® 12/31/14 $10,000 $10,000 $10,000 $10,000 12/31/15 $9,148 $10,048 $9,522 $9,756 12/31/16 $10,610 $11,327 $11,426 $11,102 12/31/17 $12,344 $13,721 $12,951 $13,158 12/31/18 $10,434 $13,002 $11,359 $11,966 12/31/19 $12,148 $17,035 $14,433 $15,621 12/31/20 $11,804 $20,593 $15,150 $18,292 12/31/21 $15,642 $25,877 $19,443 $22,424 12/31/22 $14,086 $20,907 $17,104 $18,541 12/31/23 $15,591 $26,334 $19,278 $21,735 12/31/24 $16,943 $32,604 $21,798 $25,070 |
| Average Annual Return [Table Text Block] | Name 1 Year 5 Years 10 Years Class S 8.67% 6.88% 5.41% Russell 3000 ® 23.81% 13.86% 12.55% Russell Midcap ® 13.07% 8.59% 8.10% Russell Midcap ® 15.34% 9.92% 9.63% |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect any fees and expenses charged by your insurance company under your variable annuity and variable life insurance contracts or by your qualified pension and other retirement plans whose proceeds are invested in the Fund. If such fees and expenses were reflected, returns would be less than those shown. |
| Performance Table Market Index Changed [Text Block] | On July 24, 2024, the Fund began comparing its performance to the Russell 3000 Index in order to satisfy a change in regulatory requirements. The Russell Midcap Value Index and the Russell Midcap Index will be maintained as additional indices as they show how the Fund’s performance compares to indices with characteristics that are more representative of the Fund’s investment strategy than the Russell 3000 Index. |
| AssetsNet | $ 125,026,263 |
| Holdings Count | Holding | 72 |
| Advisory Fees Paid, Amount | $ 679,824 |
| InvestmentCompanyPortfolioTurnover | 21% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics Net Assets $125,026,263 Number of Portfolio Holdings 72 Portfolio Turnover Rate 21% Total Investment Advisory Fees Paid $679,824 |
| Holdings [Text Block] | Sector Allocation (as a % of Total Investments Footnote Reference * Information Technology 26.0 % Industrials 21.2 % Consumer Discretionary 9.7 % Financials 9.1 % Utilities 8.2 % Energy 8.1 % Health Care 6.2 % Consumer Staples 3.7 % Materials 3.6 % Real Estate 2.5 % Communication Services 1.4 % Short-Term Investments 0.3 % Total 100.0% Footnote Description Footnote * Derivatives (other than options purchased), if any, are excluded from this calculation. |
| Largest Holdings [Text Block] | Top Ten Securities (as a % of Total Investments Footnote Reference * Vistra Corp. 2.6% Ciena Corp. 2.5% CenterPoint Energy, Inc. 2.3% Pure Storage, Inc. Class A 2.3% Wix.com Ltd. 2.3% Williams Cos., Inc. 2.3% Hewlett Packard Enterprise Co. 2.2% Gates Industrial Corp. PLC 2.2% Aptiv PLC 2.2% Teledyne Technologies, Inc. 2.2% Footnote Description Footnote * Derivatives (other than options purchased), if any, are excluded from this calculation. |
| Material Fund Change [Text Block] | |
| C000022328 | |
| Shareholder Report [Line Items] | |
| Fund Name | Sustainable Equity Portfolio |
| Class Name | Class I |
| No Trading Symbol [Flag] | true |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the Fund for the period of January 1, 2024 to December 31, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at www.nb.com/en/us/products/variable-investment-trusts/literature fundinfo nb.com |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the reporting period. |
| Additional Information Phone Number | 800.877.9700 |
| Additional Information Email | fundinfo@nb.com</span>" id="sjs-B150"><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 | www.nb.com/en/us/products/variable-investment-trusts/literature</span>" id="sjs-B151"><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;">www.nb.com/en/us/products/variable-investment-trusts/literature</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 I $101 0.89% |
| Expenses Paid, Amount | $ 101 |
| Expense Ratio, Percent | 0.89% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? Markets set records in 2024 despite significant uncertainty. Investors were concerned with interest rates, economic outlook, geopolitical issues and U.S. elections. Market leadership shifted between large and smaller cap stocks, and growth and value styles during the volatile period. The Fund outperformed the S&P 500 ® Performance Attribution Top Contributors Top Detractors Overweight to Financials and underweight to Energy versus the Index Financials, Consumer Discretionary and Consumer Staples Stock selection within Information Technology and an underweight to that strongly performing sector versus the Index Health Care, Industrials and Communication Services |
| 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 I $29,548 S&P 500 ® 12/31/14 $10,000 $10,000 12/31/15 $9,954 $10,138 12/31/16 $10,935 $11,351 12/31/17 $12,950 $13,829 12/31/18 $12,209 $13,223 12/31/19 $15,369 $17,386 12/31/20 $18,376 $20,585 12/31/21 $22,690 $26,494 12/31/22 $18,503 $21,696 12/31/23 $23,480 $27,399 12/31/24 $29,548 $34,254 |
| Average Annual Return [Table Text Block] | Name 1 Year 5 Years 10 Years Class I 25.84% 13.97% 11.44% S&P 500 ® 25.02% 14.53% 13.10% |
| Material Change Date | Jan. 01, 2024 |
| AssetsNet | $ 852,337,886 |
| Holdings Count | Holding | 44 |
| Advisory Fees Paid, Amount | $ 4,267,465 |
| InvestmentCompanyPortfolioTurnover | 4% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics Net Assets $852,337,886 Number of Portfolio Holdings 44 Portfolio Turnover Rate 4% Total Investment Advisory Fees Paid $4,267,465 |
| Holdings [Text Block] | Sector Allocation (as a % of Total Investments Footnote Reference * Information Technology 26.3 % Financials 26.0 % Consumer Discretionary 14.5 % Communication Services 9.7 % Health Care 9.6 % Industrials 7.1 % Consumer Staples 3.1 % Materials 1.4 % Energy 1.2 % Utilities 1.0 % Short-Term Investments 0.1 % Total 100.0% Footnote Description Footnote * Derivatives (other than options purchased), if any, are excluded from this calculation. |
| Largest Holdings [Text Block] | Top Ten Securities (as a % of Total Investments Footnote Reference * Amazon.com, Inc. 10.0% Microsoft Corp. 8.6% Alphabet, Inc. Class A 8.0% Mastercard, Inc. Class A 4.8% Berkshire Hathaway, Inc. Class B 4.7% Interactive Brokers Group, Inc. Class A 4.6% GoDaddy, Inc. Class A 4.3% Progressive Corp. 3.4% Apple, Inc. 3.1% Fiserv, Inc. 3.1% Footnote Description Footnote * Derivatives (other than options purchased), if any, are excluded from this calculation. |
| Material Fund Change [Text Block] | Material Fund Changes This is a summary of certain changes to the Fund since January 1, 2024. For more complete information, you may review the Fund's prospectus, which is available at www.nb.com/en/us/products/variable-investment-trusts/literature fundinfo nb.com |
| Summary of Change Legend [Text Block] | This is a summary of certain changes to the Fund since January 1, 2024. For more complete information, you may review the Fund's prospectus, which is available at www.nb.com/en/us/products/variable-investment-trusts/literature fundinfo nb.com |
| C000035621 | |
| Shareholder Report [Line Items] | |
| Fund Name | Sustainable Equity Portfolio |
| Class Name | Class S |
| No Trading Symbol [Flag] | true |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the Fund for the period of January 1, 2024 to December 31, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at www.nb.com/en/us/products/variable-investment-trusts/literature fundinfo nb.com |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the reporting period. |
| Additional Information Phone Number | 800.877.9700 |
| Additional Information Email | fundinfo@nb.com</span>" id="sjs-B179"><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 | www.nb.com/en/us/products/variable-investment-trusts/literature</span>" id="sjs-B180"><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;">www.nb.com/en/us/products/variable-investment-trusts/literature</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 S $130 1.15% |
| Expenses Paid, Amount | $ 130 |
| Expense Ratio, Percent | 1.15% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? Markets set records in 2024 despite significant uncertainty. Investors were concerned with interest rates, economic outlook, geopolitical issues and U.S. elections. Market leadership shifted between large and smaller cap stocks, and growth and value styles during the volatile period. The Fund outperformed the S&P 500 ® Performance Attribution Top Contributors Top Detractors Overweight to Financials and underweight to Energy versus the Index Financials, Consumer Discretionary and Consumer Staples Stock selection within Information Technology and an underweight to that strongly performing sector versus the Index Health Care, Industrials and Communication Services |
| 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 S $28,868 S&P 500 ® 12/31/14 $10,000 $10,000 12/31/15 $9,941 $10,138 12/31/16 $10,899 $11,351 12/31/17 $12,873 $13,829 12/31/18 $12,109 $13,223 12/31/19 $15,206 $17,386 12/31/20 $18,137 $20,585 12/31/21 $22,338 $26,494 12/31/22 $18,171 $21,696 12/31/23 $22,999 $27,399 12/31/24 $28,868 $34,254 |
| Average Annual Return [Table Text Block] | Name 1 Year 5 Years 10 Years Class S 25.52% 13.68% 11.18% S&P 500 ® 25.02% 14.53% 13.10% |
| Material Change Date | Jan. 01, 2024 |
| AssetsNet | $ 852,337,886 |
| Holdings Count | Holding | 44 |
| Advisory Fees Paid, Amount | $ 4,267,465 |
| InvestmentCompanyPortfolioTurnover | 4% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics Net Assets $852,337,886 Number of Portfolio Holdings 44 Portfolio Turnover Rate 4% Total Investment Advisory Fees Paid $4,267,465 |
| Holdings [Text Block] | Sector Allocation (as a % of Total Investments Footnote Reference * Information Technology 26.3 % Financials 26.0 % Consumer Discretionary 14.5 % Communication Services 9.7 % Health Care 9.6 % Industrials 7.1 % Consumer Staples 3.1 % Materials 1.4 % Energy 1.2 % Utilities 1.0 % Short-Term Investments 0.1 % Total 100.0% Footnote Description Footnote * Derivatives (other than options purchased), if any, are excluded from this calculation. |
| Largest Holdings [Text Block] | Top Ten Securities (as a % of Total Investments Footnote Reference * Amazon.com, Inc. 10.0% Microsoft Corp. 8.6% Alphabet, Inc. Class A 8.0% Mastercard, Inc. Class A 4.8% Berkshire Hathaway, Inc. Class B 4.7% Interactive Brokers Group, Inc. Class A 4.6% GoDaddy, Inc. Class A 4.3% Progressive Corp. 3.4% Apple, Inc. 3.1% Fiserv, Inc. 3.1% Footnote Description Footnote * Derivatives (other than options purchased), if any, are excluded from this calculation. |
| Material Fund Change [Text Block] | Material Fund Changes This is a summary of certain changes to the Fund since January 1, 2024. For more complete information, you may review the Fund's prospectus, which is available at www.nb.com/en/us/products/variable-investment-trusts/literature fundinfo nb.com |
| Summary of Change Legend [Text Block] | This is a summary of certain changes to the Fund since January 1, 2024. For more complete information, you may review the Fund's prospectus, which is available at www.nb.com/en/us/products/variable-investment-trusts/literature fundinfo nb.com |
