These tables describe the fees and expenses that you may pay if you buy and hold shares of the Fund. These tables do not reflect any fees and expenses charged by your insurance company under your variable contract or by your qualified plan. If the tables did reflect such fees and expenses, the overall expenses would be higher than those shown. Please refer to the prospectus for your variable contract or your qualified plan documentation for information on their separate fees and expenses.

Shareholder Fees Caption [Text]

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Shareholder Fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

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Annual Fund Operating Expenses (expenses that you pay each year as a % of the value of your investment)

Portfolio Turnover [Heading]

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Portfolio Turnover

Portfolio Turnover [Text Block]

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The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs. These costs, which are not reflected in annual operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 35% of the average value of its portfolio.

Portfolio Turnover, Rate

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35.00%

Expense Example [Heading]

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Expense Example

Expense Example Narrative [Text Block]

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The expense example can help you compare costs among mutual funds. The example assumes that you invested $10,000 for the periods shown, that you redeemed all of your shares at the end of those periods, that the Fund earned a hypothetical 5% total return each year, and that the Fund’s expenses were those in the table. Actual performance and expenses may be higher or lower.

Strategy [Heading]

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PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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To pursue its goal, the Fund normally invests at least 80% of its net assets in equity securities of mid-capitalization companies, which it defines as those with a total market capitalization within the market capitalization range of the Russell Midcap® Value Index at the time of purchase.

The Fund’s strategy consists of using a bottom-up, fundamental research driven approach to identify stocks of companies that are trading below the Portfolio Manager’s estimate of their intrinsic value and that he believes have the potential for appreciation over time. The Portfolio Manager’s estimate of a company’s intrinsic value represents his view of the company’s true, long-term economic worth, the market’s view of which may be currently distorted by market inefficiencies. The intrinsic value estimate represents what the Portfolio Manager believes a company could be worth if it is acquired, if its profitability returns to its long-term average level, or if its valuation moves in line with those companies that the Portfolio Manager sees as its publicly traded peers.

The Portfolio Manager believes that while markets are often efficient, valuations of certain types of companies are often distorted by market inefficiencies, which can lead to attractive investment opportunities. The Portfolio Manager attempts to exploit recurring market inefficiencies among the following types of companies as the Portfolio Manager believes these types of companies are often misunderstood and mispriced by investors.

■	Complex Companies: These companies typically have multiple lines of business that are in different industries or sectors and/or that have different growth rates and profitability characteristics.
■	Cyclical Companies: These companies typically have ebbs and flows in their business depending on demand patterns for their products, the length of product cycles, or other transient factors.
■	Companies in a Period of Interrupted Growth: Typically, these are companies in attractive, high growth markets that have suffered what the Portfolio Manager believes is a temporary setback and/or are in transition to a more mature, lower growth business model that focuses more on current earnings than on rapid growth.

In seeking to identify potential investment opportunities, the Portfolio Manager performs an initial screening to identify those companies that have stock prices that are trailing the performance of the overall market and that he believes are attractive relative to current cash flows. Next, the Portfolio Manager establishes an estimate of a company’s intrinsic value. The Portfolio Manager will invest in a company based on its discount to his estimate of intrinsic value and his belief in its potential for appreciation over time. In addition, the Portfolio Manager may invest in anticipation of a catalyst that can be expected to close the value/price gap, such as a merger, restructuring, liquidation, spin-off, major management change, share repurchase, or capital reallocation. The Portfolio Manager will typically visit a company and interview its management team to help understand management’s incentives (such as equity ownership in the company and compensation plans), the merits of its strategic plan, and other factors that have the potential to increase the value of the company’s stock.

The Portfolio Manager establishes an intrinsic value for a company’s stock when it is purchased and then continues to evaluate the company’s stock price versus his estimate of its intrinsic value to determine whether to maintain, add to, reduce or eliminate the position. The Portfolio Manager typically reduces or eliminates a position in a company’s stock as the stock’s price appreciates and the company’s discount to his estimate of its intrinsic value narrows. The Portfolio Manager’s decision to reduce or eliminate a position in a particular stock may also be driven by his belief that another company’s stock has a wider discount to his estimate of its intrinsic value. Changes in a company’s management or corporate strategy may also cause the Portfolio Manager to reduce or eliminate a position in that company’s stock.

Although the Fund invests primarily in domestic stocks, it may also invest in stocks of foreign companies.

The Fund seeks to reduce risk by diversifying among many companies, sectors and industries. However, at times, the Portfolio Manager may emphasize certain sectors or industries that he believes may benefit from current market or economic trends.

The Fund will not change its strategy of normally investing at least 80% of its net assets in equity securities of mid-capitalization companies, without providing shareholders at least 60 days’ notice. This test is applied at the time the Fund invests; later percentage changes caused by a change in Fund assets, market values or company circumstances will not require the Fund to dispose of a holding.

Risk [Heading]

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PRINCIPAL INVESTMENT RISKS

Risk Narrative [Text Block]

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Most of the Fund’s performance depends on what happens in the stock market, the Portfolio Manager's evaluation of those developments, and the success of the Portfolio Manager's in implementing the Fund's investment strategies. The market's behavior can be difficult to predict, particularly in the short term. There can be no guarantee that the Fund will achieve its goal. The Fund may take temporary defensive and cash management positions; in such a case, it will not be pursuing its principal investment strategies.

The Fund is a mutual fund, not a bank deposit, and is not guaranteed or insured by the Federal Deposit Insurance Corporation or any other government agency. The value of your investment may fall, sometimes sharply, and you could lose money by investing in the Fund.

The following risks, which are described in alphabetical order and not in order of importance or potential exposure, can significantly affect the Fund’s performance:

Catalyst Risk. Investing in companies in anticipation of a catalyst carries the risk that the catalyst may not happen as anticipated, possibly due to the actions of other market participants, or the market may react to the catalyst differently than expected.

Currency Risk. Changes in currency exchange rates could adversely impact investment gains or add to investment losses. Currency exchange rates can be affected unpredictably by intervention, or failure to intervene, by U.S. or foreign governments or central banks or by currency controls or political developments in the U.S. or abroad.

Foreign Risk. Foreign securities involve risks in addition to those associated with comparable U.S. securities. Additional risks include exposure to less developed or less efficient trading markets; social, political, diplomatic, or economic instability; trade barriers and other protectionist trade policies (including those of the U.S.); fluctuations in foreign currencies or currency redenomination; potential for default on sovereign debt; nationalization or expropriation of assets; settlement, custodial or other operational risks; higher transaction costs; confiscatory withholding or other taxes; and less stringent auditing, corporate disclosure, governance, and legal standards. As a result, foreign securities may fluctuate more widely in price, and may also be less liquid, than comparable U.S. securities. World markets, or those in a particular region, may all react in similar fashion to important economic or political developments. In addition, foreign markets may perform differently than the U.S. market. The effect of economic instability on specific foreign markets or issuers may be difficult to predict or evaluate. Regardless of where a company is organized or its stock is traded, its performance may be affected significantly by events in regions from which it derives its profits or in which it conducts significant operations.

Securities of issuers traded on exchanges may be suspended, either by the issuers themselves, by an exchange or by governmental authorities. Trading suspensions may be applied from time to time to the securities of individual issuers for reasons specific to that issuer, or may be applied broadly by exchanges or governmental authorities in response to market events. In the event that the Fund holds material positions in such suspended securities, the Fund’s ability to liquidate its positions or provide liquidity to investors may be compromised and the Fund could incur significant losses.

Issuer-Specific Risk. An individual security may be more volatile, and may perform differently, than the market as a whole.

Market Volatility Risk. Markets may be volatile and values of individual securities and other investments, including those of a particular type, may decline significantly in response to adverse issuer, political, regulatory, market, economic or other developments that may cause broad changes in market value, public perceptions concerning these developments, and adverse investor sentiment. Geopolitical risks may add to instability in world economies and markets generally. Changes in value may be temporary or may last for extended periods. If the Fund sells a portfolio position before it reaches its market peak, it may miss out on opportunities for better performance.

Mid-Cap Companies Risk. At times, mid-cap companies may be out of favor with investors. Compared to larger companies, mid-cap companies may depend on a more limited management group, may have a shorter history of operations, and may have limited product lines, markets or financial resources. The securities of mid-cap companies are often more volatile and less liquid than the securities of larger companies and may be more affected than other types of securities by the underperformance of a sector or during market downturns.

Operational and Cybersecurity Risk. The Fund and its service providers, and your ability to transact with the Fund, may be negatively impacted due to operational matters arising from, among other problems, human errors, systems and technology disruptions or failures, or cybersecurity incidents. Cybersecurity incidents may allow an unauthorized party to gain access to fund assets, customer data, or proprietary information, or cause the Fund or its service providers, as well as the securities trading venues and their service providers, to suffer data corruption or lose operational functionality. It is not possible for the Manager or the other Fund service providers to identify all of the cybersecurity or other operational risks that may affect the Fund or to develop processes and controls to completely eliminate or mitigate their occurrence or effects. Most issuers in which the Fund invests are heavily dependent on computers for data storage and operations, and require ready access to the internet to conduct their business. Thus, cybersecurity incidents could also affect issuers of securities in which the Fund invests, leading to significant loss of value.

Recent Market Conditions. Some countries, including the U.S., are considering or pursuing the adoption of more protectionist trade policies and moving away from the tighter financial industry regulations that followed the 2008 financial crisis. The U.S. is also said to be considering significant new investments in infrastructure and national defense which, coupled with lower federal taxes, could lead to sharply increased government borrowing and higher interest rates. The exact shape of these policies is still being worked out through the political process, but the equity and debt markets may react strongly to expectations, which could increase volatility, especially if the market’s expectations for changes in government policies are not borne out. Also, prices of many U.S. equity securities have increased substantially for the last several years, U.S. unemployment has declined and many market prognosticators reportedly expect the Fed to raise interest rates in an effort to limit inflation and/or believe the market may experience a further “correction” to lower values.

High public debt in the U.S. and other countries creates ongoing systemic and market risks and policymaking uncertainty. Interest rates have been unusually low in recent years in the U.S. and abroad. Because there is little precedent for this situation, it is difficult to predict the impact on various markets of a significant rate increase or other significant policy changes.

In addition, global economies and financial markets are increasingly interconnected, which increases the possibilities that conditions in one country or region might adversely impact issuers in a different country or region. A rise in protectionist trade policies, and the possibility of changes to some international trade agreements, could affect the economies of many nations in ways that cannot necessarily be foreseen at the present time and could negatively affect the economies of even those countries that implement the protectionist policies.

Redemption Risk. The Fund may experience periods of heavy redemptions that could cause the Fund to sell assets at inopportune times or at a loss or depressed value. Redemption risk is heightened during periods of declining or illiquid markets. Heavy redemptions could hurt the Fund’s performance.

Risk Management. Risk is an essential part of investing. No risk management program can eliminate the Fund’s exposure to adverse events; at best, it may only reduce the possibility that the Fund will be affected by such events, and especially those risks that are not intrinsic to the Fund’s investment program. The Fund could experience losses if judgments about risk prove to be incorrect.

Risk of Increase in Expenses. A decline in the Fund’s average net assets during the current fiscal year due to market volatility or other factors could cause the Fund’s expenses for the current fiscal year to be higher than the expense information presented in “Fees and Expenses.”

Sector Risk. From time to time, based on market or economic conditions, the Fund may have significant positions in one or more sectors of the market. To the extent the Fund invests more heavily in particular sectors, its performance will be especially sensitive to developments that significantly affect those sectors. Individual sectors may be more volatile, and may perform differently, than the broader market. The industries that constitute a sector may all react in the same way to economic, political or regulatory events.

Valuation Risk. The Fund may not be able to sell an investment at the price at which the Fund has valued the investment. The Fund’s ability to value its investments in an accurate and timely manner may be impacted by technological issues and/or errors by third party service providers, such as pricing services or accounting agents.

Value Stock Risk. Value stocks may remain undervalued or may decrease in value during a given period or may not ever realize what the portfolio management team believes to be their full value or intrinsic value . This may happen, among other reasons, because of a failure to anticipate which stocks or industries would benefit from changing market or economic conditions or investor preferences.

Risk Lose Money [Text]

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The value of your investment may fall, sometimes sharply, and you could lose money by investing in the Fund.

Risk Not Insured Depository Institution [Text]

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The Fund is a mutual fund, not a bank deposit, and is not guaranteed or insured by the Federal Deposit Insurance Corporation or any other government agency.

Bar Chart and Performance Table [Heading]

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PERFORMANCE

Performance Narrative [Text Block]

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The following bar chart and table provide an indication of the risks of investing in the Fund. The bar chart shows how the Fund’s performance has varied from year to year. The table next to the bar chart shows what the returns would equal if you averaged out actual performance over various lengths of time and compares the returns with the returns of one or more broad-based market indices. The indices, which are described in “Descriptions of Indices” in the prospectus, have characteristics relevant to the Fund's investment strategy. The performance information does not reflect variable contract or qualified plan fees and expenses. If such fees and expenses were reflected, returns would be less than those shown. Please refer to the prospectus for your variable contract or your qualified plan documentation for information on their separate fees and expenses.

Returns would have been lower if the Manager had not reimbursed certain expenses and/or waived a portion of the investment management fees during certain of the periods shown.

Past performance is not a prediction of future results. Visit www.nb.com or call 800-877-9700 for updated performance information.

Performance Information Illustrates Variability of Returns [Text]

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The bar chart shows how the Fund’s performance has varied from year to year. The table next to the bar chart shows what the returns would equal if you averaged out actual performance over various lengths of time and compares the returns with the returns of one or more broad-based market indices.

Performance Additional Market Index [Text]

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The table next to the bar chart shows what the returns would equal if you averaged out actual performance over various lengths of time and compares the returns with the returns of one or more broad-based market indices.

Performance Availability Phone [Text]

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800-877-9700

Performance Availability Website Address [Text]

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www.nb.com

Performance Past Does Not Indicate Future [Text]

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Past performance is not a prediction of future results.

Bar Chart [Heading]

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YEAR-BY-YEAR % RETURNS AS OF 12/31 EACH YEAR

Bar Chart Closing [Text Block]

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Best quarter: Q3 '09, 25.77%

Worst quarter: Q4 '08, -27.10%

Highest Quarterly Return, Label

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Best quarter:

Highest Quarterly Return, Date

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Sep. 30, 2009

Highest Quarterly Return

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25.77%

Lowest Quarterly Return, Label

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Worst quarter:

Lowest Quarterly Return, Date

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Dec. 31, 2008

Lowest Quarterly Return

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(27.10%)

Performance Table Heading

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AVERAGE ANNUAL TOTAL % RETURNS AS OF 12/31/17

Average Annual Return, Caption

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Mid Cap Intrinsic Value Portfolio

Class S | Mid Cap Intrinsic Value Portfolio | Russell Midcap® Value Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

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1 Year

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13.34%

5 Years

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14.68%

10 Years

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9.10%

Class S | Mid Cap Intrinsic Value Portfolio | Russell Midcap® Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

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1 Year

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18.52%

5 Years

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14.96%

10 Years

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9.11%

Class S | Mid Cap Intrinsic Value Portfolio | Class S

Risk/Return:

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Shareholder Fees (fees paid directly from your investment)

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none

Management fees

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0.85%

Distribution and/or shareholder service (12b-1) fees

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0.25%

Other expenses

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0.16%

^[1]

Total annual operating expenses

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1.26%

Expense Example, with Redemption, 1 Year

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$ 128

Expense Example, with Redemption, 3 Years

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400

Expense Example, with Redemption, 5 Years

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692

Expense Example, with Redemption, 10 Years

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$ 1,523

Annual Return 2008

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(45.95%)

Annual Return 2009

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46.16%

Annual Return 2010

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25.99%

Annual Return 2011

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(6.70%)

Annual Return 2012

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15.37%

Annual Return 2013

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36.71%

Annual Return 2014

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13.56%

Annual Return 2015

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(8.52%)

Annual Return 2016

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15.98%

Annual Return 2017

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16.35%

1 Year

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16.35%

5 Years

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13.89%

10 Years

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7.46%

[1]

The Fund has agreed that Class S will repay Neuberger Berman Investment Advisers LLC ("Manager") for fees and expenses waived or reimbursed for the class provided that repayment does not cause annual operating expenses (excluding interest, taxes, brokerage commissions, acquired fund fees and expenses, dividend and interest expenses relating to short sales, and extraordinary expenses, if any) to exceed 1.25% of the class' average net assets. Any such repayment must be made within three years after the year in which the Manager incurred the expense. "Other expenses" shown above include a repayment of 0.01%.