The Total Annual Fund Operating Expenses do not correlate to the ratio of expenses to the average net assets appearing in the Financial Highlights table which reflects only the operating expenses of the Fund and does not include AFFE.

Expense Example Narrative [Text Block]

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This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example illustrates the hypothetical expenses that you would incur over the time periods indicated if you invest $10,000 in the Fund’s shares. The example also assumes that the Fund provides a return of 5% a year and that operating expenses remain the same. This example reflects the net operating expenses with fee waiver and expense reimbursement for the one-year contractual period and the total operating expenses without fee waiver and expense reimbursement for the remaining time periods shown below. Your actual costs may be higher or lower than this example. This example does not reflect any variable contract expenses. If variable contract expenses were included, the expenses shown would be higher. The results apply whether or not you redeem your investment at the end of the given period.

Strategy Narrative [Text Block]

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The Fund may invest up to 100% of its assets in fixed income securities and up to 80% of its assets in equity securities. The Fund may gain exposure by direct holdings of such securities or via investments in pooled investment vehicles (“underlying funds”), including BlackRock equity and/or fixed income mutual funds and affiliated and unaffiliated exchange traded funds (“ETFs”). The following description of the Fund’s investment strategies includes strategies that the Fund gains exposure to through underlying funds.

The Fund may invest in fixed income securities to an unlimited extent, including corporate bonds and notes, mortgage-backed securities, asset-backed securities, convertible securities, preferred securities, government obligations, and other fixed income securities. The Fund may also invest significantly in non-investment grade bonds (high yield, junk bonds or distressed securities), non-investment grade bank loans, non-dollar denominated bonds and bonds of emerging market issuers. The Fund’s investment in non-dollar denominated bonds may be on a currency hedged or unhedged basis. Non-investment grade bonds acquired by the Fund will generally be in the lower categories of the major rating agencies at the time of purchase (BB or lower by Standard & Poor’s, a division of the McGraw Hill Companies (“S&P”), or Ba or lower by Moody’s Investors Services, Inc. (“Moody’s”)) or will be determined by the management team to be of similar quality. Split rated bonds will be considered to have the higher credit rating. The average portfolio duration of the Fund will vary based on the management team’s forecast of interest rates and there are no limits regarding portfolio duration or average maturity.

The Fund’s equity investments may include common stock, preferred stock, securities convertible into common and preferred stock and non-convertible preferred stock. The Fund generally intends to invest in dividend paying stocks. From time to time, the Fund may invest in shares of companies through initial public offerings (“IPOs”). The Fund may invest without limit in securities of U.S. and non-U.S. issuers. Such investments may be U.S. dollar based or non-U.S. dollar based and may be currency hedged or unhedged. The Fund may invest in securities of companies of any market capitalization.

The Fund may, when consistent with its investment objective, buy or sell options or futures on a security or an index of securities, or enter into total return swaps and foreign currency transactions (collectively, commonly known as derivatives). An option is the right to buy or sell a security or an index of securities at a specific price on or before a specific date. A future is an agreement to buy or sell a security or an index of securities at a specific price on a specific date. A swap is an agreement whereby one party exchanges its right to receive or its obligation to pay one type of interest or currency for another party’s obligation to pay or its right to receive another type of interest or currency in the future or for a period of time. The Fund typically uses derivatives as a substitute for taking a position in the underlying asset and/or as part of a strategy designed to reduce exposure to other risks, such as currency risk.

The Fund may also use derivatives to enhance return (for example, by enhancing yield to the Fund in the form of distributions), in which case their use may involve leveraging risk. The Fund may seek to obtain market exposure to the securities in which it primarily invests by entering into a series of purchase and sale contracts or by using other investment techniques (such as reverse repurchase agreements or dollar rolls). A dollar roll transaction involves a sale by the Fund of a mortgage-backed or other security concurrently with an agreement by the Fund to repurchase a similar security at a later date at an agreed-upon price. The securities that are repurchased will bear the same interest rate and stated maturity as those sold, but pools of mortgages collateralizing those securities may have different prepayment histories than those sold. The underlying funds may, to varying degrees, also invest in derivatives. The Fund may also engage in option writing to generate additional income in the portfolio.

The Fund may invest in master limited partnerships (“MLPs”) that are generally in energy-related industries and in U.S. and non-U.S. real estate investment trusts (“REITs”), structured products and floating rate securities (such as bank loans).

The Fund may incorporate a proprietary volatility control process that seeks to reduce risk when market volatility is expected to exceed normal ranges. The Fund may without limitation allocate assets into cash or short-term fixed income securities, and away from riskier assets such as equity and high yield fixed income securities. When volatility decreases, the Fund may move assets out of cash and back into riskier securities. The Fund may, at times, invest significantly in cash.

The Fund may engage in active and frequent trading of portfolio securities to achieve its primary investment strategies.

The Fund is non-diversified for purposes of the Investment Company Act of 1940, and as a result may invest a greater portion of its assets in a particular issuer than a diversified fund.

Risk Narrative [Text Block]

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All mutual funds carry risk. Accordingly, loss of money is a risk of investing in the Fund. Because the Fund invests its assets in shares of underlying funds, the Fund indirectly owns the same investments as those made by the underlying funds. By investing in the Fund, therefore, you indirectly assume the same types of risks as investing directly in the underlying funds. The Fund's investment performance is affected by each underlying fund's investment performance, and the Fund's ability to achieve its investment objective depends, in large part, on each underlying fund's ability to meet its investment objective. The following risks reflect the Fund's principal risks, which include the underlying funds' principal risks.

Market Risk. The value of portfolio investments may decline. As a result, your investment in a fund may decline in value and you could lose money.

Asset Allocation Risk. With an asset allocation strategy, the amount invested in various asset classes of securities may change over time. Asset allocation risk could result in an allocation to an underperforming asset class.

Value Stocks Risk. Value stocks tend to be inexpensive relative to their earnings or assets compared to other types of stocks, such as growth stocks. Value stocks can continue to be inexpensive for long periods of time, may not ever realize their potential value, and may even go down in price.

Mid- and Large-Capitalization Investing Risk. An underlying fund and/or ETF may invest a relatively large percentage of its assets in the securities of mid- and large-capitalization companies. While securities in these capitalization ranges represent a significant percentage of the market, an underlying funds’ and/or ETFs’ performance may be adversely affected if securities of mid- and large-capitalization companies underperform securities of small-capitalization companies or the market as a whole. Securities of small-capitalization companies are often more vulnerable to market volatility than securities of mid- and large-capitalization companies, but also offer greater potential for capital appreciation.

Medium-Cap Companies Risk. Securities issued by medium-sized companies may be subject to more abrupt market movements and may involve greater risks than investments in larger companies. These less developed, lesser-known companies may experience greater risks than those normally associated with larger companies. This is due to, among other things, the greater business risks of smaller size and limited product lines, markets, distribution channels, and financial and managerial resources.

Dividend Risk. Because most of the corporate loans held by the underlying funds and/or ETFs will have floating or variable interest rates, the amounts of the underlying funds’ and/or ETFs’ monthly distributions to its stockholders are expected to vary with fluctuations in market interest rates. Generally, when market interest rates fall, the amount of the distributions to stockholders will likewise decrease.

Exchange-Traded Fund (“ETF”) Risk. ETFs generally reflect the risks of owning the underlying securities they hold, although lack of liquidity in ETF shares could result in the price of the ETF being more volatile.

Master Limited Partnership Risk. Investments in securities of an MLP involve risks that differ from investments in common stock, including risks related to limited control and limited rights to vote on matters affecting the MLP, risks related to potential conflicts of interest between the MLP and the MLP’s general partner, cash flow risks, dilution risks and risks related to the general partner’s right to require unit-holders to sell their common units at an undesirable time or price due to regulatory changes or other reasons. MLPs are generally considered interest-rate sensitive investments. During periods of interest rate volatility, these investments may not provide attractive returns.

Preferred Securities Risk. Preferred securities are subject to issuer-specific and market risks applicable generally to equity securities. The value of preferred stock also can be affected by prevailing interest rates. Preferred securities may pay fixed or adjustable rates of return. In addition, a company’s preferred securities generally pay dividends only after the company makes required payments to holders of its bonds and other debt.

Rights Risk. If the Fund does not exercise its subscription rights to purchase common stock, the Fund’s interest in the issuing company would be diluted. The market for such rights is not well developed, and, accordingly, the Fund also may not always realize full value on the sale of rights.

Warrants Risk. If the price of the underlying stock does not rise above the exercise price before the warrant expires, the warrant generally expires without any value and a fund loses any amount it paid for the warrant. Thus, investments in warrants may involve substantially more risk than investments in common stock. Warrants may trade in the same markets as their underlying stock; however, the price of the warrant does not necessarily move with the price of the underlying stock.

Interest Rate Risk. When interest rates rise, fixed income securities (i.e., debt obligations) generally will decline in value. These declines in value are greater for fixed income securities with longer maturities or durations.

Credit Risk. Credit risk is the risk that the issuer of a debt obligation will be unable or unwilling to make interest or principal payments on time. Credit risk is often gauged by “credit ratings” assigned by nationally recognized statistical rating organizations (“NRSROs”). A decrease in an issuer’s credit rating may cause a decline in the value of the issuer’s debt obligations. However, credit ratings may not reflect the issuer’s current financial condition or events since the security was last rated by a rating agency. Credit ratings also may be influenced by rating agency conflicts of interest or based on historical data that are no longer applicable or accurate.

Below Investment Grade Bond Risk. Below investment grade bonds, otherwise known as “high yield” bonds (“junk” bonds), generally have a greater risk of principal loss than investment grade bonds. Below investment grade bonds are often considered speculative and involve significantly higher credit risk and liquidity risk. The value of these bonds may fluctuate more than the value of higher-rated debt obligations, and may decline significantly in periods of general economic difficulty or periods of rising interest rates and may be subject to negative perceptions of the junk bond markets generally and less secondary market liquidity.

High Yield Loan Risk. Bank loans (e.g., loan assignments and participations), like other high yield corporate debt obligations, have a higher risk of default and may be less liquid and/or become illiquid.

Asset-backed Securities Risk. Issuers of asset-backed securities may have limited ability to enforce the security interest in the underlying assets, and credit enhancements provided to support the securities, if any, may be inadequate to protect investors in the event of default. Like mortgage-backed securities, asset-backed securities are subject to prepayment and extension risks.

Collateralized Debt Obligations (CDOs) Risk. The risks of an investment in a CDO depend largely on the type of collateral held by the special purpose entity (SPE) and the tranche of the CDO in which the Fund invests. Investment risk may also be affected by the performance of a CDO’s collateral manager (the entity responsible for selecting and managing the pool of collateral securities held by the SPE), especially during a period of market volatility. CDOs may be illiquid securities and subject to the Fund’s restrictions on investments in illiquid securities. The Fund’s investment in CDOs will not receive the same investor protection as an investment in registered securities. Also, prices of CDO tranches can decline considerably.

Convertible Bond Risk. The market value of a convertible bond performs like that of a regular debt security; that is, if market interest rates rise, the value of a convertible bond usually falls. In addition, convertible bonds are subject to the risk that the issuer will not be able to pay interest or dividends when due, and their market value may change based on changes in the issuer’s credit rating or the market’s perception of the issuer’s creditworthiness. Convertible bonds are also usually subordinate to other debt securities issued by the same issuer. Since it derives a portion of its value from the common stock into which it may be converted, a convertible bond is also subject to the same types of market and issuer risks that apply to the underlying security.

Deflation Risk. Deflation risk is the risk that prices throughout the economy will decline over time (the opposite of inflation). If inflation is negative, the principal and income of an inflation-protected bond will decline, resulting in losses.

Distressed Securities Risk. Distressed securities are speculative and involve substantial risks in addition to the risks of investing in junk bonds. A fund that invests in distressed securities will generally not receive interest payments on the distressed securities and may incur costs to protect its investment. In addition, distressed securities involve the substantial risk that principal will not be repaid. These securities may present a substantial risk of default or may be in default at the time of investment. Consequently, the fund may incur additional expenses to the extent it is required to seek recovery upon a default in the payment of principal of or interest on its portfolio holdings. In any reorganization or liquidation proceeding relating to a portfolio company, the fund may lose its entire investment or may be required to accept cash or securities with a value less than its original investment. Distressed securities and any securities received in an exchange for such securities may be subject to restrictions on resale.

Dollar Rolls Risk. Dollar rolls involve the risk that the market value of the securities that the Fund is committed to buy may decline below the price of the securities the Fund has sold. These transactions may involve leverage.

Inflation Indexed Bond Risk. The value of inflation-indexed bonds generally changes in response to changes in real interest rates. Real interest rates in turn are tied to the relationship between nominal interest rates (i.e., non-inflation adjusted interest rates) and the rate of inflation. If the periodic adjustment rate measuring inflation falls, the principal value of inflation-indexed bonds will be adjusted downward and the interest payable will be reduced. The adjusted principal value of an inflation-related bond repaid at maturity may be less than the original principal. If nominal interest rates increase at a faster rate than inflation, the value of inflation indexed bonds may decrease. Inflation-indexed securities may not be protected from short-term increases in inflation.

Risks of Loan Assignments and Participations. A purchaser of an assignment typically succeeds to all the rights and obligations of the assigning institution and becomes a lender under the credit agreement with respect to the debt obligation. However, the investor may not be able unilaterally to enforce all rights and remedies under the loan and with regard to any associated collateral.

Mezzanine Securities Risk. Mezzanine securities generally are rated below investment grade and frequently are unrated. They typically are the most subordinated debt obligation in an issuer’s capital structure. Mezzanine securities also may often be unsecured. Mezzanine securities therefore are subject to the additional risk that the cash flow of the related borrower and the property securing the loan may be insufficient to repay the scheduled obligation after giving effect to any senior obligations of the related borrower. Mezzanine securities are also expected to be a highly illiquid investment.

Mortgage-Backed Securities Risk. The value of mortgage-backed securities (commercial and residential) may fluctuate significantly in response to changes in interest rates. During periods of falling interest rates, underlying mortgages may be paid early, lowering the potential total return (pre-payment risk). During periods of rising interest rates, the rate at which the underlying mortgages are pre-paid may slow unexpectedly, causing the maturity of the mortgage-backed securities to increase and their value to decline (maturity extension risk).

Municipal Securities Risk. Municipal securities risks include the ability of the issuer to repay the obligation, the relative lack of information about certain issuers of municipal securities, and the possibility of future legislative changes which could affect the market for and value of municipal securities.

Prepayment/Call Risk. Debt securities are subject to prepayment risk when the issuer can “call” the security, or repay principal, in whole or in part, prior to the security’s maturity. When the Fund reinvests the prepayments of principal it receives, it may receive a rate of interest that is lower than the rate on the called security.

Real Estate and Real Estate Investment Trusts (REITs) Risk. Investing in real estate securities (including REITs) is subject to the risks associated with the direct ownership and development of real estate. These risks include declines in real estate values, fluctuations in rental income (due in part to vacancies and rates), increases in operating costs and property taxes, increases in financing costs or inability to procure financing, potential environmental liabilities and changes in zoning laws and other regulations. REITs whose underlying properties are concentrated in a particular industry or geographic region are subject to risks affecting such industries and regions. The securities of REITs involve greater risks than those associated with larger, more established companies and may be subject to more abrupt or erratic price movements because of interest rate changes, economic conditions and other factors. Securities of such issuers may lack sufficient market liquidity to enable the Fund to effect sales at an advantageous time or without a substantial drop in price.

Repurchase Agreements and Purchase and Sale Contracts Risk. If the other party to a repurchase agreement or purchase and sale contract defaults on its obligation under the agreement, the Fund may suffer delays and incur costs or lose money in exercising its rights under the agreement. If the seller fails to repurchase the security in either situation and the market value of the security declines, the Fund may lose money.

Reverse Repurchase Agreements Risk. Reverse repurchase agreements involve the sale of securities held by the Fund with an agreement to repurchase the securities at an agreed-upon price, date and interest payment. Reverse repurchase agreements involve the risk that the other party may fail to return the securities in a timely manner or at all. The Fund could lose money if it is unable to recover the securities and the value of the collateral held by the Fund, including the value of the investments made with cash collateral, is less than the value of the securities. These events could also trigger adverse tax consequences for the Fund.

Second Lien Loans Risk. Second lien loans generally are subject to similar risks as those associated with investments in senior loans. Because second lien loans are subordinated or unsecured and thus lower in priority of payment to senior loans, they are subject to the additional risk that the cash flow of the borrower and property securing the loan or debt, if any, may be insufficient to meet scheduled payments after giving effect to the senior secured obligations of the borrower.

Senior Loans Risk. There is less readily available, reliable information about most senior loans than is the case for many other types of securities. In addition, there is no minimum rating or other independent evaluation of a borrower or its securities limiting investments. The Fund relies primarily on its own evaluation of a borrower’s credit quality rather than on any available independent sources. Any specific collateral used to secure a senior loan may decline in value or become illiquid, which would adversely affect the senior loan’s value.

No active trading market may exist for certain senior loans, which may impair the ability of the Fund to realize full value in the event of the need to sell a senior loan and which may make it difficult to value senior loans. Adverse market conditions may impair the liquidity of some actively traded senior loans.

Uncollateralized senior loans involve a greater risk of loss. Some senior loans are subject to the risk that a court, pursuant to fraudulent conveyance or other similar laws, could subordinate the senior loans to presently existing or future indebtedness of the borrower or take other action detrimental to lenders, including the Fund.

Structured Notes Risk. Structured notes and other related instruments are generally privately negotiated debt obligations where the principal and/or interest is determined by reference to the performance of a specific asset, benchmark asset, market or interest rate (“reference measure”). The purchase of structured notes exposes a fund to the credit risk of the issuer of the structured product. Structured notes may be leveraged, increasing the volatility of each structured note’s value relative to the change in the reference measure. Structured notes may also be less liquid and more difficult to price accurately than less complex securities and instruments or more traditional debt securities.

Tender Option Bonds and Related Securities Risk. The Fund’s use of tender option bonds may reduce the Fund’s return and/or increase volatility. Investments in tender option bonds expose the investor to counterparty risk and leverage risk.

U.S. Government Agency Risk. Treasury obligations may differ in their interest rates, maturities, times of issuance and other characteristics. Obligations of U.S. Government agencies and authorities are supported by varying degrees of credit but may not be backed by the full faith and credit of the U.S. Government. No assurance can be given that the U.S. Government will provide financial support to its agencies and authorities if it is not obligated by law to do so.

U.S. Government Mortgage-Related Securities Risk. There are a number of important differences among the agencies and instrumentalities of the U.S. Government that issue mortgage-related securities and among the securities that they issue. Mortgage-related securities guaranteed by the Government National Mortgage Association (“GNMA” or “Ginnie Mae”) are guaranteed as to the timely payment of principal and interest by GNMA and such guarantee is backed by the full faith and credit of the United States. GNMA securities also are supported by the right of GNMA to borrow funds from the U.S. Treasury to make payments under its guarantee. Mortgage-related securities issued by Fannie Mae or Freddie Mac are solely the obligations of Fannie Mae or Freddie Mac, as the case may be, and are not backed by or entitled to the full faith and credit of the United States but are supported by the right of the issuer to borrow from the U.S. Treasury.

Floating and Variable Rate Securities Risk. Variable rate securities (which include floating rate securities) generally are less sensitive to interest rate changes than fixed rate debt securities. However, the market value of variable rate debt securities may decline when prevailing interest rates rise if their interest rates do not rise as much, or as quickly, as interest rates in general. Conversely, variable rate securities will not generally increase in market value if interest rates decline.

In addition, floating rate securities may be rated below investment grade (such securities are commonly referred to as “junk bonds”). The floating rate corporate loans and corporate debt securities in which the Fund invests are often issued in connection with highly leveraged transactions. Leveraged buyout loans are subject to greater credit risks than other investments including a greater possibility that the borrower may default or enter bankruptcy.

Zero Coupon Securities Risk. While interest payments are not made on such securities, holders of such securities are deemed to have received income (“phantom income”) annually, notwithstanding that cash may not be received currently. The effect of owning instruments that do not make current interest payments is that a fixed yield is earned not only on the original investment but also, in effect, on all discount accretion during the life of the obligations. This implicit reinvestment of earnings at a fixed rate eliminates the risk of being unable to invest distributions at a rate as high as the implicit yield on the zero coupon bond, but at the same time eliminates the holder’s ability to reinvest at higher rates in the future. For this reason, some of these securities may be subject to substantially greater price fluctuations during periods of changing market interest rates than are comparable securities that pay interest currently. Longer term zero coupon bonds are more exposed to interest rate risk than shorter term zero coupon bonds. These investments benefit the issuer by mitigating its need for cash to meet debt service, but also require a higher rate of return to attract investors who are willing to defer receipt of cash.

Risks of Investments in a Particular Market Segment. Investing in a particular market segment may present unique risks and/or certain risks may affect that segment more significantly than other segments. The Fund may be subject to market segment risk in the areas of consumer goods, energy and natural resources, financial services industry, health sciences and healthcare, industrial, oil and gas, technology, telecommunications, and the utility industry. A market segment may be more strongly affected by, for example, consumer and social trends, governmental regulations, commodity markets, interest rates, rapid technological change and/or worldwide economic or political events.

Savings Associations Risk. Savings associations are affected by extensive regulations, interest rate increases, loan losses, decreased availability of money or asset valuation and market conditions. The deterioration of the credit market has had an adverse impact on savings associations.

Foreign Investments Risk. Foreign investments have additional risks that are not present when investing in U.S. investments. Foreign currency fluctuations or economic or financial instability could cause the value of foreign investments to fluctuate. Additionally, foreign investments include the risk of loss from foreign government or political actions including; for example, the imposition of exchange controls, confiscations and other government restrictions, or from problems in registration, settlement or custody. Investing in foreign investments may involve risks resulting from the reduced availability of public information concerning issuers. Foreign investments may be less liquid and their prices more volatile than comparable investments in U.S. issuers.

Foreign Currency Risk. Foreign currency risk is the risk that the U.S. dollar value of foreign investments may be negatively affected by changes in foreign (non-U.S.) currency rates. Currency exchange rates may fluctuate significantly over short periods of time. In addition, currency management strategies may substantially change the Fund’s exposure to currency exchange rates and could negatively affect the value of the Fund’s foreign investments, if currencies do not perform as expected. Currency management strategies also may reduce the Fund’s ability to benefit from favorable changes in currency exchange rates.

Currency Management Strategy Risk. Currency management strategies, including cross-hedging, may substantially change exposure to currency exchange rates and could result in losses if currencies do not perform as expected. In addition, currency management strategies, to the extent that they reduce exposure to currency risks, also may reduce the ability to benefit from favorable changes in currency exchange rates. Furthermore, there may not be perfect correlation between the amount of exposure to a particular currency and the amount of securities in the portfolio denominated in that currency. Currency rates may also fluctuate significantly, reducing returns.

Sovereign Debt Risk. Sovereign debt instruments are subject to the risk that a governmental entity may delay or refuse to pay interest or repay principal on its sovereign debt, due, for example, to cash flow problems, insufficient foreign currency reserves, political considerations, the relative size of the governmental entity’s debt position in relation to the economy or the failure to put in place economic reforms required by the International Monetary Fund or other multilateral agencies.

Emerging Markets Risk. Companies located in emerging markets tend to be less liquid, have more volatile prices, and have significant potential for loss in comparison to investments in developed markets.

Regional Risk. The Fund will generally have more exposure to the specific market, currency, economic, political, regulatory, geopolitical, or other risks in the regions or countries in which it invests. As a result, the Fund could experience substantial illiquidity, volatility or reduction in the value of its investments, as compared to a more geographically-diversified fund.

Supranational Entities Risk. The Fund may invest in obligations issued or guaranteed by the International Bank for Reconstruction and Development (the World Bank). The government members, or “stockholders,” usually make initial capital contributions to the World Bank and in many cases are committed to make additional capital contributions if the World Bank is unable to repay its borrowings. There is no guarantee that one or more stockholders of the World Bank will continue to make any necessary additional capital contributions. If such contributions are not made, the entity may be unable to pay interest or repay principal on its debt securities, and the Fund may lose money on such investments.

Derivatives Risk. Derivatives, such as futures, forwards, options and swaps, involve risks different from, or possibly greater than, the risks associated with investing directly in securities and other traditional investments. Derivatives prices can be volatile and may move in unexpected ways, especially in unusual market conditions. Some derivatives are particularly sensitive to changes in interest rates. In addition, there may be imperfect correlation between the price of the derivatives contract and the price of the underlying securities. Other risks include the potential inability to terminate or sell derivative positions. Further, losses could result if the counterparty to a transaction does not perform as promised. Derivative instruments may be “leveraged”, which may magnify or otherwise increase investment losses.

Leverage Risk. Investment in certain derivatives, including certain futures contracts, may have the economic effect of creating financial leverage by creating additional investment exposure, as well as the potential for greater loss. Losses on derivatives may exceed the amount invested.

Borrowing Risk. Borrowing may exaggerate changes in the net asset value of the Fund’s shares and in the return on the Fund’s portfolio.

Concentration Risk. Investments that are concentrated in particular industries, sectors or types of investments may be subject to greater risks of adverse developments in such areas of focus than investments that are spread among a wider variety of industries, sectors or investments.

Event Risk. Event risk is the risk that corporate issuers may undergo restructurings, such as mergers, leveraged buyouts, takeovers, or similar events financed by increased debt. As a result of the added debt, the credit quality and market value of a company’s bonds and/or other debt securities may decline significantly.

Initial Public Offering (IPO) Risk. IPO shares frequently are volatile in price, and may be held for only a short period of time, leading to increased portfolio turnover and expenses, such as commissions and transaction costs. When sold, IPO shares may result in realized taxable gains.

Investments in Affiliated Funds Risk. Potential conflicts of interest arise when an adviser selects underlying funds and ETFs, because the fees paid to the adviser by some underlying funds and ETFs may be higher than the fees paid by other underlying funds and ETFs. However, an investment adviser is a fiduciary and is legally obligated to act in its client’s best interests when selecting underlying funds and ETFs. If an underlying fund holds interests in an affiliated fund, the Fund may be prohibited from purchasing shares of that underlying fund.

Risks of Investing in Closed-End Funds. The shares of closed-end funds may trade at a discount or premium to, or at, their NAV. An investment in securities of closed-end funds that use leverage may expose the Fund to higher volatility in the market value of such securities and the possibility that the Fund’s long-term returns on such securities (and, indirectly, the long-term returns of the shares) will be diminished.

Liquidity Risk. Liquidity risk is the risk that securities holdings which are considered to be illiquid may be difficult to value. Illiquid holdings also may be difficult to sell, both at the time or price desired. Liquidity risk also may result from increased shareholder redemptions in the Fund. Furthermore, a potential rise in interest rates may result in a period of Fund volatility and increased redemptions, heightening liquidity risk. In addition, liquidity risk may result from the lack of an active market for fixed income securities, as well the reduced capacity of dealers to make a market for such securities.

When-Issued Securities, Delayed Delivery Securities and Forward Commitments Risk. A fund may purchase or sell securities that it is entitled to receive on a when issued basis. When-issued and delayed delivery securities and forward commitments involve the risk that the security will lose value prior to its delivery. There also is the risk that the security will not be issued or that the other party to the transaction will not meet its obligation.

Non-Diversification Risk. When a mutual fund is non-diversified, it may invest a greater percentage of its assets in a particular issuer than a diversified fund. Therefore, a fund’s value may decrease because of a single investment or a small number of investments.

Risk Nondiversified Status [Text]

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Non-Diversification Risk. When a mutual fund is non-diversified, it may invest a greater percentage of its assets in a particular issuer than a diversified fund. Therefore, a fund’s value may decrease because of a single investment or a small number of investments.

Performance Narrative [Text Block]

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The following bar chart and table provide some indication of the risks of choosing to invest in the Fund. The information shows: (a) how the Fund's Standard Class investment results have varied from year to year; and (b) how the average annual total returns of the Fund's Standard and Service Classes for various periods compare with those of a broad measure of market performance.

Information has also been included for the BlackRock Multi-Asset Income Composite, which is an unmanaged index compiled by the Fund's adviser and constructed as follows: 50% Bloomberg Barclays U.S. Aggregate Bond Index and 50% MSCI All Country World Index (net dividends). The BlackRock Multi-Asset Income Composite shows how the Fund's performance compares with the returns of an index that reflects a similar asset allocation to the market sectors in which the Fund invests. The bar chart shows performance of the Fund's Standard Class shares, but does not reflect the impact of variable contract expenses. If it did, returns would be lower than those shown. Performance in the average annual returns table does not reflect the impact of variable contract expenses. The Fund's past performance is not necessarily an indication of how the Fund will perform in the future.

Performance Additional Market Index [Text]

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Information has also been included for the BlackRock Multi-Asset Income Composite, which is an unmanaged index compiled by the Fund's adviser and constructed as follows: 50% Bloomberg Barclays U.S. Aggregate Bond Index and 50% MSCI All Country World Index (net dividends). The BlackRock Multi-Asset Income Composite shows how the Fund's performance compares with the returns of an index that reflects a similar asset allocation to the market sectors in which the Fund invests.

Bar Chart [Heading]

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Annual Total Returns (%)

Bar Chart Closing [Text Block]

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During the periods shown in the above chart, the Fund’s highest return for a quarter occurred in the second quarter of 2016 at: 3.13%.

The Fund’s lowest return for a quarter occurred in the third quarter of 2015 at: (4.34%).