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BlackRock Event Driven Equity Fund  
Risk/Return: rr_RiskReturnAbstract  
Risk/Return [Heading] rr_RiskReturnHeading Fund OverviewKey Facts About BlackRock Event Driven Equity Fund
Objective [Heading] rr_ObjectiveHeading Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock
The investment objective of BlackRock Event Driven Equity Fund (the “Fund”) is to seek long-term capital growth.
Expense [Heading] rr_ExpenseHeading Fees and Expenses of the Fund
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock
This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock Advisors, LLC (“BlackRock”) and its affiliates) (each, a “Financial Intermediary”), which are not reflected in the table and example below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in the fund complex advised by BlackRock or its affiliates. More information about these and other discounts is available from your Financial Intermediary and in the “Details About the Share Classes” and the “Intermediary-Defined Sales Charge Waiver Policies” sections on pages 31 and A-1, respectively, of the Fund’s prospectus and in the “Purchase of Shares” section on page II-89 of Part II of the Fund’s Statement of Additional Information.
Shareholder Fees Caption [Text] rr_ShareholderFeesCaption Shareholder Fees (fees paid directly from your investment)
Operating Expenses Caption [Text] rr_OperatingExpensesCaption Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination June 30, 2024
Portfolio Turnover [Heading] rr_PortfolioTurnoverHeading Portfolio Turnover:
Portfolio Turnover [Text Block] rr_PortfolioTurnoverTextBlock
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 and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 37% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 37.00%
Expenses Deferred Charges [Text Block] rr_ExpensesDeferredChargesTextBlock A contingent deferred sales charge (“CDSC”) of 1.00% is assessed on certain redemptions of Investor A Shares made within 18 months after purchase where no initial sales charge was paid at time of purchase as part of an investment of $250,000 or more.
Expense Breakpoint Discounts [Text] rr_ExpenseBreakpointDiscounts You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in the fund complex advised by BlackRock or its affiliates.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount $ 25,000
Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text] rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees The Total Annual Fund Operating Expenses do not correlate to the ratios of expenses to average net assets given in the Fund’s most recent annual report, which do not include Acquired Fund Fees and Expenses.
Expense Example [Heading] rr_ExpenseExampleHeading Example:
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock
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 assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Expense Example, No Redemption, By Year, Caption [Text] rr_ExpenseExampleNoRedemptionByYearCaption You would pay the following expenses if you did not redeem your shares:
Strategy [Heading] rr_StrategyHeading Principal Investment Strategies of the Fund
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock
Under normal circumstances, the Fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities and related derivative instruments with similar economic characteristics. The Fund seeks to achieve its investment objective by employing an event driven strategy, primarily investing in companies that have announced a material change or in companies that BlackRock expects to undergo a material change. A material change that could impact the price of securities for purposes of the Fund’s investment strategies is referred to herein as a “catalyst.” The Fund focuses on identifying investments that have a sufficiently defined catalyst. These catalysts span a broad spectrum and include, for example, announced mergers and acquisitions, spinoffs and split-offs, financial or strategic restructurings, management changes, synergistic acquisitions, as well as other transformative events. The intended goal of the Fund is to profit when the price of a security changes to reflect more accurately the likelihood and potential impact of the occurrence, or non-occurrence, of the extraordinary event. This can be done by taking a long position in a security or other financial instrument that is believed to be underpriced or a short position in a security or other financial instrument that is believed to be overpriced. The Fund expects to maintain long and short positions primarily through the use of swap agreements and other derivative instruments, although the Fund may also take long and short positions directly. At times, the Fund may have significant short positions in equity securities and equity-related instruments.
The Fund normally invests in both U.S. and non-U.S. securities. Non-U.S. securities may be denominated in either U.S. dollars or foreign currencies. The Fund may invest in securities of issuers of any market capitalization.
The Fund’s investment in equity securities may include common stock, preferred stock, securities convertible into common stock, non-convertible preferred stock and depositary receipts. The Fund may gain exposure to equity securities through derivatives.
The Fund may invest up to 20% of its net assets (plus any borrowings for investment purposes) in fixed-income securities and related derivative instruments with similar economic characteristics. The Fund’s investment in fixed-income securities may include fixed and floating rate corporate bonds and municipal securities. The Fund may invest in debt securities of any credit quality, as determined by Fund management, which may include high yield securities (commonly called “junk bonds”).
The Fund may invest in derivatives, including but not limited to, total return swaps (some of which may be referred to as contracts for difference), credit default swaps, futures, options and foreign exchange transactions, for hedging purposes, as well as to enhance the return on its portfolio investments. There is no limit to the Fund’s ability to invest in derivatives, except as may be limited by requirements of the Investment Company Act of 1940, as amended (the “Investment Company Act”), and at times the Fund may utilize derivatives to a significant extent. 
The Fund may also invest in indexed and inverse securities. 
When consistent with the Fund’s investment objective, the Fund’s investments may include short-term investments such as cash and cash equivalents, U.S. Government and agency securities, money market funds (including funds that may be affiliated with or sponsored or managed by BlackRock), commercial paper, certificates of deposit and other bank deposits and bankers’ acceptances. 
The Fund may invest in securities of companies without an identified catalyst to hedge unwanted exposures to an industry or the market as a whole. 
The Fund may engage in active and frequent trading of portfolio securities to achieve its primary investment strategies. 
Risk [Heading] rr_RiskHeading Principal Risks of Investing in the Fund
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock
Risk is inherent in all investing. The value of your investment in the Fund, as well as the amount of return you receive on your investment, may fluctuate significantly from day to day and over time. You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of the principal risks of investing in the Fund. The relative significance of each risk factor below may change over time and you should review each risk factor carefully. 
Equity Securities Risk — Stock markets are volatile. The price of equity securities fluctuates based on changes in a company’s financial condition and overall market and economic conditions.
Event Driven Strategies Risk —The Fund may invest in event driven strategies, which entail investing in companies involved, or potentially involved, in significant corporate actions. Investment decisions may take into account BlackRock’s perceptions of the likelihood that an event or transaction will occur, the amount of time that the process will take and the perceived expected value following the catalyst. The success of event driven trading depends on the successful prediction of whether various catalyst events will occur or be consummated. If a proposed transaction appears likely not to be consummated or in fact is not consummated or is delayed, the market price of the securities purchased by the Fund may decline sharply and result in losses to the Fund.
  The Fund may purchase securities at prices only slightly below the anticipated value to be paid or exchanged for the securities in the proposed merger, exchange offer, cash tender offer or other similar transaction. The purchase price to the Fund may be substantially above the prices at which such securities traded immediately prior to the announcement of such merger, exchange offer, cash tender offer or other similar transaction. If the proposed merger, exchange offer, cash tender offer or other similar transaction appears likely not to be consummated or in fact is not consummated or is delayed, or if the value of a transaction is reduced, the market price of the security to be tendered or exchanged may, and likely will, decline sharply by an amount greater than the difference between the Fund’s purchase price and the anticipated consideration to be paid.
  In addition, where a security to be issued in a merger or exchange offer has been sold short in the expectation that the short position will be covered by delivery of such security when issued, failure of the merger or exchange offer to be consummated may force the Fund to cover its short sale, with a resulting, and perhaps significant, loss.
  In addition, if BlackRock determines that the offer price for a security which is the subject of a tender offer is likely to be increased, either by the original bidder or by another party, the Fund may purchase securities above the offer price, thereby exposing the Fund to an even greater degree of risk of loss.
  Where BlackRock determines that it is probable that a transaction will not be consummated, the Fund may sell the securities of the target company short, at times significantly below the announced tender or offering prices for the securities in the transaction. If the transaction, or another transaction, such as a “defensive” merger or a “friendly” tender offer, is consummated at the announced price or a higher price, the Fund may be forced to cover the short position in the market at a higher price than the short sale price, with a resulting, and perhaps significant, loss.
  The consummation of mergers, exchange offers, cash tender offers or other similar transactions can be prevented or delayed by a variety of factors. Transactions may also be contingent on certain contractual conditions precedent.
  Offerors in tender or exchange offers customarily reserve the right to cancel such offers in a variety of circumstances. An exchange offer or a cash tender offer may be made for less than all of the outstanding securities of an issuer, with the provision that, if a greater number is tendered, securities will be accepted on a pro rata basis. Thus, after the completion of the offer, and at a time when the market price of the securities has declined below its cost, the Fund may have returned to it, and be forced to sell at a loss, a portion of the securities it tendered.
Derivatives Risk — The Fund’s use of derivatives may increase its costs, reduce the Fund’s returns and/or increase volatility. Derivatives involve significant risks, including: 
  Leverage Risk — The Fund’s use of derivatives can magnify the Fund’s gains and losses. Relatively small market movements may result in large changes in the value of a derivatives position and can result in losses that greatly exceed the amount originally invested.
  Market Risk — Some derivatives are more sensitive to interest rate changes and market price fluctuations than other securities. The Fund could also suffer losses related to its derivatives positions as a result of unanticipated market movements, which losses are potentially unlimited. Finally, BlackRock may not be able to predict correctly the direction of securities prices, interest rates and other economic factors, which could cause the Fund’s derivatives positions to lose value.
  Counterparty Risk — Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will be unable or unwilling to fulfill its contractual obligation, and the related risks of having concentrated exposure to such a counterparty.
  Illiquidity Risk — The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately.
  Operational Risk — The use of derivatives includes the risk of potential operational issues, including documentation issues, settlement issues, systems failures, inadequate controls and human error.
  Legal Risk — The risk of insufficient documentation, insufficient capacity or authority of counterparty, or legality or enforceability of a contract.
  Volatility and Correlation Risk — Volatility is defined as the characteristic of a security, an index or a market to fluctuate significantly in price within a short time period. A risk of the Fund’s use of derivatives is that the fluctuations in their values may not correlate with the overall securities markets.
  Valuation Risk — Valuation for derivatives may not be readily available in the market. Valuation may be more difficult in times of market turmoil since many investors and market makers may be reluctant to purchase complex instruments or quote prices for them.
  Hedging Risk — Hedges are sometimes subject to imperfect matching between the derivative and the underlying security, and there can be no assurance that the Fund’s hedging transactions will be effective. The use of hedging may result in certain adverse tax consequences.
  Tax Risk — Certain aspects of the tax treatment of derivative instruments, including swap agreements and commodity-linked derivative instruments, are currently unclear and may be affected by changes in legislation, regulations or other legally binding authority. Such treatment may be less favorable than that given to a direct investment in an underlying asset and may adversely affect the timing, character and amount of income the Fund realizes from its investments.
  Regulatory Risk — Derivative contracts are subject to regulation under the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”) in the United States and under comparable regimes in Europe, Asia and other non-U.S. jurisdictions. Under the Dodd-Frank Act, with respect to uncleared swaps, swap dealers are required to collect variation margin from the Fund and may be required by applicable regulations to collect initial margin from the Fund. Both initial and variation margin may be comprised of cash and/or securities, subject to applicable regulatory haircuts. Shares of investment companies (other than certain money market funds) may not be posted as collateral under applicable regulations. In addition, regulations adopted by global prudential regulators that are now in effect require certain bank-regulated counterparties and certain of their affiliates to include in certain financial contracts, including many derivatives contracts, terms that delay or restrict the rights of counterparties, such as the Fund, to terminate such contracts, foreclose upon collateral, exercise other default rights or restrict transfers of credit support in the event that the counterparty and/or its affiliates are subject to certain types of resolution or insolvency proceedings. The implementation of these requirements with respect to derivatives, as well as regulations under the Dodd-Frank Act regarding clearing, mandatory trading and margining of other derivatives, may increase the costs and risks to the Fund of trading in these instruments and, as a result, may affect returns to investors in the Fund.
  Risks Specific to Certain Derivatives Used by the Fund 
Swaps — Swap agreements, including total return swaps that may be referred to as contracts for difference, are two-party contracts entered into for periods ranging from a few weeks to more than one year. In a standard “swap” transaction, two parties agree to exchange the returns (or differentials in rates of return) earned or realized on particular predetermined investments or instruments, which can be adjusted for an interest factor. Swap agreements involve the risk that the party with whom the Fund has entered into the swap will default on its obligation to pay the Fund and the risk that the Fund will not be able to meet its obligations to pay the other party to the agreement. Swap agreements may also involve the risk that there is an imperfect correlation between the 
return on the Fund’s obligation to its counterparty and the return on the referenced asset. In addition, swap agreements are subject to market and illiquidity risk, leverage risk and hedging risk. 
Short Sales Risk — Because making short sales in securities that it does not own exposes the Fund to the risks associated with those securities, such short sales involve speculative exposure risk. The Fund will incur a loss as a result of a short sale if the price of the security increases between the date of the short sale and the date on which the Fund replaces the security sold short.
Debt Securities Risk — Debt securities, such as bonds, involve interest rate risk, credit risk, extension risk, and prepayment risk, among other things.
  Interest Rate Risk — The market value of bonds and other fixed-income securities changes in response to interest rate changes and other factors. Interest rate risk is the risk that prices of bonds and other fixed-income securities will increase as interest rates fall and decrease as interest rates rise.
  The Fund may be subject to a greater risk of rising interest rates due to the recent period of historically low interest rates. For example, if interest rates increase by 1%, assuming a current portfolio duration of ten years, and all other factors being equal, the value of the Fund’s investments would be expected to decrease by 10%. (Duration is a measure of the price sensitivity of a debt security or portfolio of debt securities to relative changes in interest rates.) The magnitude of these fluctuations in the market price of bonds and other fixed-income securities is generally greater for those securities with longer maturities. Fluctuations in the market price of the Fund’s investments will not affect interest income derived from instruments already owned by the Fund, but will be reflected in the Fund’s net asset value. The Fund may lose money if short-term or long-term interest rates rise sharply in a manner not anticipated by Fund management.
  To the extent the Fund invests in debt securities that may be prepaid at the option of the obligor (such as mortgage-backed securities), the sensitivity of such securities to changes in interest rates may increase (to the detriment of the Fund) when interest rates rise. Moreover, because rates on certain floating rate debt securities typically reset only periodically, changes in prevailing interest rates (and particularly sudden and significant changes) can be expected to cause some fluctuations in the net asset value of the Fund to the extent that it invests in floating rate debt securities.
  These basic principles of bond prices also apply to U.S. Government securities. A security backed by the “full faith and credit” of the U.S. Government is guaranteed only as to its stated interest rate and face value at maturity, not its current market price. Just like other fixed-income securities, government-guaranteed securities will fluctuate in value when interest rates change.
  A general rise in interest rates has the potential to cause investors to move out of fixed-income securities on a large scale, which may increase redemptions from funds that hold large amounts of fixed-income securities. Heavy redemptions could cause the Fund to sell assets at inopportune times or at a loss or depressed value and could hurt the Fund’s performance.
  Credit Risk — Credit risk refers to the possibility that the issuer of a debt security (i.e., the borrower) will not be able to make payments of interest and principal when due. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of the Fund’s investment in that issuer. The degree of credit risk depends on both the financial condition of the issuer and the terms of the obligation.
  Extension Risk — When interest rates rise, certain obligations will be paid off by the obligor more slowly than anticipated, causing the value of these obligations to fall.
  Prepayment Risk — When interest rates fall, certain obligations will be paid off by the obligor more quickly than originally anticipated, and the Fund may have to invest the proceeds in securities with lower yields.
Depositary Receipts Risk — Depositary receipts are generally subject to the same risks as the foreign securities that they evidence or into which they may be converted. In addition to investment risks associated with the underlying issuer, depositary receipts expose the Fund to additional risks associated with the non-uniform terms that apply to depositary receipt programs, credit exposure to the depository bank and to the sponsors and other parties with whom the depository bank establishes the programs, currency risk and the risk of an illiquid market for depositary receipts. The issuers of unsponsored depositary receipts are not obligated to disclose information that is, in the United States, considered material. Therefore, there may be less information available regarding these issuers and there may not be a correlation between such information and the market value of the depositary receipts.
Foreign Securities Risk — Foreign investments often involve special risks not present in U.S. investments that can increase the chances that the Fund will lose money. These risks include: 
The Fund generally holds its foreign securities and cash in foreign banks and securities depositories, which may be recently organized or new to the foreign custody business and may be subject to only limited or no regulatory oversight.
Changes in foreign currency exchange rates can affect the value of the Fund’s portfolio.
The economies of certain foreign markets may not compare favorably with the economy of the United States with respect to such issues as growth of gross national product, reinvestment of capital, resources and balance of payments position.
The governments of certain countries, or the U.S. Government with respect to certain countries, may prohibit or impose substantial restrictions through capital controls and/or sanctions on foreign investments in the capital markets or certain industries in those countries, which may prohibit or restrict the ability to own or transfer currency, securities, derivatives or other assets.
Many foreign governments do not supervise and regulate stock exchanges, brokers and the sale of securities to the same extent as does the United States and may not have laws to protect investors that are comparable to U.S. securities laws.
Settlement and clearance procedures in certain foreign markets may result in delays in payment for or delivery of securities not typically associated with settlement and clearance of U.S. investments.
The Fund’s claims to recover foreign withholding taxes may not be successful, and if the likelihood of recovery of foreign withholding taxes materially decreases, due to, for example, a change in tax regulation or approach in the foreign country, accruals in the Fund’s net asset value for such refunds may be written down partially or in full, which will adversely affect the Fund’s net asset value.
The European financial markets have recently experienced volatility and adverse trends due to concerns about economic downturns in, or rising government debt levels of, several European countries as well as acts of war in the region. These events may spread to other countries in Europe and may affect the value and liquidity of certain of the Fund’s investments. 
High Portfolio Turnover Risk — The Fund may engage in active and frequent trading of its portfolio securities. High portfolio turnover (more than 100%) may result in increased transaction costs to the Fund, including brokerage commissions, dealer mark-ups and other transaction costs on the sale of the securities and on reinvestment in other securities. The sale of Fund portfolio securities may result in the realization and/or distribution to shareholders of higher capital gains or losses as compared to a fund with less active trading policies. These effects of higher than normal portfolio turnover may adversely affect Fund performance.
Illiquid Investments Risk — The Fund’s illiquid investments may reduce the returns of the Fund because it may be difficult to sell the illiquid investments at an advantageous time or price. An investment may be illiquid due to, among other things, the lack of an active trading market. To the extent that the Fund’s principal investment strategies involve derivatives or securities with substantial market and/or credit risk, the Fund will tend to have the greatest exposure to the risks associated with illiquid investments. Liquid investments may become illiquid after purchase by the Fund, particularly during periods of market turmoil. Illiquid investments may be harder to value, especially in changing markets, and if the Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss. In addition, when there is illiquidity in the market for certain securities, the Fund, due to limitations on illiquid investments, may be subject to purchase and sale restrictions.
Indexed and Inverse Securities Risk — Indexed and inverse securities provide a potential return based on a particular index of value or interest rates. The Fund’s return on these securities will be subject to risk with respect to the value of the particular index. These securities are subject to leverage risk and correlation risk. Certain indexed and inverse securities have greater sensitivity to changes in interest rates or index levels than other securities, and the Fund’s investment in such instruments may decline significantly in value if interest rates or index levels move in a way Fund management does not anticipate.
Junk Bonds Risk — Although junk bonds generally pay higher rates of interest than investment grade bonds, junk bonds are high risk investments that are considered speculative and may cause income and principal losses for the Fund.
Leverage Risk — Some transactions may give rise to a form of economic leverage. These transactions may include, among others, derivatives, and may expose the Fund to greater risk and increase its costs. The use of leverage may cause the Fund to liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet any required asset segregation requirements. Increases and decreases in the value of the Fund’s portfolio will be magnified when the Fund uses leverage.
Market Risk and Selection Risk — Market risk is the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. The value of a 
  security or other asset may decline due to changes in general market conditions, economic trends or events that are not specifically related to the issuer of the security or other asset, or factors that affect a particular issuer or issuers, exchange, country, group of countries, region, market, industry, group of industries, sector or asset class. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues like pandemics or epidemics, recessions, or other events could have a significant impact on the Fund and its investments. Selection risk is the risk that the securities selected by Fund management will underperform the markets, the relevant indices or the securities selected by other funds with similar investment objectives and investment strategies. This means you may lose money.
  An outbreak of an infectious coronavirus (COVID-19) that was first detected in December 2019 developed into a global pandemic that has resulted in numerous disruptions in the market and has had significant economic impact leaving general concern and uncertainty. Although vaccines have been developed and approved for use by various governments, the duration of the pandemic and its effects cannot be predicted with certainty. The impact of this coronavirus, and other epidemics and pandemics that may arise in the future, could affect the economies of many nations, individual companies and the market in general ways that cannot necessarily be foreseen at the present time. 
Risk Lose Money [Text] rr_RiskLoseMoney You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading Performance Information
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock
Effective May 8, 2015, the Fund changed its investment strategies. Performance for the periods prior to May 8, 2015 shown below is based on the investment strategies utilized by the Fund at that time, which focused on establishing long and short positions in a diversified portfolio of equity securities issued primarily by large cap companies located in the United States.
The information shows you how the Fund’s performance has varied year by year and provides some indication of the risks of investing in the Fund. The table compares the Fund’s performance to that of the Russell 1000® Index and the ICE BofA 3-Month U.S. Treasury Bill Index. To the extent that dividends and distributions have been paid by the Fund, the performance information for the Fund in the chart and table assumes reinvestment of the dividends and distributions. As with all such investments, past performance (before and after taxes) is not an indication of future results. Sales charges are not reflected in the bar chart. If they were, returns would be less than those shown. However, the table includes all applicable fees and sales charges. If BlackRock and its affiliates had not waived or reimbursed certain Fund expenses during these periods, the Fund’s returns would have been lower. Updated information on the Fund’s performance, including its current net asset value, can be obtained by visiting http://www.blackrock.com or can be obtained by phone at (800) 882-0052.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The information shows you how the Fund’s performance has varied year by year and provides some indication of the risks of investing in the Fund.
Performance Availability Phone [Text] rr_PerformanceAvailabilityPhone (800) 882-0052
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress http://www.blackrock.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture As with all such investments, past performance (before and after taxes) is not an indication of future results.
Bar Chart [Heading] rr_BarChartHeading Investor A SharesANNUAL TOTAL RETURNSBlackRock Event Driven Equity Fund As of 12/31
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads Sales charges are not reflected in the bar chart. If they were, returns would be less than those shown.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock
During the ten-year period shown in the bar chart, the highest return for a quarter was 12.52% (quarter ended December 31, 2013) and the lowest return for a quarter was -5.16% (quarter ended March 31, 2020). The year-to-date return as of June 30, 2022 was -2.11%.
Performance Table Heading rr_PerformanceTableHeading For the periods ended 12/31/21Average Annual Total Returns
Performance Table Does Reflect Sales Loads rr_PerformanceTableDoesReflectSalesLoads However, the table includes all applicable fees and sales charges.
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on the investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown After-tax returns are shown for Investor A Shares only, and the after-tax returns for Investor C and Institutional Shares will vary.
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock
After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Investor A Shares only, and the after-tax returns for Investor C and Institutional Shares will vary.
BlackRock Event Driven Equity Fund | Investor A Shares  
Risk/Return: rr_RiskReturnAbstract  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.25%
Maximum Deferred Sales Charge (Load) (as a percentage of offering price or redemption proceeds, whichever is lower) rr_MaximumDeferredSalesChargeOverOfferingPrice none [1]
Management Fee rr_ManagementFeesOverAssets 1.09% [2]
Distribution and/or Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Other Expenses rr_OtherExpensesOverAssets 0.12%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.09% [3]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.55% [3]
Fee Waivers and/or Expense Reimbursements rr_FeeWaiverOrReimbursementOverAssets (0.03%) [2],[4]
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements rr_NetExpensesOverAssets 1.52% [2],[4]
1 Year rr_ExpenseExampleYear01 $ 672
3 Years rr_ExpenseExampleYear03 986
5 Years rr_ExpenseExampleYear05 1,323
10 Years rr_ExpenseExampleYear10 $ 2,271
2012 rr_AnnualReturn2012 14.27%
2013 rr_AnnualReturn2013 31.94%
2014 rr_AnnualReturn2014 10.12%
2015 rr_AnnualReturn2015 (1.73%)
2016 rr_AnnualReturn2016 3.94%
2017 rr_AnnualReturn2017 6.87%
2018 rr_AnnualReturn2018 5.13%
2019 rr_AnnualReturn2019 7.16%
2020 rr_AnnualReturn2020 6.03%
2021 rr_AnnualReturn2021 1.60%
Year to Date Return, Label rr_YearToDateReturnLabel year-to-date return
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Jun. 30, 2022
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn (2.11%)
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel highest return
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Dec. 31, 2013
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 12.52%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel lowest return
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Mar. 31, 2020
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (5.16%)
1 Year rr_AverageAnnualReturnYear01 (3.74%)
5 Years rr_AverageAnnualReturnYear05 4.21%
10 Years rr_AverageAnnualReturnYear10 7.62%
BlackRock Event Driven Equity Fund | Investor C Shares  
Risk/Return: rr_RiskReturnAbstract  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (Load) (as a percentage of offering price or redemption proceeds, whichever is lower) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00% [5]
Management Fee rr_ManagementFeesOverAssets 1.09% [2]
Distribution and/or Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Other Expenses rr_OtherExpensesOverAssets 0.11%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.09% [3]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 2.29% [3]
Fee Waivers and/or Expense Reimbursements rr_FeeWaiverOrReimbursementOverAssets (0.03%) [2],[4]
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements rr_NetExpensesOverAssets 2.26% [2],[4]
1 Year rr_ExpenseExampleYear01 $ 329
3 Years rr_ExpenseExampleYear03 712
5 Years rr_ExpenseExampleYear05 1,222
10 Years rr_ExpenseExampleYear10 2,438
1 Year rr_ExpenseExampleNoRedemptionYear01 229
3 Years rr_ExpenseExampleNoRedemptionYear03 712
5 Years rr_ExpenseExampleNoRedemptionYear05 1,222
10 Years rr_ExpenseExampleNoRedemptionYear10 $ 2,438
1 Year rr_AverageAnnualReturnYear01 (0.11%)
5 Years rr_AverageAnnualReturnYear05 4.57%
10 Years rr_AverageAnnualReturnYear10 7.57%
BlackRock Event Driven Equity Fund | Institutional Shares  
Risk/Return: rr_RiskReturnAbstract  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (Load) (as a percentage of offering price or redemption proceeds, whichever is lower) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Management Fee rr_ManagementFeesOverAssets 1.09% [2]
Distribution and/or Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.11%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.09% [3]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.29% [3]
Fee Waivers and/or Expense Reimbursements rr_FeeWaiverOrReimbursementOverAssets (0.03%) [2],[4]
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements rr_NetExpensesOverAssets 1.26% [2],[4]
1 Year rr_ExpenseExampleYear01 $ 128
3 Years rr_ExpenseExampleYear03 406
5 Years rr_ExpenseExampleYear05 705
10 Years rr_ExpenseExampleYear10 $ 1,554
1 Year rr_AverageAnnualReturnYear01 1.94%
5 Years rr_AverageAnnualReturnYear05 5.61%
10 Years rr_AverageAnnualReturnYear10 8.49%
BlackRock Event Driven Equity Fund | Return After Taxes on Distributions | Investor A Shares  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 (4.63%)
5 Years rr_AverageAnnualReturnYear05 2.92%
10 Years rr_AverageAnnualReturnYear10 5.64%
BlackRock Event Driven Equity Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor A Shares  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 (2.13%)
5 Years rr_AverageAnnualReturnYear05 2.69%
10 Years rr_AverageAnnualReturnYear10 5.63%
BlackRock Event Driven Equity Fund | Russell 1000® Index (Reflects no deduction for fees, expenses or taxes)  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 26.45%
5 Years rr_AverageAnnualReturnYear05 18.43%
10 Years rr_AverageAnnualReturnYear10 16.54%
BlackRock Event Driven Equity Fund | ICE BofA 3-Month U.S. Treasury Bill Index (Reflects no deduction for fees, expenses or taxes)  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 0.05% [6]
5 Years rr_AverageAnnualReturnYear05 1.14% [6]
10 Years rr_AverageAnnualReturnYear10 0.63% [6]
[1] A contingent deferred sales charge (“CDSC”) of 1.00% is assessed on certain redemptions of Investor A Shares made within 18 months after purchase where no initial sales charge was paid at time of purchase as part of an investment of $250,000 or more.
[2] As described in the “Management of the Fund” section of the Fund’s prospectus beginning on page 46, BlackRock has contractually agreed to waive the management fee with respect to any portion of the Fund’s assets estimated to be attributable to investments in other equity and fixed-income mutual funds and exchange-traded funds managed by BlackRock or its affiliates that have a contractual management fee, through June 30, 2024. In addition, BlackRock has contractually agreed to waive its management fees by the amount of investment advisory fees the Fund pays to BlackRock indirectly through its investment in money market funds managed by BlackRock or its affiliates, through June 30, 2024. The contractual agreements may be terminated upon 90 days’ notice by a majority of the non-interested directors or by a vote of a majority of the outstanding voting securities of the Fund.
[3] The Total Annual Fund Operating Expenses do not correlate to the ratios of expenses to average net assets given in the Fund’s most recent annual report, which do not include Acquired Fund Fees and Expenses.
[4] As described in the “Management of the Fund” section of the Fund’s prospectus beginning on page 46, BlackRock has contractually agreed to waive and/or reimburse fees or expenses in order to limit Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses) as a percentage of average daily net assets to 1.65% (for Investor A Shares), 2.39% (for Investor C Shares) and 1.38% (for Institutional Shares) through June 30, 2024. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested directors or by a vote of a majority of the outstanding voting securities of the Fund.
[5] There is no CDSC on Investor C Shares after one year.
[6] On March 1, 2021, the Fund began to track the 4pm pricing variant of the ICE BofA 1-3 Year U.S. Treasury Bill Index (the “Index”). Historical index data prior to March 1, 2021 is for the 3pm pricing variant of the Index. Index data on and after March 1, 2021 is for the 4 pm pricing variant of the Index.