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Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund  
Risk/Return: rr_RiskReturnAbstract  
Risk/Return [Heading] rr_RiskReturnHeading Fund OverviewKey Facts About BlackRock Credit Relative Value Fund
Objective [Heading] rr_ObjectiveHeading Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock The investment objective of BlackRock Credit Relative Value Fund (formerly known as BlackRock Global Long/Short Credit Fund) (the “Fund”), a series of BlackRock Funds IV (the “Trust”), is to seek absolute total returns over a complete market cycle.
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 $50,000 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 36 and A-1, respectively, of the Fund’s prospectus and in the “Purchase of Shares” section on page II-93 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, 2026
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 110% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 110.00%
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 the 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 $50,000 in the fund complex advised by BlackRock or its affiliates.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount $ 50,000
Expenses Restated to Reflect Current [Text] rr_ExpensesRestatedToReflectCurrent Miscellaneous Other Expenses have been restated to reflect current fees.
Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text] rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees Total Annual Fund Operating Expenses include Acquired Fund Fees and Expenses and the restatement of Miscellaneous Other Expenses to reflect current fees, which are not included in the ratio of expenses to average net assets given in the Fund’s most recent annual financial statements and additional information.
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
The Fund seeks to provide absolute total returns over a complete market cycle through diversified long and short exposure to the global fixed-income markets. A complete market cycle for fixed income funds such as the Fund is typically three to five years.
Under normal circumstances, the Fund invests at least 80% of its total assets in credit-related instruments. Credit-related instruments include, but are not limited to, U.S. Government and agency securities, foreign government and supranational debt securities, corporate bonds, including bonds of companies principally engaged in the aircraft or air transportation industries, mortgage-related securities and asset-backed securities, collateralized debt and loan obligations, including bonds collateralized by aircraft and/or aircraft equipment, emerging market debt securities, preferred securities, structured products, mezzanine securities, senior secured floating rate and fixed rate loans or debt, second lien or other subordinated or unsecured floating rate and fixed rate loans or debt, convertible debt securities, and derivatives with similar economic characteristics. The Fund’s investments in derivatives will be counted toward the Fund’s 80% policy to the extent that they provide investment exposure to the securities included within that policy or to one or more market risk factors associated with such securities. The Fund may invest in fixed, variable and floating rate instruments, including participations and assignments, of any duration or maturity.
The Fund may invest without limit in credit-related instruments rated below investment grade or deemed equivalent by Fund management, which are commonly referred to as “junk bonds.”
The Fund may invest in foreign securities (including emerging markets) without limit.
The Fund may invest in non-U.S. dollar denominated investments, including investments denominated in European and Asian currencies and in other non-U.S. and emerging market currencies. The Fund’s investments in non-U.S. dollar based assets may be made on a currency hedged or unhedged basis.
The Fund may invest up to 20% of its total assets in equity instruments, including common stock, depositary receipts, rights, warrants and other instruments whose price is linked to the value of common stock. The Fund may hold long or short positions in equity instruments, and may invest in equity instruments of issuers of any market capitalization.
The Fund may also gain both long and short exposure to credit-related instruments by entering into a series of purchase and sale contracts or by investing in, among other instruments, swaps, including total return, credit default, index and interest rate swaps; options; forward contracts; futures contracts and options on futures contracts that provide long or short exposure to other credit obligations; credit-linked notes that provide long or short exposure to other credit obligations; repurchase agreements; reverse repurchase agreements; dollar rolls; exchange-traded funds and closed-end registered investment companies, which may be managed by BlackRock or one of its affiliates; and other similar transactions.
The Fund may engage in short sales for hedging purposes or to enhance total return. The Fund also may make short sales “against the box” without limitation. In this type of short sale, at the time of the sale, the Fund owns or has the immediate and unconditional right to acquire the identical security at no additional cost.
As part of its normal operations, the Fund may hold high quality money market securities and invest in money market funds, including affiliated money market funds, pending investments or when it expects to need cash to pay redeeming shareholders. The Fund also may invest in these securities in order to achieve its investment goal. Money market securities are short term securities consisting primarily of short term U.S. Government securities, U.S. Government agency securities, securities issued by U.S. Government sponsored enterprises and U.S. Government instrumentalities, bank obligations, commercial paper, including asset backed commercial paper, corporate notes and repurchase agreements.
Fund management employs a credit relative value framework that looks at the credit spectrum as a whole (e.g., by using credit spread relationships as a proxy for determining relative value) as well as within and across capital structures, or at opportunity sets across the credit spectrum in the case of narrower spreads.
The Fund may engage in active and frequent trading of portfolio securities to achieve its primary investment strategies.
The Fund may borrow from banks for investment purposes.
Risk [Heading] rr_RiskHeading Principal Risks of Investing in the Fund
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading Performance Information
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock
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 Bloomberg Global Aggregate Bond Index and the ICE BofA 3-Month U.S. Treasury Bill Index. The ICE BofA 3-Month U.S. Treasury Bill Index is relevant to the Fund because it has characteristics similar to the Fund’s investment strategies. The Fund acquired all of the assets, subject to the liabilities, of BlackRock Global Long/Short Credit Fund, a series of BlackRock FundsSM (the “Predecessor Fund”), in a reorganization on September 17, 2018 (the “Reorganization”). The Fund adopted the performance of the Predecessor Fund as a result of the Reorganization. The performance information below is based on the performance of the Predecessor Fund for periods prior to the date of the Reorganization. The Predecessor Fund had the same investment objectives, strategies and policies, portfolio management team and contractual arrangements, including the same contractual fees and expenses, as the Fund as of the date of the Reorganization. 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 the Fund’s investment manager 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 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 Additional Market Index [Text] rr_PerformanceAdditionalMarketIndex The table compares the Fund’s performance to that of the Bloomberg Global Aggregate Bond Index and the ICE BofA 3-Month U.S. Treasury Bill Index. The ICE BofA 3-Month U.S. Treasury Bill Index is relevant to the Fund because it has characteristics similar to the Fund’s investment strategies.
Performance Availability Phone [Text] rr_PerformanceAvailabilityPhone (800) 882-0052
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress 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 Shares ANNUAL TOTAL RETURNS BlackRock Credit Relative Value 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 5.40% (quarter ended December 31, 2020) and the lowest return for a quarter was -7.25% (quarter ended March 31, 2020). The year-to-date return as of March 31, 2025 was 1.11%.
Performance Table Heading rr_PerformanceTableHeading For the periods ended 12/31/24Average Annual Total Returns
Performance Table Does Reflect Sales Loads rr_PerformanceTableDoesReflectSalesLoads However, the table includes all applicable fees and salescharges.
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.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Risk Lose Money [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Debt Securities Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Debt Securities Risk — Debt securities, such as bonds, involve risks, such as credit risk, interest rate risk, extension risk, and prepayment risk, each of which are described in further detail below:
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.
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 during a 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.
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.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Foreign Securities Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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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:
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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.
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Changes in foreign currency exchange rates can affect the value of the Fund’s portfolio.
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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.
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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.
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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.
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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.
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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.
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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.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Derivatives Risks [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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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.
To the extent derivatives are utilized to implement the Fund’s investment strategies, the transactions may involve the risks described below. For example, to the extent the Fund gains short exposure to a security through a derivative instrument, the Fund will be subject to risks associated with short sales that are described below.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Air Transportation Industry Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Air Transportation Industry Risk — The air transportation industry can be significantly affected by competition within the industry, domestic and foreign economies, government regulation, labor relations, and the price of fuel. Airline deregulation has substantially diminished the government’s role in the air transport industry while promoting an increased level of competition. However, regulations and policies of various domestic and foreign governments can still affect the profitability of individual carriers as well as the entire industry.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Borrowing Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Borrowing Risk — Borrowing may exaggerate changes in the net asset value of Fund shares and in the return on the Fund’s portfolio. Borrowing will cost the Fund interest expense and other fees. The costs of borrowing may reduce the Fund’s return. Borrowing may cause the Fund to liquidate positions when it may not be advantageous to do so to satisfy its obligations.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Collateralized Debt Obligations Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Collateralized Debt Obligations Risk — In addition to the typical risks associated with fixed-income securities and asset-backed securities, collateralized debt obligations (“CDOs”), including collateralized loan obligations (“CLOs”) carry additional risks including, but not limited to: (i) the possibility that distributions from collateral securities will not be adequate to make interest or other payments; (ii) the risk that the collateral may default or decline in value or be downgraded, if rated by a nationally recognized statistical rating organization; (iii) the Fund may invest in tranches of CDOs that are subordinate to other tranches; (iv) the structure and complexity of the transaction and the legal documents could lead to disputes among investors regarding the characterization of proceeds; (v) the investment return achieved by the Fund could be significantly different than those predicted by financial models; (vi) the lack of a readily available secondary market for CDOs; (vii) the risk of forced “fire sale” liquidation due to technical defaults such as coverage test failures; and (viii) the CDO’s manager may perform poorly.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Convertible Securities Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Convertible Securities Risk — The market value of a convertible security performs like that of a regular debt security; that is, if market interest rates rise, the value of a convertible security usually falls. In addition, convertible securities are subject to the risk that the issuer will not be able to pay interest, principal 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. Since it derives a portion of its value from the common stock into which it may be converted, a convertible security is also subject to the same types of market and issuer risks that apply to the underlying common stock, including the potential for increased volatility in the price of the convertible security.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Corporate Loans Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Corporate Loans Risk — Commercial banks and other financial institutions or institutional investors make corporate loans to companies that need capital to grow or restructure. Borrowers generally pay interest on corporate loans at rates that change in response to changes in market interest rates such as the Secured Overnight Financing Rate (“SOFR”), or the prime rates of U.S. banks. As a result, the value of corporate loan investments is generally less exposed to the adverse effects of shifts in market interest rates than investments that pay a fixed rate of interest. The market for corporate loans may be subject to irregular trading activity and wide bid/ask spreads. In addition, transactions in corporate loans may settle on a delayed basis. As a result, the proceeds from the sale of corporate loans may not be readily available to make additional investments or to meet the Fund’s redemption obligations. To the extent the extended settlement process gives rise to short-term liquidity needs, the Fund may hold additional cash, sell investments or temporarily borrow from banks and other lenders. The corporate loans in which the Fund invests are usually rated below investment grade.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Dividend Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Dividend Risk — Because certain of the corporate loans held by the Fund will have floating or variable interest rates, the amounts of the Fund’s 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.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Emerging Markets Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Emerging Markets Risk — Emerging markets are riskier than more developed markets because they tend to develop unevenly and may never fully develop. Investments in emerging markets may be considered speculative. Emerging markets are more likely to experience hyperinflation and currency devaluations, which adversely affect returns to U.S. investors. In addition, many emerging securities markets have far lower trading volumes and less liquidity than developed markets.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Event Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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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.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | High Portfolio Turnover Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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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.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | High Yield Bonds Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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High Yield 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.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Illiquid Investments Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Illiquid Investments Risk — The Fund may not acquire any illiquid investment if, immediately after the acquisition, the Fund would have invested more than 15% of its net assets in illiquid investments. An illiquid investment is any investment that the Fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment. Liquid investments may become illiquid after purchase by the Fund, particularly during periods of market turmoil. There can be no assurance that a security or instrument that is deemed to be liquid when purchased will continue to be liquid for as long as it is held by the Fund, and any security or instrument held by the Fund may be deemed an illiquid investment pursuant to the Fund’s liquidity risk management program. 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. In addition, if the Fund is limited in its ability to sell illiquid investments during periods when shareholders are redeeming their shares, the Fund will need to sell liquid securities to meet redemption requests and illiquid securities will become a larger portion of the Fund’s holdings. An investment may be illiquid due to, among other things, the reduced number and capacity of traditional market participants to make a market in fixed-income securities or 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. 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. This may be magnified in a rising interest rate environment or other circumstances where investor redemptions from fixed-income mutual funds may be higher than normal. 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.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Leverage Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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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 the applicable requirements of the Investment Company Act of 1940, as amended (the “Investment Company Act”) and the rules thereunder. Increases and decreases in the value of the Fund’s portfolio will be magnified when the Fund uses leverage.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Market Risk and Selection Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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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.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Mezzanine Securities Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Mezzanine Securities Risk — Mezzanine securities carry the risk that the issuer will not be able to meet its obligations and that the equity securities purchased with the mezzanine investments may lose value.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Mortgage and Asset Backed Securities Risks [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Mortgage- and Asset-Backed Securities Risks — Mortgage- and asset-backed securities represent interests in “pools” of mortgages or other assets, including consumer loans or receivables held in trust. Mortgage- and asset-backed securities are subject to credit, interest rate, prepayment and extension risks. These securities also are subject to risk of default on the underlying mortgage or asset, particularly during periods of economic downturn. Small movements in interest rates (both increases and decreases) may quickly and significantly reduce the value of certain mortgage-backed securities.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Operational and Technology Risks [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Operational and Technology Risks — The Fund is directly and indirectly susceptible to operational and technology risks, including those related to human errors, processing errors, communication errors, systems failures, cybersecurity incidents, and the use of artificial intelligence and machine learning (“AI”), which may result in losses for the Fund and its shareholders or may impair the Fund’s operations. While the Fund’s service providers are required to have appropriate operational, information security and cybersecurity risk management policies and procedures, their methods of risk management may differ from those of the Fund. Operational and technology risks for the issuers in which the Fund invests could also result in material adverse consequences for such issuers and may cause the Fund’s investments in such issuers to lose value.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Preferred Securities Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Preferred Securities Risk — Preferred securities may pay fixed or adjustable rates of return. Preferred securities are subject to issuer-specific and market risks applicable generally to equity securities. 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. For this reason, the value of preferred securities will usually react more strongly than bonds and other debt to actual or perceived changes in the company’s financial condition or prospects. Preferred securities of smaller companies may be more vulnerable to adverse developments than preferred securities of larger companies.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Reference Rate Replacement Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Reference Rate Replacement Risk — The Fund may be exposed to financial instruments that recently transitioned from, or continue to be tied to, LIBOR to determine payment obligations, financing terms, hedging strategies or investment value.
The United Kingdom’s Financial Conduct Authority (“FCA”), which regulates LIBOR, has ceased publishing all LIBOR settings. In April 2023, however, the FCA announced that some USD LIBOR settings would continue to be published under a synthetic methodology until September 30, 2024 for certain legacy contracts. After September 30, 2024, the remaining synthetic LIBOR settings ceased to be published, and all LIBOR settings have permanently ceased. SOFR is a broad measure of the cost of borrowing cash overnight collateralized by U.S. Treasury securities in the repurchase agreement (“repo”) market and has been used increasingly on a voluntary basis in new instruments and transactions. Under U.S. regulations that implement a statutory fallback mechanism to replace LIBOR, benchmark rates based on SOFR have replaced LIBOR in certain financial contracts.
Neither the effect of the LIBOR transition process nor its ultimate success can yet be known. While some existing LIBOR-based instruments may contemplate a scenario where LIBOR is no longer available by providing for an alternative rate-setting methodology, there may be significant uncertainty regarding the effectiveness of any such alternative methodologies to replicate LIBOR. Not all existing LIBOR-based instruments may have alternative rate-setting provisions and there remains uncertainty regarding the willingness and ability of issuers to add alternative rate-setting provisions in certain existing instruments. Parties to contracts, securities or other instruments using LIBOR may disagree on transition rates or the application of transition regulation, potentially resulting in uncertainty of performance and the possibility of litigation. The Fund may have instruments linked to other interbank offered rates that may also cease to be published in the future.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Repurchase Agreements and Purchase and Sale Contracts Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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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.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Reverse Repurchase Agreements Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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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. In addition, reverse repurchase agreements involve the risk that the interest income earned in the investment of the proceeds will be less than the interest expense.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Risk of Investing in the United States [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Risk of Investing in the United States — Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has exposure.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Second Lien Loans Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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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.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Senior Loans Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Senior Loans Risk — There is less readily available, reliable information about most senior loans than is the case for many other types of securities. An economic downturn generally leads to a higher non-payment rate, and a senior loan may lose significant value before a default occurs. Moreover, 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. Although senior loans in which the Fund will invest generally will be secured by specific collateral, there can be no assurance that liquidation of such collateral would satisfy the borrower’s obligation in the event of non-payment of scheduled interest or principal or that such collateral could be readily liquidated. To the extent that a senior loan is collateralized by stock in the borrower or its subsidiaries, such stock may lose all of its value in the event of the bankruptcy of the borrower. Uncollateralized senior loans involve a greater risk of loss. The senior loans in which the Fund invests are usually rated below investment grade.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Short Sales Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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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. Short sale transactions involve leverage because they can provide investment exposure in an amount exceeding the initial investment.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Small and Mid Capitalization Company Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Small and Mid-Capitalization Company Risk — Companies with small or mid-size market capitalizations will normally have more limited product lines, markets and financial resources and will be dependent upon a more limited management group than larger capitalized companies. In addition, it is more difficult to get information on smaller companies, which tend to be less well known, have shorter operating histories, do not have significant ownership by large investors and are followed by relatively few securities analysts.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Sovereign Debt Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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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.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Structured Securities Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
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Structured Securities Risk — Because structured securities of the type in which the Fund may invest typically involve no credit enhancement, their credit risk generally will be equivalent to that of the underlying instruments, index or reference obligation and will also be subject to counterparty risk. The Fund may have the right to receive payments only from the structured security, and generally does not have direct rights against the issuer or the entity that sold the assets to be securitized. In addition to the general risks associated with debt securities discussed herein, structured securities carry additional risks, including, but not limited to: the possibility that distributions from collateral securities will not be adequate to make interest or other payments; the quality of the collateral may decline in value or default; and the possibility that the structured securities are subordinate to other classes. The Fund is permitted to invest in a class of structured securities that is either subordinated or unsubordinated to the right of payment of another class. Subordinated structured securities typically have higher yields and present greater risks than unsubordinated structured securities. Structured securities are typically sold in private placement transactions, and there currently is no active trading market for structured securities. Structured securities are based upon the movement of one or more factors, including currency exchange rates, interest rates, reference bonds and stock indices, and changes in interest rates and impact of these factors may cause significant price fluctuations. Additionally, changes in the reference instrument or security may cause the interest rate on the structured security to be reduced to zero. Certain issuers of such structured securities may be deemed to be “investment companies” as defined in the Investment Company Act. As a result, the Fund’s investment in such securities may be limited by certain investment restrictions contained in the Investment Company Act.
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Investor A Shares  
Risk/Return: rr_RiskReturnAbstract  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 4.00%
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 0.95% [2]
Distribution and/or Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Miscellaneous Other Expenses rr_Component1OtherExpensesOverAssets 0.22% [3]
Interest Expense rr_Component2OtherExpensesOverAssets 0.28%
Other Expenses rr_OtherExpensesOverAssets 0.50%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01% [4]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.71% [4]
Fee Waivers and/or Expense Reimbursements rr_FeeWaiverOrReimbursementOverAssets (0.03%) [2],[5]
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements rr_NetExpensesOverAssets 1.68% [2],[5]
1 Year rr_ExpenseExampleYear01 $ 564
3 Years rr_ExpenseExampleYear03 914
5 Years rr_ExpenseExampleYear05 1,288
10 Years rr_ExpenseExampleYear10 $ 2,336
2015 rr_AnnualReturn2015 (1.22%)
2016 rr_AnnualReturn2016 3.28%
2017 rr_AnnualReturn2017 3.21%
2018 rr_AnnualReturn2018 (1.99%)
2019 rr_AnnualReturn2019 7.14%
2020 rr_AnnualReturn2020 3.70%
2021 rr_AnnualReturn2021 3.13%
2022 rr_AnnualReturn2022 (8.20%)
2023 rr_AnnualReturn2023 8.70%
2024 rr_AnnualReturn2024 8.07%
Year to Date Return, Label rr_YearToDateReturnLabel year-to-date return
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Mar. 31, 2025
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 1.11%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel highest return
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Dec. 31, 2020
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 5.40%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel lowest return
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Mar. 31, 2020
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (7.25%)
1 Year rr_AverageAnnualReturnYear01 3.75%
5 Years rr_AverageAnnualReturnYear05 2.06%
10 Years rr_AverageAnnualReturnYear10 2.04%
Investor A, C and Institutional | BlackRock Global Long/Short Credit 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% [6]
Management Fee rr_ManagementFeesOverAssets 0.95% [2]
Distribution and/or Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Miscellaneous Other Expenses rr_Component1OtherExpensesOverAssets 0.23% [3]
Interest Expense rr_Component2OtherExpensesOverAssets 0.29%
Other Expenses rr_OtherExpensesOverAssets 0.52%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01% [4]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 2.48% [4]
Fee Waivers and/or Expense Reimbursements rr_FeeWaiverOrReimbursementOverAssets (0.04%) [2],[5]
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements rr_NetExpensesOverAssets 2.44% [2],[5]
1 Year rr_ExpenseExampleYear01 $ 347
3 Years rr_ExpenseExampleYear03 769
5 Years rr_ExpenseExampleYear05 1,317
10 Years rr_ExpenseExampleYear10 2,624
1 Year rr_ExpenseExampleNoRedemptionYear01 247
3 Years rr_ExpenseExampleNoRedemptionYear03 769
5 Years rr_ExpenseExampleNoRedemptionYear05 1,317
10 Years rr_ExpenseExampleNoRedemptionYear10 $ 2,624
1 Year rr_AverageAnnualReturnYear01 6.32%
5 Years rr_AverageAnnualReturnYear05 2.13%
10 Years rr_AverageAnnualReturnYear10 1.84%
Investor A, C and Institutional | BlackRock Global Long/Short Credit 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 0.95% [2]
Distribution and/or Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Miscellaneous Other Expenses rr_Component1OtherExpensesOverAssets 0.23% [3]
Interest Expense rr_Component2OtherExpensesOverAssets 0.28%
Other Expenses rr_OtherExpensesOverAssets 0.51%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01% [4]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.47% [4]
Fee Waivers and/or Expense Reimbursements rr_FeeWaiverOrReimbursementOverAssets (0.01%) [2],[5]
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements rr_NetExpensesOverAssets 1.46% [2],[5]
1 Year rr_ExpenseExampleYear01 $ 149
3 Years rr_ExpenseExampleYear03 464
5 Years rr_ExpenseExampleYear05 802
10 Years rr_ExpenseExampleYear10 $ 1,757
1 Year rr_AverageAnnualReturnYear01 8.35%
5 Years rr_AverageAnnualReturnYear05 3.17%
10 Years rr_AverageAnnualReturnYear10 2.72%
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Return After Taxes on Distributions | Investor A Shares  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 1.08%
5 Years rr_AverageAnnualReturnYear05 0.17%
10 Years rr_AverageAnnualReturnYear10 0.53%
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor A Shares  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 2.27%
5 Years rr_AverageAnnualReturnYear05 0.78%
10 Years rr_AverageAnnualReturnYear10 0.92%
Investor A, C and Institutional | BlackRock Global Long/Short Credit Fund | Bloomberg Global Aggregate Bond Index (Reflects no deduction for fees, expenses or taxes)  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 (1.69%) [7]
5 Years rr_AverageAnnualReturnYear05 (1.96%) [7]
10 Years rr_AverageAnnualReturnYear10 0.15% [7]
Investor A, C and Institutional | BlackRock Global Long/Short Credit 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 5.25% [8]
5 Years rr_AverageAnnualReturnYear05 2.47% [8]
10 Years rr_AverageAnnualReturnYear10 1.77% [8]
[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 the 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 52, BlackRock has contractually agreed to waive the management fee of the Fund 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 (“ETFs”) managed by BlackRock or its affiliates that have a contractual management fee, through June 30, 2026. 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, 2026. The contractual agreements may be terminated upon 90 days’ notice by a majority of the non-interested trustees of the Trust or by a vote of a majority of the outstanding voting securities of the Fund.
[3] Miscellaneous Other Expenses have been restated to reflect current fees.
[4] Total Annual Fund Operating Expenses include Acquired Fund Fees and Expenses and the restatement of Miscellaneous Other Expenses to reflect current fees, which are not included in the ratio of expenses to average net assets given in the Fund’s most recent annual financial statements and additional information.
[5] As described in the “Management of the Fund” section of the Fund’s prospectus beginning on page 52, 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 , Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses) to 1.40% (for Investor A Shares), 2.15% (for Investor C Shares) and 1.20% (for Institutional Shares) of average daily net assets through June 30, 2026. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested trustees of the Trust or by a vote of a majority of the outstanding voting securities of the Fund.
[6] There is no CDSC on Investor C Shares after one year.
[7] The Fund has added this broad-based index in response to new regulatory requirements.
[8] On December 1, 2023, the Fund began to compare its performance to the standard pricing time of the ICE BofA 3-Month U.S. Treasury Bill Index (the “Index”). Index data prior to March 1, 2021 is for the Index’s standard pricing time of 3pm. Index data from March 1, 2021 through November 30, 2023 is for a custom 4pm pricing variant of the Index. Index returns beginning on December 1, 2023 reflect the Index’s new standard pricing time of 4pm. The change of the Index’s standard pricing time from 3pm to 4pm resulted in the discontinuation of the custom 4pm pricing variant used from March 1, 2021 through November 30, 2023.