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 34 and A‑1, respectively, of the Fund’s prospectus and in the “Purchase of Shares” section on page II‑86 of Part II of the Fund’s Statement of Additional Information.

Shareholder Fees Caption [Text]

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Shareholder Fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

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

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

June 30, 2023

Portfolio Turnover [Heading]

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Portfolio Turnover:

Portfolio Turnover [Text Block]

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The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs 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 100% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

100.00%

Expenses Deferred Charges [Text Block]

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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 $1,000,000 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

Expense Example [Heading]

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Example:

Expense Example Narrative [Text Block]

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This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example 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:

Strategy [Heading]

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Principal Investment Strategies of the Fund

Strategy Narrative [Text Block]

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The Fund invests in equity securities of issuers located throughout the world, including non‑dollar denominated securities and securities of emerging market issuers. Equity securities include, but are not limited to, common stock, preferred stock, convertible securities, depositary receipts and other financial instruments that have similar economic characteristics to such equity securities. The Fund may invest in issuers of any market capitalization, including small- to mid‑capitalization companies.

BlackRock will seek to invest in portfolio securities that BlackRock believes (i) can bring additional and measurable impact based on the Impact Themes (as defined below) and (ii) also have the potential to produce attractive long-term returns across economic sectors.

As part of its methodology, BlackRock identifies “Impact Themes” (including, but not limited to, affordable housing, education and skilling, financial and digital inclusion, public health, safety and security, efficiency, electrification and digitalization, green energy, pollution remediation and prevention, sustainable food, water and waste) that seek to encapsulate companies which are helping to address the United Nations Sustainable Development Goals (“SDGs”) through their products and services. The SDGs are a series of goals published by the United Nations that recognize that ending poverty and other deprivations must go hand-in-hand with improvements in health, education, and economic growth, and reduction in inequalities, while tackling climate change and working to preserve the planet’s oceans and forests. BlackRock maps its Impact Themes to the SDGs and considers whether a portfolio company’s core business areas align to the Impact Themes.

BlackRock considers three main criteria when selecting portfolio constituents for the investment universe:

materiality (that a majority of revenues or business activity advances one or more of the SDGs);

additionality (that a company’s products and/or services address a specific need that is unlikely to be met by other institutions); and

measurability (that the impact a company is achieving over time can be quantified).

Under normal circumstances, the Fund anticipates it will allocate a substantial amount (approximately 40% or more — unless market conditions are not deemed favorable by Fund management, in which case the Fund would invest at least 30%) of its total assets in foreign securities, which may include securities (i) of foreign government issuers, (ii) of issuers organized or located outside the United States, (iii) of issuers which primarily trade in a market located outside the United States, or (iv) of issuers doing a substantial amount of business outside the United States, which the Fund considers to be companies that derive at least 50% of their revenue or profits from business outside the United States or have at least 50% of their sales or assets outside the United States. The Fund will allocate its assets among various regions and countries, including the United States (but in no fewer than three different countries). From time to time, the Fund may invest a substantial amount of its assets in issuers located in a single country or a limited number of countries.

The Fund may enter into forward foreign exchange transactions in order to hedge (or protect) the value of its assets against adverse movements in currency exchange rates.

The Fund is classified as non‑diversified under the Investment Company Act of 1940, as amended (the “Investment Company Act”).

Risk [Heading]

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Principal Risks of Investing in the Fund

Risk Narrative [Text Block]

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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 order of the below risk factors does not indicate the significance of any particular risk factor.

∎

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 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.

∎

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.

∎

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:

Volatility 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.

Counterparty Risk — Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will not fulfill its contractual obligation.

Market and 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.

Valuation Risk — 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, including, without limitation, swaps, currency forwards and non‑deliverable forwards, 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, certain derivatives are subject to margin requirements and swap dealers are required to collect margin from the Fund with respect to such derivatives. Specifically, regulations are now in effect that require swap dealers to post and collect variation margin (comprised of specified liquid instruments and subject to a required haircut) in connection with trading of over‑the‑counter (“OTC”) swaps with the Fund. Shares of investment companies (other than certain money market funds) may not be posted as collateral under these regulations. Requirements for posting of initial margin in connection with OTC swaps will be phased‑in through at least 2021. 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.

On October 28, 2020, the Securities and Exchange Commission adopted new regulations governing the use of derivatives by registered investment companies (“Rule 18f-4”). The Fund will be required to implement and comply with Rule 18f-4 by August 19, 2022. Once implemented, Rule 18f-4 will impose limits on the amount of derivatives a fund can enter into, eliminate the asset segregation framework currently used by funds to comply with Section 18 of the Investment Company Act, treat derivatives as senior securities and require funds whose use of derivatives is more than a limited specified exposure amount to establish and maintain a comprehensive derivatives risk management program and appoint a derivatives risk manager.

∎

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.

∎

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.

∎

Focus Risk — Under normal circumstances, the Fund focuses its investments in the securities of a limited number of issuers. This may subject the Fund to greater issuer-specific risk and potential losses than a fund that invests in the securities of a greater number of issuers.

∎

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 may prohibit or impose substantial restrictions on foreign investments in their capital markets or in certain industries.

∎

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. These events may spread to other countries in Europe. These events may affect the value and liquidity of certain of the Fund’s investments.

∎

Geographic Concentration Risk — From time to time the Fund may invest a substantial amount of its assets in issuers located in a single country or a limited number of countries. If the Fund concentrates its investments in this manner, it assumes the risk that economic, political and social conditions in those countries will have a significant impact on its investment performance. The Fund’s investment performance may also be more volatile if it concentrates its investments in certain countries, especially emerging market countries.

∎

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.

A recent outbreak of an infectious coronavirus has 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. 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.

∎

Non‑Diversification Risk — The Fund is a non‑diversified fund. Because the Fund may invest in securities of a smaller number of issuers, it may be more exposed to the risks associated with and developments affecting an individual issuer than a fund that invests more widely.

∎

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.

∎

Risks of Impact Investing — The Fund intends to invest a portion of its assets in companies with measurable societal impact outcomes, pursuant to BlackRock’s qualitative, proprietary methodology. This may affect the Fund’s exposure to certain companies or industries and the Fund will forego certain investment opportunities. The Fund’s results may be lower than other funds that do not seek to invest in companies based on expected societal impact outcomes. BlackRock seeks to identify companies that it believes may have a societal impact outcome, but investors may differ in their views of what constitutes positive or negative societal impact outcomes. As a result, the Fund may invest in companies that do not reflect the beliefs and values of any particular investor.

∎

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.

Risk Lose Money [Text]

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You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments.

Risk Nondiversified Status [Text]

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Bar Chart and Performance Table [Heading]

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Performance Information

Performance Narrative [Text Block]

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Because the Fund does not have a full calendar year of operations as of the date of this prospectus, it does not have performance information an investor would find useful in evaluating the risks of investing in the Fund. The Fund’s benchmark is the MSCI All Country World Index.

Performance One Year or Less [Text]

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Investor A, Institutional | BlackRock Global Impact 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

0.65%

^[2]

Distribution and/or Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Administration Fees

rr_Component1OtherExpensesOverAssets

0.20%

Independent Expenses

rr_Component2OtherExpensesOverAssets

0.17%

^[3]

Other Expenses

rr_OtherExpensesOverAssets

0.37%

^[3]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.27%

Fee Waivers and/or Expense Reimbursements

rr_FeeWaiverOrReimbursementOverAssets

(0.17%)

^[2],[3]

Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements

rr_NetExpensesOverAssets

1.10%

^[2],[3]

1 Year

rr_ExpenseExampleYear01

$ 631

3 Years

rr_ExpenseExampleYear03

856

5 Years

rr_ExpenseExampleYear05

1,099

10 Years

rr_ExpenseExampleYear10

$ 1,795

Investor A, Institutional | BlackRock Global Impact 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

0.65%

^[2]

Distribution and/or Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Administration Fees

rr_Component1OtherExpensesOverAssets

0.20%

Independent Expenses

rr_Component2OtherExpensesOverAssets

0.13%

^[3]

Other Expenses

rr_OtherExpensesOverAssets

0.33%

^[3]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.98%

Fee Waivers and/or Expense Reimbursements

rr_FeeWaiverOrReimbursementOverAssets

(0.13%)

^[2],[3]

Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements

rr_NetExpensesOverAssets

0.85%

^[2],[3]

1 Year

rr_ExpenseExampleYear01

$ 87

3 Years

rr_ExpenseExampleYear03

271

5 Years

rr_ExpenseExampleYear05

471

10 Years

rr_ExpenseExampleYear10

$ 1,049

[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 $1,000,000 or more.
[2]	As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 48, 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, 2023. 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, 2023. 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]	Independent Expenses consist of the Fund’s allocable portion of the fees and expenses of the independent trustees of the Trust, counsel to such independent trustees and the independent registered public accounting firm that provides audit services to the Fund. BlackRock has contractually agreed to reimburse, or provide offsetting credits to, the Fund for Independent Expenses through June 30, 2032. After giving effect to such contractual arrangements, Independent Expenses will be 0.00%. Such contractual arrangements may not be terminated prior to July 1, 2032 without the consent of the Board of Trustees of the Trust.