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Label Element Value
Risk/Return: rr_RiskReturnAbstract  
Registrant Name dei_EntityRegistrantName BLACKROCK FUNDS
Prospectus Date rr_ProspectusDate Jan. 28, 2015
Supplement [Text Block] bf1_SupplementTextBlock
BLACKROCK FUNDSSM
BlackRock International Opportunities Portfolio (“International Opportunities Portfolio”)
BlackRock Science & Technology Opportunities Portfolio (“Science & Technology Opportunities Portfolio”)
(each, a “Fund” and collectively, the “Funds”)

Supplement dated June 1, 2015 to the Prospectus of the Funds, dated January 28, 2015

Effective immediately, BlackRock (as defined below) has agreed contractually to cap net expenses of the Funds at lower levels. To achieve these expense caps, BlackRock has agreed to waive or reimburse fees or expenses if a Fund’s annual fund operating expenses, excluding certain expenses described in the prospectus, exceed a certain limit. Accordingly, each Fund’s prospectus is amended as follows:

The section of International Opportunities Portfolio’s prospectus for Investor A, Investor B, Investor C and Institutional Shares entitled “Fund Overview — Key Facts About BlackRock International Opportunities Portfolio — Fees and Expenses of the Fund” is deleted in its entirety and replaced with the following:

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. 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 Advisors, LLC (“BlackRock”) and its affiliates. More information about these and other discounts is available from your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock, The PNC Financial Services Group, Inc. and their respective affiliates) (each a “Financial Intermediary”) and in the “Details About the Share Classes” section on page 48 of the Fund’s prospectus and in the “Purchase of Shares” section on page II-61 of Part II of the Fund’s Statement of Additional Information.

Shareholder Fees
(fees paid directly from your investment)		 Investor A
Shares		 Investor B
Shares		 Investor C
Shares		 Institutional
Shares
Maximum Sales Charge (Load) Imposed on Purchases 
(as a percentage of offering price)		  5.25%  None    None    None  
Maximum Deferred Sales Charge (Load) 
(as a percentage of original purchase price or 
redemption proceeds, whichever is lower)		  None1  4.50%2  1.00%3  None  
 
Annual Fund Operating Expenses
(expenses that you pay each year as a
percentage of the value of your investment)		 Investor A
Shares		 Investor B
Shares		 Investor C
Shares		 Institutional
Shares
Management Fee4   0.98%  0.98%  0.98%  0.98%
Distribution and/or Service (12b-1) Fees  0.25%  1.00%  1.00%  None  
Other Expenses  0.30%  0.41%  0.29%  0.24%
Total Annual Fund Operating Expenses  1.53%  2.39%  2.27%  1.22%
Fee Waivers and/or Expense Reimbursements4   (0.14)%  (0.13)%  (0.14)%  (0.16)%
Total Annual Fund Operating Expenses After Fee
Waivers and/or Expense Reimbursements4 		  1.39%  2.26%  2.13%  1.06%

 

1A 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.
2The CDSC is 4.50% if shares are redeemed in less than one year. The CDSC for Investor B Shares decreases for redemptions made in subsequent years. After six years there is no CDSC on Investor B Shares. (See the section “Details About the Share Classes — Investor B Shares” in the Fund’s prospectus for the complete schedule of CDSCs.)
3There is no CDSC on Investor C Shares after one year.
4As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 63, BlackRock has contractually agreed to waive 0.10% of its Management Fee until February 1, 2016. In addition, 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 1.39% (for Investor A Shares), 2.26% (for Investor B Shares), 2.13% (for Investor C Shares) and 1.06% (for Institutional Shares) until February 1, 2016. The Fund may have to repay some of these waivers and/or reimbursements to BlackRock in the following two years. The 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.

Example:

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

  1 Year 3 Years 5 Years 10 Years
Investor A Shares $659  $970  $1,303  $2,242 
Investor B Shares $679  $1,083  $1,464  $2,502 
Investor C Shares $316  $696  $1,202  $2,594 
Institutional Shares $108  $371  $655  $1,463 
 
You would pay the following expenses if you did not redeem your shares:
 
  1 Year 3 Years 5 Years 10 Years
Investor B Shares $229  $733  $1,264  $2,502 
Investor C Shares $216  $696  $1,202  $2,594 

 

Portfolio Turnover:

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 138% of the average value of its portfolio.

The section of International Opportunities Portfolio’s prospectus for Service Shares entitled “Fund Overview — Key Facts About BlackRock International Opportunities Portfolio — Fees and Expenses of the Fund” is deleted in its entirety and replaced with the following:

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold Service Shares of International Opportunities.

Annual Fund Operating Expenses
(expenses that you pay each year as a
percentage of the value of your investment)		 Service Shares
Management Fee1   0.98%
Distribution and/or Service (12b-1) Fees  0.25%
Other Expenses  0.28%
Total Annual Fund Operating Expenses  1.51%
Fee Waivers and/or Expense Reimbursements1   (0.12)%
Total Annual Fund Operating Expenses After
Fee Waivers and/or Expense Reimbursements1 		  1.39%

 

1As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 42, BlackRock Advisors, LLC (“BlackRock”) has contractually agreed to waive 0.10% of its Management Fee until February 1, 2016. In addition, 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) to 1.39% of average daily net assets until February 1, 2016. The Fund may have to repay some of these waivers and/or reimbursements to BlackRock in the following two years. The 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.

Example:

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

  1 Year 3 Years 5 Years 10 Years
Service Shares $142  $465  $812  $1,791 

 

Portfolio Turnover:

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 138% of the average value of its portfolio.

The section of Science & Technology Opportunities Portfolio’s prospectus for Investor A, Investor B, Investor C, Institutional and Class R Shares entitled “Fund Overview — Key Facts About BlackRock Science & Technology Opportunities Portfolio — Fees and Expenses of the Fund” is deleted in its entirety and replaced with the following:

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. 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 Advisors, LLC (“BlackRock”) and its affiliates. More information about these and other discounts is available from your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock, The PNC Financial Services Group, Inc. and their respective affiliates) (each a “Financial Intermediary”) and in the “Details About the Share Classes” section on page 48 of the Fund’s prospectus and in the “Purchase of Shares” section on page II-61 of Part II of the Fund’s Statement of Additional Information.

Shareholder Fees (fees paid directly
from your investment)		 Investor A
Shares		 Investor B
Shares		 Investor C
Shares		 Institutional
Shares		 Class R
Shares
Maximum Sales Charge (Load) Imposed on 
Purchases (as a percentage of offering price)		  5.25%  None    None    None    None  
Maximum Deferred Sales Charge (Load) 
(as a percentage of original purchase price or 
redemption proceeds, whichever is lower)		  None1  4.50%2  1.00%3  None    None  
                     
Annual Fund Operating Expenses
(expenses that you pay each year as a
percentage of the value of your investment)		 Investor A
Shares		 Investor B
Shares		 Investor C
Shares		 Institutional
Shares		 Class R
Shares
Management Fee  0.90%  0.90%  0.90%  0.90%  0.90%
Distribution and/or Service (12b-1) Fees  0.25%  1.00%  1.00%   —    0.50%
Other Expenses  0.49%  0.52%  0.56%  0.46%  0.51%
Total Annual Fund Operating Expenses  1.64%  2.42%  2.46%  1.36%  1.91%
Fee Waivers and/or Expense Reimbursements4   (0.09)%  (0.06)%  (0.07)%  (0.13)%  (0.07)%
Total Annual Fund Operating Expenses After Fee 
Waivers and/or Expense Reimbursements4 		  1.55%  2.36%  2.39%  1.23%  1.84%

 

1A 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.
2The CDSC is 4.50% if shares are redeemed in less than one year. The CDSC for Investor B Shares decreases for redemptions made in subsequent years. After six years there is no CDSC on Investor B Shares. (See the section “Details About the Share Classes — Investor B Shares” in the Fund’s prospectus for the complete schedule of CDSCs.)
3There is no CDSC on Investor C Shares after one year.
4As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 63, 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 1.55% (for Investor A Shares), 2.36% (for Investor B Shares), 2.39% (for Investor C Shares), 1.23% (for Institutional Shares) and 1.84% (for Class R Shares) until February 1, 2016. The Fund may have to repay some of these waivers and/or reimbursements to BlackRock in the following two years. The 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.

Example:

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

  1 Year 3 Years 5 Years 10 Years
Investor A Shares $674  $1,007  $1,362  $2,359 
Investor B Shares $689  $1,099  $1,485  $2,559 
Investor C Shares $342  $760  $1,304  $2,791 
Institutional Shares $125  $418  $732  $1,624 
Class R Shares $187  $593  $1,025  $2,227 
 
You would pay the following expenses if you did not redeem your shares:
 
  1 Year 3 Years 5 Years 10 Years
Investor B Shares $239  $749  $1,285  $2,559 
Investor C Shares $242  $760  $1,304  $2,791 

 

Portfolio Turnover:

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 99% of the average value of its portfolio.

The section of Science & Technology Opportunities Portfolio’s prospectus for Service Shares entitled “Fund Overview — Key Facts About BlackRock Science & Technology Opportunities Portfolio — Fees and Expenses of the Fund” is deleted in its entirety and replaced with the following:

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold Service Shares of Science & Technology Opportunities.

Annual Fund Operating Expenses
(expenses that you pay each year as a
percentage of the value of your investment)		 Service Shares
Management Fee  0.90%
Distribution and/or Service (12b-1) Fees  0.25%
Other Expenses  0.35%
Total Annual Fund Operating Expenses  1.50%
Fee Waivers and/or Expense Reimbursements1    —  
Total Annual Fund Operating Expenses After
Fee Waivers and/or Expense Reimbursements1 		  1.50%

 

1As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 42, BlackRock Advisors, LLC (“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) to 1.55% of average daily net assets until February 1, 2016. The Fund may have to repay some of these waivers and/or reimbursements to BlackRock in the following two years. The 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.

Example:

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

  1 Year 3 Years 5 Years 10 Years
Service Shares $153  $474  $818  $1,791 

 

Portfolio Turnover:

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 99% of the average value of its portfolio.
Investor A, B, C and Institutional | BLACKROCK INTERNATIONAL OPPORTUNITIES PORTFOLIO  
Risk/Return: rr_RiskReturnAbstract  
Supplement [Text Block] bf1_SupplementTextBlock
BLACKROCK FUNDSSM
BlackRock International Opportunities Portfolio (“International Opportunities Portfolio”)
(each, a “Fund” and collectively, the “Funds”)

Supplement dated June 1, 2015 to the Prospectus of the Funds, dated January 28, 2015

Effective immediately, BlackRock (as defined below) has agreed contractually to cap net expenses of the Funds at lower levels. To achieve these expense caps, BlackRock has agreed to waive or reimburse fees or expenses if a Fund’s annual fund operating expenses, excluding certain expenses described in the prospectus, exceed a certain limit. Accordingly, each Fund’s prospectus is amended as follows:

The section of International Opportunities Portfolio’s prospectus for Investor A, Investor B, Investor C and Institutional Shares entitled “Fund Overview — Key Facts About BlackRock International Opportunities Portfolio — Fees and Expenses of the Fund” is deleted in its entirety and replaced with the following:

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. 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 Advisors, LLC (“BlackRock”) and its affiliates. More information about these and other discounts is available from your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock, The PNC Financial Services Group, Inc. and their respective affiliates) (each a “Financial Intermediary”) and in the “Details About the Share Classes” section on page 48 of the Fund’s prospectus and in the “Purchase of Shares” section on page II-61 of Part II of the Fund’s Statement of Additional Information.

Shareholder Fees
(fees paid directly from your investment)		 Investor A
Shares		 Investor B
Shares		 Investor C
Shares		 Institutional
Shares
Maximum Sales Charge (Load) Imposed on Purchases 
(as a percentage of offering price)		  5.25%  None    None    None  
Maximum Deferred Sales Charge (Load) 
(as a percentage of original purchase price or 
redemption proceeds, whichever is lower)		  None1  4.50%2  1.00%3  None  
 
Annual Fund Operating Expenses
(expenses that you pay each year as a
percentage of the value of your investment)		 Investor A
Shares		 Investor B
Shares		 Investor C
Shares		 Institutional
Shares
Management Fee4   0.98%  0.98%  0.98%  0.98%
Distribution and/or Service (12b-1) Fees  0.25%  1.00%  1.00%  None  
Other Expenses  0.30%  0.41%  0.29%  0.24%
Total Annual Fund Operating Expenses  1.53%  2.39%  2.27%  1.22%
Fee Waivers and/or Expense Reimbursements4   (0.14)%  (0.13)%  (0.14)%  (0.16)%
Total Annual Fund Operating Expenses After Fee
Waivers and/or Expense Reimbursements4 		  1.39%  2.26%  2.13%  1.06%

 

1A 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.
2The CDSC is 4.50% if shares are redeemed in less than one year. The CDSC for Investor B Shares decreases for redemptions made in subsequent years. After six years there is no CDSC on Investor B Shares. (See the section “Details About the Share Classes — Investor B Shares” in the Fund’s prospectus for the complete schedule of CDSCs.)
3There is no CDSC on Investor C Shares after one year.
4As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 63, BlackRock has contractually agreed to waive 0.10% of its Management Fee until February 1, 2016. In addition, 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 1.39% (for Investor A Shares), 2.26% (for Investor B Shares), 2.13% (for Investor C Shares) and 1.06% (for Institutional Shares) until February 1, 2016. The Fund may have to repay some of these waivers and/or reimbursements to BlackRock in the following two years. The 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.

Example:

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

  1 Year 3 Years 5 Years 10 Years
Investor A Shares $659  $970  $1,303  $2,242 
Investor B Shares $679  $1,083  $1,464  $2,502 
Investor C Shares $316  $696  $1,202  $2,594 
Institutional Shares $108  $371  $655  $1,463 
 
You would pay the following expenses if you did not redeem your shares:
 
  1 Year 3 Years 5 Years 10 Years
Investor B Shares $229  $733  $1,264  $2,502 
Investor C Shares $216  $696  $1,202  $2,594 

 

Portfolio Turnover:

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 138% of the average value of its portfolio.
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 and hold shares of the Fund. 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 Advisors, LLC (“BlackRock”) and its affiliates. More information about these and other discounts is available from your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock, The PNC Financial Services Group, Inc. and their respective affiliates) (each a “Financial Intermediary”) and in the “Details About the Share Classes” section on page 48 of the Fund’s prospectus and in the “Purchase of Shares” section on page II-61 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 February 1, 2016
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 138% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 138.00%rr_PortfolioTurnoverRate
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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 $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 Advisors, LLC (“BlackRock”) and its affiliates.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount 25,000rr_ExpenseBreakpointMinimumInvestmentRequiredAmount
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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. This 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:
Investor A, B, C and Institutional | BLACKROCK INTERNATIONAL OPPORTUNITIES PORTFOLIO | Investor A Shares  
Risk/Return: rr_RiskReturnAbstract  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.25%rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice
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Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, whichever is lower) rr_MaximumDeferredSalesChargeOverOfferingPrice none [1]
Management Fee rr_ManagementFeesOverAssets 0.98%rr_ManagementFeesOverAssets
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Distribution and/or Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%rr_DistributionAndService12b1FeesOverAssets
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Other Expenses rr_OtherExpensesOverAssets 0.30%rr_OtherExpensesOverAssets
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Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.53%rr_ExpensesOverAssets
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Fee Waivers and/or Expense Reimbursements rr_FeeWaiverOrReimbursementOverAssets (0.14%)rr_FeeWaiverOrReimbursementOverAssets
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Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements rr_NetExpensesOverAssets 1.39%rr_NetExpensesOverAssets
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Investor A, B, C and Institutional | BLACKROCK INTERNATIONAL OPPORTUNITIES PORTFOLIO | Investor B Shares  
Risk/Return: rr_RiskReturnAbstract  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
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Investor A, B, C and Institutional | BLACKROCK INTERNATIONAL OPPORTUNITIES PORTFOLIO | Investor C Shares  
Risk/Return: rr_RiskReturnAbstract  
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Investor A, B, C and Institutional | BLACKROCK INTERNATIONAL OPPORTUNITIES PORTFOLIO | Institutional Shares  
Risk/Return: rr_RiskReturnAbstract  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
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Service | BLACKROCK INTERNATIONAL OPPORTUNITIES PORTFOLIO  
Risk/Return: rr_RiskReturnAbstract  
Supplement [Text Block] bf1_SupplementTextBlock
BLACKROCK FUNDSSM
BlackRock International Opportunities Portfolio (“International Opportunities Portfolio”)
(each, a “Fund” and collectively, the “Funds”)

Supplement dated June 1, 2015 to the Prospectus of the Funds, dated January 28, 2015

Effective immediately, BlackRock (as defined below) has agreed contractually to cap net expenses of the Funds at lower levels. To achieve these expense caps, BlackRock has agreed to waive or reimburse fees or expenses if a Fund’s annual fund operating expenses, excluding certain expenses described in the prospectus, exceed a certain limit. Accordingly, each Fund’s prospectus is amended as follows:

The section of International Opportunities Portfolio’s prospectus for Service Shares entitled “Fund Overview — Key Facts About BlackRock International Opportunities Portfolio — Fees and Expenses of the Fund” is deleted in its entirety and replaced with the following:

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold Service Shares of International Opportunities.

Annual Fund Operating Expenses
(expenses that you pay each year as a
percentage of the value of your investment)		 Service Shares
Management Fee1   0.98%
Distribution and/or Service (12b-1) Fees  0.25%
Other Expenses  0.28%
Total Annual Fund Operating Expenses  1.51%
Fee Waivers and/or Expense Reimbursements1   (0.12)%
Total Annual Fund Operating Expenses After
Fee Waivers and/or Expense Reimbursements1 		  1.39%

 

1As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 42, BlackRock Advisors, LLC (“BlackRock”) has contractually agreed to waive 0.10% of its Management Fee until February 1, 2016. In addition, 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) to 1.39% of average daily net assets until February 1, 2016. The Fund may have to repay some of these waivers and/or reimbursements to BlackRock in the following two years. The 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.

Example:

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

  1 Year 3 Years 5 Years 10 Years
Service Shares $142  $465  $812  $1,791 

 

Portfolio Turnover:

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 138% of the average value of its portfolio.
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 and hold Service Shares of International Opportunities.
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 February 1, 2016
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 138% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 138.00%rr_PortfolioTurnoverRate
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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. This 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:
Service | BLACKROCK INTERNATIONAL OPPORTUNITIES PORTFOLIO | Service Shares  
Risk/Return: rr_RiskReturnAbstract  
Management Fee rr_ManagementFeesOverAssets 0.98%rr_ManagementFeesOverAssets
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Service | BLACKROCK SCIENCE & TECHNOLOGY OPPORTUNITIES PORTFOLIO  
Risk/Return: rr_RiskReturnAbstract  
Supplement [Text Block] bf1_SupplementTextBlock
BLACKROCK FUNDSSM
BlackRock Science & Technology Opportunities Portfolio (“Science & Technology Opportunities Portfolio”)
(each, a “Fund” and collectively, the “Funds”)

Supplement dated June 1, 2015 to the Prospectus of the Funds, dated January 28, 2015

Effective immediately, BlackRock (as defined below) has agreed contractually to cap net expenses of the Funds at lower levels. To achieve these expense caps, BlackRock has agreed to waive or reimburse fees or expenses if a Fund’s annual fund operating expenses, excluding certain expenses described in the prospectus, exceed a certain limit. Accordingly, each Fund’s prospectus is amended as follows:

The section of Science & Technology Opportunities Portfolio’s prospectus for Service Shares entitled “Fund Overview — Key Facts About BlackRock Science & Technology Opportunities Portfolio — Fees and Expenses of the Fund” is deleted in its entirety and replaced with the following:

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold Service Shares of Science & Technology Opportunities.

Annual Fund Operating Expenses
(expenses that you pay each year as a
percentage of the value of your investment)		 Service Shares
Management Fee  0.90%
Distribution and/or Service (12b-1) Fees  0.25%
Other Expenses  0.35%
Total Annual Fund Operating Expenses  1.50%
Fee Waivers and/or Expense Reimbursements1    —  
Total Annual Fund Operating Expenses After
Fee Waivers and/or Expense Reimbursements1 		  1.50%

 

1As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 42, BlackRock Advisors, LLC (“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) to 1.55% of average daily net assets until February 1, 2016. The Fund may have to repay some of these waivers and/or reimbursements to BlackRock in the following two years. The 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.

Example:

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

  1 Year 3 Years 5 Years 10 Years
Service Shares $153  $474  $818  $1,791 

 

Portfolio Turnover:

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 99% of the average value of its portfolio.
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 and hold Service Shares of Science & Technology Opportunities.
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 February 1, 2016
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 99% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 99.00%rr_PortfolioTurnoverRate
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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. This 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:
Service | BLACKROCK SCIENCE & TECHNOLOGY OPPORTUNITIES PORTFOLIO | Service Shares  
Risk/Return: rr_RiskReturnAbstract  
Management Fee rr_ManagementFeesOverAssets 0.90%rr_ManagementFeesOverAssets
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Fee Waivers and/or Expense Reimbursements rr_FeeWaiverOrReimbursementOverAssets    [6]
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements rr_NetExpensesOverAssets 1.50%rr_NetExpensesOverAssets
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Investor A, B, C, Institutional and Class R | BLACKROCK SCIENCE & TECHNOLOGY OPPORTUNITIES PORTFOLIO  
Risk/Return: rr_RiskReturnAbstract  
Supplement [Text Block] bf1_SupplementTextBlock
BLACKROCK FUNDSSM
BlackRock Science & Technology Opportunities Portfolio (“Science & Technology Opportunities Portfolio”)
(each, a “Fund” and collectively, the “Funds”)

Supplement dated June 1, 2015 to the Prospectus of the Funds, dated January 28, 2015

Effective immediately, BlackRock (as defined below) has agreed contractually to cap net expenses of the Funds at lower levels. To achieve these expense caps, BlackRock has agreed to waive or reimburse fees or expenses if a Fund’s annual fund operating expenses, excluding certain expenses described in the prospectus, exceed a certain limit. Accordingly, each Fund’s prospectus is amended as follows:

The section of Science & Technology Opportunities Portfolio’s prospectus for Investor A, Investor B, Investor C, Institutional and Class R Shares entitled “Fund Overview — Key Facts About BlackRock Science & Technology Opportunities Portfolio — Fees and Expenses of the Fund” is deleted in its entirety and replaced with the following:

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. 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 Advisors, LLC (“BlackRock”) and its affiliates. More information about these and other discounts is available from your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock, The PNC Financial Services Group, Inc. and their respective affiliates) (each a “Financial Intermediary”) and in the “Details About the Share Classes” section on page 48 of the Fund’s prospectus and in the “Purchase of Shares” section on page II-61 of Part II of the Fund’s Statement of Additional Information.

Shareholder Fees (fees paid directly
from your investment)		 Investor A
Shares		 Investor B
Shares		 Investor C
Shares		 Institutional
Shares		 Class R
Shares
Maximum Sales Charge (Load) Imposed on 
Purchases (as a percentage of offering price)		  5.25%  None    None    None    None  
Maximum Deferred Sales Charge (Load) 
(as a percentage of original purchase price or 
redemption proceeds, whichever is lower)		  None1  4.50%2  1.00%3  None    None  
                     
Annual Fund Operating Expenses
(expenses that you pay each year as a
percentage of the value of your investment)		 Investor A
Shares		 Investor B
Shares		 Investor C
Shares		 Institutional
Shares		 Class R
Shares
Management Fee  0.90%  0.90%  0.90%  0.90%  0.90%
Distribution and/or Service (12b-1) Fees  0.25%  1.00%  1.00%   —    0.50%
Other Expenses  0.49%  0.52%  0.56%  0.46%  0.51%
Total Annual Fund Operating Expenses  1.64%  2.42%  2.46%  1.36%  1.91%
Fee Waivers and/or Expense Reimbursements4   (0.09)%  (0.06)%  (0.07)%  (0.13)%  (0.07)%
Total Annual Fund Operating Expenses After Fee 
Waivers and/or Expense Reimbursements4 		  1.55%  2.36%  2.39%  1.23%  1.84%

 

1A 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.
2The CDSC is 4.50% if shares are redeemed in less than one year. The CDSC for Investor B Shares decreases for redemptions made in subsequent years. After six years there is no CDSC on Investor B Shares. (See the section “Details About the Share Classes — Investor B Shares” in the Fund’s prospectus for the complete schedule of CDSCs.)
3There is no CDSC on Investor C Shares after one year.
4As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 63, 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 1.55% (for Investor A Shares), 2.36% (for Investor B Shares), 2.39% (for Investor C Shares), 1.23% (for Institutional Shares) and 1.84% (for Class R Shares) until February 1, 2016. The Fund may have to repay some of these waivers and/or reimbursements to BlackRock in the following two years. The 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.

Example:

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

  1 Year 3 Years 5 Years 10 Years
Investor A Shares $674  $1,007  $1,362  $2,359 
Investor B Shares $689  $1,099  $1,485  $2,559 
Investor C Shares $342  $760  $1,304  $2,791 
Institutional Shares $125  $418  $732  $1,624 
Class R Shares $187  $593  $1,025  $2,227 
 
You would pay the following expenses if you did not redeem your shares:
 
  1 Year 3 Years 5 Years 10 Years
Investor B Shares $239  $749  $1,285  $2,559 
Investor C Shares $242  $760  $1,304  $2,791 

 

Portfolio Turnover:

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 99% of the average value of its portfolio.
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 and hold shares of the Fund. 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 Advisors, LLC (“BlackRock”) and its affiliates. More information about these and other discounts is available from your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock, The PNC Financial Services Group, Inc. and their respective affiliates) (each a “Financial Intermediary”) and in the “Details About the Share Classes” section on page 48 of the Fund’s prospectus and in the “Purchase of Shares” section on page II-61 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 February 1, 2016
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 99% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 99.00%rr_PortfolioTurnoverRate
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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 $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 Advisors, LLC (“BlackRock”) and its affiliates.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount 25,000rr_ExpenseBreakpointMinimumInvestmentRequiredAmount
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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. This 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:
Investor A, B, C, Institutional and Class R | BLACKROCK SCIENCE & TECHNOLOGY OPPORTUNITIES PORTFOLIO | Investor A Shares  
Risk/Return: rr_RiskReturnAbstract  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.25%rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice
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Management Fee rr_ManagementFeesOverAssets 0.90%rr_ManagementFeesOverAssets
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Distribution and/or Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%rr_DistributionAndService12b1FeesOverAssets
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Other Expenses rr_OtherExpensesOverAssets 0.49%rr_OtherExpensesOverAssets
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Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.64%rr_ExpensesOverAssets
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Fee Waivers and/or Expense Reimbursements rr_FeeWaiverOrReimbursementOverAssets (0.09%)rr_FeeWaiverOrReimbursementOverAssets
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Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements rr_NetExpensesOverAssets 1.55%rr_NetExpensesOverAssets
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Risk/Return: rr_RiskReturnAbstract  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
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Other Expenses rr_OtherExpensesOverAssets 0.52%rr_OtherExpensesOverAssets
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Investor A, B, C, Institutional and Class R | BLACKROCK SCIENCE & TECHNOLOGY OPPORTUNITIES PORTFOLIO | Institutional Shares  
Risk/Return: rr_RiskReturnAbstract  
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[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 63, BlackRock has contractually agreed to waive 0.10% of its Management Fee until February 1, 2016. In addition, 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 1.39% (for Investor A Shares), 2.26% (for Investor B Shares), 2.13% (for Investor C Shares) and 1.06% (for Institutional Shares) until February 1, 2016. The Fund may have to repay some of these waivers and/or reimbursements to BlackRock in the following two years. The 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.
[3] The CDSC is 4.50% if shares are redeemed in less than one year. The CDSC for Investor B Shares decreases for redemptions made in subsequent years. After six years there is no CDSC on Investor B Shares. (See the section “Details About the Share Classes — Investor B Shares” in the Fund’s prospectus for the complete schedule of CDSCs.)
[4] There is no CDSC on Investor C Shares after one year.
[5] As described in the "Management of the Funds" section of the Fund's prospectus beginning on page 42, BlackRock Advisors, LLC ("BlackRock") has contractually agreed to waive 0.10% of its Management Fee until February 1, 2016. In addition, 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) to 1.39% of average daily net assets until February 1, 2016. The Fund may have to repay some of these waivers and/or reimbursements to BlackRock in the following two years. The 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] As described in the "Management of the Funds" section of the Fund's prospectus beginning on page 42, BlackRock Advisors, LLC ("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) to 1.55% of average daily net assets until February 1, 2016. The Fund may have to repay some of these waivers and/or reimbursements to BlackRock in the following two years. The 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.
[7] As described in the "Management of the Funds" section of the Fund's prospectus beginning on page 63, 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 1.55% (for Investor A Shares), 2.36% (for Investor B Shares), 2.39% (for Investor C Shares), 1.23% (for Institutional Shares) and 1.84% (for Class R Shares) until February 1, 2016. The Fund may have to repay some of these waivers and/or reimbursements to BlackRock in the following two years. The 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.