| Form N-CSR Cover | 6 Months Ended |
| Jul. 31, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | BlackRock Funds |
| Entity Central Index Key | 0000844779 |
| Document Period End Date | Jul. 31, 2024 |
| Shareholder Report | 6 Months Ended | |
| Jul. 31, 2024 USD ($) Holding | ||
| Shareholder Report [Line Items] | ||
| Document Type | N-CSRS | |
| Amendment Flag | false | |
| Registrant Name | BlackRock Funds | |
| Entity Central Index Key | 0000844779 | |
| Document Period End Date | Jul. 31, 2024 | |
| C000118601 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | BlackRock Real Estate Securities Fund | |
| Class Name | Institutional Shares | |
| Trading Symbol | BIREX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about BlackRock Real Estate Securities Fund (the “Fund”) for the period of February 1, 2024 to July 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports | |
| Additional Information Phone Number | (800) 441‑7762 | |
| Additional Information Website | blackrock.com/fundreports | |
| Expenses [Text Block] | What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Institutional Shares $ 0.75 % (a) (a) Annualized. | |
| Expenses Paid, Amount | $ 39 | |
| Expense Ratio, Percent | 0.75% | [1] |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. | |
| Average Annual Return [Table Text Block] | Average annual total returns 6-Month 1 Year 5 Years 10 Years Institutional Shares 9.60 % 11.52 % 4.83 % 7.04 % Russell 1000 ® 14.30 21.50 14.59 12.86 FTSE Nareit All Equity REITs Net Index 9.51 9.77 3.38 5.61 | |
| No Deduction of Taxes [Text Block] | Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit blackrock.com | |
| Net Assets | $ 300,239,828 | |
| Holdings Count | Holding | 38 | |
| Investment Company Portfolio Turnover | 24% | |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ % Number of Portfolio Holdings $ % Portfolio Turnover Rate $ % | |
| Holdings [Text Block] | What did the Fund invest in? (as of July 31, 2024) Industry allocation Industry (a) Percent of Specialized REITs 38.6 % Residential REITs 14.4 % Industrial REITs 14.3 % Retail REITs 13.2 % Health Care REITs 12.3 % Office REITs 3.2 % Hotel & Resort REITs 2.6 % Diversified REITs 1.7 % Short-Term Securities 0.3 % Liabilities in Excess of Other Assets (0.6 ) % Ten largest holdings Security (b) Percent of American Tower Corp. 8.1 % Equinix, Inc. 7.5 % Prologis, Inc. 6.8 % AvalonBay Communities, Inc. 4.9 % Welltower, Inc. 4.5 % Extra Space Storage, Inc. 4.3 % VICI Properties, Inc. 4.3 % SBA Communications Corp. 4.1 % Mid-America Apartment Communities, Inc. 3.9 % Agree Realty Corp. 3.6 % (a) For purposes of this report, industry sub-classifications may differ from those utilized for compliance purposes. (b) Excludes short-term securities. | |
| Largest Holdings [Text Block] | Ten largest holdings Security (b) Percent of American Tower Corp. 8.1 % Equinix, Inc. 7.5 % Prologis, Inc. 6.8 % AvalonBay Communities, Inc. 4.9 % Welltower, Inc. 4.5 % Extra Space Storage, Inc. 4.3 % VICI Properties, Inc. 4.3 % SBA Communications Corp. 4.1 % Mid-America Apartment Communities, Inc. 3.9 % Agree Realty Corp. 3.6 % | |
| C000118599 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | BlackRock Real Estate Securities Fund | |
| Class Name | Investor A Shares | |
| Trading Symbol | BAREX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about BlackRock Real Estate Securities Fund (the “Fund”) for the period of February 1, 2024 to July 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports | |
| Additional Information Phone Number | (800) 441‑7762 | |
| Additional Information Website | blackrock.com/fundreports | |
| Expenses [Text Block] | What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Investor A Shares $ 1.00 % (a) (a) Annualized. | |
| Expenses Paid, Amount | $ 52 | |
| Expense Ratio, Percent | 1% | [2] |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. | |
| Average Annual Return [Table Text Block] | Average annual total returns 6-Month 1 Year 5 Years 10 Years Investor A Shares 9.46 % 11.23 % 4.56 % 6.76 % Investor A Shares (with sales charge) 3.71 5.39 3.44 6.19 Russell 1000 ® 14.30 21.50 14.59 12.86 FTSE Nareit All Equity REITs Net Index 9.51 9.77 3.38 5.61 | |
| No Deduction of Taxes [Text Block] | Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit blackrock.com | |
| Net Assets | $ 300,239,828 | |
| Holdings Count | Holding | 38 | |
| Investment Company Portfolio Turnover | 24% | |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ % Number of Portfolio Holdings $ % Portfolio Turnover Rate $ % | |
| Holdings [Text Block] | What did the Fund invest in? (as of July 31, 2024) Industry allocation Industry (a) Percent of Specialized REITs 38.6 % Residential REITs 14.4 % Industrial REITs 14.3 % Retail REITs 13.2 % Health Care REITs 12.3 % Office REITs 3.2 % Hotel & Resort REITs 2.6 % Diversified REITs 1.7 % Short-Term Securities 0.3 % Liabilities in Excess of Other Assets (0.6 ) % Ten largest holdings Security (b) Percent of American Tower Corp. 8.1 % Equinix, Inc. 7.5 % Prologis, Inc. 6.8 % AvalonBay Communities, Inc. 4.9 % Welltower, Inc. 4.5 % Extra Space Storage, Inc. 4.3 % VICI Properties, Inc. 4.3 % SBA Communications Corp. 4.1 % Mid-America Apartment Communities, Inc. 3.9 % Agree Realty Corp. 3.6 % (a) For purposes of this report, industry sub-classifications may differ from those utilized for compliance purposes. (b) Excludes short-term securities. | |
| Largest Holdings [Text Block] | Ten largest holdings Security (b) Percent of American Tower Corp. 8.1 % Equinix, Inc. 7.5 % Prologis, Inc. 6.8 % AvalonBay Communities, Inc. 4.9 % Welltower, Inc. 4.5 % Extra Space Storage, Inc. 4.3 % VICI Properties, Inc. 4.3 % SBA Communications Corp. 4.1 % Mid-America Apartment Communities, Inc. 3.9 % Agree Realty Corp. 3.6 % | |
| C000118600 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | BlackRock Real Estate Securities Fund | |
| Class Name | Investor C Shares | |
| Trading Symbol | BCREX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about BlackRock Real Estate Securities Fund (the “Fund”) for the period of February 1, 2024 to July 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports | |
| Additional Information Phone Number | (800) 441‑7762 | |
| Additional Information Website | blackrock.com/fundreports | |
| Expenses [Text Block] | What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Investor C Shares $ 1.75 % (a) (a) Annualized. | |
| Expenses Paid, Amount | $ 91 | |
| Expense Ratio, Percent | 1.75% | [3] |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. | |
| Average Annual Return [Table Text Block] | Average annual total returns 6-Month 1 Year 5 Years 10 Years Investor C Shares 9.02 % 10.39 % 3.79 % 6.14 % Investor C Shares (with sales charge) 8.02 9.39 3.79 6.14 Russell 1000 ® 14.30 21.50 14.59 12.86 FTSE Nareit All Equity REITs Net Index 9.51 9.77 3.38 5.61 | |
| No Deduction of Taxes [Text Block] | Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit blackrock.com | |
| Net Assets | $ 300,239,828 | |
| Holdings Count | Holding | 38 | |
| Investment Company Portfolio Turnover | 24% | |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ % Number of Portfolio Holdings $ % Portfolio Turnover Rate $ % | |
| Holdings [Text Block] | What did the Fund invest in? (as of July 31, 2024) Industry allocation Industry (a) Percent of Specialized REITs 38.6 % Residential REITs 14.4 % Industrial REITs 14.3 % Retail REITs 13.2 % Health Care REITs 12.3 % Office REITs 3.2 % Hotel & Resort REITs 2.6 % Diversified REITs 1.7 % Short-Term Securities 0.3 % Liabilities in Excess of Other Assets (0.6 ) % Ten largest holdings Security (b) Percent of American Tower Corp. 8.1 % Equinix, Inc. 7.5 % Prologis, Inc. 6.8 % AvalonBay Communities, Inc. 4.9 % Welltower, Inc. 4.5 % Extra Space Storage, Inc. 4.3 % VICI Properties, Inc. 4.3 % SBA Communications Corp. 4.1 % Mid-America Apartment Communities, Inc. 3.9 % Agree Realty Corp. 3.6 % (a) For purposes of this report, industry sub-classifications may differ from those utilized for compliance purposes. (b) Excludes short-term securities. | |
| Largest Holdings [Text Block] | Ten largest holdings Security (b) Percent of American Tower Corp. 8.1 % Equinix, Inc. 7.5 % Prologis, Inc. 6.8 % AvalonBay Communities, Inc. 4.9 % Welltower, Inc. 4.5 % Extra Space Storage, Inc. 4.3 % VICI Properties, Inc. 4.3 % SBA Communications Corp. 4.1 % Mid-America Apartment Communities, Inc. 3.9 % Agree Realty Corp. 3.6 % | |
| [1]Annualized.[2]Annualized.[3]Annualized. | ||
| Shareholder Report, Line Graph (Details) | 6 Months Ended | 12 Months Ended | 60 Months Ended | 120 Months Ended |
| Jul. 31, 2024 | Jul. 31, 2024 | Jul. 31, 2024 | Jul. 31, 2024 | |
| C000118601 [Member] | ||||
| Account Value [Line Items] | ||||
| Line Graph and Table Measure Name | Institutional Shares | |||
| Average Annual Return, Percent | 9.60% | 11.52% | 4.83% | 7.04% |
| C000118599 [Member] | ||||
| Account Value [Line Items] | ||||
| Line Graph and Table Measure Name | Investor A Shares (with sales charge) | |||
| Average Annual Return, Percent | 3.71% | 5.39% | 3.44% | 6.19% |
| C000118599 [Member] | Without Sales Load [Member] | ||||
| Account Value [Line Items] | ||||
| Line Graph and Table Measure Name | Investor A Shares | |||
| Average Annual Return, Percent | 9.46% | 11.23% | 4.56% | 6.76% |
| C000118600 [Member] | ||||
| Account Value [Line Items] | ||||
| Line Graph and Table Measure Name | Investor C Shares (with sales charge) | |||
| Average Annual Return, Percent | 8.02% | 9.39% | 3.79% | 6.14% |
| C000118600 [Member] | Without Sales Load [Member] | ||||
| Account Value [Line Items] | ||||
| Line Graph and Table Measure Name | Investor C Shares | |||
| Average Annual Return, Percent | 9.02% | 10.39% | 3.79% | 6.14% |
| Russell 1000 Index [Member] | ||||
| Account Value [Line Items] | ||||
| Line Graph and Table Measure Name | Russell 1000® Index | |||
| Average Annual Return, Percent | 14.30% | 21.50% | 14.59% | 12.86% |
| FTSE Nareit All Equity REITs Net Index [Member] | ||||
| Account Value [Line Items] | ||||
| Line Graph and Table Measure Name | FTSE Nareit All Equity REITs Net Index | |||
| Average Annual Return, Percent | 9.51% | 9.77% | 3.38% | 5.61% |
| Shareholder Report, Holdings (Details) | Jul. 31, 2024 | |
| C000118601 [Member] | American Tower Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 8.10% | [1] |
| C000118601 [Member] | Equinix Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 7.50% | [1] |
| C000118601 [Member] | Prologis Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.80% | [1] |
| C000118601 [Member] | AvalonBay Communities Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.90% | [1] |
| C000118601 [Member] | Welltower Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.50% | [1] |
| C000118601 [Member] | Extra Space Storage Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.30% | [1] |
| C000118601 [Member] | VICI Properties Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.30% | [1] |
| C000118601 [Member] | SBA Communications Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.10% | [1] |
| C000118601 [Member] | Mid America Apartment Communities Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.90% | [1] |
| C000118601 [Member] | Agree Realty Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.60% | [1] |
| C000118601 [Member] | Specialized REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 38.60% | [2] |
| C000118601 [Member] | Residential REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 14.40% | [2] |
| C000118601 [Member] | Industrial REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 14.30% | [2] |
| C000118601 [Member] | Retail REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 13.20% | [2] |
| C000118601 [Member] | Health Care REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.30% | [2] |
| C000118601 [Member] | Office REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.20% | [2] |
| C000118601 [Member] | Hotel And Resort REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.60% | [2] |
| C000118601 [Member] | Diversified REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.70% | [2] |
| C000118601 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [2] |
| C000118601 [Member] | Liabilities in Excess of Other Assets [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.60%) | [2] |
| C000118599 [Member] | American Tower Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 8.10% | [3] |
| C000118599 [Member] | Equinix Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 7.50% | [3] |
| C000118599 [Member] | Prologis Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.80% | [3] |
| C000118599 [Member] | AvalonBay Communities Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.90% | [3] |
| C000118599 [Member] | Welltower Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.50% | [3] |
| C000118599 [Member] | Extra Space Storage Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.30% | [3] |
| C000118599 [Member] | VICI Properties Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.30% | [3] |
| C000118599 [Member] | SBA Communications Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.10% | [3] |
| C000118599 [Member] | Mid America Apartment Communities Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.90% | [3] |
| C000118599 [Member] | Agree Realty Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.60% | [3] |
| C000118599 [Member] | Specialized REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 38.60% | [4] |
| C000118599 [Member] | Residential REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 14.40% | [4] |
| C000118599 [Member] | Industrial REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 14.30% | [4] |
| C000118599 [Member] | Retail REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 13.20% | [4] |
| C000118599 [Member] | Health Care REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.30% | [4] |
| C000118599 [Member] | Office REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.20% | [4] |
| C000118599 [Member] | Hotel And Resort REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.60% | [4] |
| C000118599 [Member] | Diversified REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.70% | [4] |
| C000118599 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [4] |
| C000118599 [Member] | Liabilities in Excess of Other Assets [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.60%) | [4] |
| C000118600 [Member] | American Tower Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 8.10% | [5] |
| C000118600 [Member] | Equinix Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 7.50% | [5] |
| C000118600 [Member] | Prologis Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.80% | [5] |
| C000118600 [Member] | AvalonBay Communities Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.90% | [5] |
| C000118600 [Member] | Welltower Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.50% | [5] |
| C000118600 [Member] | Extra Space Storage Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.30% | [5] |
| C000118600 [Member] | VICI Properties Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.30% | [5] |
| C000118600 [Member] | SBA Communications Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.10% | [5] |
| C000118600 [Member] | Mid America Apartment Communities Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.90% | [5] |
| C000118600 [Member] | Agree Realty Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.60% | [5] |
| C000118600 [Member] | Specialized REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 38.60% | [6] |
| C000118600 [Member] | Residential REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 14.40% | [6] |
| C000118600 [Member] | Industrial REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 14.30% | [6] |
| C000118600 [Member] | Retail REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 13.20% | [6] |
| C000118600 [Member] | Health Care REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.30% | [6] |
| C000118600 [Member] | Office REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.20% | [6] |
| C000118600 [Member] | Hotel And Resort REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.60% | [6] |
| C000118600 [Member] | Diversified REITs [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.70% | [6] |
| C000118600 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [6] |
| C000118600 [Member] | Liabilities in Excess of Other Assets [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.60%) | [6] |
| [1]Excludes short-term securities.[2]For purposes of this report, industry sub-classifications may differ from those utilized for compliance purposes.[3]Excludes short-term securities.[4]For purposes of this report, industry sub-classifications may differ from those utilized for compliance purposes.[5]Excludes short-term securities.[6]For purposes of this report, industry sub-classifications may differ from those utilized for compliance purposes. | ||
