v3.26.1
Shareholder Report
6 Months Ended
Apr. 30, 2026
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name BlackRock Funds
Entity Central Index Key 0000844779
Entity Investment Company Type N-1A
Document Period End Date Apr. 30, 2026
C000206968  
Shareholder Report [Line Items]  
Fund Name BlackRock China A Opportunities Fund
Class Name Institutional Shares
Trading Symbol CHILX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock China A Opportunities Fund (the “Fund”) for the period of November 1, 2025 to April 30, 2026.
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. You can also request this information by contacting us at (800) 537-4942.
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)

Table Summary
Class name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Institutional Shares
$52
0.99%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 52
Expense Ratio, Percent 0.99% [1]
AssetsNet $ 24,111,853
Holdings Count | Holding 215
InvestmentCompanyPortfolioTurnover 109.00%
Additional Fund Statistics [Text Block]

Key Fund statistics

C000206969  
Shareholder Report [Line Items]  
Fund Name BlackRock China A Opportunities Fund
Class Name Class K Shares
Trading Symbol CHKLX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock China A Opportunities Fund (the “Fund”) for the period of November 1, 2025 to April 30, 2026.
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. You can also request this information by contacting us at (800) 537-4942.
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)

Table Summary
Class name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class K Shares
$50
0.94%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 50
Expense Ratio, Percent 0.94% [2]
AssetsNet $ 24,111,853
Holdings Count | Holding 215
InvestmentCompanyPortfolioTurnover 109.00%
Additional Fund Statistics [Text Block]

Key Fund statistics

[1] Annualized.
[2] Annualized.