v3.26.1
Shareholder Report
 6 Months Ended
Jun. 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 Jun. 30, 2026
C000004917 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock Exchange Portfolio
Class Name BlackRock Shares
Trading Symbol STSEX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock Exchange Portfolio (the “Fund”) for the period of January 1, 2026 to June 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) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the period?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
BlackRock Shares $43 0.88%(a)
​(a)
Annualized.
Expenses Paid, Amount $ 43
Expense Ratio, Percent 0.88% [1]
Net Assets $ 266,641,553
Holdings Count | Holding 26
Investment Company Portfolio Turnover
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $266,641,553
Number of Portfolio Holdings 26
Portfolio Turnover Rate —%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Sector allocation
Sector(a) Percent of
Net Assets
Financials 32.1 %
Information Technology 24.0 %
Health Care 18.8 %
Industrials 10.4 %
Consumer Staples 10.1 %
Energy 4.5 %
Short-Term Securities 0.6 %
Liabilities in Excess of Other Assets (0.5 )%
Ten largest holdings
Security(b) Percent of
Net Assets
Microsoft Corp. 22.0 %
Berkshire Hathaway, Inc., Class B 10.4 %
General Dynamics Corp. 10.4 %
JPMorgan Chase & Co. 8.9 %
American Express Co. 7.8 %
Johnson & Johnson 5.3 %
Visa, Inc., Class A 5.1 %
AstraZeneca PLC 4.6 %
Novartis AG, ADR 4.0 %
Walmart, Inc. 3.5 %
​(a)
For purposes of this report, sector sub-classifications may differ from those utilized by the Fund for compliance purposes.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Microsoft Corp. 22.0 %
Berkshire Hathaway, Inc., Class B 10.4 %
General Dynamics Corp. 10.4 %
JPMorgan Chase & Co. 8.9 %
American Express Co. 7.8 %
Johnson & Johnson 5.3 %
Visa, Inc., Class A 5.1 %
AstraZeneca PLC 4.6 %
Novartis AG, ADR 4.0 %
Walmart, Inc. 3.5 %
(b)Excludes short-term securities.
[1]
Annualized.