Investor A Institutional [Member] Investment Objectives and Goals - Investor A Institutional [Member] - iShares Russell Small/Mid-Cap Index Fund

Jul. 31, 2025

Prospectus [Line Items]

Risk/Return [Heading]

Fund Overview Key Facts About iShares Russell Small/Mid-Cap Index Fund

Objective [Heading]

Investment Objective

Objective, Primary [Text Block]

The investment objective of iShares Russell Small/Mid-Cap Index Fund (the “Fund”), a series of BlackRock FundsSM (the “Trust”), is to seek to track the performance of the small to mid-cap segment of the U.S. equity universe.