000000 - Document - Document and Entity Information {Elements} link:presentationLink link:calculationLink link:definitionLink 000021 - Disclosure - Risk/Return Detail Data {Elements} - BlackRock U.S. Industry Rotation ETF link:presentationLink link:calculationLink link:definitionLink 000021 - Schedule - Annual Fund Operating Expenses link:calculationLink link:presentationLink link:definitionLink