Mid Cap Index Trust Investment Objectives and Goals - Mid Cap Index Trust	Dec. 31, 2025
Prospectus [Line Items]
Risk/Return [Heading]	<span style="color:#000000;font-family:Arial Narrow;font-size:24pt;">Mid Cap Index Trust</span>
Objective [Heading]	<span style="color:#000000;font-family:Arial Narrow;font-size:10pt;font-weight:bold;">Investment objective</span>
Objective, Primary [Text Block]	Seeks to approximate the aggregate total return of a mid cap U.S. domestic equity market index.