Small Cap Index Trust Investment Strategy - Small Cap Index Trust	Dec. 31, 2025
Prospectus [Line Items]
Strategy [Heading]	<span style="color:#000000;font-family:Arial Narrow;font-size:10pt;font-weight:bold;">Principal investment strategies</span>
Strategy Narrative [Text Block]	Under normal market conditions, the fund invests at least 80% of its net assets (plus any borrowings for investment purposes) at the time of investment in: (a) the common stocks that are included in the Russell 2000 Index; and (b) securities (which may or may not be included in the Russell 2000 Index) that the subadvisor believes as a group will behave in a manner similar to the index. (The fund will provide written notice to shareholders at least 60 days prior to a change in its 80% investment policy.) As of February 28, 2026, the market capitalizations of companies included in the Russell 2000 Index ranged from $33.9 million to $47.2 billion. An index is an unmanaged group of securities whose overall performance is used as an investment benchmark. Indexes may track broad investment markets, such as the global equity market, or more narrow investment markets, such as the U.S. small cap equity market. In contrast to actively managed funds, which seek to outperform their respective benchmark indexes through research and analysis, index funds are passively managed funds that seek to mirror the performance of their target indexes, minimizing performance differences over time. The fund attempts to track the performance of the Russell 2000 Index by: (a) holding all, or a representative sample, of the securities that comprise that index; and/or (b) by holding securities (which may or may not be included in the index) that the subadvisor believes as a group will behave in a manner similar to the index. However, the fund has operating expenses and transaction costs, while a market index does not. Therefore, the fund, while it attempts to track its target index closely, typically will be unable to match the performance of the target index exactly. The composition of an index changes from time to time, and the subadvisor will reflect those changes in the composition of the fund’s portfolio as soon as practicable.

Small Cap Index Trust Investment Strategy - Small Cap Index Trust

Dec. 31, 2025

<span style="color:#000000;font-family:Arial Narrow;font-size:10pt;font-weight:bold;">Principal investment strategies</span>

Strategy Narrative [Text Block]

Under normal market conditions, the fund invests at least 80% of its net assets (plus any borrowings for investment purposes) at the time of investment in: (a) the common stocks that are included in the Russell 2000 Index; and (b) securities (which may or may not be included in the Russell 2000 Index) that the subadvisor believes as a group will behave in a manner similar to the index. (The fund will provide written notice to shareholders at least 60 days prior to a change in its 80% investment policy.) As of February 28, 2026, the market capitalizations of companies included in the Russell 2000 Index ranged from $33.9 million to $47.2 billion. An index is an unmanaged group of securities whose overall performance is used as an investment benchmark. Indexes may track broad investment markets, such as the global equity market, or more narrow investment markets, such as the U.S. small cap equity market. In contrast to actively managed funds, which seek to outperform their respective benchmark indexes through research and analysis, index funds are passively managed funds that seek to mirror the performance of their target indexes, minimizing performance differences over time. The fund attempts to track the performance of the Russell 2000 Index by: (a) holding all, or a representative sample, of the securities that comprise that index; and/or (b) by holding securities (which may or may not be included in the index) that the subadvisor believes as a group will behave in a manner similar to the index. However, the fund has operating expenses and transaction costs, while a market index does not. Therefore, the fund, while it attempts to track its target index closely, typically will be unable to match the performance of the target index exactly. The composition of an index changes from time to time, and the subadvisor will reflect those changes in the composition of the fund’s portfolio as soon as practicable.