Nasdaq-100 Index Fund Investment Strategy - Nasdaq-100 Index Fund	May 31, 2026
Prospectus [Line Items]
Strategy [Heading]	<span style="color:#000000;font-family:Arial;font-size:12pt;font-weight:bold;">Principal Investment Strategies of the Fund</span>
Strategy Narrative [Text Block]	The Fund invests in stocks that are included in the Index. The Index represents the largest and most active non-financial domestic and international securities listed on The NASDAQ Stock Market, based on market value (capitalization). This includes major industry groups, such as computer hardware and software, telecommunications, retail and wholesale trade and biotechnology.The Subadviser invests, under normal circumstances, at least 80% of the Fund’s net assets in companies that are listed in the Index. The Fund is managed to seek to track the performance of the Index. The Subadviser may endeavor to track the Index by purchasing every stock included in the Index, in the same proportions; or, in the alternative, the Subadviser may invest in a sampling of Index stocks by utilizing a statistical technique known as “optimization.” The goal of optimization is to select stocks which ensure that various industry weightings, market capitalizations, and fundamental characteristics, (e.g., price-to-book, price-to-earnings, debt-to-asset ratios and dividend yields) closely approximate those of the Index.The subadviser may use derivatives to seek to track the performance of the Index, including futures and total return swaps. The Fund may also invest in some futures contracts in order to help the Fund’s liquidity and to manage its cash position. If the market value of the futures contracts is close to the Fund’s cash balance, then that helps to minimize the tracking errors, while helping to maintain liquidity. The Fund is a non-diversified fund, which means that it will invest in a smaller number of issuers than a diversified fund. The Fund may concentrate its investments (invest more than 25% of its total assets) in the technology sector, in the proportion consistent with the industry weightings in the Index. Although the Fund seeks to track the performance of the Index, the performance of the Fund will not match that of the Index exactly because, among other reasons, the Fund incurs operating expenses and other investment overhead as part of its normal operations. In order to generate additional income, the Fund may lend portfolio securities to broker-dealers and other financial institutions provided that the value of the loaned securities does not exceed 30% of the Fund’s total assets. These loans earn income for the Fund and are collateralized by cash and securities issued or guaranteed by the U.S. Government or its agencies or instrumentalities.

Nasdaq-100 Index Fund Investment Strategy - Nasdaq-100 Index Fund

May 31, 2026

<span style="color:#000000;font-family:Arial;font-size:12pt;font-weight:bold;">Principal Investment Strategies of the Fund</span>

Strategy Narrative [Text Block]

The Fund invests in stocks that are included in the Index. The Index represents the largest and most active non-financial domestic and international securities listed on The NASDAQ Stock Market, based on market value (capitalization). This includes major industry groups, such as computer hardware and software, telecommunications, retail and wholesale trade and biotechnology.The Subadviser invests, under normal circumstances, at least 80% of the Fund’s net assets in companies that are listed in the Index. The Fund is managed to seek to track the performance of the Index. The Subadviser may endeavor to track the Index by purchasing every stock included in the Index, in the same proportions; or, in the alternative, the Subadviser may invest in a sampling of Index stocks by utilizing a statistical technique known as “optimization.” The goal of optimization is to select stocks which ensure that various industry weightings, market capitalizations, and fundamental characteristics, (e.g., price-to-book, price-to-earnings, debt-to-asset ratios and dividend yields) closely approximate those of the Index.The subadviser may use derivatives to seek to track the performance of the Index, including futures and total return swaps. The Fund may also invest in some futures contracts in order to help the Fund’s liquidity and to manage its cash position. If the market value of the futures contracts is close to the Fund’s cash balance, then that helps to minimize the tracking errors, while helping to maintain liquidity. The Fund is a non-diversified fund, which means that it will invest in a smaller number of issuers than a diversified fund. The Fund may concentrate its investments (invest more than 25% of its total assets) in the technology sector, in the proportion consistent with the industry weightings in the Index. Although the Fund seeks to track the performance of the Index, the performance of the Fund will not match that of the Index exactly because, among other reasons, the Fund incurs operating expenses and other investment overhead as part of its normal operations. In order to generate additional income, the Fund may lend portfolio securities to broker-dealers and other financial institutions provided that the value of the loaned securities does not exceed 30% of the Fund’s total assets. These loans earn income for the Fund and are collateralized by cash and securities issued or guaranteed by the U.S. Government or its agencies or instrumentalities.