Investment Strategy	May 28, 2026
ULTRA SHORT DURATION BOND FUND - Class F Prospectus \| SDIT ULTRA SHORT DURATION BOND FUND
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	Under normal circumstances, the Ultra Short Duration Bond Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in investment grade U.S. dollar-denominated debt instruments, including: (i) commercial paper and other corporate obligations; (ii) certificates of deposit, time deposits, bankers' acceptances, bank notes, and other obligations of U.S. savings and loan and thrift institutions, U.S. commercial banks (including foreign branches of such banks) and foreign banks that meet certain asset requirements; (iii) U.S. Treasury obligations and obligations issued or guaranteed as to principal and interest by agencies or instrumentalities of the U.S. Government; (iv) mortgage-backed securities; (v) asset-backed securities; (vi) fully-collateralized repurchase agreements involving any of the foregoing obligations; and (vii) U.S. dollar-denominated instruments of foreign issuers. In addition, the Fund may enter into dollar roll transactions with selected banks and broker-dealers and invest in to-be-announced mortgage-backed securities, futures contracts and forward contracts. The Fund will primarily use futures contracts for hedging purposes to manage the Fund's exposure to interest rate risk. There may also be times when the Fund utilizes futures contracts to take an active position on interest rates to either increase or reduce the interest rate sensitivity of the Fund. Using a top-down strategy and bottom-up security selection, the sub-advisers (each, a Sub-Adviser and collectively, the Sub-Advisers) seek attractively-valued securities that offer competitive yields and that are issued by issuers that are on a sound financial footing. The Sub-Advisers also consider factors such as the anticipated level of interest rates, relative valuations and yield spreads among various sectors, and the duration of the Fund's entire portfolio. Duration measures the price sensitivity of a fixed income security to changes in interest rates. For example, a five-year duration means that the fixed income security will decrease in value by 5% if interest rates rise 1% and increase in value by 5% if interest rates fall 1%. While the Fund may invest in securities with any maturity or duration, the Sub-Advisers will strive to maintain a portfolio duration for the Fund of 18 months or less under normal market conditions.
SHORT DURATION GOVERNMENT FUND - Class F Prospectus \| SDIT SHORT DURATION GOVERNMENT FUND
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	Under normal circumstances, the Short-Duration Government Fund invests substantially all of its net assets in U.S. Treasury obligations and obligations issued or guaranteed as to principal and interest by agencies or instrumentalities of the U.S. Government, including mortgage-backed securities, and repurchase agreements collateralized by such obligations. The Fund may invest in securities issued by various entities sponsored by the U.S. Government, such as the Federal National Mortgage Association and the Federal Home Loan Mortgage Corporation. These issuers are chartered or sponsored by acts of Congress; however, their securities are neither issued nor guaranteed by the U.S. Treasury and are not backed by the full faith and credit of the U.S. Government. In addition, the Fund may enter into dollar roll transactions with selected banks and broker-dealers and invest in to-be-announced mortgage-backed securities, futures contracts and forward contracts. The Fund will primarily use futures contracts for hedging purposes to manage the Fund's exposure to interest rate risk. There may also be times when the Fund utilizes futures contracts to take an active position on interest rates to either increase or reduce the interest rate sensitivity of the Fund. Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks attractively-valued securities that offer competitive yields. The Sub-Adviser also considers factors such as the anticipated level of interest rates, relative valuations and yield spreads, and the duration of the Fund's entire portfolio. Duration measures the price sensitivity of a fixed income security to changes in interest rates. For example, a five year duration means that the fixed income security will decrease in value by 5% if interest rates rise 1% and increase in value by 5% if interest rates fall 1%. While the Fund may invest in securities with any maturity or duration, the Sub-Adviser will strive to maintain a portfolio duration of up to three years under normal market conditions.
GNMA FUND - Class F Prospectus \| SDIT GNMA FUND
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	Under normal circumstances, the GNMA Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in mortgage-backed securities issued by the Government National Mortgage Association (GNMA). The Fund may also invest in U.S. Treasury securities and U.S. Government securities obligations, and repurchase agreements collateralized by such obligations. In addition, the Fund may enter into dollar roll transactions with selected banks and broker-dealers and invest in to-be-announced mortgage-backed securities, futures contracts and forward contracts. The Fund will primarily use futures contracts for hedging purposes to manage the Fund's exposure to interest rate risk. There may also be times when the Fund utilizes futures contracts to take an active position on interest rates to either increase or reduce the interest rate sensitivity of the Fund. Due to its investment strategy, the Fund may buy and sell securities and other instruments frequently. Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks attractively-valued securities that offer competitive yields. The Sub-Adviser also considers factors such as the anticipated level of interest rates, relative valuations and yield spreads, and the duration of the Fund's entire portfolio. Duration measures the price sensitivity of a fixed income security to changes in interest rates. For example, a five year duration means that the fixed income security will decrease in value by 5% if interest rates rise 1% and increase in value by 5% if interest rates fall 1%.
ULTRA SHORT DURATION BOND FUND - Class Y Prospectus \| SDIT ULTRA SHORT DURATION BOND FUND
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	Under normal circumstances, the Ultra Short Duration Bond Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in investment grade U.S. dollar-denominated debt instruments, including: (i) commercial paper and other corporate obligations; (ii) certificates of deposit, time deposits, bankers' acceptances, bank notes, and other obligations of U.S. savings and loan and thrift institutions, U.S. commercial banks (including foreign branches of such banks) and foreign banks that meet certain asset requirements; (iii) U.S. Treasury obligations and obligations issued or guaranteed as to principal and interest by agencies or instrumentalities of the U.S. Government; (iv) mortgage-backed securities; (v) asset-backed securities; (vi) fully-collateralized repurchase agreements involving any of the foregoing obligations; and (vii) U.S. dollar-denominated instruments of foreign issuers. In addition, the Fund may enter into dollar roll transactions with selected banks and broker-dealers and invest in to-be-announced mortgage-backed securities, futures contracts and forward contracts. The Fund will primarily use futures contracts for hedging purposes to manage the Fund's exposure to interest rate risk. There may also be times when the Fund utilizes futures contracts to take an active position on interest rates to either increase or reduce the interest rate sensitivity of the Fund. Using a top-down strategy and bottom-up security selection, the sub-advisers (each, a Sub-Adviser and collectively, the Sub-Advisers) seek attractively-valued securities that offer competitive yields and that are issued by issuers that are on a sound financial footing. The Sub-Advisers also consider factors such as the anticipated level of interest rates, relative valuations and yield spreads among various sectors, and the duration of the Fund's entire portfolio. Duration measures the price sensitivity of a fixed income security to changes in interest rates. For example, a five-year duration means that the fixed income security will decrease in value by 5% if interest rates rise 1% and increase in value by 5% if interest rates fall 1%. While the Fund may invest in securities with any maturity or duration, the Sub-Advisers will strive to maintain a portfolio duration for the Fund of 18 months or less under normal market conditions.
SHORT DURATION GOVERNMENT FUND - Class Y Prospectus \| SDIT SHORT DURATION GOVERNMENT FUND
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	Under normal circumstances, the Short-Duration Government Fund invests substantially all of its net assets in U.S. Treasury obligations and obligations issued or guaranteed as to principal and interest by agencies or instrumentalities of the U.S. Government, including mortgage-backed securities, and repurchase agreements collateralized by such obligations. The Fund may invest in securities issued by various entities sponsored by the U.S. Government, such as the Federal National Mortgage Association and the Federal Home Loan Mortgage Corporation. These issuers are chartered or sponsored by acts of Congress; however, their securities are neither issued nor guaranteed by the U.S. Treasury and are not backed by the full faith and credit of the U.S. Government. In addition, the Fund may enter into dollar roll transactions with selected banks and broker-dealers and invest in to-be-announced mortgage-backed securities, futures contracts and forward contracts. The Fund will primarily use futures contracts for hedging purposes to manage the Fund's exposure to interest rate risk. There may also be times when the Fund utilizes futures contracts to take an active position on interest rates to either increase or reduce the interest rate sensitivity of the Fund. Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks attractively-valued securities that offer competitive yields. The Sub-Adviser also considers factors such as the anticipated level of interest rates, relative valuations and yield spreads, and the duration of the Fund's entire portfolio. Duration measures the price sensitivity of a fixed income security to changes in interest rates. For example, a five year duration means that the fixed income security will decrease in value by 5% if interest rates rise 1% and increase in value by 5% if interest rates fall 1%. While the Fund may invest in securities with any maturity or duration, the Sub-Adviser will strive to maintain a portfolio duration of up to three years under normal market conditions.
GNMA FUND - Class Y Prospectus \| SDIT GNMA FUND
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	Under normal circumstances, the GNMA Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in mortgage-backed securities issued by the Government National Mortgage Association (GNMA). The Fund may also invest in U.S. Treasury securities and U.S. Government securities obligations, and repurchase agreements collateralized by such obligations. In addition, the Fund may enter into dollar roll transactions with selected banks and broker-dealers and invest in to-be-announced mortgage-backed securities, futures contracts and forward contracts. The Fund will primarily use futures contracts for hedging purposes to manage the Fund's exposure to interest rate risk. There may also be times when the Fund utilizes futures contracts to take an active position on interest rates to either increase or reduce the interest rate sensitivity of the Fund. Due to its investment strategy, the Fund may buy and sell securities and other instruments frequently. Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks attractively-valued securities that offer competitive yields. The Sub-Adviser also considers factors such as the anticipated level of interest rates, relative valuations and yield spreads, and the duration of the Fund's entire portfolio. Duration measures the price sensitivity of a fixed income security to changes in interest rates. For example, a five year duration means that the fixed income security will decrease in value by 5% if interest rates rise 1% and increase in value by 5% if interest rates fall 1%.
GOVERNMENT II FUND - Class F Prospectus \| SDIT GOVERNMENT II FUND
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	Under normal market conditions, the Fund intends to invest at least 99.5% of its total assets in cash and government securities. Government securities are obligations issued or guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities, including obligations issued by private issuers that are guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities. Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks to invest in securities with a remaining maturity not greater than 397 calendar days that are marketable, liquid and offer competitive yields, and which are expected to result in the Fund's portfolio having an average dollar-weighted maturity of 60 days or less and a dollar-weighted average life to maturity of 120 days or less. In making investment decisions, the Sub-Adviser also considers factors such as the anticipated level of interest rates and the maturity of individual securities relative to the maturity of the Fund as a whole. Currently, the Fund invests only in first-tier securities. The Fund values its securities using amortized cost and seeks to maintain a stable net asset value (NAV) of $1.00 per share.
TREASURY II FUND - Class F Prospectus \| SDIT TREASURY II FUND
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	Under normal market conditions, the Fund invests exclusively in U.S. Treasury obligations. Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks to invest in securities with a remaining maturity not greater than 397 calendar days that are marketable, liquid and offer competitive yields, and which are expected to result in the Fund's portfolio having an average dollar-weighted maturity of 60 days or less and a dollar-weighted average life to maturity of 120 days or less. In making investment decisions, the Sub-Adviser also considers factors such as the anticipated level of interest rates and the maturity of individual securities relative to the maturity of the Fund as a whole. Currently, the Fund invests only in first-tier securities.
GOVERNMENT FUND - Admin Class Shares Prospectus \| SDIT GOVERNMENT FUND
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	Under normal market conditions, the Fund intends to invest at least 99.5% of its total assets in cash, government securities and/or repurchase agreements that are collateralized fully with cash or government securities. Government securities are obligations issued or guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities, including obligations issued by private issuers that are guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities. Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks to invest in securities with a remaining maturity not greater than 397 calendar days that are marketable, liquid and offer competitive yields, and which are expected to result in the Fund's portfolio having an average dollar-weighted maturity of 60 days or less and a dollar-weighted average life to maturity of 120 days or less. In making investment decisions, the Sub-Adviser also considers factors such as the anticipated level of interest rates and the maturity of individual securities relative to the maturity of the Fund as a whole. Currently, the Fund invests only in first-tier securities. The Fund values its securities using amortized cost and seeks to maintain a stable net asset value (NAV) of $1.00 per share.
GOVERNMENT FUND - Wealth Class Shares Prospectus \| SDIT GOVERNMENT FUND
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	Under normal market conditions, the Fund intends to invest at least 99.5% of its total assets in cash, government securities and/or repurchase agreements that are collateralized fully with cash or government securities. Government securities are obligations issued or guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities, including obligations issued by private issuers that are guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities. Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks to invest in securities with a remaining maturity not greater than 397 calendar days that are marketable, liquid and offer competitive yields, and which are expected to result in the Fund's portfolio having an average dollar-weighted maturity of 60 days or less and a dollar-weighted average life to maturity of 120 days or less. In making investment decisions, the Sub-Adviser also considers factors such as the anticipated level of interest rates and the maturity of individual securities relative to the maturity of the Fund as a whole. Currently, the Fund invests only in first-tier securities. The Fund values its securities using amortized cost and seeks to maintain a stable net asset value (NAV) of $1.00 per share.
GOVERNMENT FUND - Institutional Shares Prospectus \| SDIT GOVERNMENT FUND
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	Under normal market conditions, the Fund intends to invest at least 99.5% of its total assets in cash, government securities and/or repurchase agreements that are collateralized fully with cash or government securities. Government securities are obligations issued or guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities, including obligations issued by private issuers that are guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities. Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks to invest in securities with a remaining maturity not greater than 397 calendar days that are marketable, liquid and offer competitive yields, and which are expected to result in the Fund's portfolio having an average dollar-weighted maturity of 60 days or less and a dollar-weighted average life to maturity of 120 days or less. In making investment decisions, the Sub-Adviser also considers factors such as the anticipated level of interest rates and the maturity of individual securities relative to the maturity of the Fund as a whole. Currently, the Fund invests only in first-tier securities. The Fund values its securities using amortized cost and seeks to maintain a stable net asset value (NAV) of $1.00 per share.

Under normal circumstances, the Ultra Short Duration Bond Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in investment grade U.S. dollar-denominated debt instruments, including: (i) commercial paper and other corporate obligations; (ii) certificates of deposit, time deposits, bankers' acceptances, bank notes, and other obligations of U.S. savings and loan and thrift institutions, U.S. commercial banks (including foreign branches of such banks) and foreign banks that meet

certain asset requirements; (iii) U.S. Treasury obligations and obligations issued or guaranteed as to principal and interest by agencies or instrumentalities of the U.S. Government; (iv) mortgage-backed securities; (v) asset-backed securities; (vi) fully-collateralized repurchase agreements involving any of the foregoing obligations; and (vii) U.S. dollar-denominated instruments of foreign issuers. In addition, the Fund may enter into dollar roll transactions with selected banks and broker-dealers and invest in to-be-announced mortgage-backed securities, futures contracts and forward contracts. The Fund will primarily use futures contracts for hedging purposes to manage the Fund's exposure to interest rate risk. There may also be times when the Fund utilizes futures contracts to take an active position on interest rates to either increase or reduce the interest rate sensitivity of the Fund.

Using a top-down strategy and bottom-up security selection, the sub-advisers (each, a Sub-Adviser and collectively, the Sub-Advisers) seek attractively-valued securities that offer competitive yields and that are issued by issuers that are on a sound financial footing. The Sub-Advisers also consider factors such as the anticipated level of interest rates, relative valuations and yield spreads among various sectors, and the duration of the Fund's entire portfolio. Duration measures the price sensitivity of a fixed income security to changes in interest rates. For example, a five-year duration means that the fixed income security will decrease in value by 5% if interest rates rise 1% and increase in value by 5% if interest rates fall 1%. While the Fund may invest in securities with any maturity or duration, the Sub-Advisers will strive to maintain a portfolio duration for the Fund of 18 months or less under normal market conditions.

Prospectus [Line Items]

Strategy Narrative [Text Block]

Under normal circumstances, the Short-Duration Government Fund invests substantially all of its net assets in U.S. Treasury obligations and obligations issued or guaranteed as to principal and interest by agencies or instrumentalities of the U.S. Government, including mortgage-backed securities, and repurchase agreements collateralized by such obligations. The Fund may invest in securities issued by various entities sponsored by the U.S. Government, such as the Federal National Mortgage Association and the Federal Home Loan Mortgage Corporation. These issuers are chartered or sponsored by acts of Congress; however, their

securities are neither issued nor guaranteed by the U.S. Treasury and are not backed by the full faith and credit of the U.S. Government. In addition, the Fund may enter into dollar roll transactions with selected banks and broker-dealers and invest in to-be-announced mortgage-backed securities, futures contracts and forward contracts. The Fund will primarily use futures contracts for hedging purposes to manage the Fund's exposure to interest rate risk. There may also be times when the Fund utilizes futures contracts to take an active position on interest rates to either increase or reduce the interest rate sensitivity of the Fund.

Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks attractively-valued securities that offer competitive yields. The Sub-Adviser also considers factors such as the anticipated level of interest rates, relative valuations and yield spreads, and the duration of the Fund's entire portfolio. Duration measures the price sensitivity of a fixed income security to changes in interest rates. For example, a five year duration means that the fixed income security will decrease in value by 5% if interest rates rise 1% and increase in value by 5% if interest rates fall 1%. While the Fund may invest in securities with any maturity or duration, the Sub-Adviser will strive to maintain a portfolio duration of up to three years under normal market conditions.

Prospectus [Line Items]

Strategy Narrative [Text Block]

Under normal circumstances, the GNMA Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in mortgage-backed securities issued by the Government National Mortgage Association (GNMA). The Fund may also invest in U.S. Treasury securities and U.S. Government securities obligations, and repurchase agreements collateralized by such obligations. In addition, the Fund may enter into dollar roll transactions with selected banks and broker-dealers and invest in to-be-announced mortgage-backed securities, futures contracts and forward contracts. The Fund will primarily use futures

contracts for hedging purposes to manage the Fund's exposure to interest rate risk. There may also be times when the Fund utilizes futures contracts to take an active position on interest rates to either increase or reduce the interest rate sensitivity of the Fund. Due to its investment strategy, the Fund may buy and sell securities and other instruments frequently.

Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks attractively-valued securities that offer competitive yields. The Sub-Adviser also considers factors such as the anticipated level of interest rates, relative valuations and yield spreads, and the duration of the Fund's entire portfolio. Duration measures the price sensitivity of a fixed income security to changes in interest rates. For example, a five year duration means that the fixed income security will decrease in value by 5% if interest rates rise 1% and increase in value by 5% if interest rates fall 1%.

Prospectus [Line Items]

Strategy Narrative [Text Block]

Under normal circumstances, the Ultra Short Duration Bond Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in investment grade U.S. dollar-denominated debt instruments, including: (i) commercial paper and other corporate obligations; (ii) certificates of deposit, time deposits, bankers' acceptances, bank notes, and other obligations of U.S. savings and loan and thrift

institutions, U.S. commercial banks (including foreign branches of such banks) and foreign banks that meet certain asset requirements; (iii) U.S. Treasury obligations and obligations issued or guaranteed as to principal and interest by agencies or instrumentalities of the U.S. Government; (iv) mortgage-backed securities; (v) asset-backed securities; (vi) fully-collateralized repurchase agreements involving any of the foregoing obligations; and (vii) U.S. dollar-denominated instruments of foreign issuers. In addition, the Fund may enter into dollar roll transactions with selected banks and broker-dealers and invest in to-be-announced mortgage-backed securities, futures contracts and forward contracts. The Fund will primarily use futures contracts for hedging purposes to manage the Fund's exposure to interest rate risk. There may also be times when the Fund utilizes futures contracts to take an active position on interest rates to either increase or reduce the interest rate sensitivity of the Fund.

Using a top-down strategy and bottom-up security selection, the sub-advisers (each, a Sub-Adviser and collectively, the Sub-Advisers) seek attractively-valued securities that offer competitive yields and that are issued by issuers that are on a sound financial footing. The Sub-Advisers also consider factors such as the anticipated level of interest rates, relative valuations and yield spreads among various sectors, and the duration of the Fund's entire portfolio. Duration measures the price sensitivity of a fixed income security to changes in interest rates. For example, a five-year duration means that the fixed income security will decrease in value by 5% if interest rates rise 1% and increase in value by 5% if interest rates fall 1%. While the Fund may invest in securities with any maturity or duration, the Sub-Advisers will strive to maintain a portfolio duration for the Fund of 18 months or less under normal market conditions.

Prospectus [Line Items]

Strategy Narrative [Text Block]

Under normal circumstances, the Short-Duration Government Fund invests substantially all of its net assets in U.S. Treasury obligations and obligations issued or guaranteed as to principal and interest by agencies or instrumentalities of the U.S. Government, including mortgage-backed securities, and repurchase agreements collateralized by such obligations. The Fund may invest in securities issued by various entities sponsored by the U.S. Government, such as the Federal National Mortgage Association and the Federal Home Loan

Mortgage Corporation. These issuers are chartered or sponsored by acts of Congress; however, their securities are neither issued nor guaranteed by the U.S. Treasury and are not backed by the full faith and credit of the U.S. Government. In addition, the Fund may enter into dollar roll transactions with selected banks and broker-dealers and invest in to-be-announced mortgage-backed securities, futures contracts and forward contracts. The Fund will primarily use futures contracts for hedging purposes to manage the Fund's exposure to interest rate risk. There may also be times when the Fund utilizes futures contracts to take an active position on interest rates to either increase or reduce the interest rate sensitivity of the Fund.

Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks attractively-valued securities that offer competitive yields. The Sub-Adviser also considers factors such as the anticipated level of interest rates, relative valuations and yield spreads, and the duration of the Fund's entire portfolio. Duration measures the price sensitivity of a fixed income security to changes in interest rates. For example, a five year duration means that the fixed income security will decrease in value by 5% if interest rates rise 1% and increase in value by 5% if interest rates fall 1%. While the Fund may invest in securities with any maturity or duration, the Sub-Adviser will strive to maintain a portfolio duration of up to three years under normal market conditions.

Prospectus [Line Items]

Strategy Narrative [Text Block]

Under normal circumstances, the GNMA Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in mortgage-backed securities issued by the Government National Mortgage Association (GNMA). The Fund may also invest in U.S. Treasury securities and U.S. Government securities obligations, and repurchase agreements collateralized by such obligations. In addition, the Fund may enter into dollar roll transactions with selected banks and broker-dealers and invest in to-be-announced

mortgage-backed securities, futures contracts and forward contracts. The Fund will primarily use futures contracts for hedging purposes to manage the Fund's exposure to interest rate risk. There may also be times when the Fund utilizes futures contracts to take an active position on interest rates to either increase or reduce the interest rate sensitivity of the Fund. Due to its investment strategy, the Fund may buy and sell securities and other instruments frequently.

Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks attractively-valued securities that offer competitive yields. The Sub-Adviser also considers factors such as the anticipated level of interest rates, relative valuations and yield spreads, and the duration of the Fund's entire portfolio. Duration measures the price sensitivity of a fixed income security to changes in interest rates. For example, a five year duration means that the fixed income security will decrease in value by 5% if interest rates rise 1% and increase in value by 5% if interest rates fall 1%.

Prospectus [Line Items]

Strategy Narrative [Text Block]

Under normal market conditions, the Fund intends to invest at least 99.5% of its total assets in cash and government securities. Government securities are obligations issued or guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities, including obligations issued by private issuers that are guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities.

Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks to invest in securities with a remaining maturity not greater than 397 calendar days that are marketable, liquid and offer competitive yields, and which are expected to result in the Fund's portfolio having an average dollar-weighted maturity of 60 days or less and a dollar-weighted average life to maturity of 120 days or less. In making investment decisions, the Sub-Adviser also considers factors such as the anticipated level of interest rates and the maturity of individual securities relative to the maturity of the Fund as a whole. Currently, the Fund invests only in first-tier securities.

The Fund values its securities using amortized cost and seeks to maintain a stable net asset value (NAV) of $1.00 per share.

Prospectus [Line Items]

Strategy Narrative [Text Block]

Under normal market conditions, the Fund invests exclusively in U.S. Treasury obligations.

Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks to invest in securities with a remaining maturity not greater than 397 calendar days that are marketable, liquid

and offer competitive yields, and which are expected to result in the Fund's portfolio having an average dollar-weighted maturity of 60 days or less and a dollar-weighted average life to maturity of 120 days or less. In making investment decisions, the Sub-Adviser also considers factors such as the anticipated level of interest rates and the maturity of individual securities relative to the maturity of the Fund as a whole. Currently, the Fund invests only in first-tier securities.

Prospectus [Line Items]

Strategy Narrative [Text Block]

Under normal market conditions, the Fund intends to invest at least 99.5% of its total assets in cash, government securities and/or repurchase agreements that are collateralized fully with cash or government securities. Government securities are obligations issued or guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities, including obligations issued by private issuers that are guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities.

Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks to invest in securities with a remaining maturity not greater than 397 calendar days that are marketable, liquid and offer competitive yields, and which are expected to result in the Fund's portfolio having an average dollar-weighted maturity of 60 days or less and a dollar-weighted average life to maturity of 120 days or less. In making investment decisions, the Sub-Adviser also considers factors such as the anticipated level of interest rates and the maturity of individual securities relative to the maturity of the Fund as a whole. Currently, the Fund invests only in first-tier securities.

The Fund values its securities using amortized cost and seeks to maintain a stable net asset value (NAV) of $1.00 per share.

Prospectus [Line Items]

Strategy Narrative [Text Block]

Under normal market conditions, the Fund intends to invest at least 99.5% of its total assets in cash, government securities and/or repurchase agreements that are collateralized fully with cash or government securities. Government securities are obligations issued or guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities, including obligations issued by private issuers that are guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities.

Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks to invest in securities with a remaining maturity not greater than 397 calendar days that are marketable, liquid and offer competitive yields, and which are expected to result in the Fund's portfolio having an average dollar-weighted maturity of 60 days or less and a dollar-weighted average life to maturity of 120 days or less. In making investment decisions, the Sub-Adviser also considers factors such as the anticipated level of interest rates and the maturity of individual securities relative to the maturity of the Fund as a whole. Currently, the Fund invests only in first-tier securities.

The Fund values its securities using amortized cost and seeks to maintain a stable net asset value (NAV) of $1.00 per share.

Prospectus [Line Items]

Strategy Narrative [Text Block]

Under normal market conditions, the Fund intends to invest at least 99.5% of its total assets in cash, government securities and/or repurchase agreements that are collateralized fully with cash or government securities. Government securities are obligations issued or guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities, including obligations issued by private issuers that are guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities.

Using a top-down strategy and bottom-up security selection, the sub-adviser (the Sub-Adviser) seeks to invest in securities with a remaining maturity not greater than 397 calendar days that are marketable, liquid and offer competitive yields, and which are expected to result in the Fund's portfolio having an average dollar-weighted maturity of 60 days or less and a dollar-weighted average life to maturity of 120 days or less. In making investment decisions, the Sub-Adviser also considers factors such as the anticipated level of interest rates and the maturity of individual securities relative to the maturity of the Fund as a whole. Currently, the Fund invests only in first-tier securities.

The Fund values its securities using amortized cost and seeks to maintain a stable net asset value (NAV) of $1.00 per share.