v3.26.1
S000001112 [Member] Investment Risks - Government Portfolio
Dec. 31, 2025
U S Treasury Obligations Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
U.S. Treasury Obligations Risk. Direct obligations of the U.S. Treasury have historically involved little risk of loss of principal if held to maturity. However, the actual or threatened failure of the U.S. Government to pay its obligations will increase credit risk. In addition, due to fluctuations in market interest rates, the market value of such securities may vary during the period of your investment in the Portfolio In addition, notwithstanding that U.S. Treasury obligations are backed by the full faith and credit of the United States, circumstances could arise that could prevent the timely payment of interest or principal, such as reaching the legislative “debt ceiling.” Such non-payment could result in losses to the Portfolio and substantial negative consequences for the U.S. economy and the global financial system.
U S Government Obligations Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
U.S. Government Obligations Risk. Certain securities in which the Portfolio may invest, including securities issued by certain U.S. Government agencies and U.S. Government sponsored enterprises, are not guaranteed by the U.S. Government or supported by the full faith and credit of the United States. In addition, circumstances could arise that could prevent the timely payment of interest or principal on U.S. Government obligations, such as reaching the legislative “debt ceiling.” Such non-payment could result in losses to the Portfolio and substantial negative consequences for the U.S. economy and the global financial system.
Repurchase Agreement Risk [Member]  
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Risk [Text Block]
Repurchase Agreement Risk. The Portfolio may enter into repurchase agreements. Under a repurchase agreement, the seller agrees to repurchase a security at a mutually agreed-upon time and price. If the seller in a repurchase agreement transaction defaults on its obligation under the agreement, the Portfolio may suffer delays and incur costs or lose money in exercising its rights under the agreement.
Credit Risks [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Credit Risk. Credit risk refers to the possibility that the issuer of a debt security (i.e., the borrower) will be unable or unwilling to make timely payments of interest and principal when due or otherwise honor their obligations. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of the Portfolio’s investment in that issuer.
Forward Commitment When Issued and Delayed Delivery Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Forward Commitment, When-Issued and Delayed Delivery Securities Risk. When-issued and delayed delivery (delayed settlement) securities involve the risk that the security the Portfolio buys will lose value prior to its delivery. There also is the risk that the security will not be issued or that the other party to the transaction will not meet its obligation. If this occurs, the Portfolio may lose both the investment opportunity for the assets it set aside to pay for the security and any gain in the security’s price.
Income Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Income Risk. Income risk is the risk that the Portfolio’s yield will vary as short-term securities in its portfolio mature and the proceeds are reinvested in securities with different interest rates.
Market Risk and Selection Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Market Risk and Selection Risk. Market risk is the risk that one or more markets in which the Portfolio invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. The value of a security or other asset may decline due to changes in general market conditions economic trends or events that are not specifically related to the issuer of the security or other asset, or factors that affect a particular issuer or issuers, exchange, countries, group of countries, regions, market, industry, group of industries, sectors or asset class. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues, like pandemics or epidemics, tariffs, trade wars, inflation, recessions, or other events could have a significant negative impact on the Portfolio and its investments. Selection risk is the risk that the securities selected by the Investment Advisor will underperform the markets, the relevant indices or the securities selected by other funds with similar investment objectives and investment strategies. This means you may lose money.
Risk of Investing in the United States [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Risk of Investing in the United States. Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Portfolio has exposure.
Stable Net Asset Value Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Stable Net Asset Value Risk. The Portfolio may not be able to maintain a stable net asset value (“NAV”) of $1.00 per Participation Certificate at all times. If the Portfolio fails to maintain a stable NAV (or if there is a perceived threat of such a failure), the Portfolio, along with other money market funds, could be subject to increased redemption activity.
Variable and Floating Rate Investment Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Variable and Floating Rate Investment Risk. Variable and floating rate securities provide for periodic adjustment in the interest rate paid on the securities. Securities with floating or variable interest rates can be less sensitive to interest rate changes than securities with fixed interest rates, but may decline in value if their coupon rates do not reset as high, or as quickly, as comparable market interest rates, and generally carry lower yields than fixed securities of the same maturity. These securities will not generally increase in value if interest rates decline. A decline in interest rates may result in a reduction in income received from variable and floating rate securities held by the Portfolio and may adversely affect the value of the Portfolio’s Participation Certificates. Benchmark interest rates may not accurately track market interest rates. Although floating rate securities are less sensitive to interest rate risk than fixed-rate securities, they are subject to credit risk and default risk, which could impair their value.
Interest Rate Risks [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Interest Rate Risk. Interest rate risk is the risk that the value of a debt security held by the Portfolio may fall when market interest rates rise, and that the value of a debt security held by the Portfolio may rise when market interest rates fall. Changing demand for debt securities relative to supply also impact their value, generally decreasing their value when demand decreases and increasing their value when demand increases. In general, the market price of debt securities with longer maturities will go up or down more in response to changes in market interest rates than the market price of shorter-term securities. Securities issued or guaranteed by the U.S. Government, its agencies, instrumentalities, and sponsored enterprises have historically involved little risk of loss of principal if held to maturity. However, due to fluctuations in market interest rates, the market value of such securities may vary during the period Participation Certificate holders own an interest in the Portfolio. Very low or negative market interest rates may magnify interest rate risk. During periods of very low or negative interest rates, the Portfolio may be unable to maintain positive returns or pay dividends. Changing interest rates, including rates that fall below zero, may have unpredictable effects on markets, may result in heightened market volatility and may detract from the Portfolio’s ability to achieve its investment objective.
Risk Lose Money [Member]  
Prospectus [Line Items]  
Risk [Text Block] You could lose money by investing in the Portfolio.
Risk Not Insured Depository Institution [Member]  
Prospectus [Line Items]  
Risk [Text Block] An investment in the Portfolio is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Risk Money Market Fund May Not Preserve Dollar [Member]  
Prospectus [Line Items]  
Risk [Text Block] Although the Portfolio seeks to preserve the value of your investment at $1.00 per Participation Certificate, it cannot guarantee it will do so.
Risk Money Market Fund Sponsor May Not Provide Support [Member]  
Prospectus [Line Items]  
Risk [Text Block] The Portfolio’s sponsor is not required to reimburse the Portfolio for losses, and you should not expect that the sponsor will provide financial support to the Portfolio at any time, including during periods of market stress.