Core Bond Fund Investment Risks - Core Bond Fund	May 31, 2026
Management Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Management Risk. The investment style or strategy used by the Fund may fail to produce the intended result. A subadviser’s assessment of a particular security or company may prove incorrect, resulting in losses or underperformance.
Active Trading Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Active Trading Risk. High portfolio turnover rates that are associated with active trading may result in higher transaction costs, which can adversely affect the Fund’s performance. Active trading tends to be more pronounced during periods of increased market volatility.
US Government Obligations Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	U.S. Government Obligations Risk. U.S. Treasury obligations are backed by the “full faith and credit” of the U.S. Government and are generally considered to have low credit risk. Unlike U.S. Treasury obligations, securities issued or guaranteed by federal agencies or authorities and U.S. Government-sponsored instrumentalities or enterprises, including FNMA and FHLMC, may or may not be backed by the full faith and credit of the U.S. Government and are therefore subject to greater credit risk than securities issued or guaranteed by the U.S. Treasury.
Mortgage Backed Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Mortgage-Backed Securities Risk. Mortgage-backed securities are similar to other debt securities in that they are subject to credit risk and interest rate risk. Mortgage-backed securities may be issued or guaranteed by the U.S. Government, its agencies or instrumentalities or may be non‑guaranteed securities issued by private issuers. These securities are also subject to the risk that issuers will prepay the principal more quickly or more slowly than expected, which could cause the Fund to invest the proceeds in less attractive investments or increase the volatility of their prices. CMOs, which are a type of mortgage-backed security, may be less liquid and may exhibit greater price volatility than other types of mortgage-and asset-backed securities. “Subprime” mortgages are subject to certain other risks, including prepayment and call risks. The risk of default, for “sub‑prime” mortgages is also generally higher than other types of mortgage-backed securities. The structure of some of these securities may be complex and there may be less available information than other types of debt securities.
Asset Backed Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Asset-Backed Securities Risk. Asset-backed securities are bonds or notes that are normally supported by a specific property. If the issuer fails to pay the interest or return the principal when the bond matures, then the issuer must give the property to the bondholders or noteholders; however, the assets backing these securities may be insufficient to support the payments on the securities. Examples of assets supporting asset-backed securities include credit card receivables, retail installment loans, home equity loans, auto loans, and manufactured housing loans. Certain asset-backed securities are issued by private parties rather than the U.S. Government or its agencies or government-sponsored entities.
Credit Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Credit Risk. The Fund may suffer losses if the issuer of a fixed-income security owned by the Fund is unable to make interest or principal payments.
Call or Prepayment Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Call or Prepayment Risk. During periods of falling interest rates, a bond issuer may “call” a bond to repay it before its maturity date. The Fund may only be able to invest the bond’s proceeds at lower interest rates, resulting in a decline in the Fund’s income.
Interest Rate Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Interest Rate Risk. Fixed income securities may be subject to volatility due to changes in interest rates. The value of fixed-income securities may decline when interest rates go up or increase when interest rates go down. The interest earned on fixed-income securities may decline when interest rates go down or increase when interest rates go up. Duration is a measure of interest rate risk that indicates how price-sensitive a bond is to changes in interest rates. Longer-term and lower coupon bonds tend to be more sensitive to changes in interest rates. For example, a bond with a duration of three years will decrease in value by approximately 3% if interest rates increase by 1%. Changing interest rates may have unpredictable effects on markets, may result in heightened market volatility, and could negatively impact the Fund’s performance. Any future changes in monetary policy made by central banks and/or their governments are likely to affect the level of interest rates.
Foreign Investment Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Foreign Investment Risk. Investment in foreign securities involves risks due to several factors, such as illiquidity, the lack of public information, changes in the exchange rates between foreign currencies and the U.S. dollar, unfavorable political, social and legal developments, or economic and financial instability. Foreign companies are not subject to the U.S. accounting and financial reporting standards and may have riskier settlement procedures. U.S. investments that are denominated in foreign currencies or that are traded in foreign markets, or securities of U.S. companies that have significant foreign operations may be subject to foreign investment risk.
Emerging Markets Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Emerging Markets Risk. In addition to the risks associated with investments in foreign securities, emerging market securities are subject to additional risks, which cause these securities generally to be more volatile than securities of issuers located in developed countries.
Currency Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Currency Risk. Because the Fund’s foreign investments are generally held in foreign currencies, the Fund could experience gains or losses based solely on changes in the exchange rate between foreign currencies and the U.S. dollar. Such gains or losses may be substantial.
Junk Bonds Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Junk Bond Risk. High yielding, high risk fixed-income securities (often referred to as “junk bonds”) may involve significantly greater credit risk, market risk and interest rate risk compared to higher rated fixed-income securities. Issuers of junk bonds are less secure financially and their securities are more sensitive to downturns in the economy. The market for junk bonds may not be as liquid as that for more highly rated securities.
Market Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Market Risk. The Fund’s share price can fall because of weakness in the broad market, a particular industry, or specific holdings or due to adverse social, political or economic developments here or abroad, changes in investor psychology, technological disruptions, or heavy institutional selling and other conditions or events (including, for example, military confrontations, war, terrorism, trade wars, disease/virus outbreaks and epidemics). The prices of individual securities may fluctuate, sometimes dramatically, from day to day. The prices of stocks and other equity securities tend to be more volatile than those of fixed-income securities.
Securities Lending Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Securities Lending Risk. Engaging in securities lending could increase the market and credit risk for Fund investments. The Fund may lose money if it does not recover borrowed securities, the value of the collateral falls, or the value of investments made with cash collateral declines. The Fund’s loans will be collateralized by securities issued or guaranteed by the U.S. Government or its agencies and instrumentalities, which subjects the Fund to the credit risk of the U.S. Government or the issuing federal agency or instrumentality. If the value of either the cash collateral or the Fund’s investments of the cash collateral falls below the amount owed to a borrower, the Fund also may incur losses that exceed the amount it earned on lending the security. Securities lending also involves the risks of delay in receiving additional collateral or possible loss of rights in the collateral if the borrower fails. Another risk of securities lending is the risk that the loaned portfolio securities may not be available to the Fund on a timely basis and the Fund may therefore lose the opportunity to sell the securities at a desirable price.
Risk Lose Money [Member]
Prospectus [Line Items]
Risk [Text Block]	If the value of the assets of the Fund goes down, you could lose money.
Risk Not Insured Depository Institution [Member]
Prospectus [Line Items]
Risk [Text Block]	Shares of the Fund are not bank deposits and are not guaranteed or insured by any bank, government entity or the Federal Deposit Insurance Corporation.

Core Bond Fund Investment Risks - Core Bond Fund

May 31, 2026

Management Risk. The investment style or strategy used by the Fund may fail to produce the intended result. A subadviser’s assessment of a particular security or company may prove incorrect, resulting in losses or underperformance.

Prospectus [Line Items]

Risk [Text Block]

Active Trading Risk. High portfolio turnover rates that are associated with active trading may result in higher transaction costs, which can adversely affect the Fund’s performance. Active trading tends to be more pronounced during periods of increased market volatility.

US Government Obligations Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

U.S. Government Obligations Risk. U.S. Treasury obligations are backed by the “full faith and credit” of the U.S. Government and are generally considered to have low credit risk. Unlike U.S. Treasury obligations, securities issued or guaranteed by federal agencies or authorities and U.S. Government-sponsored instrumentalities or enterprises, including FNMA and FHLMC, may or may not be backed by the full faith and credit of the U.S. Government and are therefore subject to greater credit risk than securities issued or guaranteed by the U.S. Treasury.

Mortgage Backed Securities Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

Mortgage-Backed Securities Risk. Mortgage-backed securities are similar to other debt securities in that they are subject to credit risk and interest rate risk. Mortgage-backed securities may be issued or guaranteed by the U.S. Government, its agencies or instrumentalities or may be non‑guaranteed securities issued by private issuers. These securities are also subject to the risk that issuers will prepay the principal more quickly or more slowly than expected, which could cause the Fund to invest the proceeds in less attractive investments or increase the volatility of their prices. CMOs, which are a type of mortgage-backed security, may be less liquid and may exhibit greater price volatility than other types of mortgage-and asset-backed securities. “Subprime” mortgages are subject to certain other risks, including prepayment and call risks. The risk of default, for “sub‑prime” mortgages is also generally higher than other types of mortgage-backed securities. The structure of some of these securities may be complex and there may be less available information than other types of debt securities.

Asset Backed Securities Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

Asset-Backed Securities Risk. Asset-backed securities are bonds or notes that are normally supported by a specific property. If the issuer fails to pay the interest or return the principal when the bond matures, then the issuer must give the property to the bondholders or noteholders; however, the assets backing these securities may be insufficient to support the payments on the securities. Examples of assets supporting asset-backed securities include credit card receivables, retail installment loans, home equity loans, auto loans, and manufactured housing loans. Certain asset-backed securities are issued by private parties rather than the U.S. Government or its agencies or government-sponsored entities.

Credit Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

Credit Risk. The Fund may suffer losses if the issuer of a fixed-income security owned by the Fund is unable to make interest or principal payments.

Call or Prepayment Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

Call or Prepayment Risk. During periods of falling interest rates, a bond issuer may “call” a bond to repay it before its maturity date. The Fund may only be able to invest the bond’s proceeds at lower interest rates, resulting in a decline in the Fund’s income.

Interest Rate Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

Interest Rate Risk. Fixed income securities may be subject to volatility due to changes in interest rates. The value of fixed-income securities may decline when interest rates go up or increase when interest rates go down. The interest earned on fixed-income securities may decline when interest rates go down or increase when interest rates go up. Duration is a measure of interest rate risk that indicates how price-sensitive a bond is to changes in interest rates. Longer-term and lower coupon bonds tend to be more sensitive to changes in interest rates. For example, a bond with a duration of three years will decrease in value by approximately 3% if interest rates increase by 1%. Changing interest rates may have unpredictable effects on markets, may result in heightened market volatility, and could negatively impact the Fund’s performance. Any future changes in monetary policy made by central banks and/or their governments are likely to affect the level of interest rates.

Foreign Investment Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

Foreign Investment Risk. Investment in foreign securities involves risks due to several factors, such as illiquidity, the lack of public information, changes in the exchange rates between foreign currencies and the U.S. dollar, unfavorable political, social and legal developments, or economic and financial instability. Foreign companies are not subject to the U.S. accounting and financial reporting standards and may have riskier settlement procedures. U.S. investments that are denominated in foreign currencies or that are traded in foreign markets, or securities of U.S. companies that have significant foreign operations may be subject to foreign investment risk.

Emerging Markets Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

Emerging Markets Risk. In addition to the risks associated with investments in foreign securities, emerging market securities are subject to additional risks, which cause these securities generally to be more volatile than securities of issuers located in developed countries.

Currency Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

Currency Risk. Because the Fund’s foreign investments are generally held in foreign currencies, the Fund could experience gains or losses based solely on changes in the exchange rate between foreign currencies and the U.S. dollar. Such gains or losses may be substantial.

Junk Bonds Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

Junk Bond Risk. High yielding, high risk fixed-income securities (often referred to as “junk bonds”) may involve significantly greater credit risk, market risk and interest rate risk compared to higher rated fixed-income securities. Issuers of junk bonds are less secure financially and their securities are more sensitive to downturns in the economy. The market for junk bonds may not be as liquid as that for more highly rated securities.

Market Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

Market Risk. The Fund’s share price can fall because of weakness in the broad market, a particular industry, or specific holdings or due to adverse social, political or economic developments here or abroad, changes in investor psychology, technological disruptions, or heavy institutional selling and other conditions or events (including, for example, military confrontations, war, terrorism, trade wars, disease/virus outbreaks and epidemics). The prices of individual securities may fluctuate, sometimes dramatically, from day to day. The prices of stocks and other equity securities tend to be more volatile than those of fixed-income securities.

Securities Lending Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

Securities Lending Risk. Engaging in securities lending could increase the market and credit risk for Fund investments. The Fund may lose money if it does not recover borrowed securities, the value of the collateral falls, or the value of investments made with cash collateral declines. The Fund’s loans will be collateralized by securities issued or guaranteed by the U.S. Government or its agencies and instrumentalities, which subjects the Fund to the credit risk of the U.S. Government or the issuing federal agency or instrumentality. If the value of either the cash collateral or the Fund’s investments of the cash collateral falls below the amount owed to a borrower, the Fund also may incur losses that exceed the amount it earned on lending the security. Securities lending also involves the risks of delay in receiving additional collateral or possible loss of rights in the collateral if the borrower fails. Another risk of securities lending is the risk that the loaned portfolio securities may not be available to the Fund on a timely basis and the Fund may therefore lose the opportunity to sell the securities at a desirable price.

Risk Lose Money [Member]

Prospectus [Line Items]

Risk [Text Block]

If the value of the assets of the Fund goes down, you could lose money.

Risk Not Insured Depository Institution [Member]

Prospectus [Line Items]

Risk [Text Block]

Shares of the Fund are not bank deposits and are not guaranteed or insured by any bank, government entity or the Federal Deposit Insurance Corporation.