Vanguard Short-Term Federal Fund Investment Risks - Retail Prospectus [Member] - Vanguard Short-Term Federal Fund	Jan. 31, 2026
General Market Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• General Market Risk. The markets in which the Fund invests can be affected by a variety of factors. These factors, which can be real or perceived, may include economic, market, political, and regulatory conditions and developments as well as local, regional, or global events such as wars, military conflicts, natural disasters, and public health issues. In addition, investor sentiment and expectations regarding these factors can also impact the markets. Different parts of the market, including different industries and sectors as well as different types of securities, may react differently to factors that affect the market. These factors can contribute to market uncertainty, market volatility, and fluctuations in the value of the Fund’s investments, thereby resulting in potential losses to the Fund over short or long periods.
Investing in Bond Markets Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Investing in Bond Markets. The Fund may be impacted by the general condition of the bond markets and by factors that affect bonds and bond issuers. For example, as a general rule, bond prices and interest rates move in opposite directions. When interest rates rise, bond prices tend to fall, and when interest rates fall, bond prices tend to go up. Bond income also is affected by changes in interest rates. Interest rates can rise or fall for a number of reasons, including, but not limited to, central bank monetary policy, inflationary or deflationary pressures, and changes in general market and economic conditions. Changing interest rates, including, but not limited to, rates that fall below zero, could have unpredictable effects on the overall market and may expose the bond markets in particular to heightened volatility and potential illiquidity. The degree to which the Fund is impacted by certain bond market risks may vary based on factors disclosed in its principal investment strategies, such as the types of bonds in which it invests and the overall credit quality, average maturity, and/or average duration of its bond holdings.
Interest Rate Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Interest Rate Risk. During periods of rising interest rates, bond prices overall may decline, which could result in a decline in the Fund’s value. The prices of longer-term bonds are more sensitive to changes in interest rates than the prices of shorter-term bonds.
Income Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Income Risk. During periods of falling interest rates, the Fund’s income may decline. The income paid by shorter-term bonds is subject to a higher degree of fluctuation than the income paid by longer-term bonds.
Credit Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Credit Risk. Credit risk refers to the chance that an issuer will default (fail to meet its credit obligations) or fail to make payments in a timely manner, which could result in a loss to the Fund. In addition, negative perceptions of an issuer’s ability to make payments can cause the price of a security to decline. While all debt securities are subject to credit risk to some extent, those with higher credit quality ratings generally pose less credit risk than those with lower credit quality ratings.
Bond Liquidity Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Bond Liquidity Risk. If the Fund is unable to sell a security at an advantageous time or price, its returns may be reduced. There may be limited trading in the secondary market for certain debt securities, which could make them more difficult to value or sell.
Prepayment Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Prepayment Risk. Certain bonds are subject to risks associated with prepayment. With respect to mortgage-backed, asset-backed, and similar debt securities, prepayment typically refers to borrowers repaying their debt early (e.g., before the maturity date). Prepayment of bonds held by the Fund would result in the Fund losing any price appreciation above the amount repaid. In addition, because prepayments occur more frequently in low interest rate environments, the Fund likely would be forced to reinvest the proceeds from any prepayments at a lower interest rate than when the prepaid bonds were purchased, resulting in a decline in the Fund’s income and a potential loss in the value of the Fund’s investments. Frequent prepayments and subsequent reinvestment of the proceeds also would increase the Fund’s turnover rate.
Extension Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Extension Risk. During periods of rising interest rates, certain bonds held by the Fund may be paid off substantially more slowly than originally anticipated. As a result, the value of the bonds may fall, resulting in a decline in the Fund’s income and a potential loss in the value of the Fund’s investments.
TBA Mortgage Backed Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• TBA Mortgage-Backed Securities. A TBA transaction represents an agreement to buy or sell mortgage-backed securities with agreed-upon characteristics for a fixed unit price at a future date, but does not specify the particular security to be delivered. TBA transactions are subject to the risk that the values of the mortgage-backed securities that the Fund has agreed to purchase will decline prior to the settlement date or that the counterparty will not deliver the securities as promised.
Active Management Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Active Management. The Fund is actively managed. The advisor’s security selection and/or strategy execution could cause the Fund to underperform relevant securities markets or other funds with a similar investment objective.
Derivatives Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Investing in Derivatives. Investing in derivatives may present risks different from, and/or greater than, those associated with investing directly in stocks, bonds, or other types of investments. Derivatives could expose the Fund to increased volatility and/or significant loss. Certain derivatives have an inherent leverage component, providing the Fund exposure to a sizable position in an underlying asset with a relatively small upfront investment at the time the Fund enters into the derivatives position. For these derivatives, an adverse change in the value or price of the underlying asset could result in a loss substantially greater than the amount invested in the derivative itself. Some derivatives require the Fund to enter into a contract with a counterparty. If the counterparty is unable or unwilling to fulfill its contractual obligation, the Fund may experience a loss. A liquid market may not always exist for the Fund’s derivatives positions. The Fund may be unable to sell or otherwise exit its derivatives position at desired times or prices, which could also result in a loss to the Fund. Some derivatives, particularly OTC derivatives, can be complex and often are valued subjectively. Valuation may be more difficult in times of market turmoil since many investors and market makers may be reluctant to purchase complex instruments or quote prices for them. Improper valuations can result in increased cash payment requirements to counterparties or a loss of value to the Fund. Derivatives may not perform as intended, which may result in losses to the Fund. For example,derivatives used for hedging or as a substitute for a portfolio instrument may not provide the expected benefits, particularly during adverse market conditions. The use of derivatives is also subject to legal risk, which includes the risk of loss resulting from insufficient or unenforceable contractual documentation, insufficient capacity or authority of the Fund’s counterparty, and operational risk, which includes documentation or settlement issues, system failures, inadequate controls, and human error.
Short-Selling Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Short Selling. The Fund may lose money in connection with its short sales of certain securities and/or derivatives. In a short sale, the Fund sells a security that it does not own and “borrows” the security from a third-party in order to settle the transaction with the original buyer. The Fund later repurchases the security on the open market and returns it to the third party. The Fund can profit from a short sale if the price of the borrowed security declines before the Fund repurchases it. However, there is no guarantee that the price of the borrowed security will decline. In fact, the security’s price may rise, which would increase the cost to the Fund to repurchase the security and ultimately result in a loss to the Fund. Because there is no upward limit on how high the price of a borrowed security could rise, the Fund’s potential for loss in connection with a short sale is theoretically unlimited.
Risk Lose Money [Member]
Prospectus [Line Items]
Risk [Text Block]	As with any investment, an investment in the Fund could lose money over any time period.
Risk Not Insured Depository Institution [Member]
Prospectus [Line Items]
Risk [Text Block]	An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Vanguard Short-Term Federal Fund Investment Risks - Retail Prospectus [Member] - Vanguard Short-Term Federal Fund

Jan. 31, 2026

• General Market Risk. The markets in which the Fund invests can be affected by a variety of factors. These factors, which can be real or perceived, may include economic, market, political, and regulatory conditions and developments as well as local, regional, or global events such as wars, military conflicts, natural disasters, and public health issues. In addition, investor sentiment and expectations regarding these factors can also impact the markets. Different parts of the market, including different industries and sectors as well as different types of securities, may react differently to factors that affect the market. These factors can contribute to market uncertainty, market volatility, and fluctuations in the value of the Fund’s investments, thereby resulting in potential losses to the Fund over short or long periods.

Prospectus [Line Items]

Risk [Text Block]

• Investing in Bond Markets. The Fund may be impacted by the general condition of the bond markets and by factors that affect bonds and bond issuers. For example, as a general rule, bond prices and interest rates move in opposite directions. When interest rates rise, bond prices tend to fall, and when interest rates fall, bond prices tend to go up. Bond income also is affected by changes in interest rates. Interest rates can rise or fall for a number of reasons, including, but not limited to, central bank monetary policy, inflationary or deflationary pressures, and changes in general market and economic conditions. Changing interest rates, including, but not limited to, rates that fall below zero, could have unpredictable effects on the overall market and may expose the bond markets in particular to heightened volatility and potential illiquidity. The degree to which the Fund is impacted by certain bond market risks may vary based on factors disclosed in its principal investment strategies, such as the types of bonds in which it invests and the overall credit quality, average maturity, and/or average duration of its bond holdings.

Interest Rate Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

• Interest Rate Risk. During periods of rising interest rates, bond prices overall may decline, which could result in a decline in the Fund’s value. The prices of longer-term bonds are more sensitive to changes in interest rates than the prices of shorter-term bonds.

Income Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

• Income Risk. During periods of falling interest rates, the Fund’s income may decline. The income paid by shorter-term bonds is subject to a higher degree of fluctuation than the income paid by longer-term bonds.

Credit Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

• Credit Risk. Credit risk refers to the chance that an issuer will default (fail to meet its credit obligations) or fail to make payments in a timely manner, which could result in a loss to the Fund. In addition, negative perceptions of an issuer’s ability to make payments can cause the price of a security to decline. While all debt securities are subject to credit risk to some extent, those with higher credit quality ratings generally pose less credit risk than those with lower credit quality ratings.

Bond Liquidity Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

• Bond Liquidity Risk. If the Fund is unable to sell a security at an advantageous time or price, its returns may be reduced. There may be limited trading in the secondary market for certain debt securities, which could make them more difficult to value or sell.

Prepayment Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

• Prepayment Risk. Certain bonds are subject to risks associated with prepayment. With respect to mortgage-backed, asset-backed, and similar debt securities, prepayment typically refers to borrowers repaying their debt early (e.g., before the maturity date). Prepayment of bonds held by the Fund would result in the Fund losing any price appreciation above the amount repaid. In addition, because prepayments occur more frequently in low interest rate environments, the Fund likely would be forced to reinvest the proceeds from any prepayments at a lower interest rate than when the prepaid bonds were purchased, resulting in a decline in the Fund’s income and a potential loss in the value of the Fund’s investments. Frequent prepayments and subsequent reinvestment of the proceeds also would increase the Fund’s turnover rate.

Extension Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

• Extension Risk. During periods of rising interest rates, certain bonds held by the Fund may be paid off substantially more slowly than originally anticipated. As a result, the value of the bonds may fall, resulting in a decline in the Fund’s income and a potential loss in the value of the Fund’s investments.

TBA Mortgage Backed Securities Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

• TBA Mortgage-Backed Securities. A TBA transaction represents an agreement to buy or sell mortgage-backed securities with agreed-upon characteristics for a fixed unit price at a future date, but does not specify the particular security to be delivered. TBA transactions are subject to the risk that the values of the mortgage-backed securities that the Fund has agreed to purchase will decline prior to the settlement date or that the counterparty will not deliver the securities as promised.

Active Management Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

• Active Management. The Fund is actively managed. The advisor’s security selection and/or strategy execution could cause the Fund to underperform relevant securities markets or other funds with a similar investment objective.

Derivatives Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

• Investing in Derivatives. Investing in derivatives may present risks different from, and/or greater than, those associated with investing directly in stocks, bonds, or other types of investments. Derivatives could expose the Fund to increased volatility and/or significant loss. Certain derivatives have an inherent leverage component, providing the Fund exposure to a sizable position in an underlying asset with a relatively small upfront investment at the time the Fund enters into the derivatives position. For these derivatives, an adverse change in the value or price of the underlying asset could result in a loss substantially greater than the amount invested in the derivative itself. Some derivatives require the Fund to enter into a contract with a counterparty. If the counterparty is unable or unwilling to fulfill its contractual obligation, the Fund may experience a loss. A liquid market may not always exist for the Fund’s derivatives positions. The Fund may be unable to sell or otherwise exit its derivatives position at desired times or prices, which could also result in a loss to the Fund. Some derivatives, particularly OTC derivatives, can be complex and often are valued subjectively. Valuation may be more difficult in times of market turmoil since many investors and market makers may be reluctant to purchase complex instruments or quote prices for them. Improper valuations can result in increased cash payment requirements to counterparties or a loss of value to the Fund.
Derivatives may not perform as intended, which may result in losses to the Fund. For example,derivatives used for hedging or as a substitute for a portfolio instrument may not provide the expected benefits, particularly during adverse market conditions. The use of derivatives is also subject to legal risk, which includes the risk of loss resulting from insufficient or unenforceable contractual documentation, insufficient capacity or authority of the Fund’s counterparty, and operational risk, which includes documentation or settlement issues, system failures, inadequate controls, and human error.

Short-Selling Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

• Short Selling. The Fund may lose money in connection with its short sales of certain securities and/or derivatives. In a short sale, the Fund sells a security that it does not own and “borrows” the security from a third-party in order to settle the transaction with the original buyer. The Fund later repurchases the security on the open market and returns it to the third party. The Fund can profit from a short sale if the price of the borrowed security declines before the Fund repurchases it. However, there is no guarantee that the price of the borrowed security will decline. In fact, the security’s price may rise, which would increase the cost to the Fund to repurchase the security and ultimately result in a loss to the Fund. Because there is no upward limit on how high the price of a borrowed security could rise, the Fund’s potential for loss in connection with a short sale is theoretically unlimited.

Risk Lose Money [Member]

Prospectus [Line Items]

Risk [Text Block]

As with any investment, an investment in the Fund could lose money over any time period.

Risk Not Insured Depository Institution [Member]

Prospectus [Line Items]

Risk [Text Block]

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.