Vanguard Target Retirement 2070 Fund Investment Risks - Investor Prospectus [Member] - Vanguard Target Retirement 2070 Fund	Sep. 30, 2025
General Market Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• General Market Risk. The markets in which the Fund and the Underlying Funds invest 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 Equity Markets Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Investing in Equity Markets. Certain Underlying Funds invest in the equity markets. Equity markets have historically been cyclical, having periods of time when stock values rise and fall. Market volatility can lead to significant fluctuations in stock values, resulting in potential losses to these Underlying Funds.
Market Capitalization Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Market Capitalization (Market Cap). Companies are generally classified into three types of market cap depending on their size: small-, mid-, and large-cap. Companies can be further classified into micro- or mega-cap. Different factors can affect each market cap uniquely, and historically small- and mid-cap stocks have typically been more volatile due to the effects of changing economic conditions. Large companies may not reach the same levels of growth or performance as smaller companies, and they may be slower to react to competitive challenges. The performance of funds that invest in a subset of market caps could diverge from the performance of a fund that is focused on a broader representation of the stock market.
Investing in Bond Markets Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Investing in Bond Markets. Certain Underlying Funds invest in bonds. As a result, these Underlying Funds 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 an Underlying 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 an Underlying 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 and/or an Underlying 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 an Underlying 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 an Underlying 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.
Call Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Call Risk. Certain bonds held by an Underlying Fund may be callable. The issuer of a callable bond has the right to “call” (redeem) the bond before its maturity date. Calls on bonds held by an Underlying Fund would result in the Underlying Fund losing any price appreciation above the bond’s call price. In addition, because bond calls occur more frequently during periods of falling interest rates, the Underlying Fund likely would be forced to reinvest the proceeds of any called bonds at a lower interest rate than that of the called bonds, resulting in a decline in the Underlying Fund’s income and a potential loss in the value of the Underlying Fund’s investments. Frequent bond calls and subsequent reinvestments of the proceeds also would increase an Underlying Fund’s turnover rate.
Prepayment Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Prepayment Risk. Certain bonds held by the Underlying Funds are subject to risks associated with prepayment. Prepayment risk for callable bonds is described under Call Risk. 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 an Underlying Fund would result in the Underlying Fund losing any price appreciation above the amount repaid (or the bond’s call price, in the case of callable bonds). In addition, because prepayments occur more frequently in low interest rate environments, the Underlying 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 Underlying Fund’s income and a potential loss in the value of the Underlying Fund’s investments. Frequent prepayments and subsequent reinvestment of the proceeds also would increase the Underlying 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 an Underlying 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 an Underlying Fund’s income and a potential loss in the value of an Underlying Fund’s investments.
Investing in Foreign Markets Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Investing in Foreign Markets. Foreign markets can perform differently than U.S. markets. World events could adversely affect the value and/or liquidity of securities of foreign companies or foreign issuers, potentially in ways that differ from impacts to U.S. companies or issuers. Further, global economies and financial markets are becoming increasingly interconnected, which increases the possibility that conditions in one country or region could adversely impact a different country or region. In addition, the rights and remedies associated with investments in a fund that invests in foreign securities may be different than a fund that invests in domestic securities. To the extent that the Underlying Funds invest a large portion of their assets in securities of companies located primarily in one country or region, the Fund’s performance may be hurt disproportionately by the poor performance of the Underlying Funds’ investments in such country or region.
Currency Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Currency Risk. Certain Underlying Funds are subject to the risk that foreign currency will perform differently than U.S. dollars and increase the potential loss to an Underlying Fund. Currency exchange rates may be volatile, move rapidly, and change as a result of changes in interest rates, inflation rates, government surpluses or deficits, and monetary policy or currency controls imposed by local governments or supranational entities such as the International Monetary Fund. Changes in currency exchange rates can affect the value of an Underlying Fund’s holdings.
Currency Hedging Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Currency Hedging. Certain Underlying Funds may attempt to offset currency risk through a hedging strategy; however, by doing so, these Underlying Funds may not be able to capture gains that they could otherwise realize if they did not have a hedging strategy. It generally is not possible to perfectly hedge the risk posed by foreign currency exposure. Hedging transactions can increase transaction costs and subject an Underlying Fund to the risk that a counterparty is unable to fulfill its contractual obligation, in which case the Underlying Fund could be subject to additional loss.
Underlying Fund Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Underlying Funds Risk. The Fund invests substantially all of its assets in Underlying Funds. This means that the Fund is exposed to all of the risks associated with the investment strategies and policies of those Underlying Funds, including the risk that the Underlying Funds will not meet their investment objectives.
Allocation to Underlying Funds Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	• Allocation to Underlying Funds. The advisor’s selection of Underlying Funds, and the allocation of a high percentage of the Fund’s assets to a relatively few number of Underlying Funds, may cause the Fund to be hurt disproportionately by the poor performance of any one Underlying Fund or to underperform other funds with a similar investment objective.
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.