485BPOS

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form N-1A

REGISTRATION STATEMENT 2-92948 UNDER

THE SECURITIES ACT OF 1933

Pre-Effective Amendment No.

Post-Effective Amendment No. 81

and

REGISTRATION STATEMENT (NO. 811-4098) UNDER THE INVESTMENT COMPANY

ACT OF 1940

Amendment No. 82

VANGUARD CHESTER FUNDS

(Exact Name of Registrant as Specified in Declaration of Trust)

P.O. Box 2600, Valley Forge, PA 19482

(Address of Principal Executive Office)

Registrant’s Telephone Number (610) 669-1000

Anne R. Robinson, Esquire

P.O. Box 876

Valley Forge, PA 19482

It is proposed that this filing will become effective (check appropriate box)

[X] immediately upon filing pursuant to paragraph (b)

[ ] on (date) pursuant to paragraph (b)

[ ] 60 days after filing pursuant to paragraph (a)(1)

[ ] on (date) pursuant to paragraph (a)(1)

[ ] 75 days after filing pursuant to paragraph (a)(2)

[ ] on (date) pursuant to paragraph (a)(2) of rule 485

If appropriate, check the following box:

[ ] This post-effective amendment designates a new effective date for a

previously filed post-effective amendment.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933 and the Investment Company Act of 1940, the Registrant hereby certifies that it meets all requirements for effectiveness of this Registration Statement pursuant to Rule 485(b) under the Securities Act of 1933 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the Town of Valley Forge and the Commonwealth of Pennsylvania, on the 27th day of July, 2017.

VANGUARD CHESTER FUNDS
BY:___________/s/ F. William Mc Nabb III*_________

F. William McNabb III
Chairman and Chief Executive Officer

     Pursuant to the requirements of the Securities Act of 1933, this Post-Effective Amendment to the Registration Statement has been signed below by the following persons in the capacities and on the date indicated:

Signature	Title	Date
/s/ F. William McNabb III*	Chairman and Chief	July 27, 2017
Executive Officer
F. William McNabb
/s/ Emerson U. Fullwood*	Trustee	July 27, 2017
Emerson U. Fullwood
/s/ Rajiv L. Gupta*	Trustee	July 27, 2017
Rajiv L. Gupta
/s/ Amy Gutmann*	Trustee	July 27, 2017
Amy Gutmann
/s/ JoAnn Heffernan Heisen*	Trustee	July 27, 2017
JoAnn Heffernan Heisen
/s/ F. Joseph Loughrey*	Trustee	July 27, 2017
F. Joseph Loughrey
/s/ Mark Loughridge*	Trustee	July 27, 2017
Mark Loughridge
/s/ Scott C. Malpass*	Trustee	July 27, 2017
Scott C. Malpass
/s/ André F. Perold*	Trustee	July 27, 2017
André F. Perold
/s/ Peter F. Volanakis*	Trustee	July 27, 2017
Peter F. Volanakis
/s/ Thomas J. Higgins*	Chief Financial Officer	July 27, 2017
Thomas J. Higgins

*By: /s/ Anne E. Robinson

Anne E. Robinson, pursuant to a Power of Attorney filed on October 4, 2016, see File Number 33-32548, Incorporated by Reference.

C-1

INDEX TO EXHIBITS
XBRL Instance Document	Ex-101.INS
XBRL Taxonomy Extension Schema Document	Ex-101.SCH
XBRL Taxonomy Extension Calculation Linkbase Document	Ex-101.CAL
XBRL Taxonomy Extension Definition Linkbase Document.	Ex-101.DEF
XBRL Taxonomy Extension Labels Linkbase Document	Ex-101.LAB
XBRL Taxonomy Extension Presentation Linkbase Document	Ex-101.PRE

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Document Type	dei_DocumentType	485BPOS
Document Period End Date	dei_DocumentPeriodEndDate	Mar. 31, 2017
Registrant Name	dei_EntityRegistrantName	VANGUARD CHESTER FUNDS
Central Index Key	dei_EntityCentralIndexKey	0000752177
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	Jul. 12, 2017
Document Effective Date	dei_DocumentEffectiveDate	Jul. 12, 2017
Prospectus Date	rr_ProspectusDate	Jul. 12, 2017

XML

Retail | Vanguard Target Retirement Income Fund

Vanguard Target Retirement Income Fund

Investment Objective

The Fund seeks to provide current income and some capital appreciation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Retail Vanguard Target Retirement Income Fund Investor Shares USD ($)
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none
Account Service Fee (for certain fund account balances below $10,000)	$ 20	[1]

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Retail Vanguard Target Retirement Income Fund Investor Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.13%
Total Annual Fund Operating Expenses	0.13%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Retail | Vanguard Target Retirement Income Fund | Investor Shares | USD ($)	13	42	73	166

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 9% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors currently in retirement. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Bond Market II Index Fund	37.4%
•	Vanguard Total Stock Market Index Fund	18.0%
•	Vanguard Short-Term Inflation-Protected Securities Index Fund	16.6%
•	Vanguard Total International Bond Index Fund	15.9%
•	Vanguard Total International Stock Index Fund	12.1%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; inflation-protected public obligations issued by the U.S. Treasury; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses. There is no guarantee that the Fund will provide adequate income through retirement. Because bonds and short-term investments usually are less volatile than stocks and because the Fund invests most of its assets in bonds and short-term investments, the Fund’s overall level of risk should be low to moderate.

• With approximately 70% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• With approximately 30% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Target Retirement Income Fund Investor Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 7.44% (quarter ended September 30, 2009), and the lowest return for a quarter was –5.47% (quarter ended December 31, 2008).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Retail - Vanguard Target Retirement Income Fund		1 Year	5 Years	10 Years
Investor Shares		5.25%	4.91%	4.88%
Investor Shares | Return After Taxes on Distributions		4.42%	4.01%	3.91%
Investor Shares | Return After Taxes on Distributions and Sale of Fund Shares		3.16%	3.55%	3.52%
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.23%	4.34%
MSCI US Broad Market Index	[1]	12.67%	14.71%	7.26%
Target Income Composite Index	[1]	5.35%	5.10%	4.94%

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] /year

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 2.45%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Retail | Vanguard Target Retirement Income Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Target Retirement Income Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide current income and some capital appreciation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 9% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

9.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors currently in retirement. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Bond Market II Index Fund	37.4%
•	Vanguard Total Stock Market Index Fund	18.0%
•	Vanguard Short-Term Inflation-Protected Securities Index Fund	16.6%
•	Vanguard Total International Bond Index Fund	15.9%
•	Vanguard Total International Stock Index Fund	12.1%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; inflation-protected public obligations issued by the U.S. Treasury; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses. There is no guarantee that the Fund will provide adequate income through retirement. Because bonds and short-term investments usually are less volatile than stocks and because the Fund invests most of its assets in bonds and short-term investments, the Fund’s overall level of risk should be low to moderate.

• With approximately 70% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• With approximately 30% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Target Retirement Income Fund Investor Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 7.44% (quarter ended September 30, 2009), and the lowest return for a quarter was –5.47% (quarter ended December 31, 2008).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Retail | Vanguard Target Retirement Income Fund | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Account Service Fee (for certain fund account balances below $10,000)

rr_MaximumAccountFee

$ 20

^[1]

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.13%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.13%

1 Year

rr_ExpenseExampleYear01

$ 13

3 Years

rr_ExpenseExampleYear03

42

5 Years

rr_ExpenseExampleYear05

73

10 Years

rr_ExpenseExampleYear10

166

1 Year

rr_ExpenseExampleNoRedemptionYear01

13

3 Years

rr_ExpenseExampleNoRedemptionYear03

42

5 Years

rr_ExpenseExampleNoRedemptionYear05

73

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 166

2007

rr_AnnualReturn2007

8.17%

^[2]

2008

rr_AnnualReturn2008

(10.93%)

^[2]

2009

rr_AnnualReturn2009

14.28%

^[2]

2010

rr_AnnualReturn2010

9.39%

^[2]

2011

rr_AnnualReturn2011

5.25%

^[2]

2012

rr_AnnualReturn2012

8.23%

^[2]

2013

rr_AnnualReturn2013

5.87%

^[2]

2014

rr_AnnualReturn2014

5.54%

^[2]

2015

rr_AnnualReturn2015

(0.17%)

^[2]

2016

rr_AnnualReturn2016

5.25%

^[2]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

2.45%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

7.44%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(5.47%)

1 Year

rr_AverageAnnualReturnYear01

5.25%

5 Years

rr_AverageAnnualReturnYear05

4.91%

10 Years

rr_AverageAnnualReturnYear10

4.88%

Retail | Vanguard Target Retirement Income Fund | Return After Taxes on Distributions | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.42%

5 Years

rr_AverageAnnualReturnYear05

4.01%

10 Years

rr_AverageAnnualReturnYear10

3.91%

Retail | Vanguard Target Retirement Income Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

3.16%

5 Years

rr_AverageAnnualReturnYear05

3.55%

10 Years

rr_AverageAnnualReturnYear10

3.52%

Retail | Vanguard Target Retirement Income Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[3]

5 Years

rr_AverageAnnualReturnYear05

2.23%

^[3]

10 Years

rr_AverageAnnualReturnYear10

4.34%

^[3]

Retail | Vanguard Target Retirement Income Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[3]

5 Years

rr_AverageAnnualReturnYear05

14.71%

^[3]

10 Years

rr_AverageAnnualReturnYear10

7.26%

^[3]

Retail | Vanguard Target Retirement Income Fund | Target Income Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.35%

^[3]

5 Years

rr_AverageAnnualReturnYear05

5.10%

^[3]

10 Years

rr_AverageAnnualReturnYear10

4.94%

^[3]

[1] /year

[2] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 2.45%.

[3] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Retail | Vanguard Target Retirement 2010 Fund

Vanguard Target Retirement 2010 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Retail Vanguard Target Retirement 2010 Fund Investor Shares USD ($)
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none
Account Service Fee (for certain fund account balances below $10,000)	$ 20	[1]

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Retail Vanguard Target Retirement 2010 Fund Investor Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.13%
Total Annual Fund Operating Expenses	0.13%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Retail | Vanguard Target Retirement 2010 Fund | Investor Shares | USD ($)	13	42	73	166

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 6% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2010 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2010, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, , the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Bond Market II Index Fund	37.1%
•	Vanguard Total Stock Market Index Fund	18.3%
•	Vanguard Short-Term Inflation-Protected Securities Index Fund	16.5%
•	Vanguard Total International Bond Index Fund	15.8%
•	Vanguard Total International Stock Index Fund	12.3%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; inflation-protected public obligations issued by the U.S. Treasury; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because fixed income securities such as bonds usually are less volatile than stocks and because the Fund currently invests a significant portion of its assets in fixed income securities, the Fund’s overall level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 69% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• With approximately 31% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Target Retirement 2010 Fund Investor Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 10.55% (quarter ended June 30, 2009), and the lowest return for a quarter was –10.63% (quarter ended December 31, 2008).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Retail - Vanguard Target Retirement 2010 Fund		1 Year	5 Years	10 Years
Investor Shares		5.22%	5.97%	4.61%
Investor Shares | Return After Taxes on Distributions		4.18%	4.94%	3.71%
Investor Shares | Return After Taxes on Distributions and Sale of Fund Shares		3.37%	4.43%	3.40%
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.23%	4.34%
MSCI US Broad Market Index	[1]	12.67%	14.71%	7.26%
Target 2010 Composite Index	[1]	5.44%	6.16%	4.67%

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] /year

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 2.53%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Retail | Vanguard Target Retirement 2010 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Target Retirement 2010 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 6% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

6.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2010 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2010, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, , the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Bond Market II Index Fund	37.1%
•	Vanguard Total Stock Market Index Fund	18.3%
•	Vanguard Short-Term Inflation-Protected Securities Index Fund	16.5%
•	Vanguard Total International Bond Index Fund	15.8%
•	Vanguard Total International Stock Index Fund	12.3%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; inflation-protected public obligations issued by the U.S. Treasury; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because fixed income securities such as bonds usually are less volatile than stocks and because the Fund currently invests a significant portion of its assets in fixed income securities, the Fund’s overall level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 69% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• With approximately 31% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Target Retirement 2010 Fund Investor Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 10.55% (quarter ended June 30, 2009), and the lowest return for a quarter was –10.63% (quarter ended December 31, 2008).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Retail | Vanguard Target Retirement 2010 Fund | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Account Service Fee (for certain fund account balances below $10,000)

rr_MaximumAccountFee

$ 20

^[1]

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.13%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.13%

1 Year

rr_ExpenseExampleYear01

$ 13

3 Years

rr_ExpenseExampleYear03

42

5 Years

rr_ExpenseExampleYear05

73

10 Years

rr_ExpenseExampleYear10

166

1 Year

rr_ExpenseExampleNoRedemptionYear01

13

3 Years

rr_ExpenseExampleNoRedemptionYear03

42

5 Years

rr_ExpenseExampleNoRedemptionYear05

73

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 166

2007

rr_AnnualReturn2007

7.70%

^[2]

2008

rr_AnnualReturn2008

(20.67%)

^[2]

2009

rr_AnnualReturn2009

19.32%

^[2]

2010

rr_AnnualReturn2010

11.43%

^[2]

2011

rr_AnnualReturn2011

3.37%

^[2]

2012

rr_AnnualReturn2012

10.12%

^[2]

2013

rr_AnnualReturn2013

9.10%

^[2]

2014

rr_AnnualReturn2014

5.93%

^[2]

2015

rr_AnnualReturn2015

(0.20%)

^[2]

2016

rr_AnnualReturn2016

5.22%

^[2]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

2.53%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

10.55%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(10.63%)

1 Year

rr_AverageAnnualReturnYear01

5.22%

5 Years

rr_AverageAnnualReturnYear05

5.97%

10 Years

rr_AverageAnnualReturnYear10

4.61%

Retail | Vanguard Target Retirement 2010 Fund | Return After Taxes on Distributions | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.18%

5 Years

rr_AverageAnnualReturnYear05

4.94%

10 Years

rr_AverageAnnualReturnYear10

3.71%

Retail | Vanguard Target Retirement 2010 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

3.37%

5 Years

rr_AverageAnnualReturnYear05

4.43%

10 Years

rr_AverageAnnualReturnYear10

3.40%

Retail | Vanguard Target Retirement 2010 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[3]

5 Years

rr_AverageAnnualReturnYear05

2.23%

^[3]

10 Years

rr_AverageAnnualReturnYear10

4.34%

^[3]

Retail | Vanguard Target Retirement 2010 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[3]

5 Years

rr_AverageAnnualReturnYear05

14.71%

^[3]

10 Years

rr_AverageAnnualReturnYear10

7.26%

^[3]

Retail | Vanguard Target Retirement 2010 Fund | Target 2010 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.44%

^[3]

5 Years

rr_AverageAnnualReturnYear05

6.16%

^[3]

10 Years

rr_AverageAnnualReturnYear10

4.67%

^[3]

[1] /year

[2] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 2.53%.

[3] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Retail | Vanguard Target Retirement 2015 Fund

Vanguard Target Retirement 2015 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Retail Vanguard Target Retirement 2015 Fund Investor Shares USD ($)
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none
Account Service Fee (for certain fund account balances below $10,000)	$ 20	[1]

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Retail Vanguard Target Retirement 2015 Fund Investor Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.14%
Total Annual Fund Operating Expenses	0.14%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Retail | Vanguard Target Retirement 2015 Fund | Investor Shares | USD ($)	14	45	79	179

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 8% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2015 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2015, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Bond Market II Index Fund	31.6%
•	Vanguard Total Stock Market Index Fund	26.8%
•	Vanguard Total International Stock Index Fund	17.9%
•	Vanguard Total International Bond Index Fund	13.4%
•	Vanguard Short-Term Inflation-Protected Securities Index Fund	10.3%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; inflation-protected public obligations issued by the U.S. Treasury; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because fixed income securities such as bonds usually are less volatile than stocks and because the Fund currently invests a significant portion of its assets in fixed income securities, the Fund’s overall level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 55% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• With approximately 45% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Target Retirement 2015 Fund Investor Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 12.21% (quarter ended June 30, 2009), and the lowest return for a quarter was –12.54% (quarter ended December 31, 2008).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Retail - Vanguard Target Retirement 2015 Fund		1 Year	5 Years	10 Years
Investor Shares		6.16%	7.22%	4.85%
Investor Shares | Return After Taxes on Distributions		4.95%	6.14%	3.94%
Investor Shares | Return After Taxes on Distributions and Sale of Fund Shares		4.10%	5.45%	3.62%
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.23%	4.34%
MSCI US Broad Market Index	[1]	12.67%	14.71%	7.26%
Target 2015 Composite Index	[1]	6.40%	7.43%	4.90%

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] /year

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 3.38%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Retail | Vanguard Target Retirement 2015 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Target Retirement 2015 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 8% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

8.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2015 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2015, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Bond Market II Index Fund	31.6%
•	Vanguard Total Stock Market Index Fund	26.8%
•	Vanguard Total International Stock Index Fund	17.9%
•	Vanguard Total International Bond Index Fund	13.4%
•	Vanguard Short-Term Inflation-Protected Securities Index Fund	10.3%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; inflation-protected public obligations issued by the U.S. Treasury; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because fixed income securities such as bonds usually are less volatile than stocks and because the Fund currently invests a significant portion of its assets in fixed income securities, the Fund’s overall level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 55% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• With approximately 45% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Target Retirement 2015 Fund Investor Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 12.21% (quarter ended June 30, 2009), and the lowest return for a quarter was –12.54% (quarter ended December 31, 2008).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Retail | Vanguard Target Retirement 2015 Fund | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Account Service Fee (for certain fund account balances below $10,000)

rr_MaximumAccountFee

$ 20

^[1]

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.14%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.14%

1 Year

rr_ExpenseExampleYear01

$ 14

3 Years

rr_ExpenseExampleYear03

45

5 Years

rr_ExpenseExampleYear05

79

10 Years

rr_ExpenseExampleYear10

179

1 Year

rr_ExpenseExampleNoRedemptionYear01

14

3 Years

rr_ExpenseExampleNoRedemptionYear03

45

5 Years

rr_ExpenseExampleNoRedemptionYear05

79

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 179

2007

rr_AnnualReturn2007

7.55%

^[2]

2008

rr_AnnualReturn2008

(24.06%)

^[2]

2009

rr_AnnualReturn2009

21.30%

^[2]

2010

rr_AnnualReturn2010

12.47%

^[2]

2011

rr_AnnualReturn2011

1.71%

^[2]

2012

rr_AnnualReturn2012

11.37%

^[2]

2013

rr_AnnualReturn2013

13.00%

^[2]

2014

rr_AnnualReturn2014

6.56%

^[2]

2015

rr_AnnualReturn2015

(0.46%)

^[2]

2016

rr_AnnualReturn2016

6.16%

^[2]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

3.38%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

12.21%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(12.54%)

1 Year

rr_AverageAnnualReturnYear01

6.16%

5 Years

rr_AverageAnnualReturnYear05

7.22%

10 Years

rr_AverageAnnualReturnYear10

4.85%

Retail | Vanguard Target Retirement 2015 Fund | Return After Taxes on Distributions | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.95%

5 Years

rr_AverageAnnualReturnYear05

6.14%

10 Years

rr_AverageAnnualReturnYear10

3.94%

Retail | Vanguard Target Retirement 2015 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.10%

5 Years

rr_AverageAnnualReturnYear05

5.45%

10 Years

rr_AverageAnnualReturnYear10

3.62%

Retail | Vanguard Target Retirement 2015 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[3]

5 Years

rr_AverageAnnualReturnYear05

2.23%

^[3]

10 Years

rr_AverageAnnualReturnYear10

4.34%

^[3]

Retail | Vanguard Target Retirement 2015 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[3]

5 Years

rr_AverageAnnualReturnYear05

14.71%

^[3]

10 Years

rr_AverageAnnualReturnYear10

7.26%

^[3]

Retail | Vanguard Target Retirement 2015 Fund | Target 2015 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

6.40%

^[3]

5 Years

rr_AverageAnnualReturnYear05

7.43%

^[3]

10 Years

rr_AverageAnnualReturnYear10

4.90%

^[3]

[1] /year

[2] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 3.38%.

[3] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Retail | Vanguard Target Retirement 2020 Fund

Vanguard Target Retirement 2020 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Retail Vanguard Target Retirement 2020 Fund Investor Shares USD ($)
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none
Account Service Fee (for certain fund account balances below $10,000)	$ 20	[1]

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Retail Vanguard Target Retirement 2020 Fund Investor Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.14%
Total Annual Fund Operating Expenses	0.14%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Retail | Vanguard Target Retirement 2020 Fund | Investor Shares | USD ($)	14	45	79	179

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 8% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2020 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2020, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	33.5%
•	Vanguard Total Bond Market II Index Fund	28.7%
•	Vanguard Total International Stock Index Fund	22.8%
•	Vanguard Total International Bond Index Fund	12.1%
•	Vanguard Short-Term Inflation-Protected Securities Index Fund	2.9%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; inflation-protected public obligations issued by the U.S. Treasury; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 56% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 44% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Target Retirement 2020 Fund Investor Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 13.49% (quarter ended June 30, 2009), and the lowest return for a quarter was –14.51% (quarter ended December 31, 2008).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Retail - Vanguard Target Retirement 2020 Fund		1 Year	5 Years	10 Years
Investor Shares		6.95%	8.17%	4.99%
Investor Shares | Return After Taxes on Distributions		6.09%	7.37%	4.30%
Investor Shares | Return After Taxes on Distributions and Sale of Fund Shares		4.31%	6.24%	3.78%
MSCI US Broad Market Index	[1]	12.67%	14.71%	7.26%
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.23%	4.34%
Target 2020 Composite Index	[1]	7.17%	8.42%	5.13%

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] /year

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 4.10%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Retail | Vanguard Target Retirement 2020 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Target Retirement 2020 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 8% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

8.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2020 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2020, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	33.5%
•	Vanguard Total Bond Market II Index Fund	28.7%
•	Vanguard Total International Stock Index Fund	22.8%
•	Vanguard Total International Bond Index Fund	12.1%
•	Vanguard Short-Term Inflation-Protected Securities Index Fund	2.9%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; inflation-protected public obligations issued by the U.S. Treasury; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 56% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 44% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Target Retirement 2020 Fund Investor Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 13.49% (quarter ended June 30, 2009), and the lowest return for a quarter was –14.51% (quarter ended December 31, 2008).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Retail | Vanguard Target Retirement 2020 Fund | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Account Service Fee (for certain fund account balances below $10,000)

rr_MaximumAccountFee

$ 20

^[1]

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.14%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.14%

1 Year

rr_ExpenseExampleYear01

$ 14

3 Years

rr_ExpenseExampleYear03

45

5 Years

rr_ExpenseExampleYear05

79

10 Years

rr_ExpenseExampleYear10

179

1 Year

rr_ExpenseExampleNoRedemptionYear01

14

3 Years

rr_ExpenseExampleNoRedemptionYear03

45

5 Years

rr_ExpenseExampleNoRedemptionYear05

79

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 179

2007

rr_AnnualReturn2007

7.52%

^[2]

2008

rr_AnnualReturn2008

(27.04%)

^[2]

2009

rr_AnnualReturn2009

23.10%

^[2]

2010

rr_AnnualReturn2010

13.12%

^[2]

2011

rr_AnnualReturn2011

0.60%

^[2]

2012

rr_AnnualReturn2012

12.35%

^[2]

2013

rr_AnnualReturn2013

15.85%

^[2]

2014

rr_AnnualReturn2014

7.11%

^[2]

2015

rr_AnnualReturn2015

(0.68%)

^[2]

2016

rr_AnnualReturn2016

6.95%

^[2]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

4.10%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

13.49%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(14.51%)

1 Year

rr_AverageAnnualReturnYear01

6.95%

5 Years

rr_AverageAnnualReturnYear05

8.17%

10 Years

rr_AverageAnnualReturnYear10

4.99%

Retail | Vanguard Target Retirement 2020 Fund | Return After Taxes on Distributions | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

6.09%

5 Years

rr_AverageAnnualReturnYear05

7.37%

10 Years

rr_AverageAnnualReturnYear10

4.30%

Retail | Vanguard Target Retirement 2020 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.31%

5 Years

rr_AverageAnnualReturnYear05

6.24%

10 Years

rr_AverageAnnualReturnYear10

3.78%

Retail | Vanguard Target Retirement 2020 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[3]

5 Years

rr_AverageAnnualReturnYear05

14.71%

^[3]

10 Years

rr_AverageAnnualReturnYear10

7.26%

^[3]

Retail | Vanguard Target Retirement 2020 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[3]

5 Years

rr_AverageAnnualReturnYear05

2.23%

^[3]

10 Years

rr_AverageAnnualReturnYear10

4.34%

^[3]

Retail | Vanguard Target Retirement 2020 Fund | Target 2020 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

7.17%

^[3]

5 Years

rr_AverageAnnualReturnYear05

8.42%

^[3]

10 Years

rr_AverageAnnualReturnYear10

5.13%

^[3]

[1] /year

[2] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 4.10%.

[3] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Retail | Vanguard Target Retirement 2025 Fund

Vanguard Target Retirement 2025 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Retail Vanguard Target Retirement 2025 Fund Investor Shares USD ($)
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none
Account Service Fee (for certain fund account balances below $10,000)	$ 20	[1]

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Retail Vanguard Target Retirement 2025 Fund Investor Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.14%
Total Annual Fund Operating Expenses	0.14%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Retail | Vanguard Target Retirement 2025 Fund | Investor Shares | USD ($)	14	45	79	179

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 11% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2025 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2025, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	38.6%
•	Vanguard Total International Stock Index Fund	26.0%
•	Vanguard Total Bond Market II Index Fund	24.9%
•	Vanguard Total International Bond Index Fund	10.5%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 65% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 35% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Target Retirement 2025 Fund Investor Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 14.84% (quarter ended June 30, 2009), and the lowest return for a quarter was –16.48% (quarter ended December 31, 2008).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Retail - Vanguard Target Retirement 2025 Fund		1 Year	5 Years	10 Years
Investor Shares		7.48%	8.86%	5.00%
Investor Shares | Return After Taxes on Distributions		6.66%	8.03%	4.30%
Investor Shares | Return After Taxes on Distributions and Sale of Fund Shares		4.63%	6.82%	3.80%
MSCI US Broad Market Index	[1]	12.67%	14.71%	7.26%
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.23%	4.34%
Target 2025 Composite Index	[1]	7.67%	9.10%	5.15%

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] /year

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 4.59%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Retail | Vanguard Target Retirement 2025 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Target Retirement 2025 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 11% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

11.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2025 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2025, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	38.6%
•	Vanguard Total International Stock Index Fund	26.0%
•	Vanguard Total Bond Market II Index Fund	24.9%
•	Vanguard Total International Bond Index Fund	10.5%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 65% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 35% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Target Retirement 2025 Fund Investor Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 14.84% (quarter ended June 30, 2009), and the lowest return for a quarter was –16.48% (quarter ended December 31, 2008).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Retail | Vanguard Target Retirement 2025 Fund | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Account Service Fee (for certain fund account balances below $10,000)

rr_MaximumAccountFee

$ 20

^[1]

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.14%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.14%

1 Year

rr_ExpenseExampleYear01

$ 14

3 Years

rr_ExpenseExampleYear03

45

5 Years

rr_ExpenseExampleYear05

79

10 Years

rr_ExpenseExampleYear10

179

1 Year

rr_ExpenseExampleNoRedemptionYear01

14

3 Years

rr_ExpenseExampleNoRedemptionYear03

45

5 Years

rr_ExpenseExampleNoRedemptionYear05

79

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 179

2007

rr_AnnualReturn2007

7.59%

^[2]

2008

rr_AnnualReturn2008

(30.05%)

^[2]

2009

rr_AnnualReturn2009

24.81%

^[2]

2010

rr_AnnualReturn2010

13.84%

^[2]

2011

rr_AnnualReturn2011

(0.37%)

^[2]

2012

rr_AnnualReturn2012

13.29%

^[2]

2013

rr_AnnualReturn2013

18.14%

^[2]

2014

rr_AnnualReturn2014

7.17%

^[2]

2015

rr_AnnualReturn2015

(0.85%)

^[2]

2016

rr_AnnualReturn2016

7.48%

^[2]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

4.59%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

14.84%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(16.48%)

1 Year

rr_AverageAnnualReturnYear01

7.48%

5 Years

rr_AverageAnnualReturnYear05

8.86%

10 Years

rr_AverageAnnualReturnYear10

5.00%

Retail | Vanguard Target Retirement 2025 Fund | Return After Taxes on Distributions | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

6.66%

5 Years

rr_AverageAnnualReturnYear05

8.03%

10 Years

rr_AverageAnnualReturnYear10

4.30%

Retail | Vanguard Target Retirement 2025 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.63%

5 Years

rr_AverageAnnualReturnYear05

6.82%

10 Years

rr_AverageAnnualReturnYear10

3.80%

Retail | Vanguard Target Retirement 2025 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[3]

5 Years

rr_AverageAnnualReturnYear05

14.71%

^[3]

10 Years

rr_AverageAnnualReturnYear10

7.26%

^[3]

Retail | Vanguard Target Retirement 2025 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[3]

5 Years

rr_AverageAnnualReturnYear05

2.23%

^[3]

10 Years

rr_AverageAnnualReturnYear10

4.34%

^[3]

Retail | Vanguard Target Retirement 2025 Fund | Target 2025 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

7.67%

^[3]

5 Years

rr_AverageAnnualReturnYear05

9.10%

^[3]

10 Years

rr_AverageAnnualReturnYear10

5.15%

^[3]

[1] /year

[2] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 4.59%.

[3] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Retail | Vanguard Target Retirement 2030 Fund

Vanguard Target Retirement 2030 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Retail Vanguard Target Retirement 2030 Fund Investor Shares USD ($)
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none
Account Service Fee (for certain fund account balances below $10,000)	$ 20	[1]

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Retail Vanguard Target Retirement 2030 Fund Investor Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.15%
Total Annual Fund Operating Expenses	0.15%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Retail | Vanguard Target Retirement 2030 Fund | Investor Shares | USD ($)	15	48	85	192

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 9% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2030 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2030, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	43.1%
•	Vanguard Total International Stock Index Fund	28.9%
•	Vanguard Total Bond Market II Index Fund	19.7%
•	Vanguard Total International Bond Index Fund	8.3%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 72% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 28% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Target Retirement 2030 Fund Investor Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 16.23% (quarter ended June 30, 2009), and the lowest return for a quarter was –18.45% (quarter ended December 31, 2008).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Retail - Vanguard Target Retirement 2030 Fund		1 Year	5 Years	10 Years
Investor Shares		7.85%	9.50%	4.98%
Investor Shares | Return After Taxes on Distributions		7.10%	8.79%	4.40%
Investor Shares | Return After Taxes on Distributions and Sale of Fund Shares		4.79%	7.38%	3.84%
MSCI US Broad Market Index	[1]	12.67%	14.71%	7.26%
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.23%	4.34%
Target 2030 Composite Index	[1]	8.11%	9.77%	5.14%

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] /year

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 5.10%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Retail | Vanguard Target Retirement 2030 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Target Retirement 2030 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 9% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

9.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2030 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2030, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	43.1%
•	Vanguard Total International Stock Index Fund	28.9%
•	Vanguard Total Bond Market II Index Fund	19.7%
•	Vanguard Total International Bond Index Fund	8.3%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 72% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 28% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Target Retirement 2030 Fund Investor Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 16.23% (quarter ended June 30, 2009), and the lowest return for a quarter was –18.45% (quarter ended December 31, 2008).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Retail | Vanguard Target Retirement 2030 Fund | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Account Service Fee (for certain fund account balances below $10,000)

rr_MaximumAccountFee

$ 20

^[1]

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.15%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.15%

1 Year

rr_ExpenseExampleYear01

$ 15

3 Years

rr_ExpenseExampleYear03

48

5 Years

rr_ExpenseExampleYear05

85

10 Years

rr_ExpenseExampleYear10

192

1 Year

rr_ExpenseExampleNoRedemptionYear01

15

3 Years

rr_ExpenseExampleNoRedemptionYear03

48

5 Years

rr_ExpenseExampleNoRedemptionYear05

85

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 192

2007

rr_AnnualReturn2007

7.49%

^[2]

2008

rr_AnnualReturn2008

(32.91%)

^[2]

2009

rr_AnnualReturn2009

26.72%

^[2]

2010

rr_AnnualReturn2010

14.43%

^[2]

2011

rr_AnnualReturn2011

(1.27%)

^[2]

2012

rr_AnnualReturn2012

14.24%

^[2]

2013

rr_AnnualReturn2013

20.49%

^[2]

2014

rr_AnnualReturn2014

7.17%

^[2]

2015

rr_AnnualReturn2015

(1.03%)

^[2]

2016

rr_AnnualReturn2016

7.85%

^[2]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

5.10%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

16.23%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(18.45%)

1 Year

rr_AverageAnnualReturnYear01

7.85%

5 Years

rr_AverageAnnualReturnYear05

9.50%

10 Years

rr_AverageAnnualReturnYear10

4.98%

Retail | Vanguard Target Retirement 2030 Fund | Return After Taxes on Distributions | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

7.10%

5 Years

rr_AverageAnnualReturnYear05

8.79%

10 Years

rr_AverageAnnualReturnYear10

4.40%

Retail | Vanguard Target Retirement 2030 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.79%

5 Years

rr_AverageAnnualReturnYear05

7.38%

10 Years

rr_AverageAnnualReturnYear10

3.84%

Retail | Vanguard Target Retirement 2030 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[3]

5 Years

rr_AverageAnnualReturnYear05

14.71%

^[3]

10 Years

rr_AverageAnnualReturnYear10

7.26%

^[3]

Retail | Vanguard Target Retirement 2030 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[3]

5 Years

rr_AverageAnnualReturnYear05

2.23%

^[3]

10 Years

rr_AverageAnnualReturnYear10

4.34%

^[3]

Retail | Vanguard Target Retirement 2030 Fund | Target 2030 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.11%

^[3]

5 Years

rr_AverageAnnualReturnYear05

9.77%

^[3]

10 Years

rr_AverageAnnualReturnYear10

5.14%

^[3]

[1] /year

[2] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 5.10%.

[3] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Retail | Vanguard Target Retirement 2035 Fund

Vanguard Target Retirement 2035 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Retail Vanguard Target Retirement 2035 Fund Investor Shares USD ($)
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none
Account Service Fee (for certain fund account balances below $10,000)	$ 20	[1]

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Retail Vanguard Target Retirement 2035 Fund Investor Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.15%
Total Annual Fund Operating Expenses	0.15%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Retail | Vanguard Target Retirement 2035 Fund | Investor Shares | USD ($)	15	48	85	192

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 10% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2035 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2035, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	47.6%
•	Vanguard Total International Stock Index Fund	32.0%
•	Vanguard Total Bond Market II Index Fund	14.4%
•	Vanguard Total International Bond Index Fund	6.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 80% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 20% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Target Retirement 2035 Fund Investor Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 17.27% (quarter ended June 30, 2009), and the lowest return for a quarter was –19.72% (quarter ended December 31, 2008).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Retail - Vanguard Target Retirement 2035 Fund		1 Year	5 Years	10 Years
Investor Shares		8.26%	10.15%	5.09%
Investor Shares | Return After Taxes on Distributions		7.47%	9.40%	4.49%
Investor Shares | Return After Taxes on Distributions and Sale of Fund Shares		5.15%	7.94%	3.95%
MSCI US Broad Market Index	[1]	12.67%	14.71%	7.26%
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.23%	4.34%
Target 2035 Composite Index	[1]	8.55%	10.42%	5.24%

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] /year

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 5.52%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Retail | Vanguard Target Retirement 2035 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Target Retirement 2035 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 10% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

10.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2035 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2035, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	47.6%
•	Vanguard Total International Stock Index Fund	32.0%
•	Vanguard Total Bond Market II Index Fund	14.4%
•	Vanguard Total International Bond Index Fund	6.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 80% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 20% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Target Retirement 2035 Fund Investor Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 17.27% (quarter ended June 30, 2009), and the lowest return for a quarter was –19.72% (quarter ended December 31, 2008).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Retail | Vanguard Target Retirement 2035 Fund | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Account Service Fee (for certain fund account balances below $10,000)

rr_MaximumAccountFee

$ 20

^[1]

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.15%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.15%

1 Year

rr_ExpenseExampleYear01

$ 15

3 Years

rr_ExpenseExampleYear03

48

5 Years

rr_ExpenseExampleYear05

85

10 Years

rr_ExpenseExampleYear10

192

1 Year

rr_ExpenseExampleNoRedemptionYear01

15

3 Years

rr_ExpenseExampleNoRedemptionYear03

48

5 Years

rr_ExpenseExampleNoRedemptionYear05

85

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 192

2007

rr_AnnualReturn2007

7.49%

^[2]

2008

rr_AnnualReturn2008

(34.66%)

^[2]

2009

rr_AnnualReturn2009

28.17%

^[2]

2010

rr_AnnualReturn2010

15.14%

^[2]

2011

rr_AnnualReturn2011

(2.24%)

^[2]

2012

rr_AnnualReturn2012

15.16%

^[2]

2013

rr_AnnualReturn2013

22.82%

^[2]

2014

rr_AnnualReturn2014

7.24%

^[2]

2015

rr_AnnualReturn2015

(1.26%)

^[2]

2016

rr_AnnualReturn2016

8.26%

^[2]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

5.52%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

17.27%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(19.72%)

1 Year

rr_AverageAnnualReturnYear01

8.26%

5 Years

rr_AverageAnnualReturnYear05

10.15%

10 Years

rr_AverageAnnualReturnYear10

5.09%

Retail | Vanguard Target Retirement 2035 Fund | Return After Taxes on Distributions | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

7.47%

5 Years

rr_AverageAnnualReturnYear05

9.40%

10 Years

rr_AverageAnnualReturnYear10

4.49%

Retail | Vanguard Target Retirement 2035 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.15%

5 Years

rr_AverageAnnualReturnYear05

7.94%

10 Years

rr_AverageAnnualReturnYear10

3.95%

Retail | Vanguard Target Retirement 2035 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[3]

5 Years

rr_AverageAnnualReturnYear05

14.71%

^[3]

10 Years

rr_AverageAnnualReturnYear10

7.26%

^[3]

Retail | Vanguard Target Retirement 2035 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[3]

5 Years

rr_AverageAnnualReturnYear05

2.23%

^[3]

10 Years

rr_AverageAnnualReturnYear10

4.34%

^[3]

Retail | Vanguard Target Retirement 2035 Fund | Target 2035 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.55%

^[3]

5 Years

rr_AverageAnnualReturnYear05

10.42%

^[3]

10 Years

rr_AverageAnnualReturnYear10

5.24%

^[3]

[1] /year

[2] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 5.52%.

[3] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Retail | Vanguard Target Retirement 2040 Fund

Vanguard Target Retirement 2040 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Retail Vanguard Target Retirement 2040 Fund Investor Shares USD ($)
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none
Account Service Fee (for certain fund account balances below $10,000)	$ 20	[1]

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Retail Vanguard Target Retirement 2040 Fund Investor Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.16%
Total Annual Fund Operating Expenses	0.16%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Retail | Vanguard Target Retirement 2040 Fund | Investor Shares | USD ($)	16	52	90	205

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 8% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2040 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2040, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	51.9%
•	Vanguard Total International Stock Index Fund	35.0%
•	Vanguard Total Bond Market II Index Fund	9.2%
•	Vanguard Total International Bond Index Fund	3.9%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 87% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 13% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Target Retirement 2040 Fund Investor Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 17.13% (quarter ended June 30, 2009), and the lowest return for a quarter was –19.62% (quarter ended December 31, 2008).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Retail - Vanguard Target Retirement 2040 Fund		1 Year	5 Years	10 Years
Investor Shares		8.73%	10.51%	5.26%
Investor Shares | Return After Taxes on Distributions		8.04%	9.89%	4.75%
Investor Shares | Return After Taxes on Distributions and Sale of Fund Shares		5.36%	8.26%	4.11%
MSCI US Broad Market Index	[1]	12.67%	14.71%	7.26%
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.23%	4.34%
Target 2040 Composite Index	[1]	8.98%	10.80%	5.41%

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] /year

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.02%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Retail | Vanguard Target Retirement 2040 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Target Retirement 2040 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 8% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

8.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2040 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2040, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	51.9%
•	Vanguard Total International Stock Index Fund	35.0%
•	Vanguard Total Bond Market II Index Fund	9.2%
•	Vanguard Total International Bond Index Fund	3.9%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 87% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 13% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Target Retirement 2040 Fund Investor Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 17.13% (quarter ended June 30, 2009), and the lowest return for a quarter was –19.62% (quarter ended December 31, 2008).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Retail | Vanguard Target Retirement 2040 Fund | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Account Service Fee (for certain fund account balances below $10,000)

rr_MaximumAccountFee

$ 20

^[1]

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.16%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.16%

1 Year

rr_ExpenseExampleYear01

$ 16

3 Years

rr_ExpenseExampleYear03

52

5 Years

rr_ExpenseExampleYear05

90

10 Years

rr_ExpenseExampleYear10

205

1 Year

rr_ExpenseExampleNoRedemptionYear01

16

3 Years

rr_ExpenseExampleNoRedemptionYear03

52

5 Years

rr_ExpenseExampleNoRedemptionYear05

90

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 205

2007

rr_AnnualReturn2007

7.48%

^[2]

2008

rr_AnnualReturn2008

(34.53%)

^[2]

2009

rr_AnnualReturn2009

28.32%

^[2]

2010

rr_AnnualReturn2010

15.17%

^[2]

2011

rr_AnnualReturn2011

(2.55%)

^[2]

2012

rr_AnnualReturn2012

15.56%

^[2]

2013

rr_AnnualReturn2013

24.37%

^[2]

2014

rr_AnnualReturn2014

7.15%

^[2]

2015

rr_AnnualReturn2015

(1.59%)

^[2]

2016

rr_AnnualReturn2016

8.73%

^[2]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

6.02%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

17.13%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(19.62%)

1 Year

rr_AverageAnnualReturnYear01

8.73%

5 Years

rr_AverageAnnualReturnYear05

10.51%

10 Years

rr_AverageAnnualReturnYear10

5.26%

Retail | Vanguard Target Retirement 2040 Fund | Return After Taxes on Distributions | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.04%

5 Years

rr_AverageAnnualReturnYear05

9.89%

10 Years

rr_AverageAnnualReturnYear10

4.75%

Retail | Vanguard Target Retirement 2040 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.36%

5 Years

rr_AverageAnnualReturnYear05

8.26%

10 Years

rr_AverageAnnualReturnYear10

4.11%

Retail | Vanguard Target Retirement 2040 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[3]

5 Years

rr_AverageAnnualReturnYear05

14.71%

^[3]

10 Years

rr_AverageAnnualReturnYear10

7.26%

^[3]

Retail | Vanguard Target Retirement 2040 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[3]

5 Years

rr_AverageAnnualReturnYear05

2.23%

^[3]

10 Years

rr_AverageAnnualReturnYear10

4.34%

^[3]

Retail | Vanguard Target Retirement 2040 Fund | Target 2040 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.98%

^[3]

5 Years

rr_AverageAnnualReturnYear05

10.80%

^[3]

10 Years

rr_AverageAnnualReturnYear10

5.41%

^[3]

[1] /year

[2] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.02%.

[3] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Retail | Vanguard Target Retirement 2045 Fund

Vanguard Target Retirement 2045 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Retail Vanguard Target Retirement 2045 Fund Investor Shares USD ($)
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none
Account Service Fee (for certain fund account balances below $10,000)	$ 20	[1]

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Retail Vanguard Target Retirement 2045 Fund Investor Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.16%
Total Annual Fund Operating Expenses	0.16%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Retail | Vanguard Target Retirement 2045 Fund | Investor Shares | USD ($)	16	52	90	205

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 8% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2045 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2045, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	53.7%
•	Vanguard Total International Stock Index Fund	36.2%
•	Vanguard Total Bond Market II Index Fund	7.1%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Target Retirement 2045 Fund Investor Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 17.15% (quarter ended June 30, 2009), and the lowest return for a quarter was –19.65% (quarter ended December 31, 2008).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Retail - Vanguard Target Retirement 2045 Fund		1 Year	5 Years	10 Years
Investor Shares		8.87%	10.54%	5.27%
Investor Shares | Return After Taxes on Distributions		8.17%	9.90%	4.71%
Investor Shares | Return After Taxes on Distributions and Sale of Fund Shares		5.46%	8.30%	4.11%
MSCI US Broad Market Index	[1]	12.67%	14.71%	7.26%
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.23%	4.34%
Target 2045 Composite Index	[1]	9.13%	10.83%	5.43%

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] /year

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.19%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Retail | Vanguard Target Retirement 2045 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Target Retirement 2045 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 8% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

8.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2045 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2045, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	53.7%
•	Vanguard Total International Stock Index Fund	36.2%
•	Vanguard Total Bond Market II Index Fund	7.1%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Target Retirement 2045 Fund Investor Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 17.15% (quarter ended June 30, 2009), and the lowest return for a quarter was –19.65% (quarter ended December 31, 2008).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Retail | Vanguard Target Retirement 2045 Fund | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Account Service Fee (for certain fund account balances below $10,000)

rr_MaximumAccountFee

$ 20

^[1]

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.16%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.16%

1 Year

rr_ExpenseExampleYear01

$ 16

3 Years

rr_ExpenseExampleYear03

52

5 Years

rr_ExpenseExampleYear05

90

10 Years

rr_ExpenseExampleYear10

205

1 Year

rr_ExpenseExampleNoRedemptionYear01

16

3 Years

rr_ExpenseExampleNoRedemptionYear03

52

5 Years

rr_ExpenseExampleNoRedemptionYear05

90

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 205

2007

rr_AnnualReturn2007

7.47%

^[2]

2008

rr_AnnualReturn2008

(34.56%)

^[2]

2009

rr_AnnualReturn2009

28.15%

^[2]

2010

rr_AnnualReturn2010

15.19%

^[2]

2011

rr_AnnualReturn2011

(2.51%)

^[2]

2012

rr_AnnualReturn2012

15.58%

^[2]

2013

rr_AnnualReturn2013

24.37%

^[2]

2014

rr_AnnualReturn2014

7.16%

^[2]

2015

rr_AnnualReturn2015

(1.57%)

^[2]

2016

rr_AnnualReturn2016

8.87%

^[2]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

6.19%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

17.15%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(19.65%)

1 Year

rr_AverageAnnualReturnYear01

8.87%

5 Years

rr_AverageAnnualReturnYear05

10.54%

10 Years

rr_AverageAnnualReturnYear10

5.27%

Retail | Vanguard Target Retirement 2045 Fund | Return After Taxes on Distributions | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.17%

5 Years

rr_AverageAnnualReturnYear05

9.90%

10 Years

rr_AverageAnnualReturnYear10

4.71%

Retail | Vanguard Target Retirement 2045 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.46%

5 Years

rr_AverageAnnualReturnYear05

8.30%

10 Years

rr_AverageAnnualReturnYear10

4.11%

Retail | Vanguard Target Retirement 2045 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[3]

5 Years

rr_AverageAnnualReturnYear05

14.71%

^[3]

10 Years

rr_AverageAnnualReturnYear10

7.26%

^[3]

Retail | Vanguard Target Retirement 2045 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[3]

5 Years

rr_AverageAnnualReturnYear05

2.23%

^[3]

10 Years

rr_AverageAnnualReturnYear10

4.34%

^[3]

Retail | Vanguard Target Retirement 2045 Fund | Target 2045 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

9.13%

^[3]

5 Years

rr_AverageAnnualReturnYear05

10.83%

^[3]

10 Years

rr_AverageAnnualReturnYear10

5.43%

^[3]

[1] /year

[2] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.19%.

[3] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Retail | Vanguard Target Retirement 2050 Fund

Vanguard Target Retirement 2050 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Retail Vanguard Target Retirement 2050 Fund Investor Shares USD ($)
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none
Account Service Fee (for certain fund account balances below $10,000)	$ 20	[1]

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Retail Vanguard Target Retirement 2050 Fund Investor Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.16%
Total Annual Fund Operating Expenses	0.16%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Retail | Vanguard Target Retirement 2050 Fund | Investor Shares | USD ($)	16	52	90	205

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 5% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2050 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2050, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	54.0%
•	Vanguard Total International Stock Index Fund	35.9%
•	Vanguard Total Bond Market II Index Fund	7.1%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in a particular country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Target Retirement 2050 Fund Investor Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 17.23% (quarter ended June 30, 2009), and the lowest return for a quarter was –19.71% (quarter ended December 31, 2008).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Retail - Vanguard Target Retirement 2050 Fund		1 Year	5 Years	10 Years
Investor Shares		8.85%	10.54%	5.27%
Investor Shares | Return After Taxes on Distributions		8.26%	9.97%	4.76%
Investor Shares | Return After Taxes on Distributions and Sale of Fund Shares		5.37%	8.29%	4.11%
MSCI US Broad Market Index	[1]	12.67%	14.71%	7.26%
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.23%	4.34%
Target 2050 Composite Index	[1]	9.13%	10.83%	5.43%

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] /year

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.19%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Retail | Vanguard Target Retirement 2050 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Target Retirement 2050 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 5% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

5.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2050 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2050, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	54.0%
•	Vanguard Total International Stock Index Fund	35.9%
•	Vanguard Total Bond Market II Index Fund	7.1%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in a particular country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Target Retirement 2050 Fund Investor Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 17.23% (quarter ended June 30, 2009), and the lowest return for a quarter was –19.71% (quarter ended December 31, 2008).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Retail | Vanguard Target Retirement 2050 Fund | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Account Service Fee (for certain fund account balances below $10,000)

rr_MaximumAccountFee

$ 20

^[1]

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.16%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.16%

1 Year

rr_ExpenseExampleYear01

$ 16

3 Years

rr_ExpenseExampleYear03

52

5 Years

rr_ExpenseExampleYear05

90

10 Years

rr_ExpenseExampleYear10

205

1 Year

rr_ExpenseExampleNoRedemptionYear01

16

3 Years

rr_ExpenseExampleNoRedemptionYear03

52

5 Years

rr_ExpenseExampleNoRedemptionYear05

90

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 205

2007

rr_AnnualReturn2007

7.49%

^[2]

2008

rr_AnnualReturn2008

(34.62%)

^[2]

2009

rr_AnnualReturn2009

28.31%

^[2]

2010

rr_AnnualReturn2010

15.20%

^[2]

2011

rr_AnnualReturn2011

(2.54%)

^[2]

2012

rr_AnnualReturn2012

15.58%

^[2]

2013

rr_AnnualReturn2013

24.34%

^[2]

2014

rr_AnnualReturn2014

7.18%

^[2]

2015

rr_AnnualReturn2015

(1.58%)

^[2]

2016

rr_AnnualReturn2016

8.85%

^[2]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

6.19%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

17.23%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(19.71%)

1 Year

rr_AverageAnnualReturnYear01

8.85%

5 Years

rr_AverageAnnualReturnYear05

10.54%

10 Years

rr_AverageAnnualReturnYear10

5.27%

Retail | Vanguard Target Retirement 2050 Fund | Return After Taxes on Distributions | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.26%

5 Years

rr_AverageAnnualReturnYear05

9.97%

10 Years

rr_AverageAnnualReturnYear10

4.76%

Retail | Vanguard Target Retirement 2050 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.37%

5 Years

rr_AverageAnnualReturnYear05

8.29%

10 Years

rr_AverageAnnualReturnYear10

4.11%

Retail | Vanguard Target Retirement 2050 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[3]

5 Years

rr_AverageAnnualReturnYear05

14.71%

^[3]

10 Years

rr_AverageAnnualReturnYear10

7.26%

^[3]

Retail | Vanguard Target Retirement 2050 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[3]

5 Years

rr_AverageAnnualReturnYear05

2.23%

^[3]

10 Years

rr_AverageAnnualReturnYear10

4.34%

^[3]

Retail | Vanguard Target Retirement 2050 Fund | Target 2050 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

9.13%

^[3]

5 Years

rr_AverageAnnualReturnYear05

10.83%

^[3]

10 Years

rr_AverageAnnualReturnYear10

5.43%

^[3]

[1] /year

[2] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.19%.

[3] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Retail | Vanguard Target Retirement 2055 Fund

Vanguard Target Retirement 2055 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Retail Vanguard Target Retirement 2055 Fund Investor Shares USD ($)
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none
Account Service Fee (for certain fund account balances below $10,000)	$ 20	[1]

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Retail Vanguard Target Retirement 2055 Fund Investor Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.16%
Total Annual Fund Operating Expenses	0.16%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Retail | Vanguard Target Retirement 2055 Fund | Investor Shares | USD ($)	16	52	90	205

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 3% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2055 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2055, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	54.1%
•	Vanguard Total International Stock Index Fund	35.8%
•	Vanguard Total Bond Market II Index Fund	7.1%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in a particular country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Target Retirement 2055 Fund Investor Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 11.30% (quarter ended March 31, 2012), and the lowest return for a quarter was –14.79% (quarter ended September 30, 2011).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Retail - Vanguard Target Retirement 2055 Fund		1 Year	5 Years	Since Inception	Inception Date
Investor Shares		8.88%	10.51%	10.16%	Aug. 18, 2010
Investor Shares | Return After Taxes on Distributions		8.30%	10.01%	9.68%	Aug. 18, 2010
Investor Shares | Return After Taxes on Distributions and Sale of Fund Shares		5.37%	8.29%	8.10%	Aug. 18, 2010
MSCI US Broad Market Index	[1]	12.67%	14.71%	14.41%	Aug. 18, 2010
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.23%	2.86%	Aug. 18, 2010
Target 2055 Composite Index	[1]	9.13%	10.83%	10.44%	Aug. 18, 2010

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] /year

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.17%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Retail | Vanguard Target Retirement 2055 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Target Retirement 2055 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 3% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

3.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2055 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2055, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	54.1%
•	Vanguard Total International Stock Index Fund	35.8%
•	Vanguard Total Bond Market II Index Fund	7.1%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in a particular country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Target Retirement 2055 Fund Investor Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 11.30% (quarter ended March 31, 2012), and the lowest return for a quarter was –14.79% (quarter ended September 30, 2011).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Retail | Vanguard Target Retirement 2055 Fund | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Account Service Fee (for certain fund account balances below $10,000)

rr_MaximumAccountFee

$ 20

^[1]

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.16%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.16%

1 Year

rr_ExpenseExampleYear01

$ 16

3 Years

rr_ExpenseExampleYear03

52

5 Years

rr_ExpenseExampleYear05

90

10 Years

rr_ExpenseExampleYear10

205

1 Year

rr_ExpenseExampleNoRedemptionYear01

16

3 Years

rr_ExpenseExampleNoRedemptionYear03

52

5 Years

rr_ExpenseExampleNoRedemptionYear05

90

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 205

2011

rr_AnnualReturn2011

(2.27%)

^[2]

2012

rr_AnnualReturn2012

15.58%

^[2]

2013

rr_AnnualReturn2013

24.33%

^[2]

2014

rr_AnnualReturn2014

7.19%

^[2]

2015

rr_AnnualReturn2015

(1.72%)

^[2]

2016

rr_AnnualReturn2016

8.88%

^[2]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2007

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

6.17%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Mar. 31, 2012

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

11.30%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(14.79%)

1 Year

rr_AverageAnnualReturnYear01

8.88%

5 Years

rr_AverageAnnualReturnYear05

10.51%

Since Inception

rr_AverageAnnualReturnSinceInception

10.16%

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 18, 2010

Retail | Vanguard Target Retirement 2055 Fund | Return After Taxes on Distributions | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.30%

5 Years

rr_AverageAnnualReturnYear05

10.01%

Since Inception

rr_AverageAnnualReturnSinceInception

9.68%

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 18, 2010

Retail | Vanguard Target Retirement 2055 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.37%

5 Years

rr_AverageAnnualReturnYear05

8.29%

Since Inception

rr_AverageAnnualReturnSinceInception

8.10%

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 18, 2010

Retail | Vanguard Target Retirement 2055 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[3]

5 Years

rr_AverageAnnualReturnYear05

14.71%

^[3]

Since Inception

rr_AverageAnnualReturnSinceInception

14.41%

^[3]

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 18, 2010

^[3]

Retail | Vanguard Target Retirement 2055 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[3]

5 Years

rr_AverageAnnualReturnYear05

2.23%

^[3]

Since Inception

rr_AverageAnnualReturnSinceInception

2.86%

^[3]

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 18, 2010

^[3]

Retail | Vanguard Target Retirement 2055 Fund | Target 2055 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

9.13%

^[3]

5 Years

rr_AverageAnnualReturnYear05

10.83%

^[3]

Since Inception

rr_AverageAnnualReturnSinceInception

10.44%

^[3]

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 18, 2010

^[3]

[1] /year

[2] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.17%.

[3] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Retail | Vanguard Target Retirement 2060 Fund

Vanguard Target Retirement 2060 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Retail Vanguard Target Retirement 2060 Fund Investor Shares USD ($)
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none
Account Service Fee (for certain fund account balances below $10,000)	$ 20	[1]

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Retail Vanguard Target Retirement 2060 Fund Investor Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.16%
Total Annual Fund Operating Expenses	0.16%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Retail | Vanguard Target Retirement 2060 Fund | Investor Shares | USD ($)	16	52	90	205

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 3% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2060 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2060, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	54.2%
•	Vanguard Total International Stock Index Fund	35.8%
•	Vanguard Total Bond Market II Index Fund	7.0%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in a particular country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Target Retirement 2060 Fund Investor Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 7.61% (quarter ended March 31, 2013), and the lowest return for a quarter was –8.00% (quarter ended September 30, 2015).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Retail - Vanguard Target Retirement 2060 Fund		1 Year	Since Inception	Inception Date
Investor Shares		8.84%	9.66%	Jan. 19, 2012
Investor Shares | Return After Taxes on Distributions		8.27%	9.20%	Jan. 19, 2012
Investor Shares | Return After Taxes on Distributions and Sale of Fund Shares		5.35%	7.59%	Jan. 19, 2012
MSCI US Broad Market Index	[1]	12.67%	13.76%	Jan. 19, 2012
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.24%	Jan. 19, 2012
Target 2060 Composite Index	[1]	9.13%	9.98%	Jan. 19, 2012

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] /year

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.16%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Retail | Vanguard Target Retirement 2060 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Target Retirement 2060 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 3% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

3.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2060 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2060, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	54.2%
•	Vanguard Total International Stock Index Fund	35.8%
•	Vanguard Total Bond Market II Index Fund	7.0%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in a particular country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Target Retirement 2060 Fund Investor Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 7.61% (quarter ended March 31, 2013), and the lowest return for a quarter was –8.00% (quarter ended September 30, 2015).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Retail | Vanguard Target Retirement 2060 Fund | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Account Service Fee (for certain fund account balances below $10,000)

rr_MaximumAccountFee

$ 20

^[1]

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.16%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.16%

1 Year

rr_ExpenseExampleYear01

$ 16

3 Years

rr_ExpenseExampleYear03

52

5 Years

rr_ExpenseExampleYear05

90

10 Years

rr_ExpenseExampleYear10

205

1 Year

rr_ExpenseExampleNoRedemptionYear01

16

3 Years

rr_ExpenseExampleNoRedemptionYear03

52

5 Years

rr_ExpenseExampleNoRedemptionYear05

90

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 205

2013

rr_AnnualReturn2013

24.35%

^[2]

2014

rr_AnnualReturn2014

7.16%

^[2]

2015

rr_AnnualReturn2015

(1.68%)

^[2]

2016

rr_AnnualReturn2016

8.84%

^[2]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

6.16%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Mar. 31, 2013

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

7.61%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2015

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(8.00%)

1 Year

rr_AverageAnnualReturnYear01

8.84%

Since Inception

rr_AverageAnnualReturnSinceInception

9.66%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 19, 2012

Retail | Vanguard Target Retirement 2060 Fund | Return After Taxes on Distributions | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.27%

Since Inception

rr_AverageAnnualReturnSinceInception

9.20%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 19, 2012

Retail | Vanguard Target Retirement 2060 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.35%

Since Inception

rr_AverageAnnualReturnSinceInception

7.59%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 19, 2012

Retail | Vanguard Target Retirement 2060 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[3]

Since Inception

rr_AverageAnnualReturnSinceInception

13.76%

^[3]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 19, 2012

^[3]

Retail | Vanguard Target Retirement 2060 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[3]

Since Inception

rr_AverageAnnualReturnSinceInception

2.24%

^[3]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 19, 2012

^[3]

Retail | Vanguard Target Retirement 2060 Fund | Target 2060 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

9.13%

^[3]

Since Inception

rr_AverageAnnualReturnSinceInception

9.98%

^[3]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 19, 2012

^[3]

[1] /year

[2] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.16%.

[3] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Retail | Vanguard Target Retirement 2065 Fund

Vanguard Target Retirement 2065 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Retail Vanguard Target Retirement 2065 Fund Investor Shares USD ($)
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none
Account Service Fee (for certain fund account balances below $10,000)	$ 20	[1]

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Retail Vanguard Target Retirement 2065 Fund Investor Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.16%
Total Annual Fund Operating Expenses	0.16%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Retail | Vanguard Target Retirement 2065 Fund | Investor Shares | USD ($)	16	52	90	205

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. The Fund has no operating history and therefore has no portfolio turnover information.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2065 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2065, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. The Fund’s asset allocation among the underlying funds is as follows:

•	Vanguard Total Stock Market Index Fund	54.0%
•	Vanguard Total International Stock Index Fund	36.0%
•	Vanguard Total Bond Market II Index Fund	7.0%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in a particular country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The Fund began operations on July 12, 2017, so performance information is not yet available.

[1] /year

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Retail | Vanguard Target Retirement 2065 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Target Retirement 2065 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. The Fund has no operating history and therefore has no portfolio turnover information.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2065 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2065, the Fund’s asset allocation should become similar to that of the Target Retirement Income Fund. The Fund’s asset allocation among the underlying funds is as follows:

•	Vanguard Total Stock Market Index Fund	54.0%
•	Vanguard Total International Stock Index Fund	36.0%
•	Vanguard Total Bond Market II Index Fund	7.0%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in a particular country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Fund began operations on July 12, 2017, so performance information is not yet available.

Performance One Year or Less [Text]

rr_PerformanceOneYearOrLess

The Fund began operations on July 12, 2017, so performance information is not yet available.

Retail | Vanguard Target Retirement 2065 Fund | Investor Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Account Service Fee (for certain fund account balances below $10,000)

rr_MaximumAccountFee

$ 20

^[1]

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.16%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.16%

1 Year

rr_ExpenseExampleYear01

$ 16

3 Years

rr_ExpenseExampleYear03

52

5 Years

rr_ExpenseExampleYear05

90

10 Years

rr_ExpenseExampleYear10

205

1 Year

rr_ExpenseExampleNoRedemptionYear01

16

3 Years

rr_ExpenseExampleNoRedemptionYear03

52

5 Years

rr_ExpenseExampleNoRedemptionYear05

90

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 205

[1] /year

XML

Vanguard Institutional Target Retirement Income Fund

Vanguard Institutional Target Retirement Income Fund

Investment Objective

The Fund seeks to provide current income and some capital appreciation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Vanguard Institutional Target Retirement Income Fund Institutional Shares
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Vanguard Institutional Target Retirement Income Fund Institutional Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.09%
Total Annual Fund Operating Expenses	0.09%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Vanguard Institutional Target Retirement Income Fund | Institutional Shares | USD ($)	9	29	51	115

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 11% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors currently in retirement. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Bond Market II Index Fund	37.3%
•	Vanguard Total Stock Market Index Fund	18.0%
•	Vanguard Short-Term Inflation-Protected Securities Index Fund	16.8%
•	Vanguard Total International Bond Index Fund	15.9%
•	Vanguard Total International Stock Index Fund	12.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; inflation-protected public obligations issued by the U.S. Treasury; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses. There is no guarantee that the Fund will provide adequate income through retirement. Because bonds and short-term investments usually are less volatile than stocks and because the Fund invests most of its assets in bonds and short-term investments, the Fund’s overall level of risk should be low to moderate.

• With approximately 70% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• With approximately 30% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Institutional Target Retirement Income Fund Institutional Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 2.28% (quarter ended March 31, 2016), and the lowest return for a quarter was –1.00% (quarter ended December 31, 2016).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Vanguard Institutional Target Retirement Income Fund		1 Year	Since Inception	Inception Date
Institutional Shares		5.29%	2.61%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions		4.52%	1.93%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions and Sale of Fund Shares		3.12%	1.75%	Jun. 26, 2015
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.60%	Jun. 26, 2015
MSCI US Broad Market Index	[1]	12.67%	5.89%	Jun. 26, 2015
Target Income Composite Index	[1]	5.35%	2.78%	Jun. 26, 2015

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 2.47%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Vanguard Institutional Target Retirement Income Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Institutional Target Retirement Income Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide current income and some capital appreciation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 11% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

11.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors currently in retirement. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Bond Market II Index Fund	37.3%
•	Vanguard Total Stock Market Index Fund	18.0%
•	Vanguard Short-Term Inflation-Protected Securities Index Fund	16.8%
•	Vanguard Total International Bond Index Fund	15.9%
•	Vanguard Total International Stock Index Fund	12.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; inflation-protected public obligations issued by the U.S. Treasury; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses. There is no guarantee that the Fund will provide adequate income through retirement. Because bonds and short-term investments usually are less volatile than stocks and because the Fund invests most of its assets in bonds and short-term investments, the Fund’s overall level of risk should be low to moderate.

• With approximately 70% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• With approximately 30% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Institutional Target Retirement Income Fund Institutional Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 2.28% (quarter ended March 31, 2016), and the lowest return for a quarter was –1.00% (quarter ended December 31, 2016).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Vanguard Institutional Target Retirement Income Fund | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.09%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.09%

1 Year

rr_ExpenseExampleYear01

$ 9

3 Years

rr_ExpenseExampleYear03

29

5 Years

rr_ExpenseExampleYear05

51

10 Years

rr_ExpenseExampleYear10

115

1 Year

rr_ExpenseExampleNoRedemptionYear01

9

3 Years

rr_ExpenseExampleNoRedemptionYear03

29

5 Years

rr_ExpenseExampleNoRedemptionYear05

51

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 115

2016

rr_AnnualReturn2016

5.29%

^[1]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

2.47%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Mar. 31, 2016

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

2.28%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2016

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(1.00%)

1 Year

rr_AverageAnnualReturnYear01

5.29%

Since Inception

rr_AverageAnnualReturnSinceInception

2.61%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement Income Fund | Return After Taxes on Distributions | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.52%

Since Inception

rr_AverageAnnualReturnSinceInception

1.93%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement Income Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

3.12%

Since Inception

rr_AverageAnnualReturnSinceInception

1.75%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement Income Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.60%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement Income Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

5.89%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement Income Fund | Target Income Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.35%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.78%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 2.47%.

[2] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Vanguard Institutional Target Retirement 2010 Fund

Vanguard Institutional Target Retirement 2010 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Vanguard Institutional Target Retirement 2010 Fund Institutional Shares
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Vanguard Institutional Target Retirement 2010 Fund Institutional Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.09%
Total Annual Fund Operating Expenses	0.09%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Vanguard Institutional Target Retirement 2010 Fund | Institutional Shares | USD ($)	9	29	51	115

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 13% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2010 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2010, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Bond Market II Index Fund	37.1%
•	Vanguard Total Stock Market Index Fund	18.3%
•	Vanguard Short-Term Inflation-Protected Securities Index Fund	16.6%
•	Vanguard Total International Bond Index Fund	15.9%
•	Vanguard Total International Stock Index Fund	12.1%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; inflation-protected public obligations issued by the U.S. Treasury; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because fixed income securities such as bonds usually are less volatile than stocks and because the Fund currently invests a significant portion of its assets in fixed income securities, the Fund’s overall level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 70% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• With approximately 30% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Institutional Target Retirement 2010 Fund Institutional Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 2.20% (quarter ended March 31, 2016), and the lowest return for a quarter was –0.98% (quarter ended December 31, 2016).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Vanguard Institutional Target Retirement 2010 Fund		1 Year	Since Inception	Inception Date
Institutional Shares		5.31%	2.37%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions		4.63%	1.77%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions and Sale of Fund Shares		3.14%	1.60%	Jun. 26, 2015
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.60%	Jun. 26, 2015
MSCI US Broad Market Index	[1]	12.67%	5.89%	Jun. 26, 2015
Target 2010 Composite Index	[1]	5.44%	2.57%	Jun. 26, 2015

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 2.52%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Vanguard Institutional Target Retirement 2010 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Institutional Target Retirement 2010 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

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The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 13% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

13.00%

Expense Example [Heading]

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Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2010 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2010, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Bond Market II Index Fund	37.1%
•	Vanguard Total Stock Market Index Fund	18.3%
•	Vanguard Short-Term Inflation-Protected Securities Index Fund	16.6%
•	Vanguard Total International Bond Index Fund	15.9%
•	Vanguard Total International Stock Index Fund	12.1%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; inflation-protected public obligations issued by the U.S. Treasury; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

Risk [Heading]

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Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because fixed income securities such as bonds usually are less volatile than stocks and because the Fund currently invests a significant portion of its assets in fixed income securities, the Fund’s overall level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 70% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• With approximately 30% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

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Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

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Annual Total Returns — Vanguard Institutional Target Retirement 2010 Fund Institutional Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 2.20% (quarter ended March 31, 2016), and the lowest return for a quarter was –0.98% (quarter ended December 31, 2016).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Vanguard Institutional Target Retirement 2010 Fund | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.09%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.09%

1 Year

rr_ExpenseExampleYear01

$ 9

3 Years

rr_ExpenseExampleYear03

29

5 Years

rr_ExpenseExampleYear05

51

10 Years

rr_ExpenseExampleYear10

115

1 Year

rr_ExpenseExampleNoRedemptionYear01

9

3 Years

rr_ExpenseExampleNoRedemptionYear03

29

5 Years

rr_ExpenseExampleNoRedemptionYear05

51

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 115

2016

rr_AnnualReturn2016

5.31%

^[1]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

2.52%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Mar. 31, 2016

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

2.20%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2016

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(0.98%)

1 Year

rr_AverageAnnualReturnYear01

5.31%

Since Inception

rr_AverageAnnualReturnSinceInception

2.37%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2010 Fund | Return After Taxes on Distributions | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.63%

Since Inception

rr_AverageAnnualReturnSinceInception

1.77%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2010 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

3.14%

Since Inception

rr_AverageAnnualReturnSinceInception

1.60%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2010 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.60%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2010 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

5.89%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2010 Fund | Target 2010 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.44%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.57%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 2.52%.

[2] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Vanguard Institutional Target Retirement 2015 Fund

Vanguard Institutional Target Retirement 2015 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Vanguard Institutional Target Retirement 2015 Fund Institutional Shares
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Vanguard Institutional Target Retirement 2015 Fund Institutional Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.09%
Total Annual Fund Operating Expenses	0.09%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Vanguard Institutional Target Retirement 2015 Fund | Institutional Shares | USD ($)	9	29	51	115

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 9% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2015 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2015, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Bond Market II Index Fund	31.6%
•	Vanguard Total Stock Market Index Fund	26.7%
•	Vanguard Total International Stock Index Fund	18.0%
•	Vanguard Total International Bond Index Fund	13.4%
•	Vanguard Short-Term Inflation-Protected Securities Index Fund	10.3%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; inflation-protected public obligations issued by the U.S. Treasury; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because fixed income securities such as bonds usually are less volatile than stocks and because the Fund currently invests a significant portion of its assets in fixed income securities, the Fund’s overall level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 55% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• With approximately 45% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Institutional Target Retirement 2015 Fund Institutional Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 2.74% (quarter ended September 30, 2016), and the lowest return for a quarter was –0.47% (quarter ended December 31, 2016).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Vanguard Institutional Target Retirement 2015 Fund		1 Year	Since Inception	Inception Date
Institutional Shares		6.27%	2.31%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions		5.58%	1.70%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions and Sale of Fund Shares		3.74%	1.58%	Jun. 26, 2015
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.60%	Jun. 26, 2015
MSCI US Broad Market Index	[1]	12.67%	5.89%	Jun. 26, 2015
Target 2015 Composite Index	[1]	6.40%	2.54%	Jun. 26, 2015

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 3.37%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Vanguard Institutional Target Retirement 2015 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Institutional Target Retirement 2015 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 9% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

9.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2015 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2015, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Bond Market II Index Fund	31.6%
•	Vanguard Total Stock Market Index Fund	26.7%
•	Vanguard Total International Stock Index Fund	18.0%
•	Vanguard Total International Bond Index Fund	13.4%
•	Vanguard Short-Term Inflation-Protected Securities Index Fund	10.3%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; inflation-protected public obligations issued by the U.S. Treasury; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because fixed income securities such as bonds usually are less volatile than stocks and because the Fund currently invests a significant portion of its assets in fixed income securities, the Fund’s overall level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 55% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• With approximately 45% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite bond/stock index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Institutional Target Retirement 2015 Fund Institutional Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 2.74% (quarter ended September 30, 2016), and the lowest return for a quarter was –0.47% (quarter ended December 31, 2016).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Vanguard Institutional Target Retirement 2015 Fund | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.09%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.09%

1 Year

rr_ExpenseExampleYear01

$ 9

3 Years

rr_ExpenseExampleYear03

29

5 Years

rr_ExpenseExampleYear05

51

10 Years

rr_ExpenseExampleYear10

115

1 Year

rr_ExpenseExampleNoRedemptionYear01

9

3 Years

rr_ExpenseExampleNoRedemptionYear03

29

5 Years

rr_ExpenseExampleNoRedemptionYear05

51

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 115

2016

rr_AnnualReturn2016

6.27%

^[1]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

3.37%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2016

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

2.74%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2016

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(0.47%)

1 Year

rr_AverageAnnualReturnYear01

6.27%

Since Inception

rr_AverageAnnualReturnSinceInception

2.31%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2015 Fund | Return After Taxes on Distributions | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.58%

Since Inception

rr_AverageAnnualReturnSinceInception

1.70%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2015 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

3.74%

Since Inception

rr_AverageAnnualReturnSinceInception

1.58%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2015 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.60%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2015 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

5.89%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2015 Fund | Target 2015 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

6.40%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.54%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 3.37%.

[2] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Vanguard Institutional Target Retirement 2020 Fund

Vanguard Institutional Target Retirement 2020 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Vanguard Institutional Target Retirement 2020 Fund Institutional Shares
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Vanguard Institutional Target Retirement 2020 Fund Institutional Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.09%
Total Annual Fund Operating Expenses	0.09%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Vanguard Institutional Target Retirement 2020 Fund | Institutional Shares | USD ($)	9	29	51	115

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 6% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2020 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2020, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	33.2%
•	Vanguard Total Bond Market II Index Fund	28.7%
•	Vanguard Total International Stock Index Fund	22.7%
•	Vanguard Total International Bond Index Fund	12.2%
•	Vanguard Short-Term Inflation-Protected Securities Index Fund	3.2%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; inflation-protected public obligations issued by the U.S. Treasury; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 56% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 44% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Institutional Target Retirement 2020 Fund Institutional Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 3.31% (quarter ended September 30, 2016), and the lowest return for a quarter was –0.19% (quarter ended December 31, 2016).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Vanguard Institutional Target Retirement 2020 Fund		1 Year	Since Inception	Inception Date
Institutional Shares		7.04%	2.35%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions		6.37%	1.74%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions and Sale of Fund Shares		4.22%	1.63%	Jun. 26, 2015
MSCI US Broad Market Index	[1]	12.67%	5.89%	Jun. 26, 2015
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.60%	Jun. 26, 2015
Target 2020 Composite Index	[1]	7.17%	2.62%	Jun. 26, 2015

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 4.12%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Vanguard Institutional Target Retirement 2020 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Institutional Target Retirement 2020 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 6% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

6.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2020 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2020, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	33.2%
•	Vanguard Total Bond Market II Index Fund	28.7%
•	Vanguard Total International Stock Index Fund	22.7%
•	Vanguard Total International Bond Index Fund	12.2%
•	Vanguard Short-Term Inflation-Protected Securities Index Fund	3.2%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; inflation-protected public obligations issued by the U.S. Treasury; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 56% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 44% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Institutional Target Retirement 2020 Fund Institutional Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 3.31% (quarter ended September 30, 2016), and the lowest return for a quarter was –0.19% (quarter ended December 31, 2016).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Vanguard Institutional Target Retirement 2020 Fund | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.09%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.09%

1 Year

rr_ExpenseExampleYear01

$ 9

3 Years

rr_ExpenseExampleYear03

29

5 Years

rr_ExpenseExampleYear05

51

10 Years

rr_ExpenseExampleYear10

115

1 Year

rr_ExpenseExampleNoRedemptionYear01

9

3 Years

rr_ExpenseExampleNoRedemptionYear03

29

5 Years

rr_ExpenseExampleNoRedemptionYear05

51

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 115

2016

rr_AnnualReturn2016

7.04%

^[1]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

4.12%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2016

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

3.31%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2016

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(0.19%)

1 Year

rr_AverageAnnualReturnYear01

7.04%

Since Inception

rr_AverageAnnualReturnSinceInception

2.35%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2020 Fund | Return After Taxes on Distributions | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

6.37%

Since Inception

rr_AverageAnnualReturnSinceInception

1.74%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2020 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.22%

Since Inception

rr_AverageAnnualReturnSinceInception

1.63%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2020 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

5.89%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2020 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.60%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2020 Fund | Target 2020 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

7.17%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.62%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 4.12%.

[2] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Vanguard Institutional Target Retirement 2025 Fund

Vanguard Institutional Target Retirement 2025 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Vanguard Institutional Target Retirement 2025 Fund Institutional Shares
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Vanguard Institutional Target Retirement 2025 Fund Institutional Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.09%
Total Annual Fund Operating Expenses	0.09%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Vanguard Institutional Target Retirement 2025 Fund | Institutional Shares | USD ($)	9	29	51	115

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 5% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2025 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2025, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	38.5%
•	Vanguard Total International Stock Index Fund	25.9%
•	Vanguard Total Bond Market II Index Fund	25.0%
•	Vanguard Total International Bond Index Fund	10.6%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 64% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 36% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Institutional Target Retirement 2025 Fund Institutional Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 3.70% (quarter ended September 30, 2016), and the lowest return for a quarter was 0.15% (quarter ended December 31, 2016).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Vanguard Institutional Target Retirement 2025 Fund		1 Year	Since Inception	Inception Date
Institutional Shares		7.56%	2.26%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions		6.90%	1.67%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions and Sale of Fund Shares		4.54%	1.58%	Jun. 26, 2015
MSCI US Broad Market Index	[1]	12.67%	5.89%	Jun. 26, 2015
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.60%	Jun. 26, 2015
Target 2025 Composite Index	[1]	7.67%	2.53%	Jun. 26, 2015

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 4.62%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Vanguard Institutional Target Retirement 2025 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Institutional Target Retirement 2025 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 5% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

5.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2025 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2025, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	38.5%
•	Vanguard Total International Stock Index Fund	25.9%
•	Vanguard Total Bond Market II Index Fund	25.0%
•	Vanguard Total International Bond Index Fund	10.6%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 64% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 36% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Institutional Target Retirement 2025 Fund Institutional Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 3.70% (quarter ended September 30, 2016), and the lowest return for a quarter was 0.15% (quarter ended December 31, 2016).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Vanguard Institutional Target Retirement 2025 Fund | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.09%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.09%

1 Year

rr_ExpenseExampleYear01

$ 9

3 Years

rr_ExpenseExampleYear03

29

5 Years

rr_ExpenseExampleYear05

51

10 Years

rr_ExpenseExampleYear10

115

1 Year

rr_ExpenseExampleNoRedemptionYear01

9

3 Years

rr_ExpenseExampleNoRedemptionYear03

29

5 Years

rr_ExpenseExampleNoRedemptionYear05

51

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 115

2016

rr_AnnualReturn2016

7.56%

^[1]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

4.62%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2016

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

3.70%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2016

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

0.15%

1 Year

rr_AverageAnnualReturnYear01

7.56%

Since Inception

rr_AverageAnnualReturnSinceInception

2.26%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2025 Fund | Return After Taxes on Distributions | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

6.90%

Since Inception

rr_AverageAnnualReturnSinceInception

1.67%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2025 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.54%

Since Inception

rr_AverageAnnualReturnSinceInception

1.58%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2025 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

5.89%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2025 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.60%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2025 Fund | Target 2025 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

7.67%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.53%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 4.62%.

[2] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Vanguard Institutional Target Retirement 2030 Fund

Vanguard Institutional Target Retirement 2030 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Vanguard Institutional Target Retirement 2030 Fund Institutional Shares
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Vanguard Institutional Target Retirement 2030 Fund Institutional Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.09%
Total Annual Fund Operating Expenses	0.09%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Vanguard Institutional Target Retirement 2030 Fund | Institutional Shares | USD ($)	9	29	51	115

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 5% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2030 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2030, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	43.0%
•	Vanguard Total International Stock Index Fund	28.9%
•	Vanguard Total Bond Market II Index Fund	19.7%
•	Vanguard Total International Bond Index Fund	8.4%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 72% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 28% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Institutional Target Retirement 2030 Fund Institutional Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 4.09% (quarter ended September 30, 2016), and the lowest return for a quarter was 0.44% (quarter ended December 31, 2016).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Vanguard Institutional Target Retirement 2030 Fund		1 Year	Since Inception	Inception Date
Institutional Shares		7.97%	2.05%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions		7.34%	1.49%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions and Sale of Fund Shares		4.80%	1.45%	Jun. 26, 2015
MSCI US Broad Market Index	[1]	12.67%	5.89%	Jun. 26, 2015
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.60%	Jun. 26, 2015
Target 2030 Composite Index	[1]	8.11%	2.39%	Jun. 26, 2015

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 5.09%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Vanguard Institutional Target Retirement 2030 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Institutional Target Retirement 2030 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 5% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

5.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2030 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2030, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	43.0%
•	Vanguard Total International Stock Index Fund	28.9%
•	Vanguard Total Bond Market II Index Fund	19.7%
•	Vanguard Total International Bond Index Fund	8.4%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 72% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 28% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Institutional Target Retirement 2030 Fund Institutional Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 4.09% (quarter ended September 30, 2016), and the lowest return for a quarter was 0.44% (quarter ended December 31, 2016).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Vanguard Institutional Target Retirement 2030 Fund | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.09%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.09%

1 Year

rr_ExpenseExampleYear01

$ 9

3 Years

rr_ExpenseExampleYear03

29

5 Years

rr_ExpenseExampleYear05

51

10 Years

rr_ExpenseExampleYear10

115

1 Year

rr_ExpenseExampleNoRedemptionYear01

9

3 Years

rr_ExpenseExampleNoRedemptionYear03

29

5 Years

rr_ExpenseExampleNoRedemptionYear05

51

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 115

2016

rr_AnnualReturn2016

7.97%

^[1]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

5.09%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2016

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

4.09%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2016

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

0.44%

1 Year

rr_AverageAnnualReturnYear01

7.97%

Since Inception

rr_AverageAnnualReturnSinceInception

2.05%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2030 Fund | Return After Taxes on Distributions | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

7.34%

Since Inception

rr_AverageAnnualReturnSinceInception

1.49%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2030 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.80%

Since Inception

rr_AverageAnnualReturnSinceInception

1.45%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2030 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

5.89%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2030 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.60%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2030 Fund | Target 2030 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.11%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.39%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 5.09%.

[2] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Vanguard Institutional Target Retirement 2035 Fund

Vanguard Institutional Target Retirement 2035 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Vanguard Institutional Target Retirement 2035 Fund Institutional Shares
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Vanguard Institutional Target Retirement 2035 Fund Institutional Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.09%
Total Annual Fund Operating Expenses	0.09%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Vanguard Institutional Target Retirement 2035 Fund | Institutional Shares | USD ($)	9	29	51	115

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 5% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2035 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2035, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	47.5%
•	Vanguard Total International Stock Index Fund	31.9%
•	Vanguard Total Bond Market II Index Fund	14.5%
•	Vanguard Total International Bond Index Fund	6.1%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 79% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 21% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Institutional Target Retirement 2035 Fund Institutional Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 4.39% (quarter ended September 30, 2016), and the lowest return for a quarter was 0.83% (quarter ended December 31, 2016).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Vanguard Institutional Target Retirement 2035 Fund		1 Year	Since Inception	Inception Date
Institutional Shares		8.39%	1.89%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions		7.79%	1.35%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions and Sale of Fund Shares		5.06%	1.35%	Jun. 26, 2015
MSCI US Broad Market Index	[1]	12.67%	5.89%	Jun. 26, 2015
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.60%	Jun. 26, 2015
Target 2035 Composite Index	[1]	8.55%	2.23%	Jun. 26, 2015

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 5.55%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Vanguard Institutional Target Retirement 2035 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Institutional Target Retirement 2035 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 5% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

5.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2035 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2035, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	47.5%
•	Vanguard Total International Stock Index Fund	31.9%
•	Vanguard Total Bond Market II Index Fund	14.5%
•	Vanguard Total International Bond Index Fund	6.1%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 79% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 21% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Institutional Target Retirement 2035 Fund Institutional Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 4.39% (quarter ended September 30, 2016), and the lowest return for a quarter was 0.83% (quarter ended December 31, 2016).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Vanguard Institutional Target Retirement 2035 Fund | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.09%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.09%

1 Year

rr_ExpenseExampleYear01

$ 9

3 Years

rr_ExpenseExampleYear03

29

5 Years

rr_ExpenseExampleYear05

51

10 Years

rr_ExpenseExampleYear10

115

1 Year

rr_ExpenseExampleNoRedemptionYear01

9

3 Years

rr_ExpenseExampleNoRedemptionYear03

29

5 Years

rr_ExpenseExampleNoRedemptionYear05

51

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 115

2016

rr_AnnualReturn2016

8.39%

^[1]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

5.55%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2016

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

4.39%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2016

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

0.83%

1 Year

rr_AverageAnnualReturnYear01

8.39%

Since Inception

rr_AverageAnnualReturnSinceInception

1.89%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2035 Fund | Return After Taxes on Distributions | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

7.79%

Since Inception

rr_AverageAnnualReturnSinceInception

1.35%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2035 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.06%

Since Inception

rr_AverageAnnualReturnSinceInception

1.35%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2035 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

5.89%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2035 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.60%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2035 Fund | Target 2035 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.55%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.23%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 5.55%.

[2] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Vanguard Institutional Target Retirement 2040 Fund

Vanguard Institutional Target Retirement 2040 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Vanguard Institutional Target Retirement 2040 Fund Institutional Shares
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Vanguard Institutional Target Retirement 2040 Fund Institutional Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.09%
Total Annual Fund Operating Expenses	0.09%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Vanguard Institutional Target Retirement 2040 Fund | Institutional Shares | USD ($)	9	29	51	115

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 5% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2040 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2040, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	52.1%
•	Vanguard Total International Stock Index Fund	34.8%
•	Vanguard Total Bond Market II Index Fund	9.2%
•	Vanguard Total International Bond Index Fund	3.9%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 87% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 13% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Institutional Target Retirement 2040 Fund Institutional Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 4.74% (quarter ended September 30, 2016), and the lowest return for a quarter was 0.86% (quarter ended March 31, 2016).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Vanguard Institutional Target Retirement 2040 Fund		1 Year	Since Inception	Inception Date
Institutional Shares		8.81%	1.67%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions		8.23%	1.17%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions and Sale of Fund Shares		5.33%	1.21%	Jun. 26, 2015
MSCI US Broad Market Index	[1]	12.67%	5.89%	Jun. 26, 2015
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.60%	Jun. 26, 2015
Target 2040 Composite Index	[1]	8.98%	2.07%	Jun. 26, 2015

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.02%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Vanguard Institutional Target Retirement 2040 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Institutional Target Retirement 2040 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 5% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

5.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2040 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2040, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	52.1%
•	Vanguard Total International Stock Index Fund	34.8%
•	Vanguard Total Bond Market II Index Fund	9.2%
•	Vanguard Total International Bond Index Fund	3.9%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 87% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 13% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Institutional Target Retirement 2040 Fund Institutional Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 4.74% (quarter ended September 30, 2016), and the lowest return for a quarter was 0.86% (quarter ended March 31, 2016).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Vanguard Institutional Target Retirement 2040 Fund | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.09%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.09%

1 Year

rr_ExpenseExampleYear01

$ 9

3 Years

rr_ExpenseExampleYear03

29

5 Years

rr_ExpenseExampleYear05

51

10 Years

rr_ExpenseExampleYear10

115

1 Year

rr_ExpenseExampleNoRedemptionYear01

9

3 Years

rr_ExpenseExampleNoRedemptionYear03

29

5 Years

rr_ExpenseExampleNoRedemptionYear05

51

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 115

2016

rr_AnnualReturn2016

8.81%

^[1]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

6.02%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2016

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

4.74%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2016

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

0.86%

1 Year

rr_AverageAnnualReturnYear01

8.81%

Since Inception

rr_AverageAnnualReturnSinceInception

1.67%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2040 Fund | Return After Taxes on Distributions | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.23%

Since Inception

rr_AverageAnnualReturnSinceInception

1.17%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2040 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.33%

Since Inception

rr_AverageAnnualReturnSinceInception

1.21%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2040 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

5.89%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2040 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.60%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2040 Fund | Target 2040 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.98%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.07%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.02%.

[2] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Vanguard Institutional Target Retirement 2045 Fund

Vanguard Institutional Target Retirement 2045 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Vanguard Institutional Target Retirement 2045 Fund Institutional Shares
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Vanguard Institutional Target Retirement 2045 Fund Institutional Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.09%
Total Annual Fund Operating Expenses	0.09%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Vanguard Institutional Target Retirement 2045 Fund | Institutional Shares | USD ($)	9	29	51	115

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 4% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2045 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2045, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	54.1%
•	Vanguard Total International Stock Index Fund	35.8%
•	Vanguard Total Bond Market II Index Fund	7.1%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Institutional Target Retirement 2045 Fund Institutional Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 4.85% (quarter ended September 30, 2016), and the lowest return for a quarter was 0.80% (quarter ended March 31, 2016).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Vanguard Institutional Target Retirement 2045 Fund		1 Year	Since Inception	Inception Date
Institutional Shares		8.94%	1.76%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions		8.38%	1.26%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions and Sale of Fund Shares		5.41%	1.28%	Jun. 26, 2015
MSCI US Broad Market Index	[1]	12.67%	5.89%	Jun. 26, 2015
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.60%	Jun. 26, 2015
Target 2045 Composite Index	[1]	9.13%	2.16%	Jun. 26, 2015

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.21%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Vanguard Institutional Target Retirement 2045 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Institutional Target Retirement 2045 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 4% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

4.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2045 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2045, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	54.1%
•	Vanguard Total International Stock Index Fund	35.8%
•	Vanguard Total Bond Market II Index Fund	7.1%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in any one country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Institutional Target Retirement 2045 Fund Institutional Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 4.85% (quarter ended September 30, 2016), and the lowest return for a quarter was 0.80% (quarter ended March 31, 2016).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Vanguard Institutional Target Retirement 2045 Fund | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.09%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.09%

1 Year

rr_ExpenseExampleYear01

$ 9

3 Years

rr_ExpenseExampleYear03

29

5 Years

rr_ExpenseExampleYear05

51

10 Years

rr_ExpenseExampleYear10

115

1 Year

rr_ExpenseExampleNoRedemptionYear01

9

3 Years

rr_ExpenseExampleNoRedemptionYear03

29

5 Years

rr_ExpenseExampleNoRedemptionYear05

51

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 115

2016

rr_AnnualReturn2016

8.94%

^[1]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

6.21%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2016

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

4.85%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2016

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

0.80%

1 Year

rr_AverageAnnualReturnYear01

8.94%

Since Inception

rr_AverageAnnualReturnSinceInception

1.76%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2045 Fund | Return After Taxes on Distributions | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.38%

Since Inception

rr_AverageAnnualReturnSinceInception

1.26%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2045 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.41%

Since Inception

rr_AverageAnnualReturnSinceInception

1.28%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2045 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

5.89%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2045 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.60%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2045 Fund | Target 2045 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

9.13%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.16%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.21%.

[2] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Vanguard Institutional Target Retirement 2050 Fund

Vanguard Institutional Target Retirement 2050 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Vanguard Institutional Target Retirement 2050 Fund Institutional Shares
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Vanguard Institutional Target Retirement 2050 Fund Institutional Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.09%
Total Annual Fund Operating Expenses	0.09%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Vanguard Institutional Target Retirement 2050 Fund | Institutional Shares | USD ($)	9	29	51	115

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 4% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2050 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2050, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	54.1%
•	Vanguard Total International Stock Index Fund	35.8%
•	Vanguard Total Bond Market II Index Fund	7.1%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in a particular country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Institutional Target Retirement 2050 Fund Institutional Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 4.79% (quarter ended September 30, 2016), and the lowest return for a quarter was 0.86% (quarter ended March 31, 2016).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Vanguard Institutional Target Retirement 2050 Fund		1 Year	Since Inception	Inception Date
Institutional Shares		8.95%	1.76%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions		8.40%	1.27%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions and Sale of Fund Shares		5.40%	1.28%	Jun. 26, 2015
MSCI US Broad Market Index	[1]	12.67%	5.89%	Jun. 26, 2015
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.60%	Jun. 26, 2015
Target 2050 Composite Index	[1]	9.13%	2.16%	Jun. 26, 2015

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.21%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Vanguard Institutional Target Retirement 2050 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Institutional Target Retirement 2050 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 4% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

4.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2050 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2050, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	54.1%
•	Vanguard Total International Stock Index Fund	35.8%
•	Vanguard Total Bond Market II Index Fund	7.1%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in a particular country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Institutional Target Retirement 2050 Fund Institutional Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 4.79% (quarter ended September 30, 2016), and the lowest return for a quarter was 0.86% (quarter ended March 31, 2016).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Vanguard Institutional Target Retirement 2050 Fund | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.09%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.09%

1 Year

rr_ExpenseExampleYear01

$ 9

3 Years

rr_ExpenseExampleYear03

29

5 Years

rr_ExpenseExampleYear05

51

10 Years

rr_ExpenseExampleYear10

115

1 Year

rr_ExpenseExampleNoRedemptionYear01

9

3 Years

rr_ExpenseExampleNoRedemptionYear03

29

5 Years

rr_ExpenseExampleNoRedemptionYear05

51

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 115

2016

rr_AnnualReturn2016

8.95%

^[1]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

6.21%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2016

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

4.79%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2016

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

0.86%

1 Year

rr_AverageAnnualReturnYear01

8.95%

Since Inception

rr_AverageAnnualReturnSinceInception

1.76%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2050 Fund | Return After Taxes on Distributions | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.40%

Since Inception

rr_AverageAnnualReturnSinceInception

1.27%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2050 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.40%

Since Inception

rr_AverageAnnualReturnSinceInception

1.28%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2050 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

5.89%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2050 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.60%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2050 Fund | Target 2050 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

9.13%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.16%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.21%.

[2] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Vanguard Institutional Target Retirement 2055 Fund

Vanguard Institutional Target Retirement 2055 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Vanguard Institutional Target Retirement 2055 Fund Institutional Shares
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Vanguard Institutional Target Retirement 2055 Fund Institutional Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.09%
Total Annual Fund Operating Expenses	0.09%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Vanguard Institutional Target Retirement 2055 Fund | Institutional Shares | USD ($)	9	29	51	115

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 4% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2055 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2055, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	54.1%
•	Vanguard Total International Stock Index Fund	35.8%
•	Vanguard Total Bond Market II Index Fund	7.1%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in a particular country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Institutional Target Retirement 2055 Fund Institutional Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 4.79% (quarter ended September 30, 2016), and the lowest return for a quarter was 0.86% (quarter ended March 31, 2016).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Vanguard Institutional Target Retirement 2055 Fund		1 Year	Since Inception	Inception Date
Institutional Shares		8.94%	1.75%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions		8.42%	1.28%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions and Sale of Fund Shares		5.38%	1.27%	Jun. 26, 2015
MSCI US Broad Market Index	[1]	12.67%	5.89%	Jun. 26, 2015
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.60%	Jun. 26, 2015
Target 2055 Composite Index	[1]	9.13%	2.16%	Jun. 26, 2015

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.25%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Vanguard Institutional Target Retirement 2055 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Institutional Target Retirement 2055 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 4% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

4.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2055 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2055, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	54.1%
•	Vanguard Total International Stock Index Fund	35.8%
•	Vanguard Total Bond Market II Index Fund	7.1%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in a particular country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Institutional Target Retirement 2055 Fund Institutional Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 4.79% (quarter ended September 30, 2016), and the lowest return for a quarter was 0.86% (quarter ended March 31, 2016).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Vanguard Institutional Target Retirement 2055 Fund | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.09%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.09%

1 Year

rr_ExpenseExampleYear01

$ 9

3 Years

rr_ExpenseExampleYear03

29

5 Years

rr_ExpenseExampleYear05

51

10 Years

rr_ExpenseExampleYear10

115

1 Year

rr_ExpenseExampleNoRedemptionYear01

9

3 Years

rr_ExpenseExampleNoRedemptionYear03

29

5 Years

rr_ExpenseExampleNoRedemptionYear05

51

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 115

2016

rr_AnnualReturn2016

8.94%

^[1]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

6.25%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2016

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

4.79%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2016

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

0.86%

1 Year

rr_AverageAnnualReturnYear01

8.94%

Since Inception

rr_AverageAnnualReturnSinceInception

1.75%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2055 Fund | Return After Taxes on Distributions | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.42%

Since Inception

rr_AverageAnnualReturnSinceInception

1.28%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2055 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.38%

Since Inception

rr_AverageAnnualReturnSinceInception

1.27%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2055 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

5.89%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2055 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.60%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2055 Fund | Target 2055 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

9.13%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.16%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.25%.

[2] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Vanguard Institutional Target Retirement 2060 Fund

Vanguard Institutional Target Retirement 2060 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Vanguard Institutional Target Retirement 2060 Fund Institutional Shares
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Vanguard Institutional Target Retirement 2060 Fund Institutional Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.09%
Total Annual Fund Operating Expenses	0.09%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Vanguard Institutional Target Retirement 2060 Fund | Institutional Shares | USD ($)	9	29	51	115

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 6% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2060 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2060, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	54.1%
•	Vanguard Total International Stock Index Fund	35.8%
•	Vanguard Total Bond Market II Index Fund	7.1%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in a particular country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Institutional Target Retirement 2060 Fund Institutional Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 4.85% (quarter ended September 30, 2016), and the lowest return for a quarter was 0.80% (quarter ended March 31, 2016).

Average Annual Total Returns for Periods Ended December 31, 2016

Average Annual Total Returns - Vanguard Institutional Target Retirement 2060 Fund		1 Year	Since Inception	Inception Date
Institutional Shares		8.94%	1.74%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions		8.42%	1.26%	Jun. 26, 2015
Institutional Shares | Return After Taxes on Distributions and Sale of Fund Shares		5.38%	1.26%	Jun. 26, 2015
MSCI US Broad Market Index	[1]	12.67%	5.89%	Jun. 26, 2015
Bloomberg Barclays U.S. Aggregate Bond Index	[1]	2.65%	2.60%	Jun. 26, 2015
Target 2060 Composite Index	[1]	9.13%	2.16%	Jun. 26, 2015

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.20%.

[1] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Vanguard Institutional Target Retirement 2060 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Institutional Target Retirement 2060 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 6% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

6.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2060 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2060, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. As of March 31, 2017, the Fund’s asset allocation among the underlying funds was as follows:

•	Vanguard Total Stock Market Index Fund	54.1%
•	Vanguard Total International Stock Index Fund	35.8%
•	Vanguard Total Bond Market II Index Fund	7.1%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in a particular country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Returns

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows the performance of the Fund in its first full calendar year. The table shows how the average annual total returns of the Fund compare with those of relevant market indexes and a composite stock/bond index, which have investment characteristics similar to those of the Fund.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-662-7447

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

vanguard.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Annual Total Returns — Vanguard Institutional Target Retirement 2060 Fund Institutional Shares

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a calendar quarter was 4.85% (quarter ended September 30, 2016), and the lowest return for a quarter was 0.80% (quarter ended March 31, 2016).

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for Periods Ended December 31, 2016

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Vanguard Institutional Target Retirement 2060 Fund | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

Purchase Fee

rr_MaximumCumulativeSalesChargeOverOther

none

Sales Charge (Load) Imposed on Purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFeeOverRedemption

none

Management Fees

rr_ManagementFeesOverAssets

none

12b-1 Distribution Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.09%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.09%

1 Year

rr_ExpenseExampleYear01

$ 9

3 Years

rr_ExpenseExampleYear03

29

5 Years

rr_ExpenseExampleYear05

51

10 Years

rr_ExpenseExampleYear10

115

1 Year

rr_ExpenseExampleNoRedemptionYear01

9

3 Years

rr_ExpenseExampleNoRedemptionYear03

29

5 Years

rr_ExpenseExampleNoRedemptionYear05

51

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 115

2016

rr_AnnualReturn2016

8.94%

^[1]

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2017

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

6.20%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2016

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

4.85%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2016

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

0.80%

1 Year

rr_AverageAnnualReturnYear01

8.94%

Since Inception

rr_AverageAnnualReturnSinceInception

1.74%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2060 Fund | Return After Taxes on Distributions | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.42%

Since Inception

rr_AverageAnnualReturnSinceInception

1.26%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2060 Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.38%

Since Inception

rr_AverageAnnualReturnSinceInception

1.26%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

Vanguard Institutional Target Retirement 2060 Fund | MSCI US Broad Market Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.67%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

5.89%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2060 Fund | Bloomberg Barclays U.S. Aggregate Bond Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.65%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.60%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

Vanguard Institutional Target Retirement 2060 Fund | Target 2060 Composite Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

9.13%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

2.16%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 26, 2015

^[2]

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 6.20%.

[2] Comparative Indexes (reflect no deduction for fees, expenses, or taxes)

XML

Vanguard Institutional Target Retirement 2065 Fund

Vanguard Institutional Target Retirement 2065 Fund

Investment Objective

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(Fees paid directly from your investment)

Shareholder Fees	Vanguard Institutional Target Retirement 2065 Fund Institutional Shares
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Vanguard Institutional Target Retirement 2065 Fund Institutional Shares
Management Fees	none
12b-1 Distribution Fee	none
Other Expenses	none
Acquired Fund Fees and Expenses	0.10%
Total Annual Fund Operating Expenses	0.10%

Example

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Vanguard Institutional Target Retirement 2065 Fund | Institutional Shares | USD ($)	10	32	56	128

Portfolio Turnover

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. The Fund has no operating history and therefore has no portfolio turnover information.

Principal Investment Strategies

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2065 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2065, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. The Fund’s asset allocation among the underlying funds is as follows:

•	Vanguard Total Stock Market Index Fund	54.0%
•	Vanguard Total International Stock Index Fund	36.0%
•	Vanguard Total Bond Market II Index Fund	7.0%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Principal Risks

The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in a particular country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Annual Total Returns

The Fund began operations on July 12, 2017, so performance information is not yet available.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

VANGUARD CHESTER FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 12, 2017

Vanguard Institutional Target Retirement 2065 Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Vanguard Institutional Target Retirement 2065 Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to provide capital appreciation and current income consistent with its current asset allocation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(Fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. The Fund has no operating history and therefore has no portfolio turnover information.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses of the Fund and its underlying funds remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests in other Vanguard mutual funds according to an asset allocation strategy designed for investors planning to retire and leave the workforce in or within a few years of 2065 (the target year). The Fund is designed for an investor who plans to withdraw the value of an account in the Fund over a period of many years after the target year. The Fund’s asset allocation will become more conservative over time, meaning that the percentage of assets allocated to stocks will decrease while the percentage of assets allocated to bonds and other fixed income investments will increase. Within seven years after 2065, the Fund’s asset allocation should become similar to that of the Institutional Target Retirement Income Fund. The Fund’s asset allocation among the underlying funds is as follows:

•	Vanguard Total Stock Market Index Fund	54.0%
•	Vanguard Total International Stock Index Fund	36.0%
•	Vanguard Total Bond Market II Index Fund	7.0%
•	Vanguard Total International Bond Index Fund	3.0%

At any given time, the Fund’s asset allocation may be affected by a variety of factors, such as whether the underlying funds are accepting additional investments.

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund’s indirect bond holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and securitized investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by Vanguard to minimize foreign currency exposure).

Risk [Heading]

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Principal Risks

Risk Narrative [Text Block]

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The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. An investment in the Fund is not guaranteed. An investor may experience losses, including losses near, at, or after the target year. There is no guarantee that the Fund will provide adequate income at or after the target year. Because stocks usually are more volatile than bonds and because the Fund currently invests most of its assets in stocks, the Fund’s overall level of risk should be higher than that of funds that invest the majority of their assets in bonds; however, the level of risk should be lower than that of funds investing entirely in stocks.

• With approximately 90% of its assets allocated to stocks, the Fund is proportionately subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund is also subject to the following risks associated with investments in foreign stocks: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of companies in a particular country or region; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Country/regional risk and currency risk are especially high in emerging markets.

• With approximately 10% of its assets allocated to bonds, the Fund is proportionately subject to the following bond risks: interest rate risk, which is the chance that bond prices will decline because of rising interest rates; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline, thus reducing the underlying fund’s return; and call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. An underlying fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the underlying fund’s income. The Fund is also subject to the following risks associated with investments in currency-hedged foreign bonds: country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign governments, government agencies, or companies; and currency hedging risk, which is the chance that the currency hedging transactions entered into by the underlying international bond fund may not perfectly offset the fund’s foreign currency exposure.

• The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of assets to them, will cause the Fund to underperform other funds with a similar investment objective.

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.

Risk Lose Money [Text]

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The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.

Risk Not Insured Depository Institution [Text]

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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.

Bar Chart and Performance Table [Heading]

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Annual Total Returns

Performance Narrative [Text Block]

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The Fund began operations on July 12, 2017, so performance information is not yet available.

Performance One Year or Less [Text]

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The Fund began operations on July 12, 2017, so performance information is not yet available.

Vanguard Institutional Target Retirement 2065 Fund | Institutional Shares

Risk/Return:

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Purchase Fee

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none

Sales Charge (Load) Imposed on Purchases

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none

Sales Charge (Load) Imposed on Reinvested Dividends

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

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none

Management Fees

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none

12b-1 Distribution Fee

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none

Other Expenses

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none

Acquired Fund Fees and Expenses

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0.10%

Total Annual Fund Operating Expenses

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0.10%

1 Year

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$ 10

3 Years

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32

5 Years

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56

10 Years

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128

1 Year

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10

3 Years

rr_ExpenseExampleNoRedemptionYear03

32

5 Years

rr_ExpenseExampleNoRedemptionYear05

56

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 128

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	VANGUARD CHESTER FUNDS
Prospectus Date	rr_ProspectusDate	Jul. 12, 2017
Document Creation Date	dei_DocumentCreationDate	Jul. 12, 2017