Shareholder Fees - Institutional - Vanguard Institutional Target Retirement 2050 Fund - Institutional Shares	Jan. 31, 2021
Shareholder Fees:
Sales Charge (Load) Imposed on Purchases	none
Purchase Fee	none
Sales Charge (Load) Imposed on Reinvested Dividends	none
Redemption Fee	none

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price). If a sales charge (load) is imposed on shares purchased with reinvested capital gains distributions or returns of capital, include the bracketed words in the third caption.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 3
-Subsection table
-Paragraph 1
-Subparagraph 1

+ Details

Name:	rr_MaximumCumulativeSalesChargeOverOther
Namespace Prefix:	rr_
Data Type:	rr:NonNegativePure4Type
Balance Type:	na
Period Type:	duration

- Definition

Maximum Deferred Sales Charge (Load) (as a percentage of ____) A.3.instructions.2.a.i "Maximum Deferred Sales Charge (Load)" includes the maximum total deferred sales charge (load) payable upon redemption, in installments, or both, expressed as a percentage of the amount or amounts stated in response to Item 7(a), except that, for a sales charge (load) based on net asset value at the time of purchase, show the sales charge (load) as a percentage of the offering price at the time of purchase. A Fund may include in a footnote to the table, if applicable, a tabular presentation showing the amount of deferred sales charges (loads) over time or a narrative explanation of the sales charges (loads) (e.g., __% in the first year after purchase, declining to __% in the __ year and eliminated thereafter). A.3.instructions.2.a.ii If more than one type of sales charge (load) is imposed (e.g., a deferred sales charge (load) and a front-end sales charge (load)), the first caption in the table should read "Maximum Sales Charge (Load)" and show the maximum cumulative percentage. Show the percentage amounts and the terms of each sales charge (load) comprising that figure on separate lines below.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 3
-Subsection table
-Paragraph 1
-Subparagraph 1

+ Details

Name:	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice
Namespace Prefix:	rr_
Data Type:	rr:NonNegativePure4Type
Balance Type:	na
Period Type:	duration

- Definition

Maximum Sales Charge (Load) Imposed on Reinvested Dividends[and other Distributions] (as a percentage of ____)

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 3
-Subsection table
-Paragraph 1
-Subparagraph 3

+ Details

Name:	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther
Namespace Prefix:	rr_
Data Type:	rr:NonNegativePure4Type
Balance Type:	na
Period Type:	duration

- Definition

"Redemption Fee" (as a percentage of amount redeemed, if applicable) If the Fund is an Exchange-Traded Fund and issues or redeems shares in creation units of not less than 25,000 shares each, exclude any fees charged for the purchase and redemption of the Fund's creation units. "Redemption Fee" includes a fee charged for any redemption of the Fund's shares, but does not include a deferred sales charge (load) imposed upon redemption.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 3
-Subsection instructions
-Paragraph 2
-Subparagraph b

+ Details

Name:	rr_RedemptionFeeOverRedemption
Namespace Prefix:	rr_
Data Type:	rr:NonPositivePure4Type
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

Name:	rr_ShareholderFeesAbstract
Namespace Prefix:	rr_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	dei_DocumentInformationDocumentAxis=chester_InstitutionalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=chester_S000049269Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	rr_ProspectusShareClassAxis=chester_C000155406Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: