Expense Example, No Redemption (Vanguard PRIMECAP Fund Participant)	Vanguard PRIMECAP Fund Vanguard PRIMECAP Fund - Investor Shares 10/1/2013 - 9/30/2014 USD ($)
Expense Example, No Redemption:
1 YEAR	45
3 YEAR	141
5 YEAR	246
10 YEAR	555

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You would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Section 3

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- Definition

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Form

-Number N-1A

-Chapter A

-Section 3

-Subsection example

-Paragraph 2

-Subparagraph 1

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Data Type:	rr:NonNegativeMonetaryType
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- Definition

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Form

-Number N-1A

-Chapter A

-Section 3

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- Definition

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Form

-Number N-1A

-Chapter A

-Section 3

-Subsection instructions

-Paragraph 4

-Subparagraph f

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Data Type:	rr:NonNegativeMonetaryType
Balance Type:	na
Period Type:	duration