Vanguard PRIMECAP Fund Investment Strategy - Retail Prospectus [Member] - Vanguard PRIMECAP Fund	Sep. 30, 2025
Prospectus [Line Items]
Strategy [Heading]	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Principal Investment Strategies</span>
Strategy Narrative [Text Block]	The Fund employs an active management approach, investing in stocks considered to have above-average earnings growth potential that is not reflected in their current market prices. The Fund’s portfolio consists predominantly of large- and mid-capitalization stocks.The Fund may invest up to 25% of its assets in foreign securities, which may include depositary receipts. Foreign securities may be traded on U.S. or foreign markets.