Vanguard Financials Index Fund Investment Strategy - Admiral Prospectus [Member] - Vanguard Financials Index Fund	Aug. 31, 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 indexing investment approach designed to track the performance of the MSCI US Investable Market Index (IMI)/Financials 25/50 (the “Target Index”), an index made up of stocks of large, mid-size, and small U.S. companies within the financials sector, as classified under the Global Industry Classification Standard (“GICS”). The GICS financials sector is made up of companies involved in banking, thrifts and mortgage finance, consumer finance, specialized finance, asset management and custody banks, investment banking and brokerage, and insurance. It also includes Financial Exchanges and Data and Mortgage REITS.Under normal circumstances, the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in the stocks that make up the Target Index. The Fund attempts to replicate the Target Index by investing all, or substantially all, of its assets in the stocks that make up the Target Index, holding each stock in approximately the same proportion as its weighting in the Target Index.The Fund is considered nondiversified, as defined under the Investment Company Act of 1940, which means that it may invest a greater percentage of its assets in the securities of particular issuers as compared with diversified funds.

Vanguard Financials Index Fund Investment Strategy - Admiral Prospectus [Member] - Vanguard Financials Index Fund

Aug. 31, 2025

<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Principal Investment Strategies</span>

The Fund employs an indexing investment approach designed to track the performance of the MSCI US Investable Market Index (IMI)/Financials 25/50 (the “Target Index”), an index made up of stocks of large, mid-size, and small U.S. companies within the financials sector, as classified under the Global Industry Classification Standard (“GICS”). The GICS financials sector is made up of companies involved in banking, thrifts and mortgage finance, consumer finance, specialized finance, asset management and custody banks, investment banking and brokerage, and insurance. It also includes Financial Exchanges and Data and Mortgage REITS.Under normal circumstances, the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in the stocks that make up the Target Index. The Fund attempts to replicate the Target Index by investing all, or substantially all, of its assets in the stocks that make up the Target Index, holding each stock in approximately the same proportion as its weighting in the Target Index.The Fund is considered nondiversified, as defined under the Investment Company Act of 1940, which means that it may invest a greater percentage of its assets in the securities of particular issuers as compared with diversified funds.