v3.26.1
Vanguard SP Small-Cap 600 Index Fund Average Annual Total Returns - ETF Prospectus [Member]
12 Months Ended 60 Months Ended 120 Months Ended
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2024
S&P SmallCap 600 Index (reflects no deduction for fees, expenses, or taxes)[Member]      
Prospectus [Line Items]      
Average Annual Return, Percent 8.70% 8.36% 8.96%
Dow Jones U.S. Total Stock Market Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)[Member]      
Prospectus [Line Items]      
Average Annual Return, Percent 23.88% 13.78% 12.48%
ETF Shares | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 8.21% 7.93% 8.54%
ETF Shares | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 5.34% 6.49% 7.20%
ETF Shares | Based on NAV[Member]      
Prospectus [Line Items]      
Average Annual Return, Percent 8.62% 8.31% 8.90%
ETF Shares | Based on Market Price[Member]      
Prospectus [Line Items]      
Average Annual Return, Percent 8.53% 8.31% 8.90%