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Vanguard Utilities 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
MSCI US IMI/Utilities 25/50 (reflects no deduction for fees, expenses, or taxes)[Member]      
Prospectus [Line Items]      
Average Annual Return, Percent 23.20% 6.14% 8.30%
MSCI US Investable Market 2500 Index (reflects no deduction for fees, expenses, or taxes)[Member]      
Prospectus [Line Items]      
Average Annual Return, Percent 23.82% 14.02% 12.64%
ETF Shares | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 22.14% 5.23% 7.38%
ETF Shares | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 14.24% 4.59% 6.48%
ETF Shares | Based on NAV[Member]      
Prospectus [Line Items]      
Average Annual Return, Percent 23.07% 6.02% 8.20%
ETF Shares | Based on Market Price[Member]      
Prospectus [Line Items]      
Average Annual Return, Percent 22.98% 6.01% 8.20%