Vanguard Information Technology Index Fund Average Annual Total Returns - Admiral Prospectus [Member]	12 Months Ended	60 Months Ended	120 Months Ended
	Dec. 31, 2024	Dec. 31, 2024	Dec. 31, 2024
Information Technology Spliced Index (reflects no deduction for fees, expenses, or taxes)[Member]
Prospectus [Line Items]
Average Annual Return, Percent	29.38%	21.55%	20.87%
MSCI US IMI/Information Technology 25/50 (reflects no deduction for fees, expenses, or taxes)[Member]
Prospectus [Line Items]
Average Annual Return, Percent	29.38%	21.55%	20.54%
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%
Admiral Shares
Prospectus [Line Items]
Average Annual Return, Percent	29.26%	21.44%	20.76%
Admiral Shares \| After Taxes on Distributions
Prospectus [Line Items]
Average Annual Return, Percent	29.06%	21.21%	20.46%
Admiral Shares \| After Taxes on Distributions and Sales
Prospectus [Line Items]
Average Annual Return, Percent	17.44%	17.54%	17.89%