Vanguard Real Estate Index Fund Average Annual Total Returns - Investor Prospectus [Member]	12 Months Ended	60 Months Ended	120 Months Ended
	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025
Real Estate Spliced Index (reflects no deduction for fees, expenses, or taxes)[Member]
Prospectus [Line Items]
Average Annual Return, Percent	3.31%	4.76%	5.25%
MSCI US Investable Market Real Estate 25/50 Index (reflects no deduction for fees, expenses, or taxes)[Member]
Prospectus [Line Items]
Average Annual Return, Percent	3.31%	4.76%
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	17.05%	13.07%	14.21%
Investor Shares
Prospectus [Line Items]
Average Annual Return, Percent	3.07%	4.49%	5.00%
Investor Shares \| After Taxes on Distributions
Prospectus [Line Items]
Average Annual Return, Percent	2.10%	3.52%	3.90%
Investor Shares \| After Taxes on Distributions and Sales
Prospectus [Line Items]
Average Annual Return, Percent	2.02%	3.11%	3.46%