Vanguard Communication Services 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
Communication Services Spliced Index (reflects no deduction for fees, expenses, or taxes)[Member]
Prospectus [Line Items]
Average Annual Return, Percent	33.06%	11.57%	8.15%
MSCI US IMI/Communication Services 25/50 (reflects no deduction for fees, expenses, or taxes)[Member]
Prospectus [Line Items]
Average Annual Return, Percent	33.06%	11.57%	9.55%
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	33.11%	11.60%	8.20%
Admiral Shares \| After Taxes on Distributions
Prospectus [Line Items]
Average Annual Return, Percent	32.73%	11.33%	7.72%
Admiral Shares \| After Taxes on Distributions and Sales
Prospectus [Line Items]
Average Annual Return, Percent	19.80%	9.19%	6.52%