Stock-Based Compensation - Additional Information (Details) - USD ($)		1 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended
	Jan. 01, 2025	Mar. 31, 2025	Jan. 31, 2025	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024	Dec. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total common stock reserved for future issuance				17,653,512		17,653,512		16,624,243
Stock-based compensation expense				$ 2,541,000	$ 2,704,000	$ 5,183,000	$ 5,016,000
Service-Based Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense related to unvested stock options not recognized				$ 14,100,000		$ 14,100,000
Common Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total common stock reserved for future issuance				9,301,334		9,301,334		7,500,591
Unrecognized stock-based compensation expense related to unvested stock options not recognized				$ 800,000		$ 800,000
Unrecognized stock-based compensation expense period of recognition						2 years 7 months 24 days
Restricted Stock Units ("RSUs")
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total common stock reserved for future issuance				35,000		35,000
Unrecognized stock-based compensation expense related to unvested resticted stock units or restricted stock not recognized				$ 200,000		$ 200,000
Unrecognized stock-based compensation expense period of recognition						10 months 20 days
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense related to unvested resticted stock units or restricted stock not recognized				$ 0		$ 0
Inducement Award Program
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares granted								330,000
Number of options outstanding				330,000		330,000
2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of options outstanding				2,154,175		2,154,175
2021 Stock Option and Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total common stock reserved for future issuance				2,368,584		2,368,584		2,248,964
Number of shares granted		1,913,000
Increase in common stock reserved	2,044,338
Number of options outstanding				6,817,159		6,817,159
Exercise price of options				$ 3.03		$ 3.03
Incremental stock compensation cost recognized						$ 800,000
2021 Stock Option and Incentive Plan \| Restricted Stock Units ("RSUs")
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of non-options outstanding				35,000		35,000
2021 Stock Option and Incentive Plan \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price of options									$ 3.03
2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total common stock reserved for future issuance				572,254		572,254		572,254
Increase in common stock reserved			0
Stock-based compensation expense						$ 0

Vigil Neuroscience, Inc. 10-Q