v3.25.3

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Jun. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average fair value, per option	$ 1.34	$ 0.99
Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unamortized compensation cost	$ 0.3
Unamortized compensation cost, vesting period	3 months 21 days
Performance Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of vested shares	970,000
2013 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance			8,700,000
Shares available for future grant	2,032,173
2013 Plan \| Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted expiration term	10 years
2013 Plan \| Stock Option \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option, vesting period	1 year
2013 Plan \| Stock Option \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option, vesting period	4 years
2023 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant	9,934,567
2023 Plan \| Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted expiration term	10 years
2023 Plan \| Stock Option \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option, vesting period	1 year
2023 Plan \| Stock Option \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option, vesting period	4 years

Aggregate number of common shares reserved for future issuance.

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MEDICINOVA INC 10-Q