CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) $ in Thousands	3 Months Ended
Mar. 31, 2023 USD ($)
CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY
Preferred stock tranche liability	$ 6,940

The amount of preferred stock tranche liability that were incurred during a noncash or partial noncash transaction.

No definition available.

Name:	vstm_IssuanceOfPreferredStockTrancheLiability
Namespace Prefix:	vstm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration