Long-Term Investments - Amortized Cost and Estimated Fair Value of Available-for-Sale Securities by Contractual Maturities (Detail) $ in Thousands	Jun. 30, 2020 USD ($)
Available-for-sale Securities, Debt Maturities [Abstract]
Due in twenty to forty years, Cost	$ 3,000
Due in twenty to forty years, Estimated Fair Value	$ 2,555

Available for sale securities debt maturities year twenty six amortized cost basis.

No definition available.

Name:	vicr_AvailableForSaleSecuritiesDebtMaturitiesYearTwentySixAmortizedCostBasis
Namespace Prefix:	vicr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant