Basis of Presentation (Details) - Consecutive Four Fiscal Quarters Ending Thereafter - Amendment No. 21 To Credit Facility [Member]	Jul. 31, 2020
Maximum
Maximum fixed charge coverage ratio	1.10
Minimum
Maximum fixed charge coverage ratio	1.00

Debt instrument, covenant, maintained fixed charge coverage ratio

No definition available.

Name:	virc_DebtInstrumentCovenantMinimumFixedChargeCoverageRatio
Namespace Prefix:	virc_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant