Note 2 - Discontinued Operations - Results of Discontinued Operations (Details) (Parentheticals) $ in Millions	Jul. 08, 2020 USD ($)
Transport Financial Services [Member] \| Discontinued Operations, Held-for-sale [Member]
Disposal Group, Including Discontinued Operation, Allowance	$ 5.4

Amount of allowance on accounts receivable, attributable to disposal group held for sale or disposed of, classified as current.

No definition available.

Name:	cvlg_DisposalGroupIncludingDiscontinuedOperationAllowance
Namespace Prefix:	cvlg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant