Note 3 - Fair Value of Financial Instruments (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Fair Value Disclosures [Abstract]
Derivative, Collateral, Right to Reclaim Cash, Net	$ 5,000,000	$ 0.0

Amount of right to receive cash collateral under master netting arrangements that has been offset against derivative liabilities.

No definition available.

Name:	cvti_DerivativeCollateralRightToReclaimCashNet
Namespace Prefix:	cvti_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant