COMMITMENTS AND CONTINGENCIES (Details)	12 Months Ended
Dec. 28, 2019 lawsuit
COMMITMENTS AND CONTINGENCIES.
Number of proceedings having material adverse effect on the consolidated results of operations, cash flows or financial condition	0

Represents the number of events occurred that would have a material effect on the estimated proved reserves.

No definition available.

Name:	cuo_LossContingencyNumberOfClaimsArisingInPeriodHavingMaterialEffectOnFinancialCondition
Namespace Prefix:	cuo_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration